Trouble getting any colour from high iso stack...

[grant.pullen]

Hi there,

I am attempting to try out StarTools, however I am unable to get any usable colour out of the attached image (DSS stack, Canon 550D, 2.5 sec x 16, 3 dark, iso 12800, fixed tripod)
Any suggestions, help or small miracles would be greatly appreciated, since I am a newb to all of this, and would love to learn the correct workflow since I can get something out using plain old ACR.
Link to stacked tif, if anyone would like to attempt to salvage something....

https://www.dropbox.com/s/pcdp2s98xjoyk0m/st2ad.TIF

Many thanks

Grant

[admin]

Hi there,

I am attempting to try out StarTools, however I am unable to get any usable colour out of the attached image (DSS stack, Canon 550D, 2.5 sec x 16, 3 dark, iso 12800, fixed tripod)
Any suggestions, help or small miracles would be greatly appreciated, since I am a newb to all of this, and would love to learn the correct workflow since I can get something out using plain old ACR.
Link to stacked tif, if anyone would like to attempt to salvage something....

https://www.dropbox.com/s/pcdp2s98xjoyk0m/st2ad.TIF

Many thanks

Grant

Hi Grant,

To achieve good (natural) color, first remove any gradients and light pollution using the Wipe module. Then, when you're done stretching, sharpening, etc., and right before your switch Tracking off, do a final color calibration using the Color module. Simply follow the advice in the popups, e.g. apply saturation liberally while varying the amount of stauraiton that is applied to the background. Find a good color balance that shows all star temperatures equally (from red, orange, yellow, white to blue).

st2ad_ST133.jpg (397.16 KiB) Viewed 7392 times

Hope that helps!

[grant.pullen]

Hi there,
Thanks a mill, I am astounded at what you managed to achieve with such bad data, and have gone ahead and purchased the tool!
I am however having an issue in that my machine dies when using the wipe module. (step 1 autodev (using defaults), step 2 wipe (using defaults)... a min or so later... dead hard reset required)
running on win7 64x, startools 1.3.3.220, any suggestions most welcome.
Also a small suggestion, how about a recent file list?

Thanks again
Grant

[admin]

Hi there,
Thanks a mill, I am astounded at what you managed to achieve with such bad data, and have gone ahead and purchased the tool!
I am however having an issue in that my machine dies when using the wipe module. (step 1 autodev (using defaults), step 2 wipe (using defaults)... a min or so later... dead hard reset required)
running on win7 64x, startools 1.3.3.220, any suggestions most welcome.

I am suspecting that what you're experiencing is your machine running out of memory and is starting to offload to disk (virtual memory). I noticed the files you produce are very, very large. Try processing a smaller data set using (for example) the Bin module (which trades resolution for noise reduction & signal fidelity) or cropping.
Extremely high resolution in astrophotography is rarely warranted, unless the optics, seeing and data acquisition equipment are absolutely top notch.

Also a small suggestion, how about a recent file list?
Thanks again
Grant

Noted!

[grant.pullen]

Thanks again for your great support,

The crash issue is resolved by doing a bin
However been a newb, I am still unable to figure out how to use the color module to achieve anything even remotely resembling what you were able to achieve.
I can only get it all to move in one color direction, with no variation, like you have achieved.... It would be great if you could provide the steps you followed in the color module.
And another general question, you obviously keep track of changes made while tracking is enabled, is there a way to save the "project/session" so that a user can continue editing at a later stage, but still have the advantages of the tracking info been maintained from the previous session.

Many thanks again for all the assistance.

Grant

[admin]

Thanks again for your great support,

The crash issue is resolved by doing a bin
However been a newb, I am still unable to figure out how to use the color module to achieve anything even remotely resembling what you were able to achieve.
I can only get it all to move in one color direction, with no variation, like you have achieved.... It would be great if you could provide the steps you followed in the color module.

No problem.
This flow should be generally useful;
Open your image, indicate it is still linear, bin your data to something that makes better use of resolution (if needed).
Next, launch AutoDev. This will show you everything in your images, warts and all. These 'warts' may include light pollution, gradients, stacking artefacts, etc.
Crop away any stacking artefacts.
Next, launch the Wipe module to wipe away any light pollution. Wipe will indicate that it is probably a good idea to re-do your stretch (AutoDev was our first stretch).
At this point, you can either use AutoDev again, or if you don't like that result, use the more 'manual' Develop module.
Congrats! You should now have a stretch, light pollution free image.
From here you can do other cool stuff, like HDR optimisation, Deconvolution, Wavelet Sharpening, etc.
Once you've done all that (or not ), do your final color calibration; read the popup messages. They will tell you to bring up saturation and use the Top End slider to apply the saturation more (or less) to the brighter parts. Same thing goes for Bottom End, which applies saturation to the darker parts of the image. You'd typically want to be careful with the latter (as you don't want to re-color the background; you'll want it nice and neutral in most cases).
Now that color is being applied, you'll want it to be the right color. Use the red, green and blue ratios to establish a good white balance.
How do you know what a good white balance is? It's easiest to look at the stars in your image. White balance is best when you can clearly see an even distribution of star temperatures (ranging from red, organge, yellow all the way to white and blue).
And that's it for your colors!
To finish off, switch Tracking Off (by clicking on the Track button) and it will allow you to perform your final noise reduction.

And another general question, you obviously keep track of changes made while tracking is enabled, is there a way to save the "project/session" so that a user can continue editing at a later stage, but still have the advantages of the tracking info been maintained from the previous session.

It's something that has been request by a number of users now. The trouble is that the amount of data that is involved is very, very large. I'm still thinking about this one!

Cheers,