Tamron 70-200 f/2.8 - AF question

**BigMackCam** · 06-09-2016, 05:51 AM

I just took delivery of a new Tamron 70-200 f/2.8 to use with my K-3 / K-3II. Lovely, lovely lens - but I notice a couple of problems...

(1) The lens is consistently front-focusing quite significantly. At +/0 adjustment, with the lens wide open and focusing on a static object approx 60 feet away, things are pretty mushy. As I adjust by -1, -2, -3, -4 all the way through to -10, things get progressively better... but I don't know if -10 is the best it could be, since I've reached the end of the available range - it's quite possible further adjustment (if possible) would improve things further.

(2) AF in Live View just doesn't seem to work at all. I get the focus confirmation from the camera, and the peaking appears to suggest that things are in focus, but when I review the image taken, it is blurry.

The front-focusing is enough for me to send the lens back for replacement with another example - and if that one does the same thing, I'll send it to Tamron for calibration, as I really like the lens. The AF in Live View isn't a deal breaker for me, as I rarely use it. In fact, the only reason I noticed the problem is that I normally switch between the OVF and Live View as part of my AF fine adjustment procedure. But I'd be interested to know if others are able to use Live View successfully with their Tamron 70-200...

Thanks in advance.

Last edited by BigMackCam; 06-09-2016 at 06:31 AM.

Reed · 06-09-2016, 06:01 AM

Mine does not work with K-s2 in LV too. I only have slight FF problem, when using this lens on 200mm and at 2.8 when focused on target less than 4meters away, other ranges and apretures work fine. On F2.8 its preety soapy on 200mm, check if it happens when you close it one click more-mine works fine then, spot on.

**BigMackCam** · 06-09-2016, 06:38 AM

Thanks, @Reed

I'm guessing the Live View issue is a common one, then... and, in fact, I vaguely recall reading about it before... As I say, not really an issue for me.

Yeah, I expected wide-open performance at 200mm to be "soapy", as you put it (great word for that, by the way

), but even stopped down a notch I can see improvements all the way from 0 to -10 in my AF fine adjustment. It may be that the result I'm getting at -10 is the best it could possibly be, in which case I'm returning the lens for no good reason... but there's no way I can be sure. If it was best at, say, -9, I would be fine with that - as I'd know I'm getting the best possible performance out of the lens.

Reed · 06-09-2016, 07:06 AM

Well mine behaves decent when closed down only half or one full step. Check it out here for example, Bartosz Zalewski almost all pictures are from that tammy, mine was on free warranty calibration in official tamron service centre for Poland, with my previous k-30 body, and well in my opinion no change, but from beggining it was only on 200/2.8 setting. I asked them if there was a FW update for that live-view problem, like there is for example for Canon version, but they say its just not supported on never bodies(shame they don't inform about it ) and no firmware is available.

**BigMackCam** · 06-09-2016, 07:22 AM

Thanks Bartosz... You've done some beautiful work! Your B&W portraits are fantastic; great lighting and poses - your models did a fine job for you too.

No problem re Live View... as you say, a shame they don't mention it (in fact, my supplier wasn't aware of any issue!), but it doesn't bother me. My lens is due to be collected tomorrow, so hopefully by early-to-mid next week I'll have the replacement. If that one is also out of adjustment range, I'll keep it and send it to Tamron for calibration

JinDesu · 06-09-2016, 07:29 AM

My Tamron 70-200 has front focus at 70mm, slight front focus at 135mm, and back focus at 200mm. So it's not unheard of for it to perform that way, I usually live with it by focusing nearer or further as needed.

My Tamron does not have the AF issue in live view that you've encountered, but I had that issue with one of my Sigma lenses (17-70). At that time, I looked around and I heard that several other Sigma users had the same issue and they sent it back to Sigma for the correction. Sigma said that they fixed the GMR sensor in the lens, which means nothing to me - but indicates that it is a in-lens issue. Perhaps your Tamron has a similar issue and you could ask Tamron about it.

