Lightroom: Focal length indication in develop mode is only correct for full-frame camera's

  • 1
  • Problem
  • Updated 6 years ago
  • Not a Problem
  • (Edited)
Any crop factor is not taken into account, i.e. only the focal length of the lens is depicted, not the actual focal length of the lens + camera combination. This makes it difficult to interpret, as calculation using the crop factor of the image sensor is needed everytime.
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schty

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  • sad

Posted 6 years ago

  • 1
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Lee Jay

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Focal length is focal length. It's a physical parameter. Neither the size of the sensor nor the size of the crop has any effect on it.

This is not a bug, it's by design, and it's as it should be.
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Mark Levesque

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Agree with Lee. This is not a bug,
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schty

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I agree with Lee, too. This is not a LR bug, more like a lacking feature.

Nevertheless, let me elaborate why it's posted as a problem (by the way, I don't mind the category, but it can hardly be a new idea):

Having taken pictures with multiple camera's, different crop factors and different lenses and consequently importing them in the same catalog, it currently is quite hard to compare those pictures taken on focal length.

For reference, please also note that simply right clicking on any photo in JPG format in W7 and then clicking properties reveals the 35mm focal length too (in case exif data was saved that is), which is very very convenient.
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jdv, Champion

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The 35mm equivalent focal length is the best you have for comparing so-called effective focal length.

This metadata is available in the SDK as com.adobe.focalLength35mm, so something interesting can be done with it.
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schty

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Thanks, John.

Good to know that effective focal length already is there in the LR SDK, so it shouldn't be hard for the developers to also display it on screen, right...
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jdv, Champion

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It would be trivial to show in the metadata panel. Harder to make it searchable -- I'm not entirely sure how this could be done.

Bear in mind that the metadata as displayed by Lr is just taken out of the file, and the various vendors are notorious for calculating this wrong, sometimes with really crazy results.

For people that really need it, I can think of a simple way to allow you to calculate the effective 35mm focal length using the crop factor (like this: http://phpgraphy.sourceforge.net/tool...) right inside Lightroom. Then you could set a custom metadata of your own.

It's an idea for someone, anyway.
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schty

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Although it can hardly be a really new idea, I have decided to move this topic over here (as it was not considered suitable for the problem category by some).

Having taken pictures with multiple camera's, different crop factors and different lenses and consequently importing them in the same catalog, it currently is quite hard to compare those pictures taken on focal length.

For reference, please also note that simply right clicking on any photo in JPG format in W7 and then clicking properties reveals the 35mm focal length too (in case exif data was saved that is), which is very very convenient.

As I was told effective focal length already is there in the LR SDK, so it shouldn't be too hard for the developers to also display it on screen.

This reply was created from a merged topic originally titled
(Effective) Focal length indication in develop mode is only correct for full-frame camera's.