The QCUIAG group has been active for some time in pushing forward the boundaries of unconventional amateur astronomical imaging, coordinating the efforts of a number of gifted and skilled individuals. There was a substantial breakthrough in 1999 by Dave Allmon with his modification of the Connectix Grayscale Camera for extended imaging, but this camera has not been manufactured for some time, and is now (2001) almost impossible to obtain.

Modern colour Web Cameras are hard wired for maximum frame rate, and appeared impossible to modify. Until Steve Chambers hacked into the hardware in the Autumn of 2001, and came up with a relatively simple hardware modification allowing unlimited exposure time for the Philips Vesta Pro camera and derivatives. The group is indebted to him, and details of his modifications can be found on his web site.

I performed my own successful modification, known as the Vesta Pro SC after Steve Chambers, and was immensely thrilled by my first colour photograph on the 29th. September 2001 of the classic planetary nebula M57, The Ring Nebula. This is shown here, but it and other images will appear on the Deep Sky page.

All pictures on this page are linked to enlargements. Just click on the thumbnail.

The success of the modification and the construction of the Vesta Pro camera which houses the CCD chip inside an alloy casing prompted me to try cooling it to minimise thermally generated noise. I'm pleased to say that the experiment has been successful, so I give details of the modification here. 

Original Camera. Note the alloy casting housing the LED, Microphone, CCD Chip and Lens.

The housing is removed from the camera case, the circuit board removed and the housing cut down to the basic cube. The surface which has the locating pins has to be filed flat - this is your cold connection, but the pins must remain intact. The tricky part - a spacer plate is made to fit on top of the housing, then holes drilled and tapped into the housing. These need to be carefully positioned, but the housing material is strong and takes a good thread. The small recess in the rear edge has been cut to allow the passage of a wire for the amplifier switch modification (see later). NOTE: If I were to do this again, or if the threads strip, I will use tension bolts either side of the housing into a clamp plate below - easier and stronger. But the spacer is still required. Without it you can't get proper contact with the cold plate - the circuit board and alignment pins are proud of the flat surface.

The Peltier cooler is sandwiched between a fan cooled heat sink and an aluminium plate mounted on top of a plastic project box. The white paste is thermal transfer compound - absolutely essential between all surfaces! Note the insulating sleeves on the heatsink clamp bolts which pass through the cold plate. They are also necessary!
The front end of the cold plate is bolted through the spacer into the CCD housing. These are the bolts I would position either side of the housing into a clamp plate if performing the modification again.
The rear of the heat sink is also bolted to the project box lid, with a spacer to prevent uneven loading of the Peltier sandwich. The thin screws shown here are for location of the main circuit board. Also a top view of the 'cold finger arrangement.
The LED and microphone are unsoldered from the CCD board, and the end carrying only model information is trimmed off. The black wire from pin 9 of the chip is for Steve Chambers' Amplifier switch modification. The board is then remounted on the housing. The yellow wire is also part of the amplifier modification. (See Steve's site)
A bit of insulation around the metal parts also makes a difference!
The main board is then mounted, with bolts and spacers supporting the rear. Although difficult to see, there are clear plastic insulating pieces below the nuts. Will the maze of wires and circuit boards fit inside the project box???
YES! The switch chooses the long exposure mode, the small socket is for control wires to the computer, the large one for the cooler power input. With an adaptor screwed into the lens housing, ready for prime focus deep sky imaging!

The Peltier chip I used was a 20 x 20 mm unit, rated at maximum 3.8 amps and 8 volts. I find it runs satisfactorily at 2.5 amps and 6.5 volts, and use the same supply for the fan. To obtain this, I simply use a high power dropper resistor (2.2 ohms, on a heat sink) in series with my Lead Acid battery. (See Power Board). Although this is wasteful of power, the Peltier chip does not perform well with a switched mode type of power supply.

The system is very effective, giving a temperature differential from ambient of around 22 degrees Centigrade. So an ambient of 18 degrees gives a chamber temperature of -4 degrees. A particular bonus of this method is the way the chip is cooled. Because the air in the chamber is colder than the chip, the chip does not dew up, and after an hour of cooling, when there is a substantial build up of ice on the outside metal, the chip is still clear. The blue glow comes from the on-chip amplifier. A further modification from Steve Chambers addresses this problem.

Schematic: To complement the photographs, there is a schematic drawing here. This shows the existing fixing screw arrangement for the cold chamber, although as mentioned above, I would recommend tension screws into a plate below the chamber.

More Pictures: For a really neat and tidy implementation of my design, visit Peter Katreniak's site. He's made a beautiful job of my lash up, and used tension screws as I suggest above. 

Postscript: Eventually the threads into the lens housing did strip, and I rebuilt the front end with tension bolts. A good solid job, and far preferable to the original construction. Later I rewired the control chip to the 'deadbug' assembly - fewer wires floating around with less stress on the fine wires to the 16510 chip.

The 'guts' removed from the project box, with insulating tape stripped from the subsidiary circuit boards. Lots of wires, all introducing interference and stressing their solder joints.
After the 'dead bug' installation. Fortunately the 74HC00 control chip was mounted in a socket in the original installation, so could be easily reused.
I kept the secondary board for the amp-off mod - this was a neater option than having the components 'floating'
Much tidier conversion for reinstalling in the box
Another view of the final assembly, showing the new clamping arrangement for the CCD head.
Back in the box and ready for action! The metal plate has a 1/4" thread for tripod mounting.

Post Postscript!

With the advent of the MX716 then the Artemis, I no longer used the Vesta for long exposure imaging, but it made a useful guide camera. And when eventually I replaced the colour chip with a much more sensitive monochrome version it retained a permanent place as a sensitive guide camera, used either with a guide scope when taking wide field images, or off-axis for better accuracy at long focal lengths. Again with the coming of the SBIG ST-8 with its self contained guide chip the camera is less used, but definitely not redundant - if I'm imaging with narrow band filters which dim the light of the guide star for the on-board guide chip of the ST-8, a separate guide camera is sometimes necessary.