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02-26-2015, 05:55 AM   #1
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URGENT: Feedback from Tamron 70-200/f2.8 users NEEDED!

Hello everybody!

I need your help ASAP with an issue I'm facing with a new Tamron P AF 70-200mm f2.8 LD (IF) Macro lens I bought to use with my K-5IIs camera.

The lens was not sharp wide open and after a few tests I did, I found out that it was back-focusing at least at 200mm and when focused at infinity.

I adjusted the camera at +10 via the "AF Fine Adjustment" and the results I got were much better (although I don't know if more + adjustment would be necessary as +10 is the maximum "in camera" adjustment). The problem continued as this +10 adjustment is not giving good results in different focal lengths and different focus distances! This +10 adjustment was not the solution

I thought that something was wrong with the lens AF as I never had until today any issues with other lenses on my K-5IIs.

MOREOVER when I turned the camera to "live view" there was no way I could focus with the lens!!! The camera beeps that has locked focus but it is completely out of focus (not even close to accurate focus!).

The lens itself seems great as when focused manually the images are sharp and contrasty.

I send the lens back to the shop I bought it from to send it to the Tamron service and they answered me that the "live view contrast detection AF doesn't function when this Tamron lens is attached to a K-5IIs"! They will look upon my other back-focusing complaints, but this is not a problem at all!

This is the first time I listen or read anything like that for that Tamron lens or any released lens (apart form the known issues with the Sigma 18-35/f1.8).

I need your feedback please from those of you that are using this Tamron P AF 70-200mm f2.8 LD (IF) Macro lens and especially those who have been using it on the K-5IIs... Do you face any AF inconsistency problems and more important does your lens auto-focuses in Live view mode?

Thank you in advance for your precious help!

02-26-2015, 07:05 AM   #2
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Toying with buying one of these so I'll be interested in how this thread evolves.
02-26-2015, 07:32 AM   #3
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QuoteOriginally posted by southlander Quote
Toying with buying one of these so I'll be interested in how this thread evolves.
Let's hope it will evolve my friend! I don't know how to attract attention to this thread, but as you see I'm in a diificult position. I research a lot before buying a lens and all negatives I could find about the Tamron 70-200/2.8 were a few complaints about slow focusing and some random misfocusing but nothing that BIG. I feel that I have a bad copy of the lens but I wait from other users to confirm me...
02-26-2015, 07:39 AM   #4
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There were some HSM lenses from Sigma that needed to have a firmware update to work with CDAF (live view), which I know because I just got one back from Sigma a few days ago to get the CDAF working. I wouldn't think that there would be a problem with screw-drive lenses but maybe that doesn't have anything to do with it. Seeing as Tamron is still selling this lens (and even if they weren't), they should be supporting it. Maybe they aren't as clever as Sigma and actually do not know how to get it to work.

Just to clarify, this message you got about it just not working is directly from Tamron and not just the shop you're dealing with? I'd contact Tamron directly myself and see if they have any firmware updates for the lens that will fix it.

02-26-2015, 07:41 AM   #5
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Issue has been reported with the K-5 as well in Jan 2012. Seems like its a carryover from then ...

https://www.pentaxforums.com/forums/115-pentax-k-5/171124-k5-tamron-70-200-2-8-focus.html
02-26-2015, 07:55 AM - 1 Like   #6
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Hi!
I owned 2 of these lenses, both had live view issues. Same happened to me - the lens locks focus but the result is way out of the right focus. You can read about this issue at photozone.de test (canon FF test). This is the known issue with that lens, and for that matter Tamron is right
As for the sharpness issue, you probably have a bad copy. Both of my copies were little soft at 200mm, lots of abberations, but closing the aperture down to 3.5 solved issues. First copy was frontfocusing, second had back focus at 200mm. But, from 70-180mm shots taken at f2.8 were pretty sharp, and closing aperture to f4 gave me prime like sharpness through all range.
Also found out that adjusting focus within camera body didn't help much, it seemed like the lens does nothing whatever value I set in my K-30.
If your sharpness problem happens only at 200mm, this is how it should be
02-26-2015, 08:16 AM - 1 Like   #7
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The only AF issue I've run across with my version of the Tamron 70-200 is that it requires a bit contrastier lines to attain accurate focus then, say, my DA* 300. So once in a while it will lock focus and yet be a tad off. My copy is sharp wide open at 200mm, although the DOF can be so narrow that if you're even a little off with the focus the image won't look sharp.
02-26-2015, 08:18 AM   #8
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My Tamron 70-200 requires different focus adjustments at the short and long end of the lens. It front focuses at 200mm and backfocuses at 70mm. It's not so bad that I can't work with it, but it's something that I noticed on my lens.

