Image solver fails on analog astrophoto

[ppistor]

I tried to find a plate solution for an A4 photograph of the Gamma Lyr area that was taken on August 7 1953 at the Heidelberg Observatory.
I scanned the photograph resulting in a tif file. The parameters I used (pixel size, image center coordinates, focal length) seem to be OK
since I geneated a synthetic star field using the CatalogStarGenerator script which fit quite well the image to be plate-solved.

Nevertheless, the plate solution failed even after an hour of processing time, even though the (possibly unusual) input data have not been rejected.

ppistor.

[pfile]

since imagesolver uses staralignment, i would open up staralignment and put it in 'detected stars' mode, and see what stars are being detected. it could be detecting a lot of noise rather than stars. try tweaking the star detection knobs until you get a detected stars image that looks good, then try the star detection settings in ImageSolver.

[Andres.Pozo]

pfile has explained what you can do. If it still fails to solve, I can give it a try if you send me the image.

[pfile]

oh, and if SA is working for an hour, it's pretty much lost. of course it depends on your machine, but probably if it works on an image for more than one minute, it's never going to converge.

[ppistor]

Hi Andres,

for reasons I do not understand yet the image solver finally succeeded on a cropped version of
the original image.

I tried to send you two tif files but failed due to image size. If you remain interested, pls. instruct
me how to get you the image material.

Thanks for your remarks.
Peter.

[Andres.Pozo]

I will be traveling until Sunday. I can post a better response then.

[Andres.Pozo]

Hi Andres,

for reasons I do not understand yet the image solver finally succeeded on a cropped version of
the original image.

I tried to send you two tif files but failed due to image size. If you remain interested, pls. instruct
me how to get you the image material.

Thanks for your remarks.
Peter.

If the solver succeeded on a cropped version probably the problem is that there is more geometric distortions than StarAlignment can cope with.

If this is the case, this image would be a good test for ManualImageSolver: http://pixinsight.com/forum/index.php?topic=5657.0. Please, read carefully the instructions PDF.

If you still can not solve the image, I can analyze it. Please upload it to Dropbox (or similar) and give me the link and the metadata of the image (approximate center and resolution).