Reed · 06-09-2016, 07:38 AM

Originally posted by BigMackCam

Thanks Bartosz... You've done some beautiful work! Your B&W portraits are fantastic; great lighting and poses - your models did a fine job for you too.

No problem re Live View... as you say, a shame they don't mention it (in fact, my supplier wasn't aware of any issue!), but it doesn't bother me. My lens is due to be collected tomorrow, so hopefully by early-to-mid next week I'll have the replacement. If that one is also out of adjustment range, I'll keep it and send it to Tamron for calibration

Please keep us updated on the case, Tamron has a heck of warranty(here its 5years door2door) but getting any feedback and info about possible DIY fix from them while not sending your stuff to repair centre is almost impossible. Maybe you will get more help than I got

And thanks for kind words on my photos

I'm still learning to use that lens, it was my first location shoot with it

biz-engineer · 06-09-2016, 11:26 AM

Originally posted by BigMackCam

(2) AF in Live View just doesn't seem to work at all. I get the focus confirmation from the camera, and the peaking appears to suggest that things are in focus, but when I review the image taken, it is blurry.

Yes, I can confirm the same observation with my Tamron 70-200 and the K3 , for the live view mode. I have no issue at all with phase detect AF. However, when I mount the Tamron 70-200 on my K1, Live view autofocus works perfectly, as well as phase detect AF. Also with my K5, live view AF was working fine. So, it's not really an issue with the lens, but a problem with the K3 live view AF and this particular lens.

**BigMackCam** · 06-09-2016, 11:28 AM

Originally posted by JinDesu

My Tamron 70-200 has front focus at 70mm, slight front focus at 135mm, and back focus at 200mm. So it's not unheard of for it to perform that way, I usually live with it by focusing nearer or further as needed.

Interesting... I guess I can put up with some variation in AF accuracy at different focal lengths, so long as I can figure out individual fine adjustment values (within the +/-10 range) that work for each focal length... That way, when AF accuracy is particularly important, I can dial in my preferred adjustment for the focal length I'm using and know that it's going to be as accurate as possible.

Originally posted by Reed

Please keep us updated on the case, Tamron has a heck of warranty(here its 5years door2door) but getting any feedback and info about possible DIY fix from them while not sending your stuff to repair centre is almost impossible. Maybe you will get more help than I got

Yes, will definitely post an update here. Tamron's warranty here in the UK is also 5 years - really excellent - but I have no experience of dealing with them... yet!

**kiwi_jono** · 06-09-2016, 12:19 PM

Mine does not work in LV as well.

Also mine BF a bit at 70mm but spot on from 100 - 200mm (which suits me!).

Reed · 06-09-2016, 12:19 PM

This is not the k-3 or other body failure, but lens firmware issue, same thing was happening with tamron 70-200 on never Canon dslr, and update was done in that case, not for Pentax version sadly

Steve T · 06-09-2016, 12:24 PM

Originally posted by BigMackCam

The lens is consistently front-focusing quite significantly. At +/0 adjustment, with the lens wide open and focusing on a static object approx 60 feet away, things are pretty mushy. As I adjust by -1, -2, -3, -4 all the way through to -10, things get progressively better... but I don't know if -10 is the best it could be, since I've reached the end of the available range - it's quite possible further adjustment (if possible) would improve things further.

I don't own this lens but I have done my fair share of fine tuning lenses if you want to check how close you are to the best focus and sharpness of a lens
Use a tripod go into live view press the ok button on the K3 and it will zoom in to the object then manually focus and take a shot then compare it to an AF shot from the same spot
Once you zoom in with Live view its pretty easy to see where the focus is
Also a great technique for doing Macro shots to nail your focus

**BigMackCam** · 06-09-2016, 12:32 PM

Originally posted by Steve T

I don't own this lens but I have done my fair share of fine tuning lenses if you want to check how close you are to the best focus and sharpness of a lens
Use a tripod go into live view press the ok button on the K3 and it will zoom in to the object then manually focus and take a shot then compare it to an AF shot from the same spot
Once you zoom in with Live view its pretty easy to see where the focus is
Also a great technique for doing Macro shots to nail your focus

Steve - thanks, but one of my points is that Live View focusing doesn't appear to work with this lens on the K3

I've also become pretty solid on AF fine tuning over the last year or two... So long as I can find a good compromise AF fine adjustment setting *within* the adjustment range available (and that's the key point here), I can live with the fact that it won't be spot on at all focal lengths from 70 to 200mm...

