SXVR-H9 handbook.pdf - Starlight Xpress

Handbook for the SXVR-H9 Issue 1 June 2009 

The SXVR-H9 USB2 CCD camera 

Thank you for purchasing a Starlight Xpress CCD camera. We hope that you will be 

very satisfied with the results. 

The SXVR-H9 is an advanced, high-resolution cooled CCD camera, especially 

designed for astronomical imaging. It is a third generation version of the very popular 

SXV-H9 and incorporates many substantial improvements and extra features. These 

include a built-in, fully programmable, USB 2 super-fast computer interface, an 

autoguider control port and output and optional integrated dual serial ports for filter 

wheel and telescope control. It also includes a CCD temperature monitoring circuit 

which provides regulated set-point cooling of the chip and a substantial reduction in 

overall size. 

The SXVR-H9 uses a Sony ICX285AL ‘ExView’ progressive scan CCD, with 1392 x 

1040 x 6.45uM pixels in an 8.98 x 6.71mm active area. ExView devices have 

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excellent quantum efficiency, with a broad spectral response peaking at around 65% 

in the green, and an extremely low dark current, well below that of any comparable 

CCD currently available. While this device has an excellent blue light sensitivity, it 

also has a strong infra-red response, which makes it ideal for all aspects of both 

planetary and deep-sky imaging, especially with an H-alpha filter. 

The full-frame download time is approximately 0.6 seconds and a binned 4x4 

download takes only 0.1 seconds, so finding and centring are very quick and easy in 

this mode. 

Please take a few minutes to study the contents of this manual, which will help you to 

get the camera into operation quickly and without problems. I am sure that you want 

to see some results as soon as possible, so please move on to the ‘Quick Start’ section, 

which follows. A more detailed description of imaging techniques will be found in a 

later part of this manual. 

‘Quick Starting’ your SXVR-H9 system 

In the shipping container you will find the following items: 

1) The SXVR-H9 camera head. 

2) A universal AC power supply module. 

3) A USB camera cable. 

4) An adaptor for 1.25” drawtubes, with a 1.25” filter thread. 

5) An adaptor for 2” drawtubes and M42 Pentax thread lenses. 

6) A guider output to guider port lead. 

7) A disk with the SXVR-H9 control software and this manual. 

Optional extra items include: 

1) A serial port adaptor and cable. 

2) An add-on guide camera head. 

You will also need a PC computer with Windows 98, Windows Me, Windows 2000 

or Windows XP/Vista installed (NOT Windows 95 or NT4). This machine must have 

at least one USB 2.0 port available and at least 256 Mbytes of memory. If you intend 

to view the finished images on its screen, then you will also need a graphics card 

capable of displaying an image with a minimum of 1024 x 768 pixels and 65,000 

colours. A medium specification Pentium with between 1GHz and 4GHz processor 

speed is ideal. Please note that USB 2.0 operates at a very high speed and cannot 

operate over very long cables. Five metres of good quality cable is the maximum 

normally possible without boosters or extra powered hubs. 

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Installing the USB system: 

First, find a free USB socket on your PC and plug in the USB cable (do not connect 

the camera at this time). If you do not have a USB2 capable computer, it is normally 

possible to install a USB 2 card into an expansion slot. 

The next operation is to run the software installer from the CD ROM provided. Insert 

the CD into the computer and wait for Windows Explorer to open with the list of 

folders on the ROM. Now find the SXVR-H9 folder and run the SETUP.EXE file that 

it contains – this will initiate the self-install software which will guide you through the 

process of installing the SX camera software (SXV_hmf_usb.exe) onto your 

computer. 

Now connect the USB cable to the socket on the camera rear panel. 

Windows will report ‘Found new hardware’ and will ask for the location of the 

drivers. Point the installer at your CD ROM and the driver installation should proceed 

smoothly. (Ignore any warnings about the driver having not been tested by Microsoft). 

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At the end of this process, the USB interface will be installed as a ‘BlockIOClass 

device’ and the camera software will be able to access it. You can confirm that the 

installation is complete by checking the status of the USB devices in the Windows 

‘Device Manager’ (see above). Start up the Windows ‘Control Panel’ and select 

‘System’. Now click on the tab labelled ‘Device Manager’, ‘Hardware’, and all of the 

system devices will be displayed in a list (see above). If the installation is successful, 

there will be a diamond shaped symbol labelled ‘BlockIOClass’ and clicking on the 

‘+’ sign will reveal it to be a ‘Starlight Xpress USB 2.0 SXV-H9 BlockIO camera 

driver’. If this device shows as faulty, try clicking on it and selecting ‘properties’ and 

then ‘update driver’. Following the on screen instructions will allow you to re-select 

the correct inf file (SXVIO_H9_119.inf) and driver files (SXVIO.sys and 

generic.sys), which should fix the problem. 

Now connect up the power supply and switch it on. The supply is a very efficient 

‘switch mode’ unit, which can operate from either 110v or 220v AC via an 

appropriate mains power cable (supplied). You can now start the ‘SXV_hmf_usb’ 

software by double clicking on the icon when you should see the main menu and 

image panel appear. If this is the first time that it has been run, you will receive a 

warning about the lack of an ‘ini’ file – just click on ‘OK’ and then open ‘Set program 

defaults’ from the ‘File’ menu. In the bottom right hand corner of this box, select 

SXV-H9. Now click on ‘Save’ and the ini file will be created and the software set for 

your camera. 

Now click on the camera icon at the top of the screen. If the USB connection is OK, a 

message box will inform you of the ‘Handle’ number for the SXVIO interface and 

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various other version details etc. Click ‘OK’ and the main camera control panel will 

now be seen. 

As can be seen above, there is a CCD temperature monitoring window at the right 

hand side of the panel. At switch-on, this will default to full power cooling with an 

end point of -40C and, needless to say, this is rather extreme. I recommend changing 

the set point to about -10C for normal use, but you can go much colder if you are 

imaging during the winter months. Under indoor conditions, the low airflow will limit 

the cooling capability, and you should use a set point of no lower than -5C for stable 

cooling. You can determine the optimum settings for your camera and ambient 

conditions when you have some experience of using the system, but do not try to 

operate at extreme cooling when the air temperature is high. 

