Captured May 20, negative EP projection, C8, 2.5x Powermate, diagonal as an extension tube, ToUcam.
All 10fps except last 2 at 15fps. Gamma = 0% for all captures, saturation at 50%. Various shutter speeds and brightness settings, and gain between 0 and 50% to achieve exposure.
21-37_0005Jupi1:
300 / 1836 frames stacked. Could not process this avi with a reference frame (illegal floating point operation!?)
Gamma 0.6, histo stretch, b1.2, g1, r1, wavelets 19.2, 3.8,1,1,1.7,5.8
21-41_0007:
297 / 1556 frames stacked.
Gamma 0.6, histo stretch, b1.5, g1.05, r0.9, wavelets 5.1,2.4,1,1,4.4,27.3
Objective lens iced up hence significant colour adjustment to compensate for lost blue.
21-40_0006Jupi1:
Underexposed on capture (histo 0 to about 80!). Aborted after about 300 frames. Stacked about 100 but didn't bother to document processing... didn't expect much from it! Ice on objective lens probably caused a lot of exposure loss.
You must be just about pushing the limits though with three minute shots. Jupiter rotates at 0.6 degree/min. At that rate you will find it difficult getting clearly defined features at three minutes unless you reduce your magnification. You may notice that some of the features looked just a little bit "stretched"?
Matt, have a look at this page. Using the extender you put an eyepiece into it and screw one end to the scope (T thread to adapter needed for SCT) and the other end to the camera (adapter needed for ToUcam to do that too). Varying the length of the tube will give you different magnifications. If you can get a hold of Michael Covingtons book "Astrophotography for the Amateur" (a loan from someone) he covers the different types of imaging very well.
You must be just about pushing the limits though with three minute shots. Jupiter rotates at 0.6 degree/min. At that rate you will find it difficult getting clearly defined features at three minutes unless you reduce your magnification. You may notice that some of the features looked just a little bit "stretched"?
Thanks Paul.
About how many frames would you suggest for jupiter? 1000? I do remember reading something about that now that you mention it . I was collecting short avis (about 300 to 500 frames) for everything, but recently started to up the avi length to about 1500 / 1800 for lunar shots. I think that's what Dennis does for lunar shots... I can see its not an issue for the moon!
I try to go for 900 frames on not so good nights and 600 frames on above average nights and 450 frames for those gobsmacking 3 times a year nights. That's 90sec at 15 fps, 10 fps and 5 fps.
Though there has been talk recently of stretching the 90 sec to 120. Don't know if the "professionals" around here have had the sky or the heart to try it yet
They're great Al, but I find the limb way too dark. Can you try capturing with gamma at 40-50%? It may look "washed out" while capturing, and even while sendnig through registax, but it can be processed down afterwards by reducing the gamma in registax or AstraImage afterwards. The very low gamma you have now does give good contrast, but I find the very dark limb distracting and not a true representation of what can be captured, or what you see through the eyepiece. but that's just me.
There's some great detail there.
At that image scale/focal length, you could easily capture for 2 minutes without rotation. It's easy to tell if you've captured too long - take the first and last frame in the avi, and "blink" them, and see if you can find any rotation of the features.
Guys with C11's and C14's capture for 130seconds (filter wheel changing involved), and their focal length is much longer than yours. So you could easily go the same time. I know I'll be capturing for 2 minutes from now on, and my focal length is usually around 6300mm.
I can see what you're saying about the limb disappearing Mike. If you look at the unprocessed image, I think the limb is already at the dark limit, so the processing I'm doing to increase the contrast in the colours kills the limb. This is the first time I've tried 0 gamma during capture (I think Dennis mentioned that's what he was doing for Jupiter?) so its been an interesting experiment!
I've just had another play, reprocessing the first two images. There's a big difference between how these pics appear on my lappy and on my desktop PC. Definitely darker on the desktop - the limb is clearly visible on my lappy (which is where I processed them).
I read your post just before having a go at reprocessing the 21-25_0002 image in K3CCDTools. I think you are right it could do with more saturation for my liking.
Anyway here's the image reprocessed in K3CCDTools. I stacked 304 images, stretched the histo and unsharp mask. Rotated, cropped and bumped up the saturation in PS CS2. ...oh, and I tried the 2x enlargement in K3CCDTools. I have to say I like the result of the 2x enlargement. My initial impression (based on this one image only! ) is that K3 does a better job on the enlarging that Registax. Just my opinion at this stage.
OOps sorry guys! Posted the one without the saturation adjustment. Did I mention I also bumped up the brightness a bit to try to compensate for the dark limb?
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. I was collecting short avis (about 300 to 500 frames) for everything, but recently started to up the avi length to about 1500 / 1800 for lunar shots. I think that's what Dennis does for lunar shots... I can see its not an issue for the moon!
Did I mention I also bumped up the brightness a bit to try to compensate for the dark limb?
