Sanity check - one 12" vs two 10" newts.. which way to go?

[Emuhead]

Hi folks,

Can i ask your thoughts on the following scenario..

The aim:
To capture as many photons in the shortest time as possible, to get the best (cleanest/deepest) image as possible.

I've got a 10" f/4 newt but am looking to either sell it & get a 12" f/4 or alternatively keep it and get a second 10" f/4 to shoot the same target.
Simplistically, the 12" gathers 44% more light then the 10", so i guess that's 144% the light of a single 10", but two 10" would be 200% more light, am I missing anything in that logic?


In addition, which sound like cons for the 12":

I currently collimate using a Catseye Infinity collimation eyepiece, which is excellent, but reaching the primary knobs is already a stretch on the 10", i have no idea how id collimate the 12".

Also, the 12" is a hefty 25kg, so lifting it onto the mount at shoulder height would be harder than the 15kg 10".

And finally, Im not sure ill get the added resolution benefit under normal seeing conditions, using 3.8 micron pixel camera. The added focal length would be nice but not essential. I'm also not really considering heading down the RASA path just yet.

Ok, what would you do?

[Retrograde]

You seem to be thinking about it visually rather than photographically?

The 10" f4 and the 12" f4 should capture the same amount of light over the same period of time as they are both f4. The difference is that the 12" will capture it from a smaller FOV with more resolution (if conditions permit). I think the decision should be dependent on the image scale and FOV you want. Practicality would come into it too as you alluded to in your post.

Hopefully that's helpful?
Pete.

[Emuhead]

Thanks Pete.

Yes that answers that, thanks. :thumbsup:

I actually was going to delete this post yesterday, but there's no way to do that unfortunately.