Lens correction profile Canon EOS 550D with EF-S 18-55 mm IS

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  • Updated 5 years ago
Apparently the lens correction profile for the combination of a Canon EOS 550D with Canon EF-S 18-55 mm IS lens and RAW files is not working right. Geometric lens distortions are over-corrected completely.

Please fix this, Adobe!
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Mr. Architect

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Posted 5 years ago

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Steve Sprengel, Champion

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Can you provide a before-after screenshot and perhaps an original raw file (via dropbox.com) that demonstrate this issue?
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Mr. Architect

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Mr. Architect

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There is, however, a user defined lens correction profile for that camera/lens combination which can be downloaded by using the Adobe lens profile downloader. That one seems to be doing a better job at correcting the distortion. I'm just wondering why that simple profile (it's categorized as a basic profile) is doing a better job than Adobe's own profile. Does someone know how Adobe creates their own profiles? The same way they recommend the creation of user-generated profiles?
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Steve Sprengel, Champion

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I think I see what you're seeing, a slight pincushion at the outer edge with the lens profile automatically applied. Your eye may be more practiced at seeing such issues, but to me it seems that the lens model doesn't quite extend all the way to the edges or the model of the lens distortions isn't quite sophisticated enough, because if I apply negative manual distortion, the outer edge is closer to right, but the inner portion has barrel distortion, again.

I do believe Adobe uses the same tool they give us to correct lens problems.

As far as why Adobe's seems inferior to a user-created lens profile, I can only guess:

Maybe the user-supplied profile may have been done more carefully at least at the 18mm end of the lens, or maybe it was done more recently with a higher-resolution sensor which would give more accuracy to the model.

It is also possible that Adobe used Canon-supplied parameters instead of profiling the lens, themselves.

This lens is a low-end consumer lens so may not have much time allocated for profiling by people getting an hourly rate to do it, or perhaps there is some variability and Adobe profiled the very first one and something has changed, slightly that the user-created profile has picked up on.
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Mr. Architect

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I guess you're right about the variability. Okay so it seems like I gotta create my own profile for the exact lens that I own. Do you know if the serial number of the lens is somehow stored in the EXIF-data? Since I borrow the camera and lens from my university I have used two different EOS 500Ds and two different 18-55 mm lenses in the past and I'm considering creating two different profiles for each combination.
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Steve Sprengel, Champion

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LR can see the camera serial number; not sure about the lens serial number.

You can use this site to look at the EXIF data in an image:
http://regex.info/exif.cgi

It may work to just make one profile that is done carefully, which if you do a good job, then you can upload yours for others to use in the Lens Profile Downloader.