Third-party lenses and EXIF data

[andnowimbroke]

I was looking through a few pics a friend had taken. When I peeked at her EXIF data, I remembered something I never thought of. Hope that last sentence made since. My language doesn't translate into english very well. It had "Canon EF 80-200mm f/4.5-5.6" listed as the lens mounted even though it was a Tamron 70mm-300mm set to 300mm. Would the camera or other software being used take that information and apply false adjustments to compensate for issues that the EXIF says it is rather than the lens that was really on it. Taking it kinda to an extreme, doesn't the camera sense/communicate when a wide angle lens is on and "thinks" about what your trying to take a picture of (ie landscape), even though it might really be a telephoto lens for bird shooting? It prolly isn't that important when shooting in manual or with RAW files. That takes all the "camera guessing" out of it I think. It just seemed odd, especially when it read out the correct focal length of 300mm, but insisted on 80-200 lens. Any thought?

[Jarhead5811]

...(Sigma/Tamron) reverse engineers (vs. licenses) manufacturer AF routines...



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It's probably based on which Canon lens Sigma or Tamron decided to emulate for compatibility. My Tamron SP AF 17-50mm f/2.8 XR Di II LD IF masquerades as a Canon EF 24-70mm f/2.8 L USM in the EXIF data. I don't see it as a problem. I'd be more concerend about focusing issues these two tend to have.

[Jordan]

OMG really! I used to have two lenses (since I have sold them) that didn't report acurruately in the EXIF their names. It was SUPER irritating! I had a Sigma 17-70mm f/2.8-4 and in the "Lens" info it would say "17-70mm"


Ugh! Then... I had a Tokina 10-17mm f/3.5 fisheye lens (REALLY nice lens btw!) and that one says "10-17mm"


Anyone know if there is a way to say that THIS is really THAT? Like label the third party lenses? I guess my situation isn't as bad as the one you described because that one is VERY detailed, but wrong. I wouldn't like that! But I also don't like it to be so vague. Anyhow, just agreeing with your frustration!

[Jordan]

Jarhead, obviously focusing issues would be MUCH more of a problem, but I'm assuming we're not talking about focusing issues here. My Sigma lens was so-so quality but good focusing, and my Tokina was a beautiful lens. I'm a bit sad I sold that. All that aside, it's nice to have good records of camera/lens types, and more-so I think, focal lengths and apertures. So if a 200mm max lens was reporting 300mm, that'd tick me off! It's confusing. Luckily, for me, I now have all Canon lenses and they all report correctly. One exception: I own the Tokina 11-16mm f/2.8 (also a very nice lens!) and just like the others, it reports "11-16mm" ugh... no manufacturer, type etc... just range. Oh well!

[Lars]

I might be wrong, but I believe the newer versions of DPP recognise more lenses, at least it said so on Canon's web-site when I checked for upgrades. My Tamron 17-50 and 11-17 are both correctly listed in the EXIF data (own a 400D from 2008). Perhaps an update of the firmware of the cameras might help?

[andnowimbroke]

Perhaps an update of the firmware of the cameras might help?

It was shot with a 40D and think it had the lastest firmware (as of January anyway when I sold it to her).

I might be wrong, but I believe the newer versions of DPP recognise more lenses

So the camera doesn't have the final say-so with what the lens really is? It's just reading a bunch of words/numbers and displaying what it thinks it is and not relabeling it. Good to know DDP won't read the wrong focal lengths and also tweak to the wrong lens. Although that Tamron needed just about every tweak available. As far as in-camera,I guess they used a proper algo. for the focal range and I shouldn't worry about it.


To be honest, I never read many of the off-brand lens reviews here and just stuck with the Canon ones. I didn't know Tamron/Sigma <span style="text-decoration: line-through;"]stole reverse-engineer Canon lens to get their specs. Can't they walk on their own two feet by now? Maybe I shouldn't judge until I hear the whole story. I'm sure a little of this goes on everywhere.


Sorry to the OP for taking this off topic[]

[neuroanatomist]

I didn't know Tamron/Sigma <span style="text-decoration: line-through;"]stole reverse-engineer Canon lens to get their specs. Can't they walk on their own two feet by now?

They don't reverse engineer the lenses from an optical standpoint - the reverse engineering is from a control standpoint, i.e. AF routines, aperture control, etc. When Canon designs a new body, they make sure (by adjustments in firmware, if necessary) that it works properly with all appropriate Canon lenses. They are under no obligation to test or make allowances for 3rd party lenses. That means older 3rd party lenses may not work electronically with bodies that are newer than the electronics in the lens - they may not autofocus, or they may be stuck at the wide open aperture. Sometimes the lenses can be re-chipped by the manufacturer to work with the newer body (which is where Tamron's 6-year warranty may come in handy).

[andnowimbroke]

Well, now I'm on the side of Tamron! Car companies tried to stop (and in some cases succeeded) aftermarket partsfrom being made by not releasing information about the designs. Now you can total a car by hitting a Mayfly. I just thought (wrongly) that cameras were more "open-sourced" than what they really are.

[Jarhead5811]

Well, now I'm on the side of Tamron!
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Why would Canon be concerned about third party lens performance? They don't make a dime off third party lenses. I'd assume Sigma/Tamron/Tokina could license Canons AF routines but they don't. Should Canon just give away proprietary information so you can buy a third part lens instead of theirs?


If you want the best results from a third party lens manufacture you couldtry a Sigma body and all Sigma lenses (at least that seems like it'd work). I'd rather stick with Canon myself.

[andnowimbroke]

Should Canon just give away proprietary information so you can buy a third part lens instead of theirs?

Tamron fills a niche that Canon should stay out of (cheap made lenses). I remember when John Deere mowers were well built. Then they decided to get into the chain stores. They cut every corner they could. Made me puke everytime I went by a lot with one of those "tin can" mowers out front painted all green and yellow. Point is, they ruined their name by making cheap tinker toys. Canon should stick with making quality lenses and have Tamron/Sigma/Tokina do what they do best, help get people in the door of the Canon camp. Not everyone can afford the good stuff up front. Plus it helps the creative juices of your design team if someone else is on their heels. And it might keep our prices down a little.


After reading what I just typed, I almost answered your question. This old age thing ain't working for me. I'm rambling and reminising alot.