Recording your first image: 

We now have the camera and computer set up to take pictures, but an optical system 

is needed to project an image onto the CCD surface. You could use your telescope, 

but this introduces additional complications, which are best avoided at this early 

stage. There are two simple options, one of which is available to everyone with a 

sheet of aluminium baking foil: 

1) Attach a standard ‘M42’ SLR camera lens to the SXVR-H9, using the 26mm 

spacer to achieve the correct focal distance. 

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Or 

2) Create a ‘Pin hole’ lens by sticking a sheet of aluminium baking foil over the end 

of the adaptor and pricking its centre with a small pin. 

If you use a normal lens, then stop it down to the smallest aperture number possible, 

(usually F22), as this will minimise focus problems and keep the light level 

reasonable for daytime testing. The pin hole needs no such adjustments and will work 

immediately, although somewhat fuzzily! 

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Point the camera + lens or pinhole towards a well-lit and clearly defined object some 

distance away. Now enter the ‘File’ menu in the SXV_H9 software and click on ‘SX 

camera interface’. Select an exposure time of 0.1 seconds and press ‘Take Photo’. 

After the exposure and download have completed (about 1 second) an image of some 

kind will appear on the computer monitor. It will probably be poorly focused and 

incorrectly exposed, but any sort of image is better than none! In the case of the 

pinhole, all that you can experiment with is the exposure time, but a camera lens can 

be adjusted for good focus and so you might want to try this to judge the high image 

quality that it is possible to achieve. 

Various other exposure options are available, as can be seen in the picture above. For 

example, you can ‘Bin’ the download 2x2, or more, to achieve greater sensitivity and 

faster download, or enable ‘Continuous mode’ to see a steady stream of images. 

‘Focus mode’ downloads a 128 x 128 segment of the image at high speed. The initial 

position of the segment is central to the frame, but can be moved by selecting ‘Focus 

frame centre’ in the ‘File’ menu and clicking the desired point with the mouse. The 

focus window has an adjustable ‘contrast stretch’, controlled by the 12-16 bit slider. 

The image will be ‘normal’ if 16 bits is selected, while setting lower values will 

increase the image brightness in inverse proportion. 

If you cannot record any kind of image, please check the following points: 

1) Ensure that the power indicator lamp is on and that the cables are properly home 

in their sockets. 

2) If the screen is completely white, the camera may be greatly overexposed. Try a 

shorter exposure time, or stop down your lens. See if covering the lens causes the 

image to darken. 

3) If the USB did not initialise properly, the camera start-up screen will tell you that 

the connection is defective. Try switching off the power supply and unplugging the 

USB cable. Now turn the power supply on and plug in the USB cable. This will reload 

the USB software and may fix the problem after restarting the SXV_hmf_usb 

program. Otherwise, check the device driver status, as previously described, and 

re-install any drivers which appear to be defective. 

4) If you cannot find any way of making the camera work, please try using it with 

another computer. This will confirm that the camera is OK, or faulty, and you can 

then decide how to proceed. Our guarantee ensures that any electrical faults are 

corrected quickly and at no cost to the customer. 

Image enhancements: 

Your first image may be satisfactory, but it is unlikely to be as clear and sharp as it 

could be. Improved focusing and exposure selection may correct these shortcomings, 

and you may like to try them before applying any image enhancement with the 

software. However, there will come a point when you say, “That’s the best that I can 

get” and you will want to experiment with the effects of image processing. In the case 

of daylight images, the processing options are many, but there are few that will 

improve the picture in a useful way. The most useful of these are the ‘Normal 

Contrast Stretch’ and the ‘High Pass Low Power’ filter. The high pass filter gives a 

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moderate improvement in the image sharpness, and this can be very effective on 

daylight images. 

Too much high pass filtering results in dark borders around well-defined features and 

will increase the noise in an image to unacceptable levels, but the Low Power filter is 

close to optimum and gives a nicely sharpened picture. 

The ‘Contrast’ routines are used to brighten (or dull) the image highlights and 

shadows. A ‘Normal’ stretch is a simple linear operation, where two pointers (the 

‘black’ and ‘white’ limits) can be set at either side of the image histogram and used to 

define new start and end points. The image data is then mathematically modified so 

that any pixels that are to the left of the ‘black’ pointer are set to black and any pixels 

to the right of the ‘white’ pointer are set to white. The pixels with values between the 

pointers are modified to fit the new brightness distribution. Try experimenting with 

the pointer positions until the image has a pleasing brightness and ‘crispness’. 

At this point, you will have a working knowledge of how to take and process an 

SXVR-H9 image. It is time to move on to astronomical imaging, which has its own, 

unique, set of problems! 

********************************************************************* 

Astronomical Imaging with the SXVR-H9 

1) Getting the image onto the CCD: 

It is fairly easy to find the correct focus setting for the camera when using a standard 

SLR lens, but quite a different matter when the SXVR-H9 is attached to a telescope! 

The problem is that most telescopes have a large range of focus adjustment and the 

CCD needs to be quite close to the correct position before you can discern details well 

enough to optimise the focus setting. An additional complication is the need to add 

various accessories between the camera and telescope in order that the image scale is 

suitable for the subject being imaged and (sometimes) to include a ‘flip mirror’ finder 

unit for visual object location. 

A simple, but invaluable device, is the ‘par-focal eyepiece’. This is an eyepiece in 

which the field stop is located at the same distance from the barrel end, as the CCD is 

from the camera barrel end. 

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When the par-focal eyepiece is fitted into the telescope drawtube, you can adjust the 

focus until the view is sharply defined and the object of interest is close to the field 

centre. On removing the eyepiece and fitting the CCD camera, the CCD will be very 

close to the focal plane of the telescope and should record the stars etc. well enough 

for the focus to be trimmed to its optimum setting 

Several astronomical stores sell adjustable par-focal eyepieces, but you can also make 

your own with a minimum of materials and an unwanted Kellner or Plossl ocular. 

Just measure a distance of 22mm from the field stop of the eyepiece (equivalent to the 

CCD to adaptor flange distance of the camera) and make an extension tube to set the 

field stop at this distance from the drawtube end. Cut-down 35mm film cassette 

containers are a convenient diameter for making the spacer tube and may be split to 

adjust their diameter to fit the drawtube. 

