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ST-402 Photometric Filter wheel problem

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onj's picture
ST-402 Photometric Filter wheel problem


I am getting back into using my ST-402. However, an old problem (present since I first purchased the camera) has  reappeared.

I thought I had it fixed, by tweaking thetightness of the washer on the centre wheel.

The (internal) filter wheel is out by 45deg (in a clockwise direction) on each filter, blocking the CCD chip from any light.

Might someone have a suggestion, before I go to the trouble and expense of returning the camera to SBIG.


KTC's picture
Turn the filter wheel over

Turn the filter wheel over.

hjg's picture
ST-402 Filter Wheel

I also had trouble with the filter wheel when I first got it.  It would turn by some random amount and end up blocking te CCDS.  No amount of tightening seemed to work.  I ended up sending it to SBIG.  What ever they did has worked perfectly for the past two years.  BTW turning the filter wheel over will result in scratched filters, because I'ved tried that.



onj's picture
Hi, Thanks for the


Thanks for the comments. The photometric filter wheel was on correctly (with the filters up), but the screw was a little loose. It seems to be working now.

When I purchased the camera the filter wheel was packaged separately. The washer that was on the shutter wheel would not work with the filter wheel. I think this was because the two wheels have different thicknesses. I experimented with different washers and found one to work with the filter wheel.

Hopefully it wil remain okay now, but if not I might follow Jeff's lead and send mine back to SBIG.




ST-402 Photometric Filter wheel problem


I had the same problem which was fixed by finding a washer with the same hole size but slightly wider than the original and not tightening too much.



Ed Wiley_WEY
Ed Wiley_WEY's picture
ST-402 Photometric Filter wheel problem

I had a similar problem and just mailed the camera and wheel to SBIG. They fixed it immediately for free and did not charge for returning it .


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