DPP - Focus distance information

Started Dec 5, 2010 | Discussions
Mjollnir Regular Member • Posts: 380
DPP - Focus distance information

In DPP, you can bring up a box with information about the images from the camera, such as the name of the lens and focal length, etc.

But I can't see any line that tells you how far away you were from the point of focus. Is there any reason for this? I would have thought there would be some way to calculate this based upon the lens's focus settings.

Is there any way to calculate it yourself with the information available from Canon RAW files?

canuck dave
canuck dave Senior Member • Posts: 2,938
Re: DPP - Focus distance information

Does any software do that?

MOD Olga Johnson Forum Pro • Posts: 24,193
Re: DPP - Focus distance information

Some software does report distance, such as Breezebrowser.

As to Canon, I found a comment made by Chuck Westfall here, scroll down a bit to see the message.

http://www.openphotographyforums.com/forums/archive/index.php/t-210.html
--
Olga

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: DPP - Focus distance information

Hi , it depends on the lens too, for example my 17-85IS should give it contrary to others.
Honestly, mostly this info is not visible. I really miss it.
The most EXIF would give Exifer free SW, if it still exists.

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: DPP - Focus distance information

Olga Johnson wrote:

As to Canon, I found a comment made by Chuck Westfall here, scroll down a bit to see the message.

http://www.openphotographyforums.com/forums/archive/index.php/t-210.html
--

Hi Olga, pls don't take me wrong, but his comment is 4 years old

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: DPP - Focus distance information

So I tried the example I gave, did found Exifer on cached server, installed in WindowsXP mode and used 17-85IS picture. There is lot of info given, but focusing distance unknown
Focus distance [m]: unknown (2)
P.S. Neither DPP nor DxO got it.

guinness2 wrote:

Hi , it depends on the lens too, for example my 17-85IS should give it contrary to others.
Honestly, mostly this info is not visible. I really miss it.
The most EXIF would give Exifer free SW, if it still exists.

MOD Olga Johnson Forum Pro • Posts: 24,193
You are correct...

guinness2 wrote:

Olga Johnson wrote:

As to Canon, I found a comment made by Chuck Westfall here, scroll down a bit to see the message.

http://www.openphotographyforums.com/forums/archive/index.php/t-210.html
--

Hi Olga, pls don't take me wrong, but his comment is 4 years old

However, there was a time when Canon did include distance info and then they stopped it (and it could have been 4-5 years ago). If I remember correctly, the distance provided was not always reliable. When they stopped providing it, Breezebrowser wasn't showing it either. I think Chris Breeze had discussed that but I cannot find his comment about it. Then Chris started adding it to BB, but not for all cameras. Sorry. Wish my memory was better than all this vague stuff.

Basically what I'm trying to say is that I believe Chuck's statements are still valid today.

-- hide signature --

Olga

MOD imqqmi Veteran Member • Posts: 8,631
Re: DPP - Focus distance information

DPP doesn't seem to support it. The only tool I know that works is ExifTool (command line) and ExifToolGui. Recently, I've noticed pbase does show the distance to my pictures and the distances seem pretty accurate. The pictures were post processed using lightroom 3 and have been tweaked in photoshop cs2 and exported using export-> jpg.

Click on full exif:
10-22mm
http://www.pbase.com/imqqmi/image/130747609

100-400L
http://www.pbase.com/imqqmi/image/130838677

sigma 18-50mm f/2.8
http://www.pbase.com/imqqmi/image/128461671

85mm f/1.8
http://www.pbase.com/imqqmi/image/128461729

24-70mm f/2.8
http://www.pbase.com/imqqmi/image/126191984

Mjollnir wrote:

In DPP, you can bring up a box with information about the images from the camera, such as the name of the lens and focal length, etc.

But I can't see any line that tells you how far away you were from the point of focus. Is there any reason for this? I would have thought there would be some way to calculate this based upon the lens's focus settings.

Is there any way to calculate it yourself with the information available from Canon RAW files?

-- hide signature --
 imqqmi's gear list:imqqmi's gear list
Canon EOS 7D Canon EOS 40D Canon EF 100-400mm f/4.5-5.6L IS USM Sigma 30mm F1.4 EX DC HSM Canon EF 85mm f/1.8 USM +2 more
ironic Regular Member • Posts: 176
Re: DPP - Focus distance information

My zenfolio account shows focus distance also, and it seems accurate.

http://ironic.zenfolio.com/p350851998

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: You are correct...

Olga Johnson wrote:

I have too strange feeling, that I saw once the distance info when on 17-85, but no way to remember when and how
Doesn't E-TTL II use it ?

I will try to search my thread from the past. My long-term memory is much better than the short-term one

However, there was a time when Canon did include distance info and then they stopped it (and it could have been 4-5 years ago). If I remember correctly, the distance provided was not always reliable. When they stopped providing it, Breezebrowser wasn't showing it either. I think Chris Breeze had discussed that but I cannot find his comment about it. Then Chris started adding it to BB, but not for all cameras. Sorry. Wish my memory was better than all this vague stuff.