It is necessary to set up a good optical match between your camera and the telescope. 

Most SCTs have a focal ratio of around F10, which is too high for most deep sky 

objects and too low for the planets! This problem is quite easy to overcome, if you 

have access to a focal reducer (for deep sky) and a Barlow lens for planetary work. 

The Meade F6.3 focal reducer is very useful for CCD imaging and I can recommend 

it from personal experience. It does not require a yellow filter for aberration 

correction, unlike some other designs, so it can also be used for tri-colour imaging. If 

you use a focal reducer, using it at maximum reduction may cause the relatively large 

chip of the SXVR-H9 to suffer from considerable ‘vignetting’ (dimming towards the 

corners) and this will be difficult to remove from your images. Experiment with the 

distance between the reducer and the camera to optimise the results. The longer the 

extension tube used, the greater the focal reduction will be. As a guide, most CCD 

astronomers try to maintain an image scale of about 2 arc seconds per pixel for deep 

sky images. This matches the telescope resolution to the CCD resolution and avoids 

‘undersampling’ the image, which can result in square stars and other unwanted 

effects. To calculate the focal length required for this condition to exist, you can use 

the following simple equation: 

F = Pixel size * 205920 / Resolution (in arc seconds) 

In the case of the SXVR-H9 and a 2 arc seconds per pixel resolution, we get 

F = 0.00645 * 205920 / 2 

= 664mm 

For a 200mm SCT, this is an F ratio of 664 / 200 = F3.32, which is rather less than 

can be achieved with the Meade converter and appropriate extension tube. However, 

moderate deviations from this focal length will not have a drastic effect and so any F 

ratio from about F4.5 to F6.3 will give good results. 

The same equation can be used to calculate the amplification required for good 

planetary images. However, in this case, the shorter exposures allow us to assume a 

much better telescope resolution and 0.25 arc seconds per pixel is a good value to use. 

The calculation now gives the following result: 

F = 0.00645 * 205920 / 0.25 = 5354mm 

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This is approximately F27 when used with a 200mm SCT and so we will need a 2.8x 

Barlow lens and the common 3x version will be good enough for all practical 

purposes. Barlow lenses are less critical than focal reducers and most types can be 

used with good results. However, if you are buying one especially for CCD imaging, I 

recommend getting a 3x or 5x amplifier, or the planets will still be rather small in 

your images. 

Achieving a good focus: 

Your starting point will depend on the focus aids, if any, which you are using. With 

the par-focal eyepiece, you should slip the eyepiece into the drawtube and focus 

visually on a moderately bright star (about 3 rd magnitude). Now withdraw the 

eyepiece and carefully insert the camera nosepiece, until it is bottomed against the 

drawtube end, and then lock it in place. 

SXV_hmf_usb.exe has a focus routine that will repeatedly download and display a 

128 x 128 pixel segment of the image at relatively high speed. This focus window 

may be positioned anywhere in the camera field and can be displayed with an 

adjustable degree of automatic contrast stretching (for focusing on faint stars). To use 

this mode, start up the software and select the SXV camera interface (File menu). Set 

the camera mode to Binned 1x1 and select an exposure time of 1 second. Press ‘Take 

Picture’ and wait for the image to download. There is a good chance that your 

selected star will appear somewhere within the image frame and it should be close to 

a sharp focus. If the focus is still poor, then it may appear as a pale disk of light, often 

with a dark centre (the secondary mirror shadow in an SCT, or Newtonian). Now 

select the ‘File’ menu again and click on ‘Focus frame centre’; you can now use the 

mouse pointer to click on the star image and the new focus frame co-ordinates will be 

displayed. Now return to the camera interface window and click on ‘Start’ in the 

Focus frame. The computer will now display a continuous series of 128 x 128 pixel 

images in the focus window and you should see your selected star appear somewhere 

close to the centre. A ‘peak value’ (the value of the brightest pixel) will also be shown 

in the adjacent text box and this can be used as an indication of the focus accuracy. 

Although the peak value is sensitive to vibration and seeing, it tends towards a 

maximum as the focus is optimised. Carefully adjust the focus control on your 

telescope until the image is as sharp as possible and the peak value reaches a 

maximum. Wait for any vibration to die down before accepting the reading as reliable 

and watch out for bursts of bad seeing, which reduce the apparent focus quality. Quite 

often, the peak value will increase to the point where it is ‘off scale’ at 4095 and in 

this case you must halt the focus sequence and select a shorter exposure if you wish to 

use the peak value as an indicator. Once you are happy with the focus quality 

achieved, you might like to trim the settings of your par-focal or flip mirror eyepiece 

to match the current camera position. 

Although you can reach a good focus by the above method, many observers prefer to 

use additional aids, such as Hartmann or Bahnitov masks (an objective cover with 

several spaced holes) or diffraction bars (narrow parallel rods across the telescope 

aperture). These make the point of precise focus easier to determine by creating 

‘double images’ or bright diffraction spikes around stars, which merge at the setting 

of exact focus. The 12-16 bit slider control allows you to adjust the contrast of the 

focus frame for best visibility of the star image. It defaults to maximum stretch (12 

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bits), which is generally ideal for stars, but a lower stretch value is better for focusing 

on planets. 

Taking your first astronomical image: 

I will assume that you are now set up with a focused camera attached to a telescope 

with an operating sidereal drive. If so, you are now in a position to take a moderately 

long exposure of some interesting deep-sky astronomical object (I will deal with 

planets later). As most drives are not very accurate beyond a minute or two of 

exposure time, I suggest that you find a fairly bright object to image, such as M42, 

M13, M27 or M57. There are many others to choose from, but these are good 

examples. 

Use the finder to align on your chosen object and then centre accurately by using the 

focus frame and a short exposure of between 1 and 5 seconds. The ’12-16 bit’ slider 

in the focus frame allows you to adjust the image contrast if you find that the object is 

too faint with a short exposure. Once properly centred and focused, take an exposure 

of about 60 seconds, and observe the result. Initially, the image may appear rather 

barren and show only a few stars, however, there is a great deal of data hidden from 

view. You can get to see a lot of this, without affecting the image data, if you go to 

the ‘View’ menu and select ‘Auto Contrast Stretch Image’. The faint image data will 

then appear in considerable detail and I think that you will be impressed by the result! 

