Lesn unknown (8 21) - Sigma 17-50mm F2.8 EX DC OS HSM

[Beholder3]

Hi,

I get the message "Unknown (8 21)" when trying to use LensID.

The lens actually is a Sigma 17-50mm F2.8 EX DC OS HSM for Pentax K-mount.

Any chance you help exiftool recognize the lens with the next update?

[Phil Harvey]

Excellent, thanks!!

As you can see the Pentax LensType values are missing a number of Sigma lenses.

But with users like you, eventually we may fill them in.

This update will appear in version 8.62 when it is released.

- Phil

[Beholder3]

Hi,

is there a list with Sigma lenses, where the value is missing?

I am active in a German Pentax forum and could ask other members who own different types of lenses to check the values and afterward forward the results to you, so we can fill the gaps. I guess at least some people will answer.

[Phil Harvey]

That would be great!  The list of known lenses for Pentax cameras is here:

https://exiftool.org/TagNames/Pentax.html#LensType

To make this easier for you, here is a sorted list of the Sigma lenses:

Sigma 4.5mm F2.8 EX DC HSM Circular Fisheye
Sigma 8-16mm F4.5-5.6 DC HSM
Sigma AF 10-20mm F4-5.6 EX DC
Sigma 12-24mm F4.5 EX DG
Sigma 17-50mm F2.8 EX DC OS HSM
Sigma 17-70mm F2.8-4.5 DC Macro
Sigma 17-70mm F2.8-4.0 DC Macro OS HSM
Sigma 18-50mm F2.8 EX DC
Sigma 18-50mm F3.5-5.6 DC
Sigma AF 18-125mm F3.5-5.6 DC
Sigma 18-200mm F3.5-6.3 DC
Sigma 20mm F1.8 EX DG Aspherical RF
Sigma 24-60mm F2.8 EX DG
Sigma 28mm F1.8 EX DG Aspherical Macro
Sigma DF EX Aspherical 28-70mm F2.8
Sigma AF 28-300mm F3.5-6.3 DG IF Macro
Sigma DL-II 35-80mm F4-5.6
Sigma 50mm F1.4 EX DG HSM
Sigma 50mm F2.8 Macro
Sigma 50-150mm F2.8 II APO EX DC HSM
Sigma 50-500mm F4.5-6.3 DG OS HSM
Sigma 55-200mm F4-5.6 DC
Sigma APO 70-200mm F2.8 EX
Sigma 70-200mm F2.8 EX DG Macro HSM II
Sigma 70-300mm F4-5.6 Macro
Sigma 70-300mm F4-5.6 DG OS
Sigma DL Zoom 75-300mm F4-5.6
Sigma EX APO 100-300mm F4 IF
Sigma APO 150-500mm F5-6.3 DG OS HSM
Sigma AF Tele 400mm F5.6 Multi-coated

- Phil

[Beholder3]

I have posted the request with a list of Sigmas which seem unknown currently. Let's wait and see for a week or so, if anyone answers.
I'll keep you informed. 

[Beholder3]

The first reply in the other forum brings up the following question:
Is there anything we can do with these "collective IDs"?
e.g. 24-70mm 2.8 EX DG HSM  = Sigma Lens (8 255)

[Beholder3]

Ok, now we've got the first hit:
Sigma 85/1.4 EX DG HSM = Lens ID: Unknown (8 22)

One thing that came up, as sidenote:
Users pinting to the tool PhotoMe ... what's relevant though is only:
As there are some Sigma entries with multiple possible lenses (see post above) PhotoMe sems to check other lens data (as help) such as focal length and aperture data and use this to identify which one it actually is of the few that it could be.
Maybe you could do something similar in exiftool sometime?

[Phil Harvey]

Ok, now we've got the first hit:
Sigma 85/1.4 EX DG HSM = Lens ID: Unknown (8 22)

Excellent, thanks!!

As there are some Sigma entries with multiple possible lenses (see post above) PhotoMe sems to check other lens data (as help) such as focal length and aperture data and use this to identify which one it actually is of the few that it could be.
Maybe you could do something similar in exiftool sometime?

ExifTool already does this.  For example, LensType "3 255" has 9 possible Sigma lenses.  The Composite LensID tag takes the LensType along with the other lens data and tries to identify the specific lens model from the list of possibilities.

- Phil

[Beholder3]

One more:
Sigma 70-200/2,8 II EX Macro HSM = Lens ID: Unknown (8 16)

[Phil Harvey]

One more:
Sigma 70-200/2,8 II EX Macro HSM = Lens ID: Unknown (8 16)

I already have 'Sigma 70-200mm F2.8 EX DG Macro HSM II' listed with ID '8 255'.  Do you think this is the same lens but just with another ID?  Or is there a non-DG version of this lens?

- Phil

[Beholder3]

Well, I have no idea. Of current lenses I only find two on Sigmas Page:
http://www.sigma-foto.de/produkte/objektive/70-200mm-f28-apo-ex-dg-os-hsm.html
http://www.sigma-foto.de/produkte/objektive/70-200mm-f28-ex-dg-makro-ii-hsm.html
Both EX DG, one mith "macro" one not.

The user posted his own data, so I have to assume its correct... (post is here http://www.dslr-forum.de/showthread.php?t=919163&page=2)

I just check the pentax.xml file of the Photome software. There is the same situation you mentioned. That lens Sigma 70-200mm F2.8 EX DG Macro HSM II' is listed with 8/255.

Strange.

[Phil Harvey]

It sounds like a different ID for the same lens.  This has happened for other Sigma lenses.  I will use the same model name as the existing "8 255" entry.

- Phil

[Beholder3]

Yep. In the forum there are lots of sample pics taken with that lens. I found four with makernotes till in. 3 of them were 8/255 and one 8/16.
Have you ever approached Sigma directly and asked for a simple list? For them all this must be the easiest thing.

[Phil Harvey]

Thanks for checking this.

I've never asked any manufacturers for information like this.  With large companies, it would be difficult to even get your question to someone who understood what you were asking.  But with Sigma, it may be worth trying.

- Phil

[Beholder3]

One more feedback:
"Sigma 50-200 F4-5.6 DC OS" also is mapped to ID 8,255.

I have written to both Pentax and Sigma asking for ID lists. I sadly also do not really expect helpful answers but it's worth a try.