Support #1241

Support for Samyang 14mm f/2.8 AE ED AS IF UMC on Canon EF

Added by Tobias E. about 1 year ago. Updated about 1 year ago.

Status:ClosedStart date:10 Oct 2016
Priority:NormalDue date:
Assignee:Robin Mills% Done:

100%

Category:lensEstimated time:1.00 hour
Target version:0.26

Description

Hello,

the chipped version of the Samyang 14mm is also available for Canon mounts (you already have it for Nikon). However, they seem to report the LensID (247) which is also used by Canon's own 14mm f/2.8. I attached a sample file. It would be great if you could find a way to distinguish those cameras.

Thanks in advance
Tobias

6Q1B7275.JPG (6.27 MB) Tobias E., 10 Oct 2016 14:18

History

#1 Updated by Robin Mills about 1 year ago

  • Category set to lens
  • Status changed from New to Closed
  • Assignee set to Robin Mills
  • Target version set to 0.26
  • % Done changed from 0 to 100
  • Estimated time set to 1.00

No problem at all with Exiv2 v0.26 (which is going through our release process). The "Camera Overflow File" enables you to define the lens name for different camera manufacturers. #1034.

Here's the state "out of the box" (on the trunk):

$ exiv2 -pa --grep lens/i http://dev.exiv2.org/attachments/download/1076/6Q1B7275.JPG
Exif.CanonCs.LensType                        Short       1  Canon EF 14mm f/2.8L II USM
Exif.CanonCs.Lens                            Short       3  14.0 mm
Exif.Canon.LensModel                         Ascii      74  14mm
Exif.Photo.LensSpecification                 Rational    4  14/1 14/1 0/1 0/1
Exif.Photo.LensModel                         Ascii       5  14mm
Exif.Photo.LensSerialNumber                  Ascii      11  0000000000
504 rmills@rmillsmbp:~/gnu/exiv2/trunk $
As you have correctly reported, LensType == 247.
$ exiv2 -pv --grep LensType http://dev.exiv2.org/attachments/download/1076/6Q1B7275.JPG
0x0016 CanonCs      LensType                    Short       1  247
So edit ~/.exiv2
$ vi ~/.exiv2
$ cat ~/.exiv2 
[canon]
247=Samyang 14mm f/2.8 AE ED AS IF UMC

[nikon]
# 14=Robin's little lens

[pentax]
# 3 255 0 0=another pentax lens

[minolta]
# 255=a sony lens

[olympus]
# 123=something
And now the lens is correctly identified by every application which uses libexiv2.
$ exiv2 -pa --grep LensType http://dev.exiv2.org/attachments/download/1076/6Q1B7275.JPG
Exif.CanonCs.LensType                        Short       1  Samyang 14mm f/2.8 AE ED AS IF UMC
$ 

#2 Updated by Tobias E. about 1 year ago

What when I use a real Canon 14mm? Will that be recognized as the Samyang, too?

#3 Updated by Robin Mills about 1 year ago

If the real Canon 14mm also has a lensType == 247, it'll be identified by the entry in ~/.exiv2. If somebody has the misfortune to have 2 lenses with the same lensType, ~/.exiv2 will not differentiate.

If have thought about extending the capability of ~/.exiv2 to say something such as:

[canon]
Exif.CanonCs.LensType==247 && Exif.Canon.InternalSerialNumber==AD0283869 = My other lens
I have no plan to implement a more sophisticated parser at the moment.

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