If you are happy with the image, go to the ‘File’ menu and save it in a convenient 

directory. 

A 60 second exposure of M42 through an H-alpha filter (non-linear stretched) 

Most competitive brands of CCD camera require a ‘dark frame’ to be subtracted from 

your images to achieve the best results. A dark frame is simply a picture which was 

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taken with the same exposure as your ‘light frame’, but with the telescope objective 

covered, so that no light can enter. It records only the ‘hot pixels’ and thermal 

gradients of your CCD, so that these defects are largely removed when the dark frame 

is subtracted from the light frame. The SXVR-H9 CCD is quite different from those 

used in other brands of camera and generates an extremely low level of dark noise. 

Indeed, it is so low that subtracting a dark frame can actually INCREASE the noise in 

your images! This is because the statistical noise of the dark frame can exceed the 

‘pattern noise’ from warm pixels and hence add to that of the subtracted result. If your 

test pictures have an exposure time of less than about 10 minutes (as above), then 

don’t bother with a dark frame, just ‘kill’ any hot pixels with your processing 

software. In SXVR-H9, the ‘Median filter’ can do this, but other software (e.g. 

Maxim DL) will provide a ‘hot pixel killer’ that can be mapped to specific locations 

in the image, or methods such as ‘Sigma combine’ may be used. 

In the unlikely event that you feel that dark frame really is necessary, please proceed 

as follows: 

To take a dark frame, just cover the telescope objective with the lens cap and take 

another exposure with the same length as that of the light frame. This image will be a 

picture of the dark signal generated during your exposure and it should be saved with 

your image for use in processing the picture. If many such darks are recorded and 

averaged together, the statistical noise will be reduced, but the gains to be had are 

rather small compared with the effort involved. 

As variations in ambient temperature will affect the dark signal, it is best to take the 

dark frames within a few minutes of capturing your images. For the same reason, it is 

not wise to use ‘old’ dark frames if you want the best possible results, however, some 

software allows you to scale library dark frames to match the image (e.g. AstroArt) 

and this can be useful as a time saver. 

‘Bias frames’ are somewhat more useful than dark frames when using the SXVR-H9. 

A bias frame is essentially a zero exposure dark frame and records any minor readout 

defects that the CCD may possess, so a ‘bias frame subtraction’ can clean up any 

‘warm columns’ or shadings that are created during readout. To record a bias frame, 

cover the camera aperture and take a 1000 th of a second exposure. If you take at least 

10 such frames and average them together, the resulting ‘master bias’ can be used to 

clean up readout defects for many months before CCD ageing changes require another 

set to be recorded. 

‘Flat fields’ are often recommended for optimising the results from your CCD 

camera, but these are generally less important than dark frames, especially if you 

make sure that the optical window of the camera is kept dust-free. The purpose of a 

flat field is to compensate for uneven illumination and sensitivity of the CCD and it is 

better to avoid the need for one by keeping the optics clean and unvignetted. I will 

ignore flat fielding for current purposes and describe the process in detail at a later 

stage. 

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Processing a deep-sky image: 

The following instructions include the subtraction of a dark frame, but this may be 

regarded as optional. 

1) Make sure the ‘Auto Contrast Stretch’ is switched off and load your image into 

SXV_hmf_usb. Select ‘Merge’ and then ‘Subtract Dark Frame’. Pick the appropriate 

dark frame and the software will then remove the dark signal from your image, 

leaving it somewhat darker and slightly smoother than before. 

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3) The resulting image will probably look faint and dull, with a pale background due 

to light pollution. It is now time to process the ‘luminance’ (brightness and contrast) 

of the image to get the best visual appearance. First, use the ‘Normal’ contrast stretch 

to darken the background by setting the ‘Black’ slider just below the main peak of the 

histogram. Alternatively, you can use the ‘Remove Background’ option to let the 

software decide on the best setting. This will greatly reduce the background 

brightness and the image will begin to look rather more attractive, although dark. You 

can now try brightening the highlights with another ‘Normal’ stretch, in which you 

bring down the ‘White’ slider to just above the main image peak. The best setting for 

this is rather more difficult to guess and you may need several attempts before the 

result is ideal. Just use the ‘Undo last filter’ function, if necessary, to correct a 

mistake. 

4) The image will now look quite impressive and I hope that you are pleased with 

your first efforts! 

In many cases, a ‘Normal’ contrast stretch will give a good result, but may ‘burn out’ 

the bright regions and leave the faint parts of the image rather lacking in brightness. 

To combat this, many imagers will use a combination of ‘Normal’ and ‘Non-linear’ 

contrast stretches. The best settings are different for different objects, but performing 

a non-linear or power law stretch, followed by normalising the background to black 

with a normal stretch, is the usual procedure. 

Further small refinements are usually possible and you will become expert at judging 

the best way to achieve these as your experience increases. As a rough guide, the 

‘Filters’ menu can be used to sharpen, soften or noise reduce the image. Strong ‘High 

Pass’ filters are usually not a good idea with deep sky images, as the noise will be 

strongly increased and dark rings will appear around the stars, but a ‘Median’ filter 

can remove odd speckles and a mild ‘Unsharp Mask’ (Radius 3, Power 1) will 

sharpen without too much increase in noise. 

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Other things to try, include summing several images for a better signal to noise ratio. 

Summing can be done in the ‘Merge’ menu and involves loading the first processed 

image, selecting a reference point (a star) then loading the second image and finding 

the same star with the mouse. Once the reference is selected, you can either add 

directly, or average the images together. Averaging is generally better, as you are less 

likely to saturate the highlights of the picture. The signal-to-noise ratio will improve 

at a rate proportional to the square root of the number of summations (summing 4 

images will double the signal-to-noise), but different exposures must be used. 

Summing an image with itself will not improve the S/N ratio! 

