[Edomath]

Hello,
in the first time sorry for my bad english....
I have a little problem with my k-50 and 3 lenses ( i have 4 lenses ).
My exifs are false ( only the name of my lens ), for exemple my "Tokina 80-200 f2.8 af atx pro" as named on lightroom "smc PENTAX-F 35-105mm F4-5.6" ( aperture and flocal are good on my exif for all my lens )
And my "Sigma 10-20mm f4-5.6" as named "Sigma or Tamron Lens"...
And the last are my old kit lens ( 18-55 ) as named "Objectifs inconnus" -> in english "unknow lens".
I have only my Tamron 28-75 work... My last lens don't have contact ( Elicar 90mm f2.5 macro ).

It's bad problem when i search a photo on lightroom or when a share on flickr...

Thanks for your help

[Adam]

It's up to the post processing software to decode the exif data, so the camera isn't to blame. Be sure to update LR to the latest version, and if it still provides ambiguous data you may need to set the lens info manually, or try a utility such as exiftool.

[jatrax]

The camera EXIF only contains a code that the EXIF reader has to look up. And unfortunately some third party makers just reused codes that were from other lenses. Try looking at the EXIF in a different EXIF reader such as Faststone or Irfanview or Exifreader. Also make sure you have the latest updates for Lightroom.

[enoeske]

It's up to the post processing software to decode the exif data, so the camera isn't to blame. Be sure to update LR to the latest version, and if it still provides ambiguous data you may need to set the lens info manually, or try a utility such as exiftool.

additionally, Pentax has no obligation to support third party lens manufacturers or their lenses info in their cameras.

[UncleVanya]

An easy way to test this would be to take an in Camera JPG with no extra processing and examine it using this:
http://regex.info/exif.cgi

Most likely the EXIF issues at least with the 18-55 and other Pentax lenses will clear up.

[Edomath]

Thanks for your reply, i have try with 3 software and your website and the exifs don't change...
for exemple :
or direct link or other photo : http://www.arnaud-regnier.ovh/blog/aberwrach/images/large/IMGP4657

And i use lightroom 6

i go to sleep and i check your message tommorow, thanks you

[UncleVanya]

Only the Old Kit lens is likely to work accurately. I know some people setup EXIF batch processes to modify the exif to reflect their third party lenses - and this is not just a Pentax issue or a K50 issue.

[stevebrot]

My exifs are false ( only the name of my lens ), for exemple my "Tokina 80-200 f2.8 af atx pro" as named on lightroom "smc PENTAX-F 35-105mm F4-5.6" ( aperture and flocal are good on my exif for all my lens )
And my "Sigma 10-20mm f4-5.6" as named "Sigma or Tamron Lens"...
And the last are my old kit lens ( 18-55 ) as named "Objectifs inconnus" -> in english "unknow lens".

This is a known issue with some lenses and is not limited to Pentax product. The lens sends the camera a lens id number and that is what is stored in the EXIF.

The camera EXIF only contains a code that the EXIF reader has to look up. And unfortunately some third party makers just reused codes that were from other lenses.

In this case, Tokina used an existing Pentax code and both Sigma and Tamron used the same code. Lightroom was unable to tell the difference. Why Lightroom was unable to detect your 18-55 kit is a puzzle.

Try looking at the EXIF in a different EXIF reader such as Faststone or Irfanview or Exifreader. Also make sure you have the latest updates for Lightroom.

I suspect that all the tools suggested will return the same or similar answers. An ambiguous lens id cannot be resolved.

Here is a link to a table of lens ids known to the ExifTool utility.

Pentax Tags

In the left column is a representation of the number stored in the exif in the form "# #.n" where "n" is optional and represent an id that maps to more than one lens. An example would be my Sigma 50/2.8 EX DG Macro:

Code stored: "3 41"
Duplicate to: Pentax-F 50/2.8 Macro
ExifTool output: "smc PENTAX-F Macro 50mm F2.8 or Sigma Lens"
Lightroom displays: "Pentax-F 50/2.8 Macro"

Lightroom is not quite as nimble at displaying an appropriate name.


Steve

[stevebrot]

i go to sleep and i check your message tommorow, thanks you

Here is the list of lenses that use the same code ("3 25") as was stored in the EXIF for the image you linked to:

smc PENTAX-F 35-105mm F4-5.6
Sigma AF 28-300mm F3.5-5.6 DL IF
Sigma 55-200mm F4-5.6 DC
Sigma AF 28-300mm F3.5-6.3 DL IF
Sigma AF 28-300mm F3.5-6.3 DG IF Macro
Tokina 80-200mm F2.8 ATX-Pro

Only the code for the Pentax lens is legitimate. Lightroom arbitrarily displays the name for the Pentax lens. Programs that use the ExifTool libraries will display "smc PENTAX-F 35-105mm F4-5.6 or Sigma or Tokina Lens".


Steve

[Edomath]

Thanks for all your reply

Only the Old Kit lens is likely to work accurately. I know some people setup EXIF batch processes to modify the exif to reflect their third party lenses - and this is not just a Pentax issue or a K50 issue.

How to set a lens on my exifs for all the time ?

[UncleVanya]

Thanks for all your reply



How to set a lens on my exifs for all the time ?

Now we have travelled past the end of my knowledge. Someone else who uses Lightroom or other PP tools on a PC/Mac will need to explain this. I use a Chromebook and have more limited options with respect to EXIF manipulation. My understanding is that people add the EXIF manipulation to their batch process often making it part of their overall workflow.

Me I have no such option. My tools do not allow me to edit/manipulate EXIF so I lose my EXIF data when I Post Process. I tend to capture it from an unmodified file and post it as a comment with the modified file.

[stevebrot]

How to set a lens on my exifs for all the time ?

Where the code is shared by two or more lenses and yours is not the lens that Lightroom displays, there is nothing you can do to make it display a different lens automatically.

It is possible to use a utility to write a descriptive name directly into the LensModel tag of the EXIF. The most commonly used is called ExifTool. It is a very useful and capable command-line program, but is rather difficult to use if you are not real familiar with EXIF structure. ExifTool does have a separate graphical user interface for Windows called ExifToolGUI that allows for easy batch writing or overwriting of lens names. I regularly use the combination to write lens names into the EXIF for my manual focus glass.

ExifTool download (install first):

ExifTool by Phil Harvey

ExifToolGUI (install second):

Download Link
ExifToolGUI Online Manual

For best results, use ExifToolGUI to write the proper LensModel to the EXIF before doing the import into Lightroom. Good luck!


Steve

[UncleVanya]

Where the code is shared by two or more lenses and yours is not the lens that Lightroom displays, there is nothing you can do to make it display a different lens automatically.

It is possible to use a utility to write a descriptive name directly into the LensModel tag of the EXIF. The most commonly used is called ExifTool. It is a very useful and capable command-line program, but is rather difficult to use if you are not real familiar with EXIF structure. ExifTool does have a separate graphical user interface for Windows called ExifToolGUI that allows for easy batch writing or overwriting of lens names. I regularly use the combination to write lens names into the EXIF for my manual focus glass.

ExifTool download (install first):

ExifTool by Phil Harvey

ExifToolGUI (install second):

Download Link
ExifToolGUI Online Manual

Good luck!


Steve

This is a very helpful post.

[stevebrot]

This is a very helpful post.

Thanks! ExifTool is sort of opaque if you are unclear at all as to what it does and how it does it. The ExifToolGUI helps a lot. With any luck, the OP will find a workable solution.

BTW...You may be interested to note that it can be used to insert camera and lens info for digital scans from film negatives.


Steve

[Edomath]

Thanks for your help, i go check that