[Bus Pass]

Hi everyone,

So I bought a new Tamron 70-200 and have sent it back to Amplis for repairs twice regarding no focus then front and back focus issues.

I got the lens back last week and now have some new issues I'm hoping people can help me out with.

When shooting wide open f2.8 at 200mm pictures are overexposed (blown out) compared to f3.5, also in these instances the camera uses the same settings for shutter and iso for both shots in AV mode. This would account for the f2.8 being brighter as the lens is not making a shutter adjustment to compensate for a change in aperture. Going from f3.5 working down to f8 the lens works as expected with the shutter changing to keep relative exposure the same. So this seems to be an issue of metering wide open.

Also when at 200mm I am unable to select f3.2 unless I reduce the zoom a little, but at the rest of the zoom range going down to 70mm I can select f3.2 in the camera. At 200mm my only option from f2.8 is straight to f3.5 and then I can pick the rest of the 1/3 f stops.

I suspect this is probably related to sticky or rough aperture blades because when I activate the lever between this lens and my tamron 28-75 f2.8, the later feels snappy while the 70-200 feels rough.

I have tried changing exposure modes matrix, center weighted and spot and it did not stop the fix the issue. If I get the f2.8 closer to a proper exposure then the stopped down shots are all under exposed.

I'm using a k-30 and have tested this lens on another k-30 and got the same results. Also when stopping down with my Tamron 28-75 f2.8 I get normal behavior in AV mode with the shutter being adjusted as you stop down the apertures.

So for others that have this lens have you had any of these issues and should I try to send this lens in for a third repair.

Thanks to everyone in advance for your assistance.

[victormeldrew]

No, I've not had any of these issues with mine, it focuses and exposes very well.
I wouldn't be sending it for any repairs, let alone a third one...I would send it for refund and find another copy.

[originalwinger]

I've had nothing but stellar results with my K3, as per your testing with a second K30 it certainty points to the lens. If the problems is consistent all of the time a technician should be able to repair the lens, however if it is intermittent I would be requesting a replacement. How old is the lens ?

[funkathustra]

I wouldn't be sending it for any repairs, let alone a third one...I would send it for refund and find another copy.

I agree. I've never had any problems with mine; I think you got a lemon. Sell as-is on eBay (there are plenty of people who like to buy broken crap), and go pick up a different copy.

Unless those repairs are under warranty, you're throwing money away. I got my Tammy for I think $400 on eBay, in immaculate condition. It's not an expensive lens, and they're readily available.

[Bus Pass]

I got the lens in November and is has been pretty much in a state of repair with Amplis. When I first got it the lens it would not focus at all so you couldn't take pictures with it, so I sent it back and that took along time as they ended up sending to the States because they couldn't get it to work in Canada. Fast forward a month or two and I get it back and it does focus but front focuses and back focuses depending on zoom range in opposite directions by a few feet or more so that is no good. I then arrange for it to go back for repairs again, which takes a couple of weeks because I did not feel that I should have to keep paying for shipping and insurance to them as it runs about 50 bucks each time. So they agree to pay the shipping back to them and after several weeks I get it back, and post here on the forums because it is still not working right.

By the way do you find that the lens is sharp at f2.8 at 135 mm but soft at f2.8 at 200mm and 70mm?

Thanks.

[funkathustra]

By the way do you find that the lens is sharp at f2.8 at 135 mm but soft at f2.8 at 200mm and 70mm?

Your lens should be tack sharp in the center at 70-150/2.8, but quite soft at 200/2.8. Stopping down to even f/3.5 should sharpen up the center of the image dramatically at the 200mm end. The corners at all focal lengths are a bit soft until f/4.0-5.6.

Here's a DxOMark map of sharpness at different focal lengths and apertures:

(This is a common trait I've seen among fast zooms — the Nikon 70-200/2.8 is the same)

[victormeldrew]

I got the lens in November

I don't know what consumer protection you have in Canada, but here in the UK you would be entitled to a full refund or replacement. It's not fit for purpose, it shouldn't be costing you time and money to get it working.

[6BQ5]

I'll echo other's positive comments about this lens. I've used it on my K-3 with stellar results - well, stellar to me! Sounds like something is wonky with the lens electronics. The camera seems to have a hard time communicating aperture data. Maybe the contacts are a little wonky? It could be fine on a bench that doesn't experience much shock and turbulence but real world performance could be different. What camera body did Amplis use to verify functionality?

[Bus Pass]

I'll echo other's positive comments about this lens. I've used it on my K-3 with stellar results - well, stellar to me! Sounds like something is wonky with the lens electronics. The camera seems to have a hard time communicating aperture data. Maybe the contacts are a little wonky? It could be fine on a bench that doesn't experience much shock and turbulence but real world performance could be different. What camera body did Amplis use to verify functionality?

Amplis never told me what camera body they tested with. I'm under warranty still as I bought new from Henry's so I will email Amplis about these issues and hopefully they will cover the return shipping again and maybe just give me new copy instead. Oh I would like to know if live view works with this lens for any of you because I have had no luck with that so far, as in everything is completely out of focus when I try.

[theEight]

I have a Tamron 70-200 2.8 - was a dog on the K-01, improved on the K5 and even more on the K5iis - stellar performer on the K1 with some fine adjustments programmed in for tendency to back-focus. Same lens, different bodies. Tried to get Tamron to look at it, they wouldn't respond. I suspect my copy may have been one of those grey market copies so they ignored me.

[clackers]

I'm loving mine now on the K-1, sorry to say it but I agree with those who think yours is a lemon.

[Bus Pass]

Well thought I would post and update for everyone. Got an email back from Amplis today saying they think it is a problem with aperture priority and therefore a pentax camera body problem and I should use the lens in manual mode. I emailed back saying I don't think they have read the actual information in my emails as I have indicated that I tested it on two camera bodies and I can't select f3.2 at 200mm on any setting mode of the camera on both k30 bodies. Pretty upset right now as I don't think they are going to do anything else for me at this point even though this was bought new and is under warranty. Might have to look into other means of getting help with this like consumer protection organizations, news outlets and or Tamron corporate. Any thoughts on what I should do next if they leave me high and dry at Amplis would be much appreciated.

[victormeldrew]

Sorry it still seems pretty simple to me. You bought a costly item...it never worked...you gave them a chance (that I wouldn't have) to fix it and it still doesn't work...it's not fit for purpose and so I would be in contact with the seller to ask for my money back. They can then sort out their own refund with the manufacturer or distributor.

[Wingincamera]

I've used my Tammy 70-200 on both a K-5 II and K-S2 with excellent results. As someone else said, at 200mm & F2.8 it is a little soft if you pixel peek , but from 3.2 it is sharp.