All StarTools Experts - Help Please!

[Astrosurf]

OK my lovelies, I have a TIFF here of the Pacman Neb, and cannot get StarTools to work well. I just don't understand the software to be honest. It's not the best image as I had dew issues, but if you can have a go, and give me your workflow, that would be brilliant! Thanking you in advance. Google Drive link:

https://drive.google.com/open?id=1W_fuuxTRTkDyEg9LIXUBnsQcbU0_mTdY

Alexxx

 

[bottletopburly]

This is by far the best tutorial I know of for Startools by sgl member Ecuador http://astro.ecuadors.net/processing-a-noisy-dslr-image-stack-with-startools/  startools forum has good info too , I will take a look later ?

[symmetal]

The uploaded image has already been stretched by the looks of it. Startools likes to work with linear (unstretched) data. The first thing to do in Startools is to crop off the stacking artifacts around the edges as they cause havoc with the 'Wipe' module. I normally use Photoshop to crop as it's quick but you can use the Startools 'Crop' tool to do it. Do an 'Autodev' before cropping to show up the edges clearly. The Autodev is temporary and you can reset it afterwards. Can you upload an unstretched image instead.

Alan

[Astrosurf]

Thank guys. I thought it was unstretched. It's the stack straight from DSS. Then, when I opened it in ST, I chose 'Linear, was not Bayered or is whitebalanced'. How can you see it's been stretched and how do I stop it?

[Astrosurf]

I've just read the stretching info on ST and it's 'cause mine's too bright. I used TIFFs right the way through which I think was a mistake. I've just stacked the FITS files and produced a FIT file so I'm trying that now.

[Astrosurf]

Here's a link to the FITS file if you want to have a go:

https://drive.google.com/open?id=1hJVslkh_wFXVupAQYwsDXeQQ_jD9HrGm

[jjosefsen]

58 minutes ago, symmetal said:

The first thing to do in Startools is to crop off the stacking artifacts around the edges as they cause havoc with the 'Wipe' module.

Damn.. This might be why I never got star tools to work on my data..

[alacant]

Hi. Very quick...

AutoDev > crop > wipe > Dev > Decon > Tracking-off > Denoise

Nice data: there's loads more in there. Have a look at contrast, sharpen, life, flux... Remember StarTools' strength that you can redo and undo the stretches as much as you like AND the image behaves linearly:)

HTH

 

[Astrosurf]

I'm having no luck with the FITS file. It's far too dark. Yet with the TIFF files I get lots of noise and then blotchiness as I try to reduce noise. I've had to take the image into Photoshop and done a layer over the top in Overlay Blending Mode and all sorts of jiggery pokery. I'm not too happy with it. It's not very dark in my garden due to LED lights and the dew was a problem. 

How can I prevent the blotchiness?

TIFF image:

 

[Astrosurf]

3 minutes ago, alacant said:

Hi. Very quick...

AutoDev > crop > wipe > Dev > Decon > Tracking-off > Denoise

Nice data: there's loads more in there. Have a look at contrast, sharpen, life, flux... Remember StarTools' strength that you can redo and undo the stretches as much as you like AND the image behaves linearly:)

HTH

 

 

Thank you! I just can't do anything with the noise! The cooler was on to -15 so why do I still have a noise problem?

[happy-kat]

To make sure use the optimum dss settings these are in bottletpburly's post link.

[alacant]

1 minute ago, Astrosurf said:

why do I still have a noise problem?

The usual answer is to take many more light frames. Otherwise very difficult to say without knowing how you captured the image and your st workflow;)

HTH

[Astrosurf]

2 minutes ago, alacant said:

The usual answer is to take many more light frames. Otherwise very difficult to say without knowing how you captured the image and your st workflow;)

HTH

I took 4 subs of 7 mins and 6 subs of 15 mins. Just seeing if my guiding was good enough.

[Astrosurf]

This is an Autosave.fit processing in ST and PS. Is this any better do you think?

 

[bottletopburly]

Quick play

[Astrosurf]

2 minutes ago, bottletopburly said:

Quick play

 

Thank you! That shows just how much detail there is. I don't think I can push it much further. I need a whole night at a very dark site!

[symmetal]

2 hours ago, Astrosurf said:

I'm having no luck with the FITS file. It's far too dark. Yet with the TIFF files I get lots of noise and then blotchiness as I try to reduce noise. I've had to take the image into Photoshop and done a layer over the top in Overlay Blending Mode and all sorts of jiggery pokery. I'm not too happy with it. It's not very dark in my garden due to LED lights and the dew was a problem. 

The FITS file should be the same as the TIFF file if they are both unstretched. Here's my effort in Startools with the FITS. I usually set the manual develop slider below the default setting to avoid lifting the sky background too much. Didn't do any Decon or Sharpening as it enhanced the noise too much. I set the noise reduction more aggressive than I normally do and did a final slight stretch in Photoshop to enhance the highlights. 6 subs is not really enough to give a good S/N though. Did you use Bias or Darks when you calibrated them? Also can you go lower than -15C this time of year. 

 

4 hours ago, jjosefsen said:

Damn.. This might be why I never got star tools to work on my data..

Yes, bright or coloured patches at the edges are a sure sign that some more cropping needs to be done. 

Alan