Why are my lunar captures red?

[Swoop1]

Did a couple of runs on the moon last night using Sharpcap- the first time I have used it. The product is red as below which baffles me. What have I done wrong here?

Celestron C6 SCT, ASI290MC, 1000 frames, the best 205 of which have been stacked and sharpened in Autostakkert!

[carastro]

Did you use an IR filter?

Carole 

[symmetal]

This is fairly normal for OSC cameras. Whenever I do Moon images with OSC, in the capture program camera colour balance setting the red gain has to be reduced quite a bit and the blue gain turned up to near maximum to get a grey output. If you look at the response curve of your camera, red responds to a wider band of wavelengths compared to green and blue, and the blue output is significantly reduced as the QE is lower at the blue end compared to red.

Also if you look at the colour response of the moons reflected light, it's highest in red and way down in blue, so a pink moon is more realistic than the grey one our eyes are seeing, due to the brain making the predominant colour more neutral.

Alan

Edited July 11, 2022 by symmetal

[newbie alert]

Simply the wrong de- Bayer format

[Swoop1]

On 11/07/2022 at 21:04, carastro said:

Did you use an IR filter?

Carole 

Hi Carole,

No I didn't use a filter.

Matt

[Swoop1]

On 11/07/2022 at 21:35, symmetal said:

This is fairly normal for OSC cameras. Whenever I do Moon images with OSC, in the capture program camera colour balance setting the red gain has to be reduced quite a bit and the blue gain turned up to near maximum to get a grey output. If you look at the response curve of your camera, red responds to a wider band of wavelengths compared to green and blue, and the blue output is significantly reduced as the QE is lower at the blue end compared to red.

Also if you look at the colour response of the moons reflected light, it's highest in red and way down in blue, so a pink moon is more realistic than the grey one our eyes are seeing, due to the brain making the predominant colour more neutral.

Alan

Thanks for the info Alan.

Not had this before on other lunar captures using the same rig. Could it be the altitude of the moon at the moment?

[Swoop1]

9 hours ago, newbie alert said:

Simply the wrong de- Bayer format

How do I correct this error?

Thanks,

Matt.

[symmetal]

43 minutes ago, Swoop1 said:

Thanks for the info Alan.

Not had this before on other lunar captures using the same rig. Could it be the altitude of the moon at the moment?

Being at low altitude, yes, it would be more red than if higher in the sky. On Sharpcap Image Controls-White Balance was the blue set to around 95 and the red around 45 which is what I use for a more neutral colour result. This is visible with 'debayer preview' on. It will autodetect the pattern (most likely RGGB) but can be overridden. The video is recorded as raw, (not debayered) to save using processor time doing debayering, which would impact the frame rate.

Autostakkert does the actual debayering during stacking, set by the Colour menu item. Auto detect is usually fine, though you can force other patterns or mono. I assume the Sharpcap preview and Autostakkert gave the same colour result (assuming you used debayer preview in Sharpcap).

Alan

[Swoop1]

Thanks @symmetal I will revisit the processing based on your tips.

I am currently at the stage in my processing journey where, in most cases, the default options are left as they are as I don't know enough abut stuff to feel confident in meddling.