I wonder if anyone has tested the existing lens profiles in PL3 to make sure they’re actually any good? I photographed my daughter’s socially-distanced, masked wedding Friday night, it was under a gazebo, and in a couple of shots that showed vertical columns, the automatic lens profile (Nikkor 24-120F/4) showed distinct pincushion effect. I had to switch to manual to adjust that out. The same images looked right in Lightroom with the lens profile applied.
Of course, these are things that are only obvious in situations like that.
Can only speak for myself, but “no”. OTOH I haven’t noticed any obvious errors on the few of my long-discontinued lenses for which PL3 has profiles.
The nature of the system, though, is that the quality of one lens profile doesn’t guarantee that of another - the process of making them might, as long as the lens manufacturer’s process for constructing the lens were equally bulletproof.
I think you would buy into my proposal if it meant that an individual user was able to modify the DxO supplied lens profile when it clearly produced imperfect results in his body/lens combo!
DxO has had to periodically fix lens correction errors. Once or twice for my lenses over the years. In my experience, they are very willing to help with lens correction questions, even when it turns out that the profiles don’t need to be fixed. So I suggest submitting a test RAW photo with description of the problem to support.dxo.com.
Not that I expect to get my wish (commercial sensitivity and all) but I would LOVE to know what DxO are doing in the lens modules to pull the sharpness out of my images. Because try as I might, I cannot get any other software to get the same level of sharpness out of the files.
It may simply be that I am unskilled in such things, but it seems like magic to me that pin sharp images come from my camera.
There should be an option to bake in a lens profile using a DxO supplied test target.
- user prints test target on high quality printer
- user scans test target using a calibrated scanner
- user takes several shots of the printed target using a DxO-supplied procedure
- user sends all to a DxO app or cloud service for baking in a custom profile.
Profile would be usable for viewpoint, for vignette correction and for lens sharpness correction.
User-defined profiles would be sharable in DxO cloud library.
Separate suggestion created.
I could live with that, though I confess I don’t understand the reason for your second bullet. I think its attraction to DxO should lie in the fact that it allows multiple users to provide results for the same body/lens calculation, and thus to even out any errors in the third bullet step. As I understand it, that is the process by which the lensfun database is kept sensible.
The reason for the second bullet is to account for errors in the printing process (ink-printer-paper combination).
I am afraid that a full profile will requires several multiple targets: one with a grid for the geometrical correction, another with strips of different sizes and orientations for the definition mapping, maybe again another with spots of color and calibrated grey for the color shift, and so on.
Another difficulty is the relative position of the test target with the camera. It must be in a strictly perpendicular plane, centered on the optical axis, controlled horizontally, and vertically. The quality of the light must also be controlled (power and color spectrum).
In short, a complete test bench is necessary to guarantee the reliability of the measurements.
Calculate a mean of different profiles will not improve the process, because the sources of errors cannot be compared neither evaluated.
It is why beskope profiles never compete with professional ones. But the interest of the feature still remains!
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