Binning

[Stu Wilson]

Ok I've been at this a while but until tonight never tried binning.

I've got 20 images taken binned 2x2

Put them in DSS and final image comes out in black and white/grey scale

Any ideas?

I'd love some colour.

Qhy8l camera if settings need changed in dss somewhere.

My normal images with no binning work fine.

[Seelive]

Normally, 2 x 2 binning of a colour camera results in a monochrome image since the RGB pixels are combined into a single pixel hence loosing the colour information.

[Stu Wilson]

Will 3x3 and 4x4 binning be in monochrome too?

[ollypenrice]

2 hours ago, Stu Wilson said:

Will 3x3 and 4x4 binning be in monochrome too?

Yes. Your camera has a 'Bayer matrix' of colour filters, red-green-green-blue, arranged in a pattern designed to sample each individual colour over as small an area on the chip as possible. Each pixel has just one filter, so a block of four might have RGGB arranged anyhow on the block. B might be top left, or top right, or whatever. When you bin 2x2 you read the entire block of four pixels as one, so there is no colour information contained in that reading. The same applies to any binning scale. Only in Bin1 do you read different values for different colours, so allowing the software to create and then reassemble three images, R,G and B.

This is why the term 'One Shot Colour' is slightly misleading. In reality it's 'Quarter of a shot red, half a shot green, quarter of a shot blue!'

Olly

Edited October 16, 2020 by ollypenrice
clarification

[wimvb]

If you want to use binning with a osc camera, you need to do it in software, so called super pixel debayering. The debayering process takes a group of 4 pixels and creates one pixel with the colour information of the original pixels. The R pixel provides red, the B pixel blue, and the average of the G pixels provides green. PixInsight has this as a deBayer option. Don’t know if DSS can do the same.

[Seelive]

Once the image has been debayered, most astroprocessing software should give you the means to bin the data to reduce the image size and still retain colour.

[michael8554]

I'm not sure any binning at all is a good idea.

2x2 will up your image scale from a sensible value to over 2arcsecs /pixel, and 3x3 and 4x4 would make it even worse ?

Michael

[vlaiv]

13 minutes ago, michael8554 said:

I'm not sure any binning at all is a good idea.

2x2 will up your image scale from a sensible value to over 2arcsecs /pixel, and 3x3 and 4x4 would make it even worse ?

Michael

I would say that over 2"/px is still sensible value and over 4"/px as well - it really depends on what you are doing.

You can't shoot M31 with regular camera and single panel if you don't go at 2-3"/px. M31 is over 3 degrees long, that is 3 x 60 x 60 = 10800 arc seconds. If you camera has something like 3000 x 2000 px, you are bound to use 3"/px to get it in frame.

One can always do 3x3 panel over M31 at 1"/px but that is going to take some time to complete