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Jbunky86
20-03-2012, 07:15 PM
Hi guys im currently imaging with an Orion ed80t with field flattener, c5gt mount, Orion mini auto guider package, unmodded cannon 1100d and post processing using dss.

Im managing some great images of carina, horse head, Orion nebular. Basically anything fairly wide field. Lately I have been attempting galaxies which are further away, sombrero and the like.

What is the best way of imaging more distant things? Is it a matter of trying to produce better as low noise images as possible and after processing blow them up? I find if I do this I lose a lot of resolution.

Is it as easy as chucking in a 2" Barlow between the DSLR and telescope to take the scope up to f12?

I really had to save a lot and stretch finances to afford what I belive to be a good entry level astro imaging setup and would hate have to buy a new mount with better error correction or super expensive 120mm apo.

I noticed a trend towards really fast newts, F4 etc. would this give an even wider view? As compared to an ed80 which is F6.

Any advise would be great
Thanks Jason

ballaratdragons
20-03-2012, 07:23 PM
Hi Jason,

don't fall into the common trap of thinking that a faster scope (f4, f3 etc) will give a wider field than a slower scope (f6, f7 etc).

The focal ratio is only part of the story.
The more critical point is the Focal Length, not the ratio.

You need a short focal length to achieve a wider field.
As you go up in apature, so does the focal length. :thumbsup:

As an example:
a 12" f4 newt will have a focal length of 1500mm.
a 10" f4 newt will have a focal length of 1200mm.

The 10" will give a wider field :)

I hope that is what you want to know, and that I made sense :P

A Barlow will give you a smaller field of View (FOV). Object will appear larger :thumbsup:

Poita
21-03-2012, 01:19 AM
An F4 newt won't give a wider view than your ED80 at F6, it will just allow you to image faster, and possibly get more detail.

You can pop in a powermate or barlow into your ED80 to get more up close and personal, but there is a limit to how much detail you can get when the light coming in is restricted to an 80mm diameter.

You could chuck a $400 2nd hand C8 on there and get masses of light and detail, or a 105mm/650 refractor and get quite a bit more detail at the same exposure length and have more room for blowups so to speak.

Borrow a barlow or powermate and see how you go. You will get larger images of distant objects, but will need to take longer exposures.

Jbunky86
21-03-2012, 08:18 PM
Cool thanks for the advice guys I'll give that a go
Cheers