Exif -- lens reporting incorrect data

I have noticed that the exif data reads my Sigma 10-20 lens as a 28-80mm, has anybody else noticed this, is this a 'glitch' or a major problem. Any help or advice would be much appreciated.

Note this thread is an aggregation of three similar threads.

Edited by brettania - 04 July 2012 at 11:08

What software are you using?

The EXIF data only contains a lens ID, and the reading software looks up the lens from the ID. Unfortunately Sigma does not play by the rules and uses lens IDs that were already used for other lenses. So reading software often picks the wrong lens name when reading a Sigma lens ID.

There are two solutions:

1. Make Sigma play by the rules and use truly unique lens IDs (unlikely), or
2. Reading software should cross-check other EXIF data, like focal length and aperture, to decide between lenses with non-unique lens IDs.

My Sigma 70-300 DG Macro reads as 75-300. Are Sigma just sloppy?

Benoni wrote: Are Sigma just sloppy?

Yeah.

kampej wrote: perhaps Sigma were not so sloppy in the past!?

coincidence can cause a lot of things to happen

This thread was started in 2009 so it's a problem that's been around for some time, and is still not fixed.
I recently purchased an as new Sigma 15mm f2.8 EX DG diagonal fisheye lens for use on my a900.
I post-process my images using Apple Aperture 3.2.2.
I noticed that in the EXIF data embedded in the images, the lens is mis-recognised as a Sony/Minolta 16mm f2.8 fisheye. It accordingly registers the focal length incorrectly as 16mm, despite it being 15mm. Aperture, shutter speed and ISO are all correct.
Having read this and related threads here on EXIF and Sigma lenses, it seems the problem is the way Sigma engineers its lenses so they are not distinctively identifiable and recognisable.
When I looked back at past images taken with my Sigma 10-20mm f4-5.6 EX DG on my a700, I also found that the lens in those EXIFs was mis-recognised as the Minolta 28-80mm f3.5-5.6 which is nowhere near similar, although in that case the focal length was correctly stated as 10mm through to 20mm, and aperture, shutter and ISO were all correct.
Probably not such a big deal, but a bit annoying, and of course misleading for anyone clicking onto images to get accurate EXIF data.
I have emailed Sigma tech support, but based on earlier entries in this thread, I'm not expecting any joy from them.
Joe

I refer to a thread that started in 2009 in the Equipment Forums, Camera Talk, APSC DSLR section:http://www.dyxum.com/dforum/exif_topic46107_post994323.html#994323
However, I feel it more properly belongs here in the Lens Talk section so I'm placing my thoughts here. (If the mods don't agree, feel free to do what you think is best).

I recently purchased an as new Sigma 15mm f2.8 EX DG diagonal fisheye lens for use on my a900.
I post-process my images using Apple Aperture 3.2.2.
I noticed that in the EXIF data embedded in the images, the lens is mis-recognised as a Sony/Minolta 16mm f2.8 fisheye. It accordingly registers the focal length incorrectly as 16mm, despite it being 15mm. Aperture, shutter speed and ISO are all correct.
Having read this and related threads here on EXIF and Sigma lenses, it seems the problem is the way Sigma engineers its lenses so they are not distinctively identifiable and recognisable.
When I looked back at past images taken with my Sigma 10-20mm f4-5.6 EX DG on my a700, I also found that the lens in those EXIFs was mis-recognised as the Minolta 28-80mm f3.5-5.6 which is nowhere near similar, although in that case the focal length was correctly stated as 10mm through to 20mm, and aperture, shutter and ISO were all correct.
Probably not such a big deal, but a bit annoying, and of course misleading for anyone clicking onto images to get accurate EXIF data.
I have emailed Sigma tech support, but based on earlier entries in the original thread, I'm not expecting any joy from them.
Joe

Edited by Jozioau - 22 February 2012 at 02:06