Can someone explain

[spiezzy]

hi to all
just wanting to know about Binning I have a Sbig 8300c and I use Nebulosity 4 to capture my images I have never used 2 x 2 binning with this but have seen lots of images taken with 2x2 binning what are the advantages of using binning many thanks in advance
cheers Pete :thanx:

[speach]

mmmm! not a lot of reply's, I like to know too.

[glend]

Well the 8300 chip has 5.4 micron pixels. What focal length is your scope? More info is required for people to help out.

[Shiraz]

Binning combines the signal from each block of four pixels and makes one super pixel . that way you get 4x the signal in each new pixel and only one lot of read noise - in theory. You also only get 1/2 the resolution, so you tradeoff resolution to get the extra signal-to-noise ratio. In practice, with your 8300, you will get 4x the signal (at reduced gain), but the level at which saturation sets in will only be about 2x that of a single pixel and the read noise will be about 2x normal - so binning does not give you as much advantage as it should

So why bother? Well, you still get 4x the signal in dim regions, so, with the right sub length, you get ~2x better signal to noise ratio from the same total exposure time. This can be useful for RGB colour data, where the loss of resolution and early saturation onset may be acceptable, or for imaging very faint features where sensitivity is what counts and the loss of resolution and dynamic range is not as important. In addition, if the seeing is so bad that full resolution is not available, binning may be a good idea to make the best us of available photons.

Nebulosity allows you to do software binning - if you want an idea of what happens to resolution, image scale and SNR, try it out on one of your subs.

edit: hardware binning does not apply to colour sensors - see later post.

[spiezzy]

hi there Glenn I have a 10" newtonian truss f4 astrograph and its 1000mm fl which I am told this camera suits this scope very well and I have to agree .
its just on a lot of images posted I have seen taken with 2x2 binning I kind of thought this increases the sensitivity of the imager for better results .
I have not had a chance to try it out yet so I thought I would find out a bit more info many thanks
cheers Pete :thanx:

[spiezzy]

hi there Ray
thank you for the detailed reply I did your test in Nebulosity 4 and see what you mean it does bring out a lot more detail .
now if I want to use 2x2 binning should I be using it during capture of Subs it seems on your test the loss of resolution is minimal but the increase of detail is rather large .
many thanks cheers Pete

[Shiraz]

Take your pick - you can use hardware binning during capture, but software binning after stacking should give fairly similar SNR results and better dynamic range. With your scope and camera, you will lose a significant amount of fine detail with binning, but the increase in SNR will bright out fainter features.

[Shiraz]

oops, I gave you some bad advice there Pete - just realised that you have an OSC. You can still do software binning with one of these, but it is not as simple as with a mono camera and hardware binning is probably not an option. I will check what Nebulosity does and get back. Sorry about that - should have read your post more carefully. regards Ray

edit: Nebulosity will do software binning on a colour image after deBayer, so you have that option with your camera - but if you do hardware bin, you will lose colour info.