[Tweeters] Getting distance to subject from your camera

[John Riegsecker]

You can also get this information using ExifToolGui available here:

https://www.portablefreeware.com/index.php?id=1450

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