Nikon 200-500mm lens (480mm in Lightroom)

[DarkVisa]

Hi All,
I have been using my Nikon 200 to 500 mm lens for years with no problems.... except I've now noticed that when using Lightroom (Library details of the image) the lens focal length only states 480mm - has anyone any ideas why this should happen? As I say the lens is working fine and giving good results, just curious as to why.

 

[Charles Loy]

I have read in discussions that It may show this if at 500mm setting while taking a close photo

 

[Darrellhar]

Stupid question but are you certain you are zoomed out all the way. I use the 200-500 a lot and have no issues with meta data in LR.

 

[DarkVisa]

Stupid question but are you certain you are zoomed out all the way. I use the 200-500 a lot and have no issues with meta data in LR.

Hi, Yes, I did think this at first but tried it again at fully zoomed out and with a 1.4 convertor attached - the readings in lightroom where 480mm at 500 mm and 680mm at 700 mm

 

[SoCalRick]

Hi All,
I have been using my Nikon 200 to 500 mm lens for years with no problems.... except I've now noticed that when using Lightroom (Library details of the image) the lens focal length only states 480mm - has anyone any ideas why this should happen? As I say the lens is working fine and giving good results, just curious as to why.

Is this the case straight after import? E.g., no cropping, lens profiles, etc. have been performed? I believe that Lightroom is just reading this information from the EXIF data that the camera has provided. You can look at the info yourself on your camera.

 

[bleirer]

That is interesting. I believe the published focal length is intended to be at infinity, and some lenses have focus breathing where the field of view from focal length can vary a little if you focus at different distances.

Does the exif read 480 or does it read 500 and is it being changed to 480 by lightroom?

 

[DarkVisa]

Is this the case straight after import? E.g., no cropping, lens profiles, etc. have been performed? I believe that Lightroom is just reading this information from the EXIF data that the camera has provided. You can look at the info yourself on your camera.

Hi, Yes straight after importing into Lightroom and yes I have checked my camera (D5) and the settings are FX full frame.

That is interesting. I believe the published focal length is intended to be at infinity, and some lenses have focus breathing where the field of view from focal length can vary a little if you focus at different distances.

Does the exif read 480 or does it read 500 and is it being changed to 480 by lightroom?

Hi, The exif reads 480 - I have not changed it in Lightroom. The only thing I haven't done yet is try the 200-500 mm lens on my other camera D850 and then see what Lightroom states. I suspect the same result. I will report back.

 

[bleirer]

Hi, Yes straight after importing into Lightroom and yes I have checked my camera (D5) and the settings are FX full frame.

Hi, The exif reads 480 - I have not changed it in Lightroom. The only thing I haven't done yet is try the 200-500 mm lens on my other camera D850 and then see what Lightroom states. I suspect the same result. I will report back.

So not a Lightroom issue. I'm curious if it changes with focusing near objects vs. Infinity? I don't really know how cameras derive the focal length info. I believe it is supposed to be the distance from the sensor to the point where light rays are crossing, but I don't know if the camera is deriving this or if the lens is reporting it.

 

[Darrellhar]

Was it a close object that you were shooting? I suspect that Charles's comment on close focus might be the issue then. LR is just reading data off the file so it has to be from the camera. If you do have another camera and can shoot similar or same thing that might solve the mystery. Shooting in DX wouldn't change the focal length (only the TC that you said did change it). It has to be some kind of focus breathing that is causing it. I've never run into that with my copy on either D850 or Z9 (at least not that I know of) although I have to be honest I don't look that closely at focal length other than for reference.

 

[DRwyoming]

I'd probably shoot some images at varying focus distances from fairly close to very far away and see if the EXIF data on focal length changes with focusing distance. That said, there's some funny things about focal length and captured EXIF data. For instance when I use a TC-14e III with my 600mm f/4 E FL lens the reported EXIF focal length is always 850mm when it really should be 840mm. That's true in the straight EXIF data and what LR shows as well, I don't worry about the extra 10mm reported but it is strange.

[edit] Thinking more about this, in theory a 1 stop TC would have 1.414 [sqrt(2)] focal length magnification so a bit more than 1.4 and the total focal length when mounted on a 600mm lens would be almost 849mm so perhaps Nikon just rounds up the EXIF data...