Gan

very helpful information, Thanks to ratskrad. In regards to GT81 and 6AIII, a small correction if I may: the second number ( Backfocus) for GT81 is 62.1. ( from the same link as above) I haven't used this measurement in practice as yet, but I should try because last night I got very elongated stars in the periphery. I am still struggling with the full kit.

That's great. Thank you Skipper Billy. I had a good couple of hours of clear skies last night and took more images of M 42 with NINA and simply took the subs in FITS file. They came out in colour when I processed in GIMP. However, I have a feeling software like Pixinsight may bring out more out of it. I am not very good at post processing and heard that Pixinsight is a bit more complex programme with a steep learning curve. Just not very confident at present to try even the trial version.

I would try Flats wizard in NINA.

I had a similar problem once, but I was very stupid not to realise that the dust cap was still on one of the attachments in the image train! It took a while to realise that and I didn't tell anyone about that, until now!

I am eagerly waiting for a session of imaging, but skies are not cooperative. Hopefully soon. Thanks for your help Skipper Billy. -Gan

Ok. Will try that Thank you David_Taurus!

1. Yes, that's right. Now I realised that it would be better saved in FITS in NINA as I mentioned above. 2. Here is the DSS autosave TIFF file ( stack of 10 lights and 10 darks and 10 flats and 10 dark flats), I have not stretched the image in GIMP yet, because I don't know how to debayer using GIMP. Autosave.tif

2021-01-23_21-05-40__-10.00_120.00s_0001.tifI thought I did, but very sorry if I had mistakenly uploaded a stacked image, but just in case I will upload once more a sub direct from camera. Not stacked. 2021-01-23_21-05-40__-10.00_120.00s_0001.tif

Wow, that looks good. This is a single sub ( not stacked). How did you you do that debayering?

I changed them from FITS files to TIFF thinking that I will be able to see them in GIMP directly for a 'preview' before stacking in DSS. I will try again taking FITS files and debayer and stack in DSS, to see if it makes a difference. Thank you

I presume you mean once we open this file in a stacking programme or when we are doing the post processing. I tored that in DSS with no benefit because the Tiff files have no facility for debyering in DSS. Perhaps I should try once again taking FITS files and try debayering in DSS.

I guess you are referring to this page. I have ticked this anyway but I suspect this is for a preview purpose but not actually the downloaded image.

2021-01-23_21-21-18__-10.00_120.00s_0001.tifI opened the files in DSS and stacked. the Autosave file ( not attached) also showed no colour. Thanks for the help. 2021-01-23_21-21-18__-10.00_120.00s_0001.tif

I wonder if someone could be kind enough to suggest what settings need to be changed to see images in colour, obtained in NINA using ASI 071 MC Pro camera ( saved as TIFF files). Much appreciated

Almost always it said couldn't align, but didn't see any obvious explanation. I will check the log this time. I will try these measures as you suggested and will see. Thanks a lot.