Pentax Maker Infos

[Beholder3]

Hi,

as I am using a Pentax camera now, I found that there are three (!) FocalLength tags shown in ExifTool GUI.
I understand only two of them, the always equal values of "EXIF:FocalLength" and one of the "Maker:FocalLength" tags.

What I don't understand is what the second Maker:FocalLenght tag is. In my case while the other two values show up as "16mm" in an example file, this one is set to "16.3mm" at the same time.


The first one is listed after "WhiteBalance" tag, the second after the "LensFStops" tag.

Anyone with an idea what the difference between those two fields is?

[Phil Harvey]

This question is very similar to FAQ number 4.  Sometimes the EXIF numbers are rounded off from more accurate numbers calculated by the camera, and occasionally the camera stores these more accurate numbers in the MakerNotes information.

- Phil

[BogdanH]

Thank you Phil

Bogdan

[Beholder3]

Thanks. I still need to understand all those millions of information pieces in the exif+ data.
Many items are there multiple times and different apllications only use certain ones.
Mademorecomplex if you have a combination of camera + lens that (in my situation) transfers some data only 90% of the time fully correct.

[Beholder3]

Ah. One more question:
How can I found out the precise namesof those two tags mentioned above?
In GUI the both are called exactly the same but contain different values.
If I want to use one of them I have no idea how to adress them specifically.

[BogdanH]

Hi,
So I don't forget: tag names displayed in GUI are as given by Exiftool -that is, GUI doesn't display some "custom" names.
As you have noticed, inside metadata area, there can exist more than one FocalLength tag. You can distinguish between them by determining in what group particular tag resides; in this case, ExifIFD or Pentax(Makernote).
It's similar in case you're modifying tags with ExifTool direct. If you wish to modify tag in Exif, you would write, i.e:
-ExifIFD:FocalLength=28
All tag names (and corresponding groups) can be found on ExifTool main page (first paragraph).
I hope this answers your question.

Bogdan

[Phil Harvey]

Hi Bogdan,

Can ExifToolGUI display the family 4 group names?  It seems that there are 2 same-named tags in the Pentax maker notes that need to be differentiated:

see this post

- Phil

[BogdanH]

Hi Phil,

I wasn't sure, so I though it's Exif vs Makernote after all... After trying -G4 it became clear and I wondered before why would someone need G4... clear now.
Right now GUI is using -g1 for displaying metadata, but I will add -g4 option for sure (nicer output than with -G4 in GUI). Very usefull!
Thank you for pointing me to the right direction.

Bogdan

[Phil Harvey]

Hi Bogdan,

If convenient it would be good if the user could select the family in the settings for ExifToolGUI.  The various group families are useful for different reasons.  Right now, officially ExifTool has families 0-4, but unofficially family 5 actually exists, and ExifTool is designed to be able to add more in the future if there is a need for them.

- Phil

Edit: Also, you may not realize that you can combine families by separating the numbers with a colon.  For example, organizing by both family 1 and 4 is done with -g1:4, and gives output like this:

