C8 Jupiter 29th May

asimov (John) · #1 30-05-2006, 01:14 AM

Fired off a few through the C8 tonight. Seeing was really bad; 3/10.

This is the best out of about 13 AVI's.

C8/toucam. 2X Barlow, 2 extension tubes stacked.

1/25th sec @ 20FPS Gain 60% Gama 25%.

364 frames stacked.

Edit: Added second image taken @ 10FPS. Barlow & one extension tube. If I live long enough to see good seeing again, the C8 will produce some respectable images. These two are laughable but I felt the need to post.

I did get a few with the GRS in view but got onion-ringed badly on them..

ozzmosis · #2 30-05-2006, 03:51 AM

nice pic and very good for 20 frames a sec...

[1ponders] (Paul) · #3 30-05-2006, 07:54 AM

Laughable images

I'd be laughing if I could get anything like that atm

Seriously though they are fine Asi. Sure they might not look like the ones you get through the 14" and 9.25" on good nights but there is nothing shabby about them either. I reacon there would be some astronomers from the late nineties that would have loved to get their hands on shots like that.

Lester · #4 30-05-2006, 07:57 AM

The C8 will be glad to be used again. I know the conditions were very awful, so good imaging Asi considering all that.

What was the image shift like compared to your 9.25?

asimov (John) · #5 30-05-2006, 08:09 AM

Morning Lester.

A little bit less image shift than the C9.25.

Thanks Paul.

Very interesting capturing at 20 FPS...After seeing the image on screen @ 15FPS one would conclude 20FPS would look even worse, but the toucam does something weird (not sure what) but it looks....I dunno

less compressed? for want of a better term. I suggest a few other toucam owners try it to see the results for themselves. Loss of brightness is the biggest drawback, but it ups the anti on getting detail in crook seeing.

Lester · #6 30-05-2006, 08:18 AM

Hi Asi,

Here is a 9.25 shot at 5 fps 2x barlow no extention tube.

asimov (John) · #7 30-05-2006, 08:22 AM

Thanks for that Lester. No onions, good good!

Detail is smeared due to the nasty conditions. I hope the re-collimating we did kicks that problem I had last session.

Roll-on anything above 5 seeing conditions!!!!!!!

allan gould · #8 30-05-2006, 08:35 AM

Well I was shooting last night with my C8 and 2x barlow in Brisbane at about 10:00 AEST and the seeing was terrible here [about 3/10] as well.
One avi worth processing
Regards, Allan

asimov (John) · #9 30-05-2006, 12:39 PM

Hi Allan. Good detail on that one.

Lester · #10 30-05-2006, 01:01 PM

Hi Asi,

Here is a theory of mine on the onion rings. Capture size must be smaller when seeing is causing Jupiter to pulsate like a heart beat.

Last nights image done with your 9.25 was acceptable= no onion rings although the seeing wasn't sharp. Used 2x barlow only.

The images I captured with my 14 with 2x barlow = larger image scale were bad for onion rings. If it clears up tonight will try just prime focus for seeing of 5/10 or less.

Lester · #11 30-05-2006, 01:32 PM

Okay call me thick. Found image taken with 14 last night at 50 gain and guess what much less onions. So just like you have been saying Asi it doesn't need to always look the best on the laptop. And I know it is not in your nature to say this, so I will say it , Lester I TOLD YOU SO.

Just reprocessed image to improve colour

Robert_T · #12 30-05-2006, 01:41 PM

Hi Asi/Lester - where's this C8 come from. You guys are getting overcrowded with SCT... are they starting to breed

Onion rings - my new theory is that the key is shorter exposure time (e.g. use 1/33rd instead of 1/10th ot 1/20th)... though this of course also demands more gain so that can't be ruled out. I have had success with removing onions using 1/33rd running lesser exposure (say 180-190) on the KCCCD scale - e.g. compared to if I say ran 1/20th sec at the same gain and got 230 on the KCCCD metery thing.... if that makes any sense at all

cheers,

Lester · #13 30-05-2006, 04:42 PM

Hi Robert,

Yes the shorter exposure goes hand in hand with more gain so that is probably helping as well. I don't understand the settings on KCCCD though. As I am using Amcap.

Lester · #14 30-05-2006, 04:48 PM

Sorry Robert,

The C8 I got new in about 1974. It was my main scope till 1980 when I got the Meade ds 16" f4.5 optics, but the C8 was best for planetary use over the 16". The 16" was fantastic for DSO. The 16" mirror is on its way to Ian at Canberra.

ving (David) · #15 30-05-2006, 04:49 PM

seems every time a c8 comes out to image the seeing auto-drops to 3/10

nomore c8s plz!!!

fine imaging guys

asimov (John) · #16 30-05-2006, 06:20 PM

Yeah, tried all that a few moon orbits ago Lester...capturing at smaller image scale I mean, to kick those onions. No dice.

I still make the fatal mistake on occasion of going by wot looks nice on the screen too...