lens distortion correction: Nikon Z9 + 50mm micro

Forum|Forum|3 years ago
July 7, 2022
3 replies
959 views

Hello,

I am getting noticeable pincushion distortion from my brand new Nikon Z7 + Z mount Nikkor 50/f2.8 macro.

I shot a series of flat-art paintings, and need to correct these ASAP (not sure why the distortion even happened, but that's a separate discussion with Nikon).

These will all be uprez'd by 3x the original size, and then used as sources for online orders for the artist. The finished images will be printed on giclee. At 3x, the pincushion will be significantly visible, so this has to be corrected.

I went into PS lens correction options, and neither the Z9, nor the lens show in the lists of recognized gear. In fact, the most current camera body I can see appears to be the D5, and the lens isn't listed (only the Sigma 50/2.8 as the closesst match that I could see).

Questions:
1. Is there a more current list of bodies and lenses in PS? I'm current on my CC PS subscription (ver 23.4.1). And if so, how do I update this list, please?

2. is there a suggested method for correcting the distortion that's reasonably fast?

3. Each painting was suspended, and shot horizontally, not top-down, so there are "twists" since the art isn't perfectly normal to the camera plane. (i.e. right edge may be a half inch further away from the camera plan, the art may not be perfectly vertical, etc.) Once the twists are corrected for, the pin-cushion becomes immediately obvious. That's easy to correction via transform. But the pincusion is a bit more time-consuming, each edge needing this.

4. If #2 is yes, can I assume the distortion is the same, is consistently the same for all images, regardless of the amount of twist there may be?

Hoping you can help. I have 12 images to correct in post, so that's 48 edges on large files (46 mpx camera).

Running PS CC v 23.4.1 on Win10/64 (also current).

Thank you, hoping for a working solution!
Jerry

PS - If this help request needs to be posted in a different community group, please advise. Thank you.

Windows

This topic has been closed for replies.

B

Barry Rudick

Inspiring

Shooting flat art at an angle is going to be a problem from the start. There is no lens profile that will correct everything you need to get your images to size and proportion.

I might suggest this approach. It is not fast but it is somewhat accurate.

Using Perpective Crop Tool, crop the art to it's edges without clipping very much of the image. Remember, the Perpspective Crop Tool allows you to move the endpoints independently. Don't worry about distorion or curves at this point. After cropping, measure the art for exact dimensions. Using image size with Resample off, type in the width. Then note the height, if resizing of the height is necessary, then uncheck the resample button and uncheck the proportion mark next to the size data and put in the exact height, then ok. You now have the image at the size of the original. If there are areas outside of the art showing you will then BEND the sides to align the edges and make them straight and have "art" data only.

First, double click the background layer to make it a editable layer. The go to Edit, Tranform, Warp and you will see the blue control lines around the image. Zoomed in, gently move the offending areas out or in, (usually out) until everything is aligned and straight. When pleased with the adjustment, flatten the layer.

Now you have a square image that is sized to the original. You may need to use the Enhance feature in Camera Raw to increase resolution.

Not quick but probably usable.

JerryandLoisPhotographyAuthor

Known Participant

Hi Barry,
Thanks for joining in on the conversation. I've shot flat art for many years, and have been aware of the inherent issues of getting the art normal (perpendicular) to the film plane. I also measure each piece carefully so I know what my output/target dimensions need to be, and use Transform/Warp to get things square. All that goes pretty quickly for me. A bit tedious, but I have it down to a smooth workflow. All previous assignments with flat art used a Nikon d850 or earlier DSLR.

But - here's what triggered this thread. I used the Z format of Nikon's 50mm micro/macro. With all my F-mount micros, straight lines were straight lines, and long ago, learned to not use zooms.

The new Z version of the 55 has distinctive pincushion distortion, which was a complete and unwanted surprise. Because of short working distance and larger pieces, I couldn't use my 105mm which I know is distortion-free.

So all of this discussion was that I wanted get rid of the pincushion distortion programmatically, and am surprised that PS is 6+ years slow to the party. In my current installation of PS CC 2022, neither the body (Z9) nor the 55 micro are in the dropdown lists. The most current body is the D5, no Z bodies at all.

Thanks again...

Kevin Stohlmeyer

Community Expert

The latest Camera Raw plugin supports your camera:

https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-supported-cameras.html#Nikon

JerryandLoisPhotographyAuthor

Known Participant

Hi Kevin, thanks for sharing this. I didn't realize that ACR was an update-able component.

However I'm trying to correct TIFs that were generated via Nikon NXStudio as that's my default app of choice.

The portion of PS that I was hoping to utilize is FILTER/lens correction. In that set of dropdowns, the list of camera bodies and lenses are significantly out of date.

And perhaps I missing some steps here (all too likely) - is there a way to correct barrel or pincushion manually withing ACR, with pre-existing TIFs rather than via importing NEFs and inheriting lens distortion corrections automatically (if that's how it works)?

If I'm really out in the weeds on the process, I'd love to understand how the steps necessary to straigten out the TIFs applying camera make/model/lens info that's current.

Many thanks!

Kevin Stohlmeyer

Community Expert

The ACR plugin adds those features to PS incouding lens correction.

It should automatically be listed if the camera metadata is captured in the TIF file itself.

Kevin Stohlmeyer

Community Expert

What version of the Camera Raw Plugin are you running?

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded