Debayer Preview

[MLM]

I recently got a new OSC camera (ZWO ASI 2600 MC) and found when using a dual narrow band filter that images displayed with Debayer Preview on have a lurid pink background instead of gray/black . I don't remember this with my prior camera (ZWO ASI 071 MC), but maybe I'm not remembering correctly. Both are RGGB with the major difference being the size of pixel array and file (larger in 2600).

Images from the 2600 display with correct color balance using ASI Fits Viewer, and in PixInsight (in the latter RGB channels must be unlinked). Does SharpCap display RGB images with the channels linked? Is it possible to unlink the channels in SharpCap? Am I missing something obvious?

[admin]

Hi,

for 'normal' colours, Debayer Preview should be set to 'On' (there are various force options in case ON picks the wrong pattern, but those should not be necessary for ZWO cameras). Also make sure the white balance controls are set the the defaults of 50,50 .

Setting a 'flip' option other than none can affect the pattern, but SharpCap should auto-correct for that for ZWO camers. Best to try None anyway.

A good way to check the pattern is to shine a red torch onto the sensor - if it shows up as red then the pattern is correct. If it shows up as green or blue then it is set wrongly.

cheers,

Robin

[woldsweather]

Where do you set debayer preview to on?

[woldsweather]

I have found this now but whether it's on, off or on Force RGGB I still get the same green screen.

What am I doing wrong?

[admin]

Probably nothing wrong - modern cameras are often more sensitive to green light than other cameras and can produce a green tinted image. Depending on the brand of camera you have, there may be white balance controls on the right hand side that you can adjust to correct this. Alternatively, many people do not try to adjust out the green while capturing, instead they do it when processing the images.

cheers,

Rboin

[woldsweather]

Camera is Altair Astro 26c.

[turfpit]

The (land based) image was captured using an Altair 183C. FITS entries are ROWORDER=TOP-DOWN and BAYERPAT=RGGB. The images show before & after processing. The 'before' (processing) show the green caste and the 'after' (processing) are an accurate representation of the colours I can see. The processing examples used:

• PixInsight - Process > NoiseReduction > SCNR

• Siril - Image Processing > Remove Green Noise

• GIMP - Colors > Curves & select green channel

Dave

PixInsight_before-after.JPG (98.19 KiB) Viewed 4886 times

Siril-before-after.JPG (101.73 KiB) Viewed 4886 times

GIMP-remove-green-hue.JPG (80.53 KiB) Viewed 4886 times