New ASI294MC - gridded background & lack of colour?

[Sterrenland]

I finally managed to get outside last night and try out my newly purchased ASI294MC.

Getting used to the ASIAIR PRO software there's plenty of scope to mess things up!

Below is the first stacked image from the camera - it's supposed to be the Wizard Nebula NGC7380. This hasn't been adjusted in Pixinsight other than being cropped and having run DBE.

Despite debayering RGGB there seems to be almost no colour in the image. It opens as an RGB image in Pixinsight, but seems almost greyscale.

Also the background seems to be gridded almost as if showing the chip row/columns. I tried out guiding and dithering last night for the first time and both seemed to be running OK at the time. The camera was run with Gain=121 and the exposures were 120 seconds.

Any ideas what I've done wrong concerning the lack of colour and the background?

 

[Budgie1]

How did you stack the subs?

If it was with DSS did you set RGGB under Options > Raw/FITS DDP Settings ...... > FITS Files tab > put a tick in the box by "Monochrome 16bit FITS files are RAW files created by a DSLR or a colour CCD camera".

Under that is a drop-down titled "Camera" and you need "Generic RGGB" selected. Then click "Apply" and OK to close the window.

Now re-stack the subs and you should have colour images.

[steppenwolf]

It does look like the wrong Bayer matrix decode has been selected.

Can you post up a single unprocessed FITS file please?

[Sterrenland]

5 hours ago, steppenwolf said:

It does look like the wrong Bayer matrix decode has been selected.

Can you post up a single unprocessed FITS file please?

I use Pixinsight WBPP and have tried manually selecting RGGB (which I believe is the right pattern for the ASI291MC Pro) and using Auto - both produce the same gridded background.

I've attached one of the subs. Any help is very much appreciated!

Light_NGC7380_120.0s_Bin1_20210719-001646_0C_0034.fit

[Sterrenland]

13 hours ago, Budgie1 said:

How did you stack the subs?

If it was with DSS did you set RGGB under Options > Raw/FITS DDP Settings ...... > FITS Files tab > put a tick in the box by "Monochrome 16bit FITS files are RAW files created by a DSLR or a colour CCD camera".

Under that is a drop-down titled "Camera" and you need "Generic RGGB" selected. Then click "Apply" and OK to close the window.

Now re-stack the subs and you should have colour images.

Thanks for your reply...I use WBPP in Pixinsight and have manually selected RGGB as well as trying Auto - both produce the gridded background and no colour.

[Big Jim Slade]

I do't shoot OSC so can't offer a lot of help, but running Debayer using Auto produces the right result. So I would guess your aren't setting up WBPP to debayer correctly during calibration. Have you watched Adam Block's videos on WBPP, he spends a fair bit of time on OSC/DSLR stuff?

[steppenwolf]

Thank you for posting up the single frame which does de-Bayer correctly in PixInsight using the RGGB setting (also the 'Auto' setting) in the Debayer process and I get the same (correct) result using WBPP at default settings so I am at a loss to explain why your mileage differs! In MaxIm DL it also de-bayers correctly using 'Generic RGB' with no offsets.

 

[Sterrenland]

Thanks to you both for checking the sub I attached.

So it would seem to be possibly something in my copy of Pixinsight that isn't playing ball 🙄

Thanks again for helping.

[Budgie1]

If you're relatively new to PI, this set of video tutorials by Mitch are worth a watch, numbers 3, 4 & 12 deal with batch processing and debayering.