Atik 490EX with an MN190 and 100% crop size?

[AndyUK]

Hi there 

I've been really happy with my 314L+ on my MN190, as it's enabled me to get in really quite close on some DSO's (1.32"/px).  However, I've now got myself an APM 80/f4.5 refractor and even though the field is obviously a lot wider, I'm still finding for many DSO's that I'm having to consider mosaics...

The 460 / 490 would be an obvious choice for the APM, but with the MN190, I'd be getting 0.94"/px with the 460 and 0.75"/px with the 490... and sadly I can't afford to have two cameras, so if I were to go for bigger chip camera the 314L+ would have to go 

I know I could 2x2 bin everything with either the 460 or 490 on the MN190 (giving 1.88"/px and 1.5"/px respectively), but on this score it would therefore seem that the 490 would be the better "fit".  (I must admit, I don't really like the idea of binning luminance, but I can't see any other way around this whilst still keeping my 1.25" filters!)

However, by putting a 490 on the MN190, I'm going to obviously have a wider FoV than my beloved 314L+... but I'm wondering if the fact that it has c. 3x more MP (even when 2x2 binned) this would mean that at a 100% crop I'd end up with a useable FoV not dissimilar to the 314L+(?)

Is there an algorithm for working this out, or can anyone advise if they've tried / had any success using a 490 on a c. 1000mm FL scope?

Cheers

Andy

[MicroAstro]

I'm not really understanding your question Andy because FOV depends only on chip size and is independent of pixel number or binning? However, have you tried Ron Wodaski's CCDcalc program (http://www.newastro.com/book_new/camera_app.php )? It's great for modelling how FOV and image scale change with different camera/scope combinations.
...Keith