Steve T · 06-09-2016, 01:29 PM

Ya sorry I did read that your AF doesn't work with the Live view you can use the view finder for the AF shot.
You were just wondering if the shot could get better after -10 I was just thinking with this way it might be already perfect at -10 and save you the trouble of sending the lens in

**BigMackCam** · 06-09-2016, 03:50 PM

Originally posted by Steve T

Ya sorry I did read that your AF doesn't work with the Live view you can use the view finder for the AF shot.
You were just wondering if the shot could get better after -10 I was just thinking with this way it might be already perfect at -10 and save you the trouble of sending the lens in

No worries, Steve - I appreciated your input

I do typically compare OVF vs Live View AF results as part of my calibration process. You're right, it's generally a handy way to confirm whether phase-detect AF is adjusted correctly - although you need to bear in mind, as others have indicated above, that zoom lenses have been known to vary their back & front-focus behaviour at different points in their range. Hence, OVF vs Live View comparison can be less reliable with zooms than it is with primes.

06-09-2016, 05:51 AM	#1
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670	Tamron 70-200 f/2.8 - AF question I just took delivery of a new Tamron 70-200 f/2.8 to use with my K-3 / K-3II. Lovely, lovely lens - but I notice a couple of problems... (1) The lens is consistently front-focusing quite significantly. At +/0 adjustment, with the lens wide open and focusing on a static object approx 60 feet away, things are pretty mushy. As I adjust by -1, -2, -3, -4 all the way through to -10, things get progressively better... but I don't know if -10 is the best it could be, since I've reached the end of the available range - it's quite possible further adjustment (if possible) would improve things further. (2) AF in Live View just doesn't seem to work at all. I get the focus confirmation from the camera, and the peaking appears to suggest that things are in focus, but when I review the image taken, it is blurry. The front-focusing is enough for me to send the lens back for replacement with another example - and if that one does the same thing, I'll send it to Tamron for calibration, as I really like the lens. The AF in Live View isn't a deal breaker for me, as I rarely use it. In fact, the only reason I noticed the problem is that I normally switch between the OVF and Live View as part of my AF fine adjustment procedure. But I'd be interested to know if others are able to use Live View successfully with their Tamron 70-200... Thanks in advance. Last edited by BigMackCam; 06-09-2016 at 06:31 AM.

06-09-2016, 06:38 AM	#3
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670 Original Poster	Thanks, @Reed I'm guessing the Live View issue is a common one, then... and, in fact, I vaguely recall reading about it before... As I say, not really an issue for me. Yeah, I expected wide-open performance at 200mm to be "soapy", as you put it (great word for that, by the way ), but even stopped down a notch I can see improvements all the way from 0 to -10 in my AF fine adjustment. It may be that the result I'm getting at -10 is the best it could possibly be, in which case I'm returning the lens for no good reason... but there's no way I can be sure. If it was best at, say, -9, I would be fine with that - as I'd know I'm getting the best possible performance out of the lens. Last edited by BigMackCam; 06-09-2016 at 07:14 AM.

