SX Lodestar high sensitive guiding camera by Starlight Xpress
  


For a long time I have used my DMK31-video camera camera from TIS (ThelmagingSource) as a guiding camera. Regrettably for some objects it was sometimes difficult to find a suited guidestar with the off-axis guider.
After reading a test where different guiding cameras have been compared, I decided to purchase a Lodestar guiding cam from StarlightXpress.
 
 

The SX Lodestar is intended to be a pure guiding camera.

Main properties are:

  • compact size
  • very little weight even though completely made up of robust metal
  • extremely sensitive chip
  • direct guiding interface
  • short flange back of ccd
  • compatible with the common guiding programs
 

This direct comparison shows the proportions between the SX Lodestar and a 9mm Nagler eyepiece. The housing of the Lodestar has a diameter of 1 ¼” throughout

View at the Sony ICX429AL-chip.
The camera has a c-mount thread but can also be put directly in any 1 ¼” adapter.
 

Rear connections:

  • mini-USB for connecor to the computer
  • direct guiding interface compatible with ST4 (extra guiding cable is included in delivery)
  • red LED as status indicator

A c-mount-1 ¼” adapter can be screwed on as an optional
(Not included)
 

Image-train with OAG, Lodestar guiding camera and ALccd 6c.

The Lodestar can be operated with passive USB cables of lengths up to 5m. Active USB cables with an integrated signal amplifier do not work because the operating current is not sufficient. For longer distances between computer and camera it is advisable to interconnect an active USB hub with own power supply.

The manufacuter suggests using the camera in 2x2 binning mode due to following advantages:

  1. in binning mode more guiding stars can be found (due to a higher sensitivity)
  2. even faster image transfer
  3. no interlace artefacts, allows even higher precision for guiding
  4. smoother guiding on the OAG because the pixels are larger and the effective resolution decreases

 
 

My personal conclusion:
As mentioned above, the Lodestar is solely designed to be used as a guiding camera. It is easy to find enough guiding stars with exposure times of 1 sec due to the highly sensitive Sony chip. The Lodestar is significantly more sensitive than a DMK31 or even a webcam. The compact construction layout, short flange back and little weight are very beneficial in application.

I noticed the following points for comparison: even if it turns out to be hard to find a suited guiding star with the DMK31 at exposure times of 1sec, the Lodestar is able to find from 5 to 10 guide stars under equal circumstances.

Thus my absolute commendation for this camera!

Manufacturer:
- StarlightXpress

Technical data:
- CCD chip: ICX429AL Sony Exview interline / CCD 8.2µm x 8.4µm / 752 x 580 pixels
- CCD-size: 6.4mm (horizontally) x 4.75mm (vertically).
- CCD- quality: Grade 1

- spectral response: QE max. at 620nm (~65%), 35% at 400nm and 770nm
- readout-noise: less than 15 electrons RMS – typically only 10 electrons
- full-well capacity: more than 50,000 e- (unbinned)
- file format: 16 bits.
- system-gain: 0.9 electrons per ADU

Position of ccd-chip level:
- 12.5 mm from the housing edge

Supported software:
- MaximDL
- PHD

Telescope connection
- 1 ¼“ nose piece / C-mount thread

Electrical connections:
- USB to PC
- ST4-cable to guiding port

Size and weight
- 32 x 72 mm black anodised aluminium casing
- 25 x 0.75 mm C-mount thread
- weight approx. 50 g