Although I have concentrated on the use of a telescope for deep-sky imaging, do not 

forget that you have the option of using an ordinary camera lens for impressive widefield 

shots! A good quality 200mm F3.5 lens with an infrared blocking filter will yield 

very nice images of large objects, such as M31, M42, M45 etc. If you cannot obtain a 

large IR blocker for the front of the lens, it is quite acceptable to place a small one 

behind the lens, inside the adaptor tube. You can even try using a hydrogen-alpha 

filter to bring out nebulae, reduce light pollution and sharpen the star images to pinpoints. 

Taking pictures of the planets: 

Planetary imaging is in many ways quite different from deep sky imaging. Most deep 

sky objects are faint and relatively large, so a short focal length and a long exposure 

are needed, while planets are bright and very small, needing long focal lengths and 

short exposures. High resolution is critical to achieving good results and I have 

already shown how a suitable focal length can be calculated and produced, using a 

Barlow lens. 

Many camera users comment on the difficulty of finding the correct focus when 

taking pictures of Jupiter etc. This is usually due to poor seeing conditions, which are 

only too common, but may also be due in part to poor collimation of your telescope. 

Please ensure that the optics are properly aligned as shown by star testing, or by using 

one of the patent collimation aids that are widely available. It is also better to use a 

star for initial focusing, as planetary detail is difficult to judge in bad seeing. Although 

the star will also suffer from blurring, the eye can more easily gauge when the most 

compact blur has been achieved! 

You could begin by imaging lunar craters, or the planets, Jupiter, Saturn or Mars. The 

rapid variations of seeing which accompany planetary imaging, will ruin the 

definition of about 95% of your images and so I recommend setting the camera to run 

in ‘Autosave’ mode. This will automatically take a sequence of images and save them 

with sequential file names in your ‘Autosave’ directory. Dozens of images will be 

saved, but only one or two will be satisfactory for further processing. The ‘Subframe’ 

mode of the SXV may be found useful for limiting the wasted area and reducing the 

download time of small planetary images. 

To start the Autosave process, call up the SXV Camera Interface and select the 

‘Continuous Mode’ check box at the top (make sure the rest are unchecked). Now 

check the ‘Autosave Image’ checkbox near the bottom of the window. If you now 

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click on ‘Take Picture’ the automatic sequence will begin and will not stop until you 

press a computer key. The images will be saved in FITs format with sequential names 

such as ‘Img23, Img24….’ and will be found in the ‘Autosave’ directory (or a subdirectory 

of Autosave, set up in the program defaults menu). 

The exposure time needed for good planetary images is such that the image histogram 

has a peak value at around 200 and does not extend much above 220 (Ignore the 

major peak near zero, due to the dark background). If you use too short an exposure 

time, the image noise level will be increased, and if too long a time is used you will 

saturate the highlights and cause white patches on the image. With the recommended 

focal length, Jupiter and Mars will both need an exposure time of between 0.1 and 1 

seconds and Saturn will need between 0.5 and 2 seconds. 

Processing a planetary image: 

Planetary images have one major advantage over deep sky images, when you come to 

process them – they are MUCH brighter, with a correspondingly better signal to noise 

ratio. This means that aggressive sharpening filters may be used without making the 

result look very noisy and so some of the effects of poor seeing can be neutralised. 

A raw image 

Try applying an ‘Unsharp Mask’ filter with a radius of 5 and a power of 5. This will 

greatly increase the visibility of any detail on the planet, but the optimum radius and 

power will have to be determined by experiment. 

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After the application of an ‘Unsharp mask’ 

In general terms, the larger the image and the worse the seeing, then the wider the 

radius for best results. My Jupiter shots are usually about one third the height of the 

CCD frame and I find that the ‘radius 5, power 5’ values are good for most average 

seeing conditions. If you have exceptionally good conditions, then a reduction to R=3, 

P=3 will probably give a more natural look to the image, as too large a radius and 

power tends to outline edges with dark or bright borders. 

As a finishing touch, the application of a Median filter or a Weighted Mean Low Pass 

filter can be useful to smooth out the high frequency noise after a strong Unsharp 

Mask. 

As with deep-sky images, it is advantageous to sum planetary images together to 

improve the signal to noise ratio. In this case, the ‘averaging’ option should always be 

used, or the result is likely to exceed the dynamic range of the software and saturate 

the highlights. Aligning the images is always something of a problem, as there are 

rarely any stars to use when imaging the planets, but Jupiter’s satellites can be useful 

reference points. Otherwise, you will have to find a well-defined feature on the planet, 

or estimate where the centre of the disk is located. Some more sophisticated software 

can automatically align planetary images and you may find these programs (e.g. 

‘Registax’) to be very useful. 

********************************************************************* 

Using the add-on autoguider: 

A very useful accessory is the add-on autoguider head, which takes its power and 

control signals directly from the SXVR camera, via the 18 way socket on its rear 

panel. The autoguider is only 1.25” in diameter and has a video style ‘CS’ mount 

thread in its nose, so video lenses may be attached. The guider may be used with 

17


either an off-axis prism assembly mounted in front of the SXVR camera, or with a 

separate guide telescope, rigidly mounted alongside your imaging telescope. I 

personally use it with a 70mm aperture, F10, inexpensive refractor as a guide ‘scope, 

but a shorter focal length lens will make more guide stars available in any given 

region of sky (See the picture below). 

To use the autoguider, first orient it so that the connector plug is roughly parallel to 

the declination axis of your mount. This is not absolutely essential, as the training 

routine will learn the angle of the head and compensate for it, but it is easier to 

understand the motion of the guide star if the guider frame is aligned with the RA and 

Dec axes. Now connect the head to the camera, using the 18 way connector lead, 

including the port divider box, if it is to be used. 

The recommended way of connecting the autoguider output to the mount is to use an 

RJ11 telephone lead between the socket on the SXV camera and the autoguider input 

of your mount. This output is ‘active low’ (i.e. the control relays pull the guider inputs 

down to zero volts when applying a guide correction) and matches most of the 

autoguider inputs on commercial mounts. If ‘active high’ inputs are needed, or a very 

low control voltage drop is essential, then you will need to add a Starlight Xpress 

‘relay box’ between the guider output and the input to the mount. Please contact your 

local distributor if a relay box is required. Some mounts (Vixen, for example) use a 

similar guider input socket, but have re-arranged connections. Details are given on our 

web pages at the end of the ‘STAR2000’ section. 

