Picking the right Barlow/reducer to couple telescope to camera for Nyquist sampling

[Rchurt]

Hello,

 

I recently purchased my first telescope and camera, and now I want to make sure I have the correct Barlow or reducer to couple them together to achieve Nyquist sampling on the camera (or slight over-sampling). In case it’s important, I’m interested in planetary imaging—in theory that shouldn’t matter for this sampling question, but maybe there are other considerations to take into account.

 

I used this calculator (https://astronomy.tools/calculators/ccd_suitability) and plugged in my info:

Telescope: Celestron 8 SE

Camera: ZWO ASI462MC

Seeing: experimented with this one, but would like to get optics that allow for poor or very poor

Binning: prefer 1x1 to preserve spatial resolution, but could consider higher if SNR is a problem

 

I’ve seen on several forum posts that people often use a 2x Barlow to couple the two. However, according to this calculator, that will always lead to over-sampling. If anything, it says I should use no intermediate optics or even a reducer.

 

So my questions are:

 

Binning: Will I be able to see anything with 1x1 binning, or should I expect to need to bin to collect enough light?

 

Is there some other consideration that’s more important here than achieving correct sampling? It seems like most others are over-sampling, and perhaps there’s a good reason for this. If so, is there another formula that would let me determine the appropriate optics to buy?

 

Thanks in advance for any help!

Edited December 11, 2020 by Rchurt
Typo

[CraigT82]

Hi and welcome to SGL!

If it were my choice I'd probably go for a 1.5x barlow, and failing that no barlow at all.  But don't get too hung up on perfect sampling...  It wont be the biggest factor affecting your planetary images, not by a long shot. 

Scope collimation, cooling and above all else, seeing, is what will affect your images the most.  Oh and if you don't have one, a motorised focuser is highly recommended. 1x1 binning will be fine, the planets are very bright!

Edited December 11, 2020 by CraigT82

[Rchurt]

Thanks very much!