Feature #1141

Manual lens does not get recogniced: Pentax macro 100mm

Added by Simon Harhues about 1 year ago. Updated about 1 year ago.

Status:ClosedStart date:22 Dec 2015
Priority:NormalDue date:
Assignee:Niels Kristian Bech Jensen% Done:

100%

Category:lensEstimated time:1.00 hour
Target version:0.26

Description

simon@vmubuntu1510:~$ exiv2 --version
exiv2 0.25 001900 (64 bit build) [...]
simon@vmubuntu1510:~$ exiv2 pt /tmp/fotos/101_2212/IMGP2241.PEF | grep Lens
Exif.PentaxDng.LensType Byte 4 K
oder M-Linsen
Exif.PentaxDng.LensInfo Undefined 128 0 1 128 1 0 0 3 32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
simon@vmubuntu1510:~$ exiv2 pt /tmp/fotos/101_2212/IMGP2241.JPG | grep Lens
Exif.PentaxDng.LensType Byte 4 K
oder M-Linsen
Exif.PentaxDng.LensInfo Undefined 128 0 1 128 1 0 0 3 32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
simon@vmubuntu1510:~$ exiv2 pt /tmp/fotos/101_2212/_IGP9296.DNG | grep Lens
Exif.PentaxDng.LensType Byte 3 K
oder M-Linsen
Exif.PentaxDng.LensInfo Undefined 69 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Tested with two Pentax bodies. I'm not sure if it is possible to improve the recognition of manual lenses. But now it look pretty generic and not suitable for e.g. lensfun.
The lens is physically labeled as:
6845970 ASAHI OPT. CO., JAPAN
smc PENTAX-M MACRO 1:4 100mm

It is a fixed 100mm macro lens, the f-stop reaches from 4 to 32.
As the raw files are rather big, I've uploaded them to: https://www.dropbox.com/sh/irdznxeve9xra8o/AAAi0JZGMS-qUVLeTtrlQsUAa?dl=0
I grant you all rights to use them for the further development of exiv2 or other FOSS software.

History

#1 Updated by Robin Mills about 1 year ago

  • Status changed from New to Assigned
  • Assignee set to Robin Mills
  • Target version set to 0.26

Thanks, Simon. I'll investigate and update this issue report.

#2 Updated by Niels Kristian Bech Jensen about 1 year ago

It is not possible to identify manual lenses since they do not communicate with the camera body. Hence there are no lens metadata available in the file to help identification.

Best regards,
Niels Kristian Bech Jensen

#3 Updated by Robin Mills about 1 year ago

  • Status changed from Assigned to Closed
  • Assignee changed from Robin Mills to Niels Kristian Bech Jensen
  • % Done changed from 0 to 100
  • Estimated time set to 1.00

I don't know what a manual lens is. However if there is no metadata, nothing can be done.

#4 Updated by Robin Mills about 1 year ago

Simon

I'm just having a little tidy up to see if there is anything outstanding. Just looking at this issue report, the PEF and JPG have 128 bytes in LensInfo. The DNG has 69. I think the number of bytes in LensInfo depends on the camera body. Your *ist had 36bytes, K-10 had 69 and K-3 had 128. http://dev.exiv2.org/issues/816#note-37

However there's almost no data - just lots of 0's. So although there is LensInfo, I believe it's saying "I don't know anything about this Lens.".

#5 Updated by Simon Harhues about 1 year ago

I feared so. Although comparing with #1142 it seems that the camera has different LensInfo for different "I don't know anything about this Lens." cases. :) Anyway, if there is nothing to do I'm happy with keeping it closed and sorry for the noise.
I'll do a couple of calibration shots for lensfun instead. :)

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