About 10% of my exposures are thwarted by problem similar to this post.. http://forum.diffractionlimited.com/threads/stf-8300-shutter-problem.3884/ I know when it has occurred, as the shutter makes a load clack at the end of the exposure. The follow on exposure is usually OK, unless I'm exceptionally unlucky that night. Is there anything I can do to improve this?
I'm guessing as I am the 2nd owner, serno 83F010606, but I get the impression it has about 4000 exposures
Could be an alignment issue, could be the motor... Have you seen it during the warmer months as well? -Bill
Cold does not seem to be a factor, last night it showed up several times in the short exposure, continuous focus loop... but"clack" noise only, without obvious partial opening.
Hi Wally - I haven't been on the forums in a while, but just saw your message. When I bought my STF-8300M 2nd hand, I had huge frustration with this exact problem. Temperature had no effect, and the occurrence was random though common. What fixed it for me is the phase adjustment described in this forum post: http://forum.diffractionlimited.com/threads/sticking-shutter.50/#post-168 I altered my motor phase as described, and the problem went away. (Unfortunately I don't recall from what phase and to what phase.) I've used the camera for years now without a single shutter issue. Perhaps one of the SBIG folks can comment if this is a recommended troubleshooting step / solution. Best, ~Rick
There are only 4 motor phases available for the STF-8300. If you want to align/adjust the shutter, you will need to try each of the motor phases, (0-3), power cycling the camera each time. Choose the phase that best aligns the shutter. Final adjustments to the shutter can be done by loosening the 2 phillips head screws on the shutter motor, and you should be able to rotate the entire motor slightly in either direction. Then power cycle the camera again to ensure it is aligned.