[Tweeters] Getting distance to subject from your camera

dgrainger at birdsbydave.com dgrainger at birdsbydave.com
Fri Oct 15 13:10:28 PDT 2021

This is known to me to be true with Nikon and Canon cameras, I do not
know whether it is true for other makes.

Photographers that process using Photoshop or Lightroom can determine
fairly precisely how far away their subject was from the camera by a
simple method. Here's how it works:

In Photoshop, open an image (doesn't matter whether RAW or TIFF or JPG)
and then chose File menu at top of screen, scroll down to File Info and
click on that. Next, within File Info, at the bottom of the resulting
menu, you will see RAW Data at bottom. Click on RAW Data, which will
expose all of the EXIF information. That will look a lot like a Chinese
Restaurant Menu in complexity, but, "not to worry" , as there is just
one piece of information you need.

Somewhere in the first quarter of all the data, you will find a section
that starts each line with <AUX followed by some other characters.
Amongst those lines you will find one that looks like the following:

That's the one you want. Distance is expressed metrically. In this
example, 473 divided by ten gives us a distance of 47.3 meters. Now,
convert that to "'Melican money" meaning feet, or 153.72 feet camera to
subject. (My example is taken from an image I shot in 2016 of an Osprey
just lifting off from a tree limb.)

One thing that I have not been able to determine is whether that
distance is measured from sensor plane or from lens front element or
whether it is a distance to first sharp focus point optically, which is
implied by the terminology. This beats spending $$$ for a rangefinder!

Dave Grainger at birdsbydave.com

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