Wrong Lens Type Applied

[mklass]

I am using PM Plus version 2026.6, build 9175 (2cfdfbb) on a M4 MacBook Pro running MacOS 27.0 (Golden Gate).

For a long time I have used a Megadap ETZ21 Pro so that I can mount Sony E mount lenses on my Nikon Z cameras. This has worked flawlessly, until a recent problems came up. When I shoot on my Z50II with a Sony 20mm f/2.8 lens, PM reports the Lens Type as SAMYANG AF 135mm F1.8, but with the lens focal length as 20mm. (See attached Info Text screen shot. However, if I look at the EXIF in FastRaw Viewer, it shows the lens correctly (see attached FastRaw Viewer screenshot.)

I have checked against a shot using the actual SAMYANG AF 135mm F1.8 as well as another lens SAMYANG AF 35mm F2.8. PM reports the lens type of those 2 correctly.

What is happening with the Sony lens and how do I fix this?

[mklass]

Some additional info:

I tried this lens on my Nikon Z8. The 20mm Sony lenstype, {lt}, is reported as an AF SAMYANG 35mm F2.8. Same basic problem, but with different, but still incorrect results.

When I used this lens some time ago on my original Z50, PM did report the ciorect lens type. The most recent file I have using that combination is from February 2023. I don't know what version of PM+ I was using at the time, but it would have been the most recent update available. The file is attached.

[Maury-Support]

Hi mklass,

May you email us additional NEF sample files to support@camerabits.com and compress them into a ZIP folder please?

The previous sample file downloads as a TIFF. That TIFF shows 20mm f/2.8 for EXIF Lens Info.

In Photo Mechanic 2026.6 build 9175 on macOS Tahoe, {lenstype} evaluates to "AF 20mm f/2.8G".

[mklass]

I tried E-mailing, but I don't think it when through as my email serves won't send a file that size (99GB). Do you have a way to FTP to you?

[Maury-Support]

We received the emailed sample files, thank you.

For the {lenstype} variable, Photo Mechanic is reporting the information in the EXIF Lens Model tag. I am guessing FastRawViewer may be displaying the EXIF Lens Info tag information instead. If you open the sample files in Exiftool, you will see the same Samyang information in EXIF Lens Model.

We can look into having Photo Mechanic read from EXIF Lens Info tag in the future.

In the meantime, I found some related forum posts that may be helpful.
https://www.fredmiranda.com/forum/topic/1914094/0
https://www.dpreview.com/forums/threads/strange-exif-with-megadap-etz21-pro.4814613/

Can you confirm the behavior mentioned that if the adapter is left on the camera mount while the lens itself is changed, that the camera continues to record some or all of the EXIF information from the previously mounted lens because the camera did not detect a lens change?

If you do, does a firmware update resolve that behavior? https://megadap.net/update/

[mklass]

Yes, I can see, using a different EXIF editor, what you mean about the lens model field. This field is not an available variable in PM, but it is what PM uses to fill the lenstype field, is that correct?

So it is only the Sony 20mm f/2.8 lens that is causing me problems. If i switch to any other lens the PM data is correct. And the data for the Sony lens is incorrect regardless of whether I mount the lens with or without the adapter attached to the camera, or which camera I am using. I do have the latest firmware installed in the adapter, V2.04. The camera firmware is also up-to-date.

[Maury-Support]

The {lenstype} variable gets the EXIF Lens Model tag information, if it exists.


Do you know of anyone with a Sony camera you can borrow to mount your 20mm f/2.8 to it so we can see the EXIF metadata for that lens recorded by a Sony camera? It would be helpful to see a comparison of how the bytes for the EXIF metadata for that specific lens are recorded by a Sony camera compared to how the bytes are recorded for that lens mounted to a Nikon via the Megadap adapter.

[mklass]

I can do this, but not for about a month. I'll get back with a sample then.