Jupiter - harder than i thought.

[kirkster501]

Jupiter was jumping around like a dice in a shaker. Was really struggling to get focus too - I do not have a Bahtiniov yet for my CPC 1100 (coming for xmas... ). Looked still by naked eye but maybe a SPC900 at F20 (with X2 PowerMate) at 2800 FL is too much for last night?

What is the effective FL of a SPC 900 ?

What would the effective magnification have been do you think ?

Anyway, don't laugh here goes...

And another at F10 - i.e. without the PowerMate

Rgds, Steve

[atmenterprises]

Steve, that focal length shouldn't be too much. What I did was try for what I thought was the best focus, capture the avi, move the focuser just a hair, capture another avi and so forth. Jupiter is very tough to focus.

The web can doesn't have a focal ratio necessarily (learned this from Olly) - it's just reduces - significantly - the field of view. I asked the same question you did a few days ago.

[PH-R]

Great shots and with the added moons as a bonus.

[JamesF]

There isn't really any such thing as magnification when you're imaging. What you can do is work out the image scale (as 206265 / focal length), so I think about 37 arcseconds per mm for your 2x barlowed setup, which means Jupiter will occupy about 1.25mm of the sensor at the moment.

f/20 isn't an extreme focal ratio to be imaging at. I work at around f/35 with my 127 Mak and others here regularly get up to around f/40. When you're pushing things to extremes though, seeing and collimation are very important (as is focus, obviously).

James

[Ewan]

Hi Steve, you could try focussing on one of Jupiters moons, if you can get them as round & bright as possible with the normal brightness for Jupiter you shoot with then you should be good to go. Failing that if Moon is about focus on that first then slew to Jup.

I have just posted my first DMK from the other night & wondering if my image is worth taking any further so i guess we all suffer probs.

[Jupiterholic]

If you think Jupiter's hard wait until you try and get Saturn on your camera chip!

But don't despair, stick at it, practice really does pay off with this hobby and your Jupiter shots show loads of promise. You'll find focusing and photographing it easier the more you do it. The slightly disconcerting truth is that Jupiter really is the easiest of the planets to photograph, but planetary photography itself is VERY challenging, but equally rewarding.

[kirkster501]

Thanks for your thoughts guys,

Scope had been in cold garage all day and I took it out an hour or so before running this session so it should have cooled sufficiently I think. I do hear the big Cats such as the C11/CPC1100 do need a long time to get into equilibrium though.

So could be a number of factors. Focus, seeing (Rigel was also all over the place) and maybe not cooled enough to ambient. Collimation is pretty good though. I will see how things progress !

[JamesF]

If the seeing was poor then you're going to struggle a bit. I focus by eye using the image from SharpCap, but I do have a motorised focuser fitted which makes life so much easier.

James

[kirkster501]

Yes James, I suppose it's a question of experience to know whether the seeing is bad or not so bad. Comes with time I suppose - experience that is not so easy to get in our climate....

[sologuitarist61]

Great images