SharpCap Forums

Is there any application you know of that can debayer these files especially as a batch file?

A good starting place for debayering and other basic image manipulation : https://sites.google.com/site/astropipp/

Robin

Have a look at viewtopic.php?f=35&t=254.

Dave

Hi Everyone: I made this mistake and ended up with a load of compressed tiff files that PIPP would not debayer.

This program will do them one at a time, which is a tad tedious, but at least I did not lose a night's work.

https://www.fitswork.de/software/downlo ... k447en.zip

Well, now, that was a challenge. But I got there. Deep Sky Stacker only sort of played: it did make master dark, bias and flat frames. But beyond that, no. It would not touch my debayered compressed tiff files with a ten-foot pole. Anyway, my recipe is as follows.

1. Manually register in Gimp. Make all but the first layer into "screen mode" and manually superimpose. Then go to Image -> Flatten Image. This stacks the images. Gimp uses the word 'stack' to mean something totally else.

2. Play with the colour curves in Gimp. This improved the image, but did not get rid of a fairly aggressive blue cast. Export as 8-bit png

3. Convert the master dark, flat & bias to 8-bit png.

4. Now load everything into Registax in the usual way. Use Gamma and Histogram to get rid of as much of the blue background as possible. Registax was too slow with 16-bit png files.

5. Move into Photoshop Elements 14. Use Auto haze removal, then Enhance-> Shadows/Highlights and adjust to taste. Playing with the colour cast removal, trying different stars to be my 'white', eventually brought out the blue spiral arms.

6. Use Topaz Denoise to taste.

7. Go back into Photoshop to crop.

The resultant image is not great. I am trying to get a cooled colour ZWO ASI 294MC camera to photograph galaxies. With practice I will no doubt improve. Every day is a school day and all that. But at least I now know (a) not to let SharpCap compress TIFF files, and (b) how to get out of trouble if I didn't do this.

Have had another go at the colour balance. I think I have lost some detail but improved the realism of the colours. I used a combination of Gimp & Microsoft Photo Editor.

Hi Jane,

Registax is traditionally used for lunar and planetary. For Deep Sky there are several choices, some paid and others free. The free offerings include Deep Sky Stacker (DSS) and Siril. They perform calibration and stacking. Choose either one. I was happy with DSS, but I learned that Siril's authors revamped the user interface to make it easier to use. Menno, one of the moderators on this forum, uses DSS. He might have some helpful pointers for you. There are lots of YouTube videos, some better than others, so be sure to watch a bunch before jumping in. Are you capturing calibration frames, like darks, flats, and bias? No one is forcing you, so start off processing just your light frames, and then as you gain familiarity you can add calibration incrementally into your process.

EDIT: I recommend selecting "FITS" output file type.

Brian

Jane

As Brian stated, the conventional way to capture deep sky objects is to capture to FITS and use the highest bit level available. If capturing using a one shot colour camera you are going to run into this, found under File > Sharpcap Settings > 'Saving' tab :



If the Bayer pattern written out to RAW FITS is not in the correct order for the processing software used then the resultant image will run into issues such as incorrect colour and a grid pattern. Therefore before you start capturing hours worth of data it is really important to decide on the processing software to be used and set the appropriate setting in Sharpcap 4. If this is not done then incorrect colours/grid pattern will result. This can be fixed by hand but will involve telling the processing software what Bayer Pattern to use.

For the software listed above:

• Deep Sky Stacker, which is free, can be used to build master dark/flat/bias frames and calibrate the light frames, registering and stacking the frames to produce a single file which can be exported (usually as a TIFF) for further manipulation in a graphics program such as GIMP. Unfortunately wild stretching in GIMP can result in washed out colours and the introduction of noise (been there).

• Siril, which is free, can provide a complete solution. https://siril.org/download/ Siril provides a script for processing the individual files https://siril.org/tutorials/first-steps/

• Astro Pixel Processor provides a 30 day free trial license. The software provides all the functionality to produce a finished image using inbuilt Digital Development Processing techniques.

• Affinity Photo, cost £50. This has emerged recently with a long series of articles in Astronomy Now magazine and a £10 starter book by Dave Eagle.

• There are other applications which can be used.

viewtopic.php?f=35&t=2552 will give you an outline of a workflow for deep sky imaging. Some results are:
viewtopic.php?f=16&t=4529
viewtopic.php?f=16&t=4553

Have a look in the Gallery sub-forum at the images and see what software has been used to produce them.

Some other suggestions:

• Make sure you have turned off TIFF compression:
  

  

  TIIF-compression.JPG (31.46 KiB) Viewed 1351 times

• The stars in your image look slightly bloated. This will be because of over-exposure and/or poor focus. Buy a Bahtinov Mask for your telescope to help with focusing.

What telescope do you have?

Dave

Thanks for all your trouble, Dave and Brian.

I have a Celestron C11 XLT Schmidt-Cassegrain telescope, on a CGT mount, guided with a separate guidescope and PHD2. I focus with a Bahtinov Mask using the SharpCap focusing tool manually. Since this picture was taken, I have invested in an IDAS LPS D3 light pollution filter.

I'll have a read of the links you have supplied.

Regards, Jane.