EXIF Info Question

navcom · 06-20-2009, 06:40 AM

Is there any place in a file's EXIF data where the focus distance would be stored? Not the focal length of the lens, but actual distance the lens was focused at when the photo was taken, such as 20 ft, etc.?

jimby · 06-20-2009, 08:53 AM

There is a metadata field for subject distance. See below as the last entry under "image specific properties."

Leaf Fan · 06-23-2009, 12:28 PM

How about the lens used?

I'm constantly taking notes of the lens I use for photos, but it's tedious and I'll admit sometimes I don't do it until a few days later and I try to go from memory - which seems to be fading...

alohadave · 06-23-2009, 01:58 PM

Check out PhotoME. It will show you all of the EXIF fields.

I use Lightroom, and it reads the focal length from the EXIF information.

It's in the Camera tab, under Focal Length. It also shows in the Overview when you open the file.

navcom · 06-25-2009, 06:58 AM

I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.).

I'm not sure if it's even recorded or if there is a means to record it.

alohadave · 06-25-2009, 02:29 PM

Originally posted by navcom

I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.).

I'm not sure if it's even recorded or if there is a means to record it.

I don't think so, at least not directly.

In the Lens Info section of the Camera tab, there is a field called Distance Code Data (LC2). You might be able to figure out what the code means.

HGMonaro · 06-25-2009, 10:07 PM

In PhotoMe there is a field called "subject distance range" (last field of Camera section) that seems to report a couple of very broad settings (Macro, Close View, Distant view & Unknown). Seems to be appropiate based upon looking at various images but is very general. The field Dave mentions (Distance Code Data) seems to be more detailed but is not a direct measurement and needs to be interpreted.

It would be nice to see accurately what the camera decided was the focus distance.

bymy141 · 06-26-2009, 05:55 AM

Originally posted by navcom

I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.).

I'm not sure if it's even recorded or if there is a means to record it.

It can be recorded in the EXIF header, if the camera is capable of recording it.
According to the EXIF specifications, there is a field called SubjectDistance.
Here is the original text:

SubjectDistance
The distance to the subject, given in meters. Note that if the numerator of the recorded value is FFFFFFFF.H,
Infinity shall be indicated; and if the numerator is 0, Distance unknown shall be indicated.
Tag = 37382 (9206.H)
Type = RATIONAL
Count = 1
Default = none

SubjectLocation is something different, it is a vector that points to the subject relative witin the picture. See the original text:

SubjectLocation
Indicates the location of the main subject in the scene. The value of this tag represents the pixel at the center of the
main subject relative to the left edge, prior to rotation processing as per the Rotation tag. The first value indicates
the X column number and second indicates the Y row number.
Tag = 41492 (A214.H)
Type = SHORT
Count = 2
Default = none
When a camera records the main subject location, it is recommended that the SubjectArea tag be used instead of this tag.

- Bert

06-20-2009, 06:40 AM	#1
navcom Veteran Member Join Date: Feb 2008 Location: Minnesota USA Photos: Gallery Posts: 807	EXIF Info Question Is there any place in a file's EXIF data where the focus distance would be stored? Not the focal length of the lens, but actual distance the lens was focused at when the photo was taken, such as 20 ft, etc.?

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06-20-2009, 08:53 AM	#2
jimby Forum Member Join Date: Feb 2007 Location: Los Angeles Posts: 77	There is a metadata field for subject distance. See below as the last entry under "image specific properties."

06-23-2009, 12:28 PM	#3
Leaf Fan Inactive Account Join Date: Nov 2007 Location: Canada eh! Photos: Gallery Posts: 673	How about the lens used? I'm constantly taking notes of the lens I use for photos, but it's tedious and I'll admit sometimes I don't do it until a few days later and I try to go from memory - which seems to be fading...

06-23-2009, 01:58 PM	#4
alohadave Veteran Member Join Date: Jan 2008 Location: Quincy, MA Photos: Gallery \| Albums Posts: 2,024	Check out PhotoME. It will show you all of the EXIF fields. I use Lightroom, and it reads the focal length from the EXIF information. It's in the Camera tab, under Focal Length. It also shows in the Overview when you open the file.

06-25-2009, 06:58 AM	#5
navcom Veteran Member Join Date: Feb 2008 Location: Minnesota USA Photos: Gallery Posts: 807 Original Poster	I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.). I'm not sure if it's even recorded or if there is a means to record it.

06-25-2009, 02:29 PM	#6
alohadave Veteran Member Join Date: Jan 2008 Location: Quincy, MA Photos: Gallery \| Albums Posts: 2,024	Originally posted by navcom I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.). I'm not sure if it's even recorded or if there is a means to record it. I don't think so, at least not directly. In the Lens Info section of the Camera tab, there is a field called Distance Code Data (LC2). You might be able to figure out what the code means.

06-25-2009, 10:07 PM	#7
HGMonaro Veteran Member Join Date: Apr 2007 Location: Melb. Aust Posts: 840	In PhotoMe there is a field called "subject distance range" (last field of Camera section) that seems to report a couple of very broad settings (Macro, Close View, Distant view & Unknown). Seems to be appropiate based upon looking at various images but is very general. The field Dave mentions (Distance Code Data) seems to be more detailed but is not a direct measurement and needs to be interpreted. It would be nice to see accurately what the camera decided was the focus distance.

06-26-2009, 05:55 AM	#8
bymy141 Veteran Member Join Date: Aug 2007 Photos: Gallery Posts: 1,563	Originally posted by navcom I use Lightroom and I also have PhotoMe. I guess my question might be a bit confusing. I'm trying to figure out if there is EXIF data recorded that tells the distance of focus... or maybe more specifically where the focus ring is set to (infinity, 12 feet, 7, feet, etc.). I'm not sure if it's even recorded or if there is a means to record it. It can be recorded in the EXIF header, if the camera is capable of recording it. According to the EXIF specifications, there is a field called SubjectDistance. Here is the original text: SubjectDistance The distance to the subject, given in meters. Note that if the numerator of the recorded value is FFFFFFFF.H, Infinity shall be indicated; and if the numerator is 0, Distance unknown shall be indicated. Tag = 37382 (9206.H) Type = RATIONAL Count = 1 Default = none SubjectLocation is something different, it is a vector that points to the subject relative witin the picture. See the original text: SubjectLocation Indicates the location of the main subject in the scene. The value of this tag represents the pixel at the center of the main subject relative to the left edge, prior to rotation processing as per the Rotation tag. The first value indicates the X column number and second indicates the Y row number. Tag = 41492 (A214.H) Type = SHORT Count = 2 Default = none When a camera records the main subject location, it is recommended that the SubjectArea tag be used instead of this tag. - Bert