Recent Imaging Results and Queries Please

[PembrokeSteve]

Hi,

I have recently processed images of a small section of the Chain Cluster in Virgo (see the image uploaded) after selecting the  final choice in Deep Sky Stacker (DSS) of "Non-Embed".
I am aware that for the final saving in DSS, it is recommended to opt for "Embed" and afterwards "pull out" the image details using the "Levels tool" (I am using GIMP).
However when I try to process my images after selecting the DSS final "Embed" option, and via GIMP, things start to go downhill !
My finished images have reddish/pink blobs within the centre of the brighter galaxies, and stars. (see image of this problem).   What causes this?
I reverted to the DSS "Non Embed" option, because by doing so, it got rid of the reddish/pink blob problem.
The  main image that you see is from 45 (1 minute) light subs and x1 (1 min) Dark. 
Note: The processed images in which I encountered the reddish/pink blob problem, I had applied 45 (1 minute) light subs, x7 (1 min) Darks, x13 Flats and x13 Bias (the 1st time I have ever tried doing lights and bias frames).
What I would like to know please (finding an answer to this online, seems impossible) is if one shoots say 45 Lights, then how many Darks do you need, how many Flats and how many Bias?
Do I need to be shooting  MORE Light subs before I even begin to think about adding Flats and Bias frames?
Regards,

Steve

[wimvb]

Calibration of light frames adds  the noise of the darks, bias and flat masters that you use. If you only use one dark frame, you're adding a lot of noise, which is not randon from image to image. So it won't average out in stacking, unless there's a natural dithering (movement between subs).

To avoid this, you need to create masters from as many subframes as possible. I use at least 15 - 20 subframes for each master. That way, the masters add as little noise as possible to the light frames.

[alacant]

Hi. Deault DSS creates as file called autosave.fits or autosave.tif. Once you have it, take it straight into gimp. Do nothing with it in DSS.. Use DSS only for stacking. Your artefacts will not then show. Just my theory but HTH.

[PembrokeSteve]

Many thanks for taking time to give me some advice, much appreciated.
Thanks,

Steve

[Stub Mandrel]

If you use the curves tool in DSS some settings cause the very right hand end of the curve to 'droop'.

This has the effect of making any very bright parts of the image darker than their surroundings in the final image.

Always check your brightest stars to see if they have become 'doughnuts'