[Tweeters] Getting distance to subject from your camera

John Riegsecker jriegsecker at pobox.com
Fri Oct 15 13:45:54 PDT 2021

You can also get this information using ExifToolGui available here:


I have not tried it for Canon or JPG, but for Nikon and Olympus RAW you
can find it as Focus Distance under the Maker Tab.

There is also a simple formula for finding the distance to an object if
you know the size of the target. For example, for a bird you can use an
average size to estimate how far away it is.

John Riegsecker
Gig Harbor

On 10/15/2021 1:10 PM, dgrainger at birdsbydave.com wrote:

> 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:

> <aux:ApproximateFocusDistance>473/10</aux:ApproximateFocusDistance>


> 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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John Riegsecker

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