18


The autoguider installed on a 70mm refractor guide ‘scope in the author’s garden (the 

camera shown is the older SXVF version, but the connections are the same). 

To use the autoguider, please proceed as follows: 

1) Having started the SXVR-H9 software, open the autoguider control panel by 

clicking on the autoguider menu button. 

19


The autoguider control panel with a guide star selected 

2) Press the ‘Start’ button and a series of 1 second exposure guider images will 

begin to appear in the picture frame. If the images look too dim, use the 

‘Stretch Image’ slider to increase its contrast and brightness until the noise 

begins to be visible. 

3) If you haven’t focused the guider lens or ‘scope, move the mount until a bright 

star is visible on the guider image and then adjust the focus until it is as sharp 

as possible. 

4) At this point, you may want to test the guiding control by pressing the manual 

‘Move Telescope’ buttons at the bottom left corner of the control panel. You 

can watch the position of any stars in the guider image and confirm that they 

move in response to the buttons. The movement should be slow if the correct 

guiding rate is selected on your mount (typically 2x sidereal). Adjust this, if 

necessary. 

5) Move the mount until the required object for imaging is properly framed in the 

main CCD image (leave the guider menu and use the main camera control 

panel, as necessary). 

6) Re-open the guider control panel, start imaging and try to locate a clearly 

visible guide star. If necessary, make adjustments to the guide telescope or offaxis 

guider until one is found. 

7) Press ‘Stop’ and then press ‘Select Guide Star’. Use the mouse to left click on 

the selected star and a green cross will highlight it and the co-ordinates will 

appear in the text boxes above the image window. 

8) The various guiding rate defaults, listed on the right-hand side of the control 

panel, are unlikely to be perfect for your particular telescope and mount. You 

have the option of manually selecting values, or asking the software to attempt 

to determine what they should be. This is done by pressing the ‘Train’ button 

and waiting for the software to complete a sequence of automatic moves and 

calculations. The training will also determine the angle at which the guide 

camera is oriented with respect to the RA and Dec axes. If you do not wish to 

train the system at this time, the default values of 6 pixels per second will 

serve as a starting point. 

20


9) Now press ‘Go to main camera’ and the guider control panel will be replaced 

by the camera control panel. Set the required exposure time for the image (say 

5 minutes) and press the ‘Autoguide next image’ button. The autoguider 

window will reappear and, after a few seconds, you should see error values 

appearing in the text windows at the top. The guide star will be fairly close to 

the green cross, although not necessarily accurately centred, and you should 

see the power/ guide LED on the rear of the camera brighten and change 

colour with each correction. 

10) If the star begins to drift away from the cross, despite the corrections being 

made, the chances are that the N/S and/or E/W directions are set wrongly. 

Judge which axis is incorrectly set by observing the direction of the drift and 

then stop the exposure by pressing ‘Esc’. Open the guider control panel and 

check the appropriate swap box(es). After this operation, you will probably 

need to find the guide star again by taking a guider image and reselecting the 

star, as before. Now return to the main camera menu and try the ‘Autoguide 

next image’ button again. 

11) Once guiding is taking place without problems, the main exposure can be 

allowed to finish and, if all is well, you should see an image with tiny circular 

stars. 

If the stars are not circular, you may need to alter the guiding parameters, or 

investigate the rigidity and drive performance of your mount. A lot of information 

can be deduced by watching the behaviour of the guide star in the guider frame. If 

it is continually moving between two locations, either side of the green cross, then 

the RA or Dec pixels per second value is set too low. The higher these values are 

set, the gentler the guiding becomes. Too low a value will cause an overaggressive 

correction to be made and result in oscillation of the star position 

between two points. 

Another source of guiding errors can be an accurately balanced telescope mount! 

Good balance can result in the telescope mount ‘bouncing’ between the gear teeth 

as corrections are made. A simple fix is to add a weight of about 0.5kg (1 pound) 

on the eastern end of the declination axis, so that there is always some pressure 

acting against the gear teeth. 

Getting a good result from an autoguider will often entail a lot of detective work 

to eliminate the sources of gear error, telescope flexure, mirror shift etc., but the 

final result is well worth the effort! 

********************************************************************* 

Using the built-in serial ports 

The SXVR-H9 incorporates two fast serial ports for use with external accessories. 

The ports are available on 5 pins of the 18 way connector that is provided for the 

autoguider and may be accessed by plugging in a ‘serial port divider box’. The divider 

box and cables are available as an accessory and may be chained in series with the 

autoguider cable, when the guider is in use, or may be used on its own. 

21


The two serial connections are in the form of standard RS232 PC style plugs and 

provide TX, RX and Ground connections at RS232 levels. Access is via commands 

sent through the USB connection and, at the time of writing, is limited to any serial 

controls that are provided by the SXV software. It is expected that many more 

functions will be added as the software is upgraded. 

********************************************************************* 

Other features of the SXVR-H9 hardware and software 

‘Slew & Sum’ imaging: 

The SXVR-H9 can be used in an automatic image-stacking mode, called ‘Slew & 

Sum’. The camera is set to take several sequential exposures, which are automatically 

‘slewed’ into alignment and then summed together by the software. This mode can 

help to overcome a poor RA drive by summing images that have exposure times 

shorter than the drive error period. The resulting image has more noise than a single 

exposure of the same total length, but this method of imaging is still an effective way 

of making long exposures without a guider. 

To take an S&S image, go to the camera interface window and select an exposure 

time for one image of the sequence. Do not use a very short exposure time, as the 

read-out noise will become dominant. About 30 seconds is a reasonable minimum. 

Now go to the ‘Multiple Exposure Options’ and select a number of exposures to take. 

You can also select to average the images, rather than adding them, and there is a 

‘Alternative Slew Mode’ available, which uses the correlation of image areas, rather 

than a single star. This mode can be better in dense star fields. 

Another option is ‘Auto remove dark frame’. This is advisable with S&S images, as 

the slewing will mis-register the images with a single dark frame that is applied to the 

finished sequence. To use this option, you will need a dark frame, taken with the same 

exposure time as a single image from the sequence. This is stored on drive C with the 

name ‘dark.def’ 

Now click on ‘Take Picture’ and the sequence will begin. 

