StarTools

Hi,

My images are taken with an OSC QHY8L (color CCD)

Before I open my image in Startools, I calibrate it in Pixinsight.

I follow a very standard:

1. Calibrate (dark, bias, flats) the lights
2. De-Bayered the lights
3. Star align the lights
4. ...and finally integrate

When I open the integrated image, I get a question

1. Linear, was not bayered or is white balance
2. Linear, was bayered, is not white balanced

Which option should I select?

Thank you,

M.

If your OSC (or DSLR) uses a standard bayer matrix color filter array (with one red, two green and one blue pixel for every cluster of four pixels), and you are sure the white balance was not in any way modified from what was recorded, then choose 'Linear, was bayered, is not white balanced'. This will give you a small boost in signal noise reduction effectiveness, as StarTools can use the assumption that green channel data is more precise than the the red and blue channels (2 samples per 4 pixels, versus 1 sample per 4 pixels) when reconstructing the true signal throughout its 'Tracking' feature.

admin wrote:If your OSC (or DSLR) uses a standard bayer matrix color filter array (with one red, two green and one blue pixel for every cluster of four pixels), and you are sure the white balance was not in any way modified from what was recorded, then choose 'Linear, was bayered, is not white balanced'. This will give you a small boost in signal noise reduction effectiveness, as StarTools can use the assumption that green channel data is more precise than the the red and blue channels (2 samples per 4 pixels, versus 1 sample per 4 pixels) when reconstructing the true signal throughout its 'Tracking' feature.

I don't have a lot of documentation on this camera QHY8L but I believe it has the standard matrix. I assume that just because I'm de-bayering the images (i.e. converting them to color), that is not affecting anything else in the image. My images are going to have a strong green tint as I use a LP filter. When I debayer, I have to use the GRBG option to get the image to be green instead of purple or light blue.

Thanks for your help. I'll use that option.

M.

M.
I have the QHY8 (not the QHY8L) camera and use the "Linear, was bayered, is not white balanced option", I do not use any filters. You should be able to find all the documentation you need for your camera on the QHY website http://www.qhyccd.com/
Che

Cheman wrote:M.
I have the QHY8 (not the QHY8L) camera and use the "Linear, was bayered, is not white balanced option", I do not use any filters. You should be able to find all the documentation you need for your camera on the QHY website http://www.qhyccd.com/
Che

Cheman,

Thanks a lot for the validation.

M.

What if a SkyGlow filter (LP filter) was used and the image usually has strong green cast?

My Orion StarShoot Pro v2 has the same chip as QHY8. And I always use the SkyGlow filter. When I start ST, I always choose the linear, bayered, and not white balanced option. Will the green cast from SkyGlow filter messed up ST's assumption?

puckja wrote:What if a SkyGlow filter (LP filter) was used and the image usually has strong green cast?

My Orion StarShoot Pro v2 has the same chip as QHY8. And I always use the SkyGlow filter. When I start ST, I always choose the linear, bayered, and not white balanced option. Will the green cast from SkyGlow filter messed up ST's assumption?

Not a problem. All that matters is your bayer filter configuration. A LP filter won't change this (the bayer filter is glued to the chip! )