Hi
I'm trying to read out FocusDistanceUpper/FocusDistanceLower on a Canon EOS 5D Mark II with an EF 50mm f/2.5 Macro lens attached and get always 0. Other combinations with the same camera (e.g. with an EF70-200mm f/4L USM attached) seems to work perfect.
Has somebody any idea what's going wrong? Is maybe the EF 50mm f/2.5 Macro lens faulty because other cameras show the same result.
Thanks for support.
It seems that these numbers aren't written for all lenses.
I have 5DmkII samples with 4 different 50mm lenses. Of these, pictures with the Canon EF 50mm f/1.2L and Sigma 50mm f/2.8 EX (which has the same LensType number as your Canon EF 50mm f/2.5 Macro) have these values written properly, but pictures with the Canon EF 50mm f/1.4 USM and Carl Zeiss Planar T* 50mm f/1.4 do not. I can't say why.
But I wouldn't lose too much sleep over this. I don't think these numbers are very accurate anyway.
- Phil
Hi Phil,
Thanks for your reply. At least I know now that there is no mistake in our maker note reader nor that the lens is faulty.
- Peter
Quote from: Phil Harvey on June 01, 2010, 12:27:47 PM
It seems that these numbers aren't written for all lenses. [...] I can't say why.
That's simply because not all Canon lenses report distance information to the camera body. Check the lists at http://www.bobatkins.com/photography/eflenses/lens_list.php (http://www.bobatkins.com/photography/eflenses/lens_list.php) or http://canon-eos.serveblog.net/geraet/index.htm (http://canon-eos.serveblog.net/geraet/index.htm) and note the "E-TTL II support" information. (E-TTL II relies - among other things - on the focusing distance information to compute the appropriate flash power.)
Regards,
Sebastian
Quote from: sjs on June 06, 2010, 09:58:46 AM
That's simply because not all Canon lenses report distance information to the camera body.
Makes perfect sense.
- Phil