Quote:
Originally Posted by gregbradley
Weren't you imaging at F8 or longer with small aperture though?
At longer f ratios and smaller apertures yes you won't have a problem. Its a question of how much signal builds up in the chip's wells. At 25,500 that isn't a lot for all scopes. So for example I would expect with Mikes F3.6 12 inch scope you would see bloated bright stars pretty quickly QSI, Apogee, FLi, SBIG the lot as its the chips specification here not the camera maker. It can only hold so much. The 11002 chip holds 60,000. the 16803 about 105,000 most of the commonly used chips have decent well depths. That just one of the compromises so as you point out it may not be a problem with a smaller scope of longer f ratio. It depends on the object with my scopes. I have quite a few like you mention yours worked out. But then I also have done quite a few where a few bright stars
Also the 8300 is a better match for your TSA due to its shorter focal length than the RC where it will be oversampling and losing sensitivity as a result ( it will perform noticeably better in good seeing compared than say an 11002 camera on the same night). At least that is the theory.
Its something to consider when buying a particular chipped camera independent of brand. Another brand can't make the wells deeper and it will vary depending on the object and scope. Larger aperture or faster F ratio with an object with lots of bright stars may do better with 5 or 7 minute subs instead of 10. At least that the theory and something I intend to do with mine next time I use it to see if it works. I see lots of images with 8300 cameras and all the stars are perfect but usually I also see they used 5 minute subs. Wolfgang Promper for example.
|
You know it is funny because recently I have been imaging with the TSA at f5.8 and I have not noticed any bloat at all. I had been using just the flattener but I bought a reducer and now that gives me a faster f ratio, but have not noticed anything going on. Granted, with the RC I get bloated stars simply from the oversample, but not so from the TSA now.
Yes Promper does do 5 minutes subs and some of the other notable imagers. How that means going really deep is not really an option. Sort of weighing up the pros and cons I suppose. Mind you Promper does have a very large scope, so 5 minutes is probably equivilant much longer subs. I generally aim to get my background on subs over 1000 ADU.
Despite all this though you wrote a great review of both cameras. Sorry to have hi jacked your thread.