First Saturn - Help Please.

[2020BC (Bill Christie)]

Hi,

Here's my first Saturn image, and I would really value your help to improve the quality of my efforts.

The data was acquired from color video camera to Mini-DV tape camcorder then fed later via firewire into PC - captured in Astrovideo and saved to color .AVI files.

.AVI files were edited and cut to 600 frames duration in Arcsoft Showbiz (so as not to kill Registax).

.AVI files were aligned and stacked in Registax. Mild wavelets applied (layers 3 and 5 only - at increment of 1).

Focus was acheived visually by using a Hartman mask and watching on TV.

The data was captured in a Meade SN-8" LXD-75 using Mintron 62V1P-Ex color video camera. An Orion Shorty (x2) Barlow stacked into a Televue Powermate x4. Digital zoom off. Effective focal length about f/35. Shutter was 1/100, AGC gain maximum, no filters.

[Robert_T]

you've got the main features, cassini division and such, just a little washed out in colour and lacking sharpness in detail (this could be as much due to poor seeing as anything else).

I'm not familiar with these cameras, but 1/100 sec seems a very short exposure - try running something like 1/20th second and reduce your gain settings.

cheers,

[asimov (John)]

Yes, as Rob says...1/100th is too short for saturn. Are you committed to this exposure or does the camera have options. Nice image though for your 1st one!

[davidpretorius]

i agree, have you any control over saturation??? that should be 100% if possible?

[2020BC (Bill Christie)]

Thanks,

The camera can reduce shutter speed to 1/50 sec (or slower - by frame integration up to 2.56 sec.). It would probably be too bright if I went any slower than 1/50sec. Are you trying to help with the color or is it a requirement for planetary imaging that slower is better? I was trying to go faster to "freeze" (i.e. capture) one or more frames of good Seeing (but I haven't found any yet though ...)

I can adjust the color hue pretty much how I want via the camera's White Balance options.

With regards the detail of Saturn, or lack thereof, is the problem Seeing (30deg elevation) or is it more likely to be in in the processing or data capture technique?

[asimov (John)]

Re the details: you actually have good details present, but what we are referring to is the slightly blurry image. 30 degree elevation doesn't help, because your shooting through a slightly thicker atmosphere if that makes sense. The presence of the jetstream will cause havoc with imaging too. If you shoot with bad seeing conditions, one will end up with blurry images. I judge seeing conditions on naked eye observations of bright stars at the zenith...if they are twinkling a lot, you can be pretty certain it's not going to be a good night for imaging.

If you found no nice clear frames then yeah, sounds like you had fairly poor seeing conditions at the time.

[2020BC (Bill Christie)]

Cheers,

Here's one from the same tape that had a different color balance in the camera.

[rumples riot]

Some good detail here for your first. However focus is a little out or your collimation is out. Seeing can also affect your ability to image. Check Thierry Legaults (web page for definitions of seeing and collimation) Also check Damien Peachs website at http://www.damianpeach.com/index.htm . He has some really informative articles there.

Focus, can be achieved with a hartman mask, but I think you will find that focus can be achieved by looking at the screen and going in and out of focus. Nights of good seeing make this easy, on nights of bad seeing it will take some time. As for your settings, they are probably right given that your scope is quite fast. You have the right idea about freezing the image. So just play around a bit to find what works for you.

You might consider removing the shorty barlow and just using the 4x. With that much glass you will be getting some distortions and a huge loss of detail. Less is more sometimes.
Good first try.