06-09-2016, 12:32 PM	#13
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670 Original Poster	Originally posted by Steve T I don't own this lens but I have done my fair share of fine tuning lenses if you want to check how close you are to the best focus and sharpness of a lens Use a tripod go into live view press the ok button on the K3 and it will zoom in to the object then manually focus and take a shot then compare it to an AF shot from the same spot Once you zoom in with Live view its pretty easy to see where the focus is Also a great technique for doing Macro shots to nail your focus Steve - thanks, but one of my points is that Live View focusing doesn't appear to work with this lens on the K3 I've also become pretty solid on AF fine tuning over the last year or two... So long as I can find a good compromise AF fine adjustment setting within the adjustment range available (and that's the key point here), I can live with the fact that it won't be spot on at all focal lengths from 70 to 200mm... Last edited by BigMackCam; 06-09-2016 at 12:56 PM.

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06-09-2016, 06:01 AM	#2
Reed Pentaxian Join Date: Mar 2015 Location: Warsaw Photos: Gallery Posts: 638	Mine does not work with K-s2 in LV too. I only have slight FF problem, when using this lens on 200mm and at 2.8 when focused on target less than 4meters away, other ranges and apretures work fine. On F2.8 its preety soapy on 200mm, check if it happens when you close it one click more-mine works fine then, spot on.

06-09-2016, 07:06 AM	#4
Reed Pentaxian Join Date: Mar 2015 Location: Warsaw Photos: Gallery Posts: 638	Well mine behaves decent when closed down only half or one full step. Check it out here for example, Bartosz Zalewski almost all pictures are from that tammy, mine was on free warranty calibration in official tamron service centre for Poland, with my previous k-30 body, and well in my opinion no change, but from beggining it was only on 200/2.8 setting. I asked them if there was a FW update for that live-view problem, like there is for example for Canon version, but they say its just not supported on never bodies(shame they don't inform about it ) and no firmware is available.

06-09-2016, 07:22 AM	#5
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670 Original Poster	Thanks Bartosz... You've done some beautiful work! Your B&W portraits are fantastic; great lighting and poses - your models did a fine job for you too. No problem re Live View... as you say, a shame they don't mention it (in fact, my supplier wasn't aware of any issue!), but it doesn't bother me. My lens is due to be collected tomorrow, so hopefully by early-to-mid next week I'll have the replacement. If that one is also out of adjustment range, I'll keep it and send it to Tamron for calibration

06-09-2016, 07:29 AM	#6
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	My Tamron 70-200 has front focus at 70mm, slight front focus at 135mm, and back focus at 200mm. So it's not unheard of for it to perform that way, I usually live with it by focusing nearer or further as needed. My Tamron does not have the AF issue in live view that you've encountered, but I had that issue with one of my Sigma lenses (17-70). At that time, I looked around and I heard that several other Sigma users had the same issue and they sent it back to Sigma for the correction. Sigma said that they fixed the GMR sensor in the lens, which means nothing to me - but indicates that it is a in-lens issue. Perhaps your Tamron has a similar issue and you could ask Tamron about it.

06-09-2016, 07:38 AM	#7
Reed Pentaxian Join Date: Mar 2015 Location: Warsaw Photos: Gallery Posts: 638	Originally posted by BigMackCam Thanks Bartosz... You've done some beautiful work! Your B&W portraits are fantastic; great lighting and poses - your models did a fine job for you too. No problem re Live View... as you say, a shame they don't mention it (in fact, my supplier wasn't aware of any issue!), but it doesn't bother me. My lens is due to be collected tomorrow, so hopefully by early-to-mid next week I'll have the replacement. If that one is also out of adjustment range, I'll keep it and send it to Tamron for calibration Please keep us updated on the case, Tamron has a heck of warranty(here its 5years door2door) but getting any feedback and info about possible DIY fix from them while not sending your stuff to repair centre is almost impossible. Maybe you will get more help than I got And thanks for kind words on my photos I'm still learning to use that lens, it was my first location shoot with it

06-09-2016, 11:26 AM	#8
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,231	Originally posted by BigMackCam (2) AF in Live View just doesn't seem to work at all. I get the focus confirmation from the camera, and the peaking appears to suggest that things are in focus, but when I review the image taken, it is blurry. Yes, I can confirm the same observation with my Tamron 70-200 and the K3 , for the live view mode. I have no issue at all with phase detect AF. However, when I mount the Tamron 70-200 on my K1, Live view autofocus works perfectly, as well as phase detect AF. Also with my K5, live view AF was working fine. So, it's not really an issue with the lens, but a problem with the K3 live view AF and this particular lens.

