3 replies to this topic

[revans]

The sky stayed clear into the evening and seeing was about average but at least there was no breeze.  I used my C9.25 and 224MC camera with a UV/IR block filter and no barlow, a 1.5 barlow plus atmospheric dispersion corrector, and a 2x barlow.  The details are in the filenames.

 

Rick

 

 

 

 

[RedLionNJ]

If I'm reading those filenames correctly, you need a LOT more frames in your resulting stacks.

 

More frames will increase the signal-to-noise ratio and allow for more precise sharpening (i.e. more of the signal gets sharpened, with less of the noise).

 

The top one looks like (if I'm reading right) just over 400 frames? Try an order of magnitude more.

[revans]

If I'm reading those filenames correctly, you need a LOT more frames in your resulting stacks.

 

More frames will increase the signal-to-noise ratio and allow for more precise sharpening (i.e. more of the signal gets sharpened, with less of the noise).

 

The top one looks like (if I'm reading right) just over 400 frames? Try an order of magnitude more.

In the filenames I usually write something like:  -5pctOf8447frames-  or -1pct12Kframes - or -1pct32K- and I haven't gotten very consistent, but later on I can usually descramble what I meant.  I usually stack the best 1, 5, 10, and 30 percent of total frames.  I look at the 1.5 drizzle conv stack results in AutoStakkert for each of these and pick the one with the most detail and acceptable noise to see if I can improve it.  This usually involves levels adjustment, flipping/rotation, scaling, color adjustment, and sometimes AI sharpening using AstroSharp.  My total capture times for a stack vary between about 1 minute and 2 minutes.  I usually capture in a 340x240 window as this allows a faster frame rate than using a larger window.  Jupiter usually will say near the center of the 340x240 window for at least 2 minutes without drifting much, at least at f/10 with my C9.25.  

 

The number of frames I end up stacking can typically be as low as a few hundred or as high as a few thousand. My largest stacks tend to occur at my highest frame capture rates and my smallest stacks at my lowest frame capture rates. Usually, I end up working on stacks of 1, 5, or 10 percent of total frames taken. 

 

I found including an atmospheric deconvolution (ADC) device somewhat useful when Jupiter gets about midway between the zenith and the horizon but it isn't easy to get the two prism levers dialed in perfectly.   One thing I have not done yet anyway, is to try using WinJupos and I don't know much about it.  I think the learning curve there is fairly steep but it is probably worth trying.  I'm probably not yet at a level of crispness that would further benefit from use of this approach though.  It is hard to know when using a barlow is beneficial or not.  My seeing conditions when average to below average really only allow me to image at about 2350mm FL.  On better than average seeing nights, I can sometimes use 4700mm FL.  Sometimes the best I can do is 3500mm FL and still get a reasonably detailed image.

 

Rick

[Seany79]

I heard x7 rule is better for planetary.. i have not tested. With your sensor x5 rule gives you F18.8 and x7 rule gets you at F26.3. With that try experimenting with F25 (2.5 barlow) , this should get you to 3.75x oversampling which is good and rez 0.1317 arch sec/px.. another one is F30 (barlow 3), giving you oversampling of 4.5x and rez of 0.1273 arch sec/px