Using the ‘Binned’ modes: 

Up to this point, I have assumed that the full resolution, imaging mode is being used. 

This is fine for most purposes, but it will often provide more resolution than the 

optical system, or the seeing, allows. ‘Binned 2x2’ mode sums groups of 4 pixels into 

one output pixel, thus creating a 696 x 520 pixel image with 4 times the effective 

sensitivity. Using 2x2 binning, you can considerably improve the sensitivity of the 

SXVR-H9 without losing a great deal of resolving power, so you may like to use this 

mode for many faint deep-sky objects. Other binning modes (3x3 and 4x4) are 

available and will further increase the image brightness and reduce its resolution. 

However, generally, these are more useful for finding faint objects, than for imaging. 

Taking and using a flat field: 

22


Flat fields are images, which display only the variations of illumination and 

sensitivity of the CCD and are used to mathematically modify a wanted image in such 

a way that the errors are removed. Common flat field errors are due to dust motes on 

the camera window and vignetting effects in the optical system of the telescope. Dust 

motes act as ‘inverse pinholes’ and cast out-of-focus images of the telescope aperture 

onto the CCD chip, where they appear as shadow ‘do-nuts’. Most optical systems 

show some vignetting at the edges of the field, especially when focal reducers are 

used. This causes a brighter centre to show in images, especially when there is a lot of 

sky light to illuminate the field. 

If dust motes are your main problem, it is best to clean the camera window, rather 

than to rely on a flat field to remove the do-nuts. Flat fields always increase the noise 

in an image and so physical dust removal is the best option. If you have serious 

vignetting, first check whether the optical system can be improved. The most likely 

cause of this problem is trying to use too powerful a degree of optical compression 

with a focal reducer and you might want to try moving the camera closer to the 

reducer lens. 

If you really do need to use a flat field for image correction, then it must be taken with 

care. It is most important that the optical system MUST NOT be disturbed between 

taking your original images and taking the flat field. Any relative changes of focus 

and rotation etc. will upset the match between flat field and image and the result will 

be poor correction of the errors. The other necessity for recording a good flat field is a 

source of very even illumination of the telescope field. This is surprisingly difficult to 

achieve and many designs of light source have appeared in the literature and on the 

Web. These usually consist of a large wooden box, containing several lamps and an 

internal coating of matt white paint, which is placed over the objective of the 

telescope to provide an evenly illuminated surface. These can work well, but I prefer a 

simpler method, as follows: 

Most imaging sessions begin or end in twilight and so the dusk or dawn sky can 

provide a distributed source of light for a flat field. However, using the sky directly is 

likely to result in recording many unwanted stars, or patches of cloud etc., so a 

diffuser needs to be added to the telescope. An ideal material is Mylar plastic drafting 

film, obtained from an office supplies warehouse. It is strong and water resistant and 

can be easily replaced if damaged. Stretch a piece of the film loosely across the 

aperture of your telescope and point the instrument high in the sky, to avoid any 

gradient in the light near the horizon. Now take several images with exposure times 

adjusted to give a bright, but not overloaded, picture. A histogram peaking at around 

128 is ideal. Averaging flat fields together is a good way to reduce their noise 

contribution and so recording 4, or more, images is a good idea. 

To use your flat fields, they must first have a dark frame subtracted. Although this 

may appear to be unimportant with such brightly lit and short exposures, there is the 

‘bias offset’ of the camera in each image and this can produce an error in the final 

correction. As we are mainly interested in the bias, any very short exposure dark 

frame will give a good result. The dark subtracted images should then be averaged 

together before use. 

23


After the above procedures have been executed, the flat field will be ready for use. 

Load up your image for processing, subtract the dark frame and then select ‘Apply 

flat field’ in the ‘Merge’ menu. The result should be an image with very few signs of 

the original artefacts and you can then process it in the normal way. 

********************************************************************* 

The SXVR-H9 accessory ports 

The SXVR-H9 is provided with two ports for use with accessories. The Autoguider 

output port is a 6 way RJ11 socket, which is compatible with the standard autoguider 

input of most telescope mounts. It provides 4 active-low opto-isolator outputs and a 

common return line, capable of sinking a minimum of 5mA per output. This socket 

may be used for telescope control if the SXVR-H9 is employed as an autoguider, but 

is primarily intended to be the control output for the optional add-on autoguider 

camera head, available for use with the SXVR-H9. 

24


The high density parallel port socket provides both control and power for the add-on 

autoguider, but also includes a pair of serial ports for use with other devices. 

********************************************************************* 

Camera maintenance: 

Very little maintenance is needed to keep the SXVR-H9 in excellent operating order, 

however two problems, which are common to all CCD equipment, might show up on 

occasion. These are dust and condensation. 

Removing Dust: 

1) Dust can be deposited on either the optical window (not a big problem to cure), or 

on the CCD faceplate (very difficult to eliminate entirely). When small particles 

collect on the window they may not be noticed at all on deep sky (small F ratio) 

images, as they will be very much out of focus. However, if a powerful contrast boost 

of the image is carried out, they may well begin to show as the shadow ‘Do-nuts’ 

mentioned earlier. Images taken with a large F ratio optical system are more likely to 

be affected by such dirt, owing to the smaller and sharper shadows that they cast. A 

light polluted sky will also make these marks much more obvious. There is no great 

difficulty in removing such particles on the outside surface by the careful use of a lens 

cleaning cloth, ‘lens pen’, or ‘air duster’ and so you should have little trouble with 

this aspect of maintenance. Dust on the CCD faceplate is a much greater nuisance, as 

it casts very sharply defined and dark shadows and it entails dismantling the camera to 

get rid of it! To clean the CCD you will need a good quality lens cloth (no silicone) or 

tissues and some high-grade acetone or isopropyl alcohol. A very suitable cloth is the 

‘Micro-Fibre’ type marketed by PENTAX etc., and suitable alcohol is available from 

Maplin or Radio Shack etc. as tape head cleaning fluid. Most pharmacist shops will 

have small bottles of pure acetone. A bright light and a strong watchmakers eyeglass 

will also be found to be essential. 

