Quote:
Originally Posted by TrevorW
Excuses,excuses !!!
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No excuse, just another stuff up.
Quote:
Originally Posted by Paul Haese
Incredible for the resolution. Stars are really nice and round and despite being monchrome the image shows a lot of detail. Maybe some selective sharpening might be in order. Looks forward to the colour version.
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Thanks Paul. Now I have to compete with the moon for some colour. Maybe next new moon.
Quote:
Originally Posted by gregbradley
You raise an interesting approach with the use of refractors. They do have a cool down time. I was wondering about that with mine. Not sure if you take yours out from a warm house into the outside? Mine is usually setup in an observatory but there is the temperature drop after sunset to contend with.
FSQ is well known for its relatively high sensitivity to temperature and focus shifts. Perhaps a consequence of the Petsval lens setup.
You can train a Robofocus for temperature compensation and have a thermometer attached. That way it takes care of it automatically and even during the exposure if its taken during a period of temp drop.
Every 1C drop in temp in an FSQ is slightly visible in temp shift. 2C for sure. A little digital thermometer next to your setup would be handy for that and if the temp was stable there should be no need to refocus but if different by 2C then a refocus is needed by a small amount.
Its worse when using the reducer. Slightly off focus with the reducer makes for a lousy image.
Greg.
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Hi Greg. Yes the FSQ is definitely a focus beast requiring a bit of work to keep focus but I have found that delaying the start of my imaging by about an hour gives me a much better chance holding focus for a while.
I have tried temprature compensation but found I spent just as much time confirming or fixing focus as I do doing a manual focus every half hour to hour.
The quality of the scope make focusing worth the effort though. It's a keeper for sure.
