Well saw a clear sky and went out last night to get some more of Saturn.
I used Qfocus (thanks Dave, K3ccd keeps crashing on me).
10fps, 20% gain, 1/24th, default brightness/contrast/sat settings.
With and without barlow. Then Stacked them in registax, used ppmcentre to centre the output bmp's.
I then stacked the non-barlowed bmps together, first picture and rescaled (mitchel in registax).
Second picture is half the stacked barlowed bmp's. Third picture is the rest, i splits these as a i changed the settings half way dont recall what i changed.
I dont know why but the results are not as good as my last attempt in my humble opinion anyway. Perhaps because i did not get as many frames, previously i did not let saturn just move accross the screen, rather i moved the dob to keep saturn in the centre and did longer captures. But comparing my frames from last time to this time, the details are not as clear.
How do yout tell if it is in focus or not just looking at the laptop screen? And should i change the saturation and brightness settings, will this make a diffrence?
Dave is there a way in qfocus to increase the displayed imagescale (zoom in), it may help me focus.
have the adjust option ticked and it fills the screen, i use it all the time.
re focus with saturn, well i am not on speaking turns with saturn at the moment. went to bed early, got up at 11pm to have a go at saturn. conditions were warm and still. mirror was the same as ambient. scope star tested beautifully.
i spent 10 minutes trying to find saturn at 1000x and then 45 minutes trying to get a focus. the planet and rings were still, but whether because of high cloud or something else, i could not get the casinni division to come up.
gave up in disgust!!
another method, try a bright star like procyon, crank up the gain and brightness and gamma and see if you can get the star with diffraction pattern focussed, and then swing back to saturn.
this for me is more accurate than estimating a hartmann mask focus
qfocus has a focus section, but without electronic adjustment at the moment, it is too hard
I could baerly make out the casini on the screen in a few frames. Not sure what was going on. But the clouds did come in after a while maybe there were some higher up.
I am thinking about geting the Accufocus, seems to be good reviews of it and I have the R&P focuser so should fit. But till then. It took me about 45 mins to switch from non-barlow to barlow. Finding Saturn with the barlow is a pain, and it did not help that my Astromaster was not hitting the spot right on. My alignment was off i think. I spent about 4 hours to get a total of 6000 frames at 10fps.. 10mins worth.. i too dont want to talk to Saturn, but alas its not ver often i get clear skies on Friday and Saturday (i hope) the only nights i can really go out.
Are you capturing at 640X480 wolfie? If you are I'm not sure what to suggest.
What I do is brighten the image up on the laptop screen (it does not matter how you do this), get the best focus possible (so you make out the cassini division) & then go back in & alter the settings to how it should be captured at. If you can't see the Cassini division, it could mean your seeing conditions are terrible.
Don't discount something low tech like a magnifying glass held over the laptop screen to get a bigger image to help you with focus either..
Naturally I am going to have a go at reprocessing your images!
Hey Netwolf, focus is probably the trickiest thing about planetary imaging. I spend a lot of time going back and forward with an electric focusser (almost essential) waiting for those brief snaps of good seeing. Except under good conditions you should expect to see the cassini division come and go on the screen - so long as when it does come clear it looks reasonably sharp you should be OK. The shadow of Saturn's globe on the rings is another high contrast feature that's useful to focus on.
Believe it or not, your data this time around is better Wolfie. I suggest your focus was not far out actually...hard to predict the seeing from the photo's but I'm guessing 3-4/10. Please correct me if I'm wrong.
Anyway this is the best I could do. Your really close to pulling out a good image!
I've added 2 versions of each of your 3 photos. The 1st of each image is cropped & gamma alteration/contrast/RGB split & adjusted/etc.
The 2nd of each image is after putting them thru neatimage.
Dont know asimov, i am not sure exactly how one rates seeing conditions. If it is as i think by looking at the amount the stars twinkle it seemed ok to me. In my eyepiece view images were sharp.
Oh btw i have never colimated my scope, its one thing i have just not got around to doing as well as centre spotting my scope. I just keep putting it off but i do do a star test and the rings are prety symetric in and out of focus.
Is there a way to measure collimation using a phot taken with a webcam or Eyepiece projection onto digtal camera? It simply boils down to time, i just dont have enough of it.
I used to rate seeing by star twinkle with the naked eye. But now I go by how much the planet on the laptop is going in & out of focus. I have seen very little star twinkle naked eye & a terrible view on the laptop at the same time, not sure what to make of that?
Yes, simply get a medium bright star on the laptop & put it slightly out of focus just like you would in the eyepice visually. I do this all the time to test collimation. Make sure the star is exactly in the centre of the FOV before you decide if its out of collimation first though. No easy task for you with no tracking.
asimov, I have taken one of the clips with barlow and split it into two and converted them into gif animations attached. If i were to guess i would say you were right transperancy was not good.