Basically what I'm trying to say is that I believe Chuck's statements are still valid today.

hbx2004 Veteran Member • Posts: 3,162
Re: DPP - Focus distance information

Hi,

All current Canon dslr cameras support "distance" info. Why I quoted distance here? Because this value is never exact distance value (because camera isn't distance metering device).

Camera only need "good enough" distance information to determine exposure parameters when flash is used.

Distance info is comming from lens and depends on focus barrel/ring position. Inside lens, there are physical contacts, which read position/rotation of focus barrel. Resulting value is sent to camera (which, of course make use of this value) and is also written into image metadata (Makernote section).

In case of Canon, there isn't single distance value, but two of them: Focus distance lower value and Focus distance upper value. If image is in focus, then actual distance is allways between lower and upper value.

Scale of reported lower/upper distance values given by lens isn't linear. Reason is simple: flash need more precise values in cases when subject is closer. Let's take EF-S 17-55 f/2.8 as example. This lens can report 28 different distance value pairs, starting at 0.33m. The distance sequence is:

Low. Upper
0.33 0.34
0.34 0.41
0.41 0.44
0.44 0.47
0.47 0.49
0.49 0.52
... ....
... ....
6.43 12.33
12.33 136.23
81.91 655.35

-as you can see, closer distances are more densed (more precise) as far distances.
Of course, some other lens can have more (or less) distance value pairs.

Some software packages (LR, for example) show single distance value (which should give impression of "exact" value). What they basically do is:
(Low+Upp) / 2 = distance

-this is "precise" enough for distances up to (let's say) 3 meters, but missleading for bigger distances. Assuming you use above lens and subject is at distance of 15 m:
(12.33+136.23) / 2= 74.28 m!
-which is totally wrong.

DPP doesn't show distance values -anyway, DPP does make use of it for Lens Correction option.

Thanks for reading,
Bogdan

azakeyh Regular Member • Posts: 206
Re: DPP - Focus distance information

Hello,
I use Bridge with PS CS 5 of Adobe.
I can see the distance from the subject only when shot Raw.

-- hide signature --

az03

 azakeyh's gear list:azakeyh's gear list
Sony RX100 Canon EOS 5D Mark III Canon EOS 550D Canon EF 17-40mm f/4.0L USM Canon EF 24-70mm f/2.8L USM +5 more
PhilPreston3072 Senior Member • Posts: 2,583
Re: DPP - Focus distance information

DPP can give you rough guide of the focus position, not focus distance in the "Lens Aberration Correction" tool under the NR/Lens/ALO tab if you've shot in RAW. You can see whether the focus was closer to infinity or closer to the minimum focus distance with the shooting distance slider.

I think one of the difficulties with embedding shooting distance information is that some zoom lenses aren't parfocal, meaning that the focus is not constant across the zoom range. But I'm sure shooting distance can be calculated given the info from the exif.

 PhilPreston3072's gear list:PhilPreston3072's gear list
Canon EOS 450D Canon EF-S 18-200mm f/3.5-5.6 IS +1 more
Himanshu Gaurav Regular Member • Posts: 473
Wow what a reply

..I don't know where u got all that data from but I am really impressed !!

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: DPP - Focus distance information... to hbx2004

Hi Bogdan,
an impressive info.
Where exactly do you see fucusing distance in LR3 ?
I tried all presets for metadata in library and still don't see it.
Thanks

Boardhead Senior Member • Posts: 1,120
Re: DPP - Focus distance information

An excellent post, Bogan. Thanks!

I can vouch for this. I did similar tests with my Canon 300D and came to similar conclusions.

hbx2004 Veteran Member • Posts: 3,162
Focus distance info in LR..

Hi,

guinness2 wrote:

...Where exactly do you see fucusing distance in LR3 ?

Some LR users have reported they can "get" focus distance info in LR. I don't use LR on regular basis, so I'm no expert on it's usage -there might be some plug-ins, though.
Anyway, in LR, if you export metadata to XMP file, there you can see
ApproximateFocusDistance value.

Bogdan

hbx2004 Veteran Member • Posts: 3,162
Thank you, Phil...

Hi Phil,

Boardhead wrote:

An excellent post, Bogan. Thanks!

Compliments written by you, have special weight for me. Thank you.

Actually I have been waiting before posting, because of my limited english grammar. At the end, I'm happy I could contribute something usefull

Greetings,
Bogdan

guinness2
guinness2 Veteran Member • Posts: 4,347
Re: Focus distance info in LR..thanks

hbx2004 wrote:
Hi,

guinness2 wrote:

...Where exactly do you see fucusing distance in LR3 ?

Some LR users have reported they can "get" focus distance info in LR. I don't use LR on regular basis, so I'm no expert on it's usage -there might be some plug-ins, though.
Anyway, in LR, if you export metadata to XMP file, there you can see
ApproximateFocusDistance value.

Bogdan

Keyboard shortcuts:
FForum MMy threads