LR bug with Lens Profile Correction for Pentax 645z

[jwlimages]

I seem to have stumbled onto a very odd bug in LR 5.7 processing of DNGs from my Pentax 645z. Shooting with the 120mm f/4 Macro, when I have LR apply the Adobe lens profile for it, the image looks as if major white vignetting had been applied. The first screen shot below shows this. The second screen shot is same file, identical settings except I disabled Lens Profile Corrections.

(Hmm, not sure if these screen shots will come thru - I have used the "Attach:" feature to choose them, but they don't preview. If they don't show up I'll try again)

This happens *only* with this lens, and *only* when the shooting aperture is f/11. In fact, I thought it was a lens malfunction with the 120mm I bought, so I returned it. Now I have a second copy, and the same phenomenon occurs, again *only* at f/11. Have not seen anything like this with 35mm, 45-85mm, or 80-160mm lenses.

Has no one else seen this?

Thanks,

John

JWL Images
Emeryville, CA

[jwlimages]

Hmm, only the second screen image showed up. Here's the first (with lens correction profile applied)...

[jwlimages]

So this experience is unique to me, I guess. Maybe nobody uses LR to process 645z .dng's, or if they do, no use of Lens Correction? Well, fortunately I can just turn off LC, and/or use Iridient Developer.

John