Who has Lightroom "lens correction" profiles for Large Format lenses ?

[sinarleica]

HI ,
I 'd like to use the "lens correction" profile option of Lightroom for my LF lenses
SINARON 90 MM F4.5; 65 MM NIKON F4, and others

WHo has these profiles ?


Thanks

[Walter Calahan]

Adobe has a lens profile software program you can download and create your own profiles.

[DJG]

Just wondering, but would this even be possible if you start using things like tilts and swings?

[Kirk Gittings]

As with Tilt shift lenses, this would really complicate the calibration as the lens would need a separate calibration if unshifted vs. shifted up 5cm etc.

[Kirk Gittings]

As with Tilt shift lenses, this would really complicate the calibration as the lens would need a separate calibration if unshifted vs. shifted up 5cm etc.

OP what problems are you trying to correct?

[Ken Lee]

Are those lenses not rectilinear ? Or is the issue merely the distortion and light falloff typical of wide-angle lenses ?

[rdenney]

Ken, it's mostly lateral color. Just last night I spent time correcting, as best I could, the lateral color of a Pentax 67 fisheye. I then just saved the settings as a lens profile. That was using the lens correction filter in Photoshop--I don't know if that feature, with its detailed controls, is available in Lightroom.

With shifts, I expand the canvas so that the optical axis is in the middle of the frame. Then, I can apply corrections for falloff and lateral color, which are both symmetrical about the optical axis. I then crop it back down to the portion of the canvas filled with image. I learned this trick with the first Canon 24mm TSE lens, which suffers from lateral color.

Rick "who will look into the Adobe profile builder" Denney

[Greg Miller]

Lightroom uses ACR (Adobe Camera RAW). ACR has similar corrections and the ability to save custom settings.

[C. D. Keth]

Just wondering, but would this even be possible if you start using things like tilts and swings?

It's possible (I don't know if it's possible in lightroom), we do it for effects work in movies sometimes, but you need first a very detailed profile of the lens' behavior. Then, you need recorded any movements and how much, as precise as possible. I'm satisfied doing it all by eye rather than spending my time recording "film portrait layout, 27mm of rise, 2.6 degrees tilt forward"

[Kirk Gittings]

Are those lenses not rectilinear ? Or is the issue merely the distortion and light falloff typical of wide-angle lenses ?

Once you shift the lens, aberrations like barrel distortion are no longer symmetrical. The more you shift the less symmetrical the aberrations are. With LR4 CA is treated differently so that is no longer an issue with shift lenses. The newest Canon T/S lenses require very little correction however.

Only Capture One V7 software has a lens correction module which allows you to offset the center allowing for better correction of shifted lenses. I have not tried it however.

[Ken Lee]

Are we talking about Large Format lenses, or tilt/shift lenses for small cameras ?

I don't recall seeing barrel or pin cushion distortion with LF lenses - but I don't shoot wide lenses.

[Kirk Gittings]

the Op was talking LF lenses, but most advances in this area are designed for DSLR of MFD and are applicable to LF lenses. I frankly don't worry about it on my LF lenses when shooting B&W but do worry about it when shooting DSLR when the final output is some form of color OR b&w.

[David R Munson]

Does Capture One 7 let you do LCC corrections for any camera now? To my knowledge LCC function has been limited to use with the Phase backs.

[Kirk Gittings]

Supported cameras; http://www.phaseone.com/en/Supported-cameras.aspx I'm not positive that all features work on all "supported" cameras, but I've ben told yes.

[rdenney]

Once you shift the lens, aberrations like barrel distortion are no longer symmetrical. The more you shift the less symmetrical the aberrations are. With LR4 CA is treated differently so that is no longer an issue with shift lenses. The newest Canon T/S lenses require very little correction however.

The problem with the newest Canon TSE lenses is the correction they require to my checkbook.

But you can use the lens correction filter for shifted images--maybe not for tilted images (I haven't tried that). I said it before, but I'll explain it better this time. I take the original image, figure out where in the image was actually in front of the camera, and make that the center of a larger frame. The center line of the camera, passing through and at right angles to the film, intersects the subject plane. That would be the center of the image if the lens was unshifted. Make that the center of a larger frame by increasing the size of the "canvas" (in Photoshop). For example, if the lens in front of a 4x5 negative is shifted one inch to the left, the center will be 2 inches from top and bottom, and 3-1/2 inches from the left and 1-1/2" inches from the right. I make a canvas that is 7 inches wide and 4 inches tall, and then place the image so that the center of the unshifted image is in the middle of the canvas. The actual image will be all the way over to the left, leaving blank canvas on the right two inches. Now, the effects of the lens distortion are centered on the frame, and the lens correction filter works fine. When I'm done making the correction, I just crop it back to the original frame.

Providing access to the filter only in ACR doesn't make this easy, because it's hard to increase the canvas size in a raw file and leave it in the raw format so that ACR can play with it. I was extremely happy when Photoshop added the lens correction filter to the filter menu so that I didn't have to do it in ACR. And I see that CS5 has put it right on the menu rather than burying it in the "distort" group as was the case with CS4.

I've done this for both falloff and for lateral color corrections, and it works, even if it is a bit cumbersome.

Rick "whose spare cash just got blown away, again, by the weather" Denney

[Kirk Gittings]

I'm familiar with that technique Denney, but I don't use it, because A) I'm too addled to ever remember to make a note about the amount of rise/fall used and B) I can do it quicker with the Warp tool in PS (again because the new Canon T/Ss have so little distortion.

[Kirk Gittings]

Capture ones shift lens profiles: http://www.luminous-landscape.com/forum/index.php?topic=71881.0;topicseen