Procedure: 

1) Disconnect the lead from the camera head and remove it from the telescope. Place 

it on a table with the optical window facing downward. 

2) Remove the two M3 screws and the M8 nut from the camera back plate and ease 

the plate out of the camera body. Unplug the fan lead from the camera PCB. 

3) Withdraw the body cylinder and unscrew the two top spacer pillars from the PCB. 

Now gently lift the PCB off the 20 way connector NOTING THE ORIENTATION 

OF THE BOARD for correct replacement later. Now remove the lower two spacers 

from the heat sink plate assembly. 

4) The camera heat sink assembly can now be lifted away from the camera front 

barrel and the CCD will be exposed. Note that a layer of white heat-sink compound is 

applied to the periphery of the heat sink disc and this should be left undisturbed by 

subsequent operations. 

5) You can now closely examine the CCD faceplate under the spotlight using the 

watchmaker's glass when any dust motes will show clearly. If there is only an odd 

particle or two and the CCD is otherwise clean, carefully brush away the dust with a 

corner of your lens cloth. A smeared or very dusty CCD will need a few drops of 

alcohol to clean thoroughly and you may have to make several attempts before the 

25


surface is free of contamination. One gentle wipe from one end to the other, with no 

return stroke, will be found to be the most effective action. DO NOT rub vigorously 

and be very careful to avoid scratching the window. 

6) Before re-assembly, make certain that the inside surface of the front window is also 

clean, and then carefully replace the camera front barrel and screw it into place. (If the 

heat sink seal is disturbed, renew it with fresh compound before reassembling). 

7) Replace all the camera parts in reverse order and the job is done. 

Dealing with condensation: 

The SXVR-H9 is designed to avoid condensation by minimising the volume of air 

trapped within the CCD cavity and by preventing moisture ingress. This normally 

works very well, but storage of the camera in a humid location can lead to the trapped 

air becoming moist by diffusion through the optical window mounting thread etc. and 

can result in condensation on the CCD window. If this becomes a problem, try storing 

the camera in a warm, dry place, or in a plastic lunch box containing a sachet of silica 

gel desiccant. If this is not effective, try opening the main barrel and loosening the 

stand-offs to allow a gap to form between the heat sink and the front barrel assembly. 

Now put the camera into a desiccator box (as above) or leave it in a warm place for 

several hours before re-sealing it. 

N.B. DO NOT leave the camera switched on for long periods between uses. The 

cold CCD will collect ice by slow diffusion through any small leaks and this will 

become corrosive water on the cooler and CCD pins when the power is removed. If 

substantial amounts of moisture are seen, dismantle the camera and dry it 

thoroughly. 

********************************************************************* 

Alternative Software 

Although we hope that you will be satisfied with our ‘SXV_hmf_usb’ software, other 

companies are offering alternative programs with more powerful processing 

functions. One of these is programs is ‘AstroArt’ by MSB software. You can purchase 

AstroArt from many dealers Worldwide and more information may be obtained from 

their web site at http://www.msb-astroart.com 

‘Maxim DL’ is another popular choice and you can find out more by visiting 

http://www.cyanogen.com 

********************************************************************* 

Some details of the camera and CCD characteristics 

CCD type: 

CCD size: 

Sony ICX285AL Exview interline imager. 

Active area 8.95mm x 6.7mm 

CCD pixels: 1392 x 1040 pixel array. Each pixel is 6.45 x 6.45uM (or 12.9 x 

12.9uM in binned 2x2 mode). 

26


Well depth: Full res. mode 25,000e. Binned 2x2 mode approx. 40,000e 

Mean visual QE: 60%, 65% at peak (540nM) 

Useful spectral response: 360nM – 1100nM 

Readout noise: Approx. 4e RMS typical, 8e max. 

Back focal distance: The CCD is approximately 17.5mm from the barrel front. 

Camera size: 63mm diameter x 62mm long 

27


Dear Observer, 

Thank you for purchasing a Starlight Xpress CCD Imaging System. We are confident that you will gain 

much satisfaction from this equipment, but please read carefully the accompanying instruction manual 

to ensure that you achieve the best performance that is capable of providing. 

As with most sophisticated equipment a certain amount of routine maintenance is necessary to keep the 

equipment operating at its optimum performance. The maintenance has been kept to a minimum, and is 

fully described in the manual. 

In the unfortunate instance when the equipment does not perform as expected might we recommend 

that you first study the fault finding information supplied. If this does not remedy the problem, then 

contact Starlight Xpress for further advice. Our message board service on the Starlight Xpress web site 

will often provide solutions to any problems. 

The equipment is covered by a 12-month guarantee covering faulty design, material or workmanship in 

addition to any statutory Consumer Rights of Purchasers. 

CONDITIONS OF GUARANTEE 

1) The equipment shall only be used for normal purposes described in the standard operating 

instructions, and within the relevant safety standards of the country where the equipment is used. 

2) Repairs under guarantee will be free of charge providing proof of purchase is produced, and that the 

equipment is returned to the Service Agent at the Purchaser’s expense and risk, and that the equipment 

proves to be defective. 

3) The guarantee shall not apply to equipment damaged by fire, accident, wear an tear, misuse, 

unauthorised repairs, or modified in any way whatsoever, or damage suffered in transit to or from the 

Purchaser. 

4) The Purchaser’s sole and exclusive rights under this guarantee is for repair, or at our discretion the 

replacement of the equipment or any part thereof, and no remedy to consequential loss or damage 

whatsoever. 

5) This guarantee shall not apply to components that have a naturally limited life. 

6) Starlight Xpress’s decision in all matters is final, and any faulty component which has been replaced 

will become the property of Starlight Xpress Ltd. 

For further info. or advice, please call: 

Mr Michael Hattey, 

Starlight Xpress Ltd., 

The Offices, Foxley Green Farm, 

Ascot Road, Holyport, 

Berkshire, 

England. SL6 3LA 

Tel: 01628 777126 

Fax: 01628 580411 

Email: michael.hattey@starlight-xpress.co.uk 

Web site: http://www.starlight-xpress.co.uk 

28

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