Imagemaster wrote:
Has anyone seen this confirmed in writing from Tamron, or is it just hearsay
(Please note, I am copying my comment from another thread, since this one seems more appropriate for the subject.)
Today, I spoke with a Brian at Tamron USA Service Department. He said he was not aware of a firmware update, but said if I would send in my lens in they would check it out. He did say if I wanted to send my one of my cameras (7D or 5DIII) they would tune the lens to the camera, with usually about a 3 day turnaround.
I am considering sending it in with my 7D, but first want to carefully document my actions and the problems I'm seeing on the next sunny day when I'm off work.
Based on Brian's comments I am not so sure about a FW update.
Imagemaster wrote:
Has anyone seen this confirmed in writing from Tamron, or is it just hearsay
Imagemaster, sometime ago I posted in another thread on this lens as to the fact that it worked fine on my 1D MkIII and you asked me to prove it. I posted a reply yesterday to the first respondent to my post who also welcomed me to the forum. Subsequently I also replied to your own response to me there and I don't know if you missed it. I appreciate that it is tantamount to illegal to double post but could you take a look for me and tell me what you think. Your views are important.
The thread was https://www.fredmiranda.com/forum/topic/1270895/7 and I have posted links to 4 photo's which are from a sequence of 11 and all 11, in my personal view of course, were sharp. They were shot in Ai-servo mode on my 1D MkIII but according to some the tracking shouldn't be working on this camera. If you could take a look and scroll a little further you will also see my reply to you.
Imagemaster wrote:
Denis, yes they do look sharp. Were they taken with the shutter button held down half-depressed or the shutter button pumped?
Good to hear it works with your body. Now you just have to try on some smaller birds that are travelling faster.
Tony
Thanks Tony that seems to make things a little clearer for me. They were taken with the shutter button pressed half way to obtain focus then fully depressed and held down.
At the moment though, me, 600mm and small fast birds just don't get on too well. I need much more practice in that field and at f6.3 largest f-stop I would expect the lens to be a little slower than say an f4. I believe all Canon cameras are geared to f5.6 anyway with anything higher giving a different response.
I can "make" my 1D3 have the 7D problem by changing the settings closer to my favourites. In this case though I set the camera to work with the lens from default mode. So, at least in my case the Tamron 150-600 is not faulty. It works on my camera just not at my favourite settings.
Perhaps Canon's fixation with AF up to f5.6 may be part of the problem here although the 1D3 did get a firmware upgrade for f8. Was the 7D upgraded to this as well?
What about the 8 images missing from the above sequence?
Perhaps Canon's fixation with AF up to f5.6 may be part of the problem here although the 1D3 did get a firmware upgrade for f8. Was the 7D upgraded to this as well?
1D series have always been able to AF at f8. No, the 7D will only AF up to f5.6. The Tamron lens "lies" to the 7D and says it is a f5.6, not a f6.3.
alundeb wrote:
Are you sure about that?
Judging by exif data, the lens reports itself as f/6.3, not f/5.6 at the focal lengths where f/6.3 is the maximum aperture.
The normal focusing is at the maximum aperture of a lens, with the lens stopping down to your selected aperture to take the photo. So when he says it is lying, it is probably telling the camera that the lens has a maximum aperture of 5.6 and a selected aperture of 6.3 (or 8, 11, etc.) that is recorded with the exif data of the photo.
alundeb wrote:
Are you sure about that?
Judging by exif data, the lens reports itself as f/6.3, not f/5.6 at the focal lengths where f/6.3 is the maximum aperture.
Most DSLRs will only autofocus with lenses which are f5.6 or faster. A few models, such as the Canon EOS series 1 DSLRs can AF at f8, but only using the center AF zone. For most lenses this isn't a big issue since all Canon lenses are f5.6 or faster. There are a few 3rd party AF lenses which are as slow as f6.3 but which still AF on all EOS bodies. f6.3 is only 1/3 stop slower than f5.6 and these lenses "trick" the EOS AF system into believing the lens is actually f5.6 so that the camera will attempt AF (and usually succeed). ...Show more →
Sjjindra wrote:
The normal focusing is at the maximum aperture of a lens, with the lens stopping down to your selected aperture to take the photo. So when he says it is lying, it is probably telling the camera that the lens has a maximum aperture of 5.6 and a selected aperture of 6.3 (or 8, 11, etc.) that is recorded with the exif data of the photo.
I am fully aware how focusing works. Check an image taken at 600 mm f/8 and it will report f/8 as the aperture and f/6.2 as the maximum aperture.
Actually it reports f/6.2 not f/6.3 as the maximum aperture.
While capturing our sample images, both a Canon 50D and Canon 60D were used. With both cameras we had some difficulty using the AF system. Since this happened with both camera bodies, we are looking at an issue with the lens. In both cases, we would have to manually focus and get close before the AF system would take over.
Apparently Tamron US hasn't recieved the same notice. Contacted them again and they are still saying there are no problems. Mine is going back for credit against an EF 400 f5.6. Monday is the last day for return so I'm out of time. Only a little over 200 more right now with the rebate and I'm sure a lot less hassle. Its a shame really. I have other Tamron lenses that work just fine. As I told the rep I can deal with you not knowing how to fix problem right now I can understand it taking some time what I can't deal with is stone walling.