06-09-2016, 11:28 AM	#9
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670 Original Poster	Originally posted by JinDesu My Tamron 70-200 has front focus at 70mm, slight front focus at 135mm, and back focus at 200mm. So it's not unheard of for it to perform that way, I usually live with it by focusing nearer or further as needed. Interesting... I guess I can put up with some variation in AF accuracy at different focal lengths, so long as I can figure out individual fine adjustment values (within the +/-10 range) that work for each focal length... That way, when AF accuracy is particularly important, I can dial in my preferred adjustment for the focal length I'm using and know that it's going to be as accurate as possible. Originally posted by Reed Please keep us updated on the case, Tamron has a heck of warranty(here its 5years door2door) but getting any feedback and info about possible DIY fix from them while not sending your stuff to repair centre is almost impossible. Maybe you will get more help than I got Yes, will definitely post an update here. Tamron's warranty here in the UK is also 5 years - really excellent - but I have no experience of dealing with them... yet!

06-09-2016, 12:19 PM	#10
kiwi_jono Loyal Site Supporter Join Date: Dec 2009 Location: Christchurch, New Zealand Photos: Gallery \| Albums Posts: 2,437	Mine does not work in LV as well. Also mine BF a bit at 70mm but spot on from 100 - 200mm (which suits me!).

06-09-2016, 12:19 PM	#11
Reed Pentaxian Join Date: Mar 2015 Location: Warsaw Photos: Gallery Posts: 638	This is not the k-3 or other body failure, but lens firmware issue, same thing was happening with tamron 70-200 on never Canon dslr, and update was done in that case, not for Pentax version sadly

06-09-2016, 12:24 PM	#12
Steve T New Member Join Date: Apr 2015 Photos: Albums Posts: 17	Originally posted by BigMackCam The lens is consistently front-focusing quite significantly. At +/0 adjustment, with the lens wide open and focusing on a static object approx 60 feet away, things are pretty mushy. As I adjust by -1, -2, -3, -4 all the way through to -10, things get progressively better... but I don't know if -10 is the best it could be, since I've reached the end of the available range - it's quite possible further adjustment (if possible) would improve things further. I don't own this lens but I have done my fair share of fine tuning lenses if you want to check how close you are to the best focus and sharpness of a lens Use a tripod go into live view press the ok button on the K3 and it will zoom in to the object then manually focus and take a shot then compare it to an AF shot from the same spot Once you zoom in with Live view its pretty easy to see where the focus is Also a great technique for doing Macro shots to nail your focus

06-09-2016, 01:29 PM	#14
Steve T New Member Join Date: Apr 2015 Photos: Albums Posts: 17	Ya sorry I did read that your AF doesn't work with the Live view you can use the view finder for the AF shot. You were just wondering if the shot could get better after -10 I was just thinking with this way it might be already perfect at -10 and save you the trouble of sending the lens in

06-09-2016, 03:50 PM	#15
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670 Original Poster	Originally posted by Steve T Ya sorry I did read that your AF doesn't work with the Live view you can use the view finder for the AF shot. You were just wondering if the shot could get better after -10 I was just thinking with this way it might be already perfect at -10 and save you the trouble of sending the lens in No worries, Steve - I appreciated your input I do typically compare OVF vs Live View AF results as part of my calibration process. You're right, it's generally a handy way to confirm whether phase-detect AF is adjusted correctly - although you need to bear in mind, as others have indicated above, that zoom lenses have been known to vary their back & front-focus behaviour at different points in their range. Hence, OVF vs Live View comparison can be less reliable with zooms than it is with primes.