Code Select Expand

---- ExifTool ----
ExifTool Version Number         : 8.51
---- System ----
File Name                       : a.jpg
Directory                       : .
File Size                       : 441 kB
File Modification Date/Time     : 2011:03:06 11:31:57-05:00
File Permissions                : rw-r--r--
---- File ----
File Type                       : JPEG
MIME Type                       : image/jpeg
Exif Byte Order                 : Little-endian (Intel, II)
Current IPTC Digest             : 3e355a5e349bacdd2020c2b3028b3a6e
Comment                         : test, xyz.comment
Image Width                     : 1024
Image Height                    : 768
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:2 (2 1)
---- JFIF ----
JFIF Version                    : 1.01
---- JFIF:Copy1 ----
Resolution Unit                 : cm
X Resolution                    : 772
Y Resolution                    : 772
---- IFD0:Copy1 ----
Image Width                     : 11024
Image Height                    : 7768
Bits Per Sample                 : 88
Y Cb Cr Sub Sampling            : YCbCr4:2:2 (2 1)
---- IFD0 ----
X Resolution                    : 772
Y Resolution                    : 772
Resolution Unit                 : inches
Artist                          : -
Y Cb Cr Positioning             : Co-sited
---- ExifIFD ----
Exposure Time                   : 1/120
ISO                             : 230
Exif Version                    : 0220
Create Date                     : 2011:03:06 06:51:37
Components Configuration        : Y, Cb, Cr, -
Flashpix Version                : 0100
Color Space                     : sRGB
Exif Image Width                : 22048
Exif Image Height               : 11536
Contrast                        : High
Saturation                      : High
Sharpness                       : Hard
Serial Number                   : P900BD03000480
---- ExifIFD:Copy1 ----
Date/Time Original              : 2010:06:25 13:26:00
---- Reconyx ----
Maker Note Version              : 0xf101
Firmware Version                : 3.0.1
Firmware Date                   : 2010:04:20
Trigger Mode                    : Motion Detection
Sequence                        : 1 of 3
Event Number                    : 664
Date/Time Original              : 2010:06:25 13:26:00
Moon Phase                      : Full
Ambient Temperature Fahrenheit  : 84 F
Ambient Temperature             : 29 C
Infrared Illuminator            : Off
Motion Sensitivity              : 100
Battery Voltage                 : 10.67 V
User Label                      : PC900 COVERT PRO
---- Reconyx:Copy1 ----
Serial Number                   : xxxxxxxxxxxxxxx
Contrast                        : 1159
Brightness                      : 2223
Sharpness                       : 664
Saturation                      : 2255
---- IPTC ----
Keywords                        : 1, 2, 3, 1, 2, 3
Application Record Version      : 4
---- XMP-x ----
XMP Toolkit                     : Image::ExifTool 8.51
---- XMP-dc ----
Creator                         : a, b, c
---- XMP-mwg-rs ----
Region Area H                   : 8
Region Area W                   : 8
Region Area X                   : 0
Region Area Y                   : 0
Region Name                     : Region 1
Region Type                     : Face
Region See Also                 : plus:Licensee
Region Extensions Artwork Title (de): verfänglich
Region Extensions Flash Mode    : On
Region Extensions Flash Return  : Return not detected
Region Extensions Usage Terms (fr): libre
---- XMP-crs ----
Brightness                      : 2223
---- Composite ----
Base Name                       : a
File Extension                  : jpg
File Type Description           : Joint Photographic Experts Group
Image Size                      : 1024x768
Shutter Speed                   : 1/120


You may combine any number of families this way.

[BogdanH]

Thanks for suggestions, Phil.
I've gone thru various -g/G combinations and here are some of my observations related to GUI -where my goal is: showing as much as possible of what ExifTool can show, and at the same time avoiding confusion of what's being shown.

Since beginning, GUI shows all metadata in -g1 mode. I believe this is the most logical way to group metadata. And as far I can see, if there wouldn't be Makernotes section, there wouldn't be much need for -g4 output. I mean, for all other types of metadata (Exif, Iptc, Xmp,..) I can access any tag by specifying group as displayed by using -g1 option.

The problem (as is see it) is, if metadata is displayed in -g:1:4 mode, then one can get confused... simple example:
-a -g:1:4 -ExifIFD:All photo.jpg
-and then I start to think: "ok, I see ExifIFD:Copy1 ISO value value... should I look after another (Copy2) ISO tag in ExifIFD? No, it's not there... it is inside Makernotes!?... but I've specified ExifIFD only...".
As a result, I've decided to implement -g4 only when viewing Makernotes section -because there exist no other way to access particular duplicated tag than specifying Copy1, Copy2,... prefix.

Just for info: At first, I actually wanted -g:1:4 (more informative than -g4 only), but I soon noticed there's quite old catch in GUI: sign ":" is used as TagName:TagValue separator as given by Exiftool. Now, if "double grouping" is used, ":" character appears inside group name as well... thus, group name gets divided in two parts, because GUI thinks, it's a TagName/TagValue pair. I've tried to override this behaviour, but it got complicated...
It's ok for now, but -g5, -g6, etc. was mentioned... so, I ask you anyway Phil: is there a possibility you would use another character (instead of ":") when displaying group names? So result would be, for example:
---- ExifIFD^Copy1 ----
I know, you don't like such ideas (having your reasons), so any answer is good for me.

Bogdan

[Phil Harvey]

Hi Bogdan,

I appreciate your efforts to make exifool easier to use and understand, so of course whatever you decide is fine with me.

About changing the ":" to something else... No, I'm afraid that at this point it would cause too many problems if I changed this.

- Phil