Weird Jupiter

[asimov (John)]

Hi all.

I think I have some sort of problem with the C9.25.

Have a look at the double moon shadow in the pic.

I could see this while I was capturing & put it down to crook seeing, but Lester was capturing right next to me & on his screen, the shadow was nice & round & not jumping around. It was like I had 3/10 seeing & Lester 8/10 yet both scopes are kept in the same spot ie: his observatory 24/7. That rules out scope temp problems I think.

After stacking some AVI's I suspected collimation was out so we spent some time getting it spot on. It was not out far enough to create this double moon look IMO.

It was like looking at 2 shadows attached by a rubber band, & they were seperating 50% of the time whilst capturing.

I have 8 or 9 AVIs like this...all worthless! Waste of a good night..

I've seen this once before, but I can't remember when or what scope I was using now.

Any ideas guys?

[Lester]

Hi mate,

Just a thought, because the whole planet looks like it is blury, could there be moisture on the chip. I will try your telescope tonight with my neximage and if it is okay then that counts out the scope and puts blame back on the toucam.

[[1ponders] (Paul)]

Tube currents Asi?

[Robert_T]

Hi Asi, how was your tracking. Just wondered whether big jerks across the screen in correcting might have contributed. Also I think I got something lie this once when I didn't have the Neximage tube squarely in the focusser so the chip was not square on to the light path.

cheers,

[iceman (Mike)]

hmm yeh I'd start ruling out things one at a time:
1) Swap capture devices and see if it fixes it
2) Diagonal?
3) Barlow/extension?
4) Collimation
5) Tube currents

I would've said seeing but if Lester's don't show it, it has to be something else!

Hope you figure it out asi.

[matt]

I think I saw something like that last night too with my 9.25.

Although it didn't look like that in my final image in registax.

But i think I know what you are talking about asi. It's like the moon's shadow switching backwards between the 2 spots like a really fast flickering switch?

weird

[Lester]

Hi Robert,

I think you might be on to something, with the chip not being square to the light hitting it. Because Asi's barlow doesn't fit into the extention tube very far. Will see what Asi says when he sees this.

[Lester]

Just went back to look at the 9.25 vs 14 round one when Asi wasn't there and I used my neximage in both scopes.

The image taken with the 9.25 shows the transit shadow as a cross and not a dot. The image taken with my 14 is not perfect but much better, as far as the transit shadow. I think this counts out the Toucam and puts the blame onto something else.

Can't be the drive or mount cause both scopes are on the same mount.

[asimov (John)]

Hmmmm. Thanks for the feedback guys. Re tube currents: Both mine & Lesters scopes are in the same environment, If I was having thermals due to not being at ambient, Lester would have been too. Specially his mirror being a lot bigger than mine = My scope would come to ambient sooner than Lesters. Ruled out.

2 things that I'm certainly doing wrong is having the shiny toucam adapter & the dewshield is shiny on the inside too..but that would scatter light/lower contrast, not this problem...New dewshield & paint the adapter is one project happening soon, the idea of anything shiny in the lightpath is just plain stoopid!

Yes, 2 suspected culprits are collimation & the toucam chip not being 100% square on. Collimation was out slighly as I said, which has since been rectified after the AVI's....Yeah I should have taken one more after to see if it solved the problem but by then I was pretty jacked off with the whole thing..

Thanks for the comments so far.