PhotometricColorCalibration

[John_Gill]

Hi,

Running the latest PixInsight and processing DSLR images.  I have used the PPC on a couple of images without any problems.  I am now trying to re-processing a couple of images using PCC.  I reset the tool and under Image Parameters, I select Search Parameters and type in "Swan Nebula/Rosette Nebula/Jewel Box" and then get the RA and Dec.  I fill in the date and time of the image capture.  The focal length of the scope is 2032mm  (Celestron 8"EdgeHD) but if I select "Aquire from Image" I get a 50mm. The pixel size of the DSLR is 4.3microns.  I then push the New Instance or the Apply button.

Now PixInsight tries to plate solve a number of times and fails saying not enuff stars.  The are hundreds of stars visible and the images are pretty good with no elongated stars etc etc.  I change the log sensativity, noise reduction and various other combination of settings, but nothing works.  I have used nova.astrometry.net to plate solve and that works and the RA and Dec match the previous settings.

Any ideas, complaints, suggestions are most welcome
Look up
John

[sreilly]

My few successful uses of the tool have all gone well. One thing I have done is open one of the subframes and let PCC read the fits header to fill in the needed information and that has always worked. Then I close that image and apply it to the (L) RGB image and save. It's always worked fine this way for me. That said I haven't done more than a dozen or two images since the process was released. I'm certainly no pro at this.

Steve

[John_Gill]

Thanks for that tip on reading the FITS header.  Tried more combinations but still no resolution.

[pscammp]

John,
   Why don't you load your image on Dropbox or something like that & link it in this thread so guy's here can have a go at it, they might even find a solution.

One things for sure, if one of the dev's reads this thread they will ask for a copy of the image for testing anyway, could even be a bug  ! !

Paul

[sharkmelley]

The focal length of the scope is 2032mm  (Celestron 8"EdgeHD) but if I select "Aquire from Image" I get a 50mm. The pixel size of the DSLR is 4.3microns.  I then push the New Instance or the Apply button.

Which focal length did you use?  50mm or 2032mm?  If you use 50mm then the plate solving is certain to fail.

Mark

[John_Gill]

Hi,

I have uploaded two images of the Swan and Rosette nebula to https://drive.google.com/open?id=0B1V2LqJCaPPib190UE0xQ2lMWDA

I have tried various focal lengths - acquired from image 50mm, the default of 100 mm and the actual focal length of the scope at 2032mm.

I don't think this is a bug as I get great results on most images.  Perhaps the data is not so good, but at least I then understand the what, why and how

Look up
John

[sharkmelley]

Your Rosette image worked fine for me but I had to do a little trick.

Firstly I performed a "Search Coordinates" on NGC2244.  Then I set the focal length to 2000 and the pixel size to 4.3

I noticed that the saturation level for the green channel was lower than the other two and its saturation level was around 0.4  So I set the Saturation Threshold to 0.40

However the plate solve completely failed. The trick I then used was to apply "$T/0.4" in PixelMath to scale up the brightness of the whole image.  I could then set the "Saturation Threshold" back to the default of 0.95

The plate solve then worked fine and so did the star color calibration.  I'm afraid I don't know enough about the plate solving to know what exactly caused it to fail nor whether or not my workaround is the best way around the problem.

I didn't look at your other image.

Mark

[freed]

For what it is worth, I have had multiple plate solving failures with 600mm and 6micron combination which corresponds to my set-up. However plate solving works every time in SGPro. That may not be relevant but for now I have reverted to Color calibration.
Thanks

[Herbert_W]

In a roundabout way you can solve the image with "ImageSolver" and use in PCC the button "Acquire from Image".
It works for me one time, as PCC couldn't solve the image.
Best regards!
Herbert, Austria

[Andres.Pozo]

In a roundabout way you can solve the image with "ImageSolver" and use in PCC the button "Acquire from Image".
It works for me one time, as PCC couldn't solve the image.
Best regards!
Herbert, Austria

If the image has already been solved by ImageSolver, PCC doesn't need to solve it again (unless the option "Force plate solving" is checked). In this case, the parameters of the sections "Image parameters", "Plate solving parameters" and "Advanced Plate Solving Parameters" are not used.

Also, PCC uses internally the script ImageSolver so you should get the same result if you solve the image with ImageSolver or if you let PCC do it.

If you want to test several configurations of PCC (white reference, saturation threshold, ...) I would recommend to run ImageSolver before. This way, if after running PCC you do an undo the image doesn't lose the astrometric solution and each test with PCC runs much faster because it doesn't have to solve the image again.

Andrés.

[John_Gill]

Update:

I think there was a PCC update and now I enable "Force plate solving" and "Ignore existing metadata" and all is good in the world of astrophotography ... 

Look up
John

[slackingCamel]

I was struggling with something similar, imagesolver script, and some parameter tweaks, helped me get the PCC working.

Thanks guys.