I haven't had trouble with it in liveview.

02-26-2015, 08:20 AM   #9
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If you read through the reviews of the lens here on the forum , at one time there were 3 returned as non-functioning lenses, out of 33 reviews, pretty near a 10% DoA rate. if you have a bad copy of this lens return it immediately. At least that would be my advice. People love the lens when they get a good one, just sometimes it takes a while to get a good one.
02-26-2015, 08:31 AM   #10
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QuoteOriginally posted by eminker Quote
Issue has been reported with the K-5 as well in Jan 2012. Seems like its a carryover from then ...

https://www.pentaxforums.com/forums/115-pentax-k-5/171124-k5-tamron-70-200-2-8-focus.html
You're right! More or less the same problems... I wonder what they did with their lenses...

---------- Post added 02-26-15 at 08:35 AM ----------

QuoteOriginally posted by vonBaloney Quote
Just to clarify, this message you got about it just not working is directly from Tamron and not just the shop you're dealing with? I'd contact Tamron directly myself and see if they have any firmware updates for the lens that will fix it.
Thanks my friend. The shop has sent to the official service provider in Greece. I will also directly contact Tamron, I just wanted to know if this was something known that I've missed...
02-26-2015, 08:40 AM   #11
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Starting to sound like just a bad copy -- return it if you can.
02-26-2015, 08:40 AM   #12
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QuoteOriginally posted by JinDesu Quote
My Tamron 70-200 requires different focus adjustments at the short and long end of the lens. It front focuses at 200mm and backfocuses at 70mm. It's not so bad that I can't work with it, but it's something that I noticed on my lens.

I haven't had trouble with it in liveview.
@JinDesu and how do you handle your lens? Are you continuously readjusting the AF fine adjustment or in manual focus? It seems a bit weird and too hard to function for an AF lens.

---------- Post added 02-26-15 at 08:51 AM ----------

@normhead @vonBaloney This is what I also believe, that I have a bad copy of the lens. I sent it back immediately and hope that Tamron will accept to replace it with a good copy. The problem is that there are no big dealers like B&H in Greece that offer top level customer service and I'm kind of worried that they may try to persuade me that the faults of my copy of the lens are normal and within the specifications... I have a lot of lenses and third party ones (some with drawbacks and peculiarities) but none with so many issues that I can't find a way to overcome. This is not a manual lens after all...
02-26-2015, 08:58 AM - 1 Like   #13
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Well since I know it front focuses at 200mm, I just aim for something slightly behind my target.

Supposedly there's quite a lot of zoom lenses that have varying focus behavior through their zoom ranges - and that's why Sigma introduced their lens dock system. Most lenses don't show such great variance to require it, but I know my 70-200 does. I set my focus adjustment in between the front and back focus limits and bias it towards the front focus at 200mm, because at 70mm the DOF is deeper than at 200mm.
02-26-2015, 09:44 AM   #14
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QuoteOriginally posted by hegedus Quote
Hi!
I owned 2 of these lenses, both had live view issues. Same happened to me - the lens locks focus but the result is way out of the right focus. You can read about this issue at photozone.de test (canon FF test). This is the known issue with that lens, and for that matter Tamron is right
As for the sharpness issue, you probably have a bad copy. Both of my copies were little soft at 200mm, lots of abberations, but closing the aperture down to 3.5 solved issues. First copy was frontfocusing, second had back focus at 200mm. But, from 70-180mm shots taken at f2.8 were pretty sharp, and closing aperture to f4 gave me prime like sharpness through all range.
Also found out that adjusting focus within camera body didn't help much, it seemed like the lens does nothing whatever value I set in my K-30.
If your sharpness problem happens only at 200mm, this is how it should be
Thanks for your reply! The problem is that it backfocuses at 200mm but it also frontfocuses on other focal lengths. So there is no way of fixing the problem by applying AF fine adjustment. Sharpness is great when I manual focus, so optically there is no problem... The AF function is the problem.
02-26-2015, 11:52 AM - 1 Like   #15
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This lens doesn't auto focus with my K-01 either (live view only). It finds a focus point that seems perfect and then the camera seems to issue a focus shift command, taking it out of focus. It is very repeatable and makes the lens unusable with my K-01, I suspected that it was a firmware bug on the camera, but now I'm wondering if there is too much play in the lens's focus mechanism for the camera to get a repeatable position reading. I haven't tried it on the K-3 yet.
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