[bossa]

Thanks Mike.

[GDRoth]

Thanks to all for the thoughtful advice generously given...................
I ordered the Tamron 70-200 late yesterday from Amazon, (but sold by Beach Camera) for $699.
I'm not experienced at testing a lens..................what steps should I take immediately upon arrival so I can send back if necessary?

Dave

[HenrikDK]

what steps should I take immediately upon arrival so I can send back if necessary?

Surely someone can provide better guidance than me, but here is my simple approach:

I take pictures of a brick wall (the side of my house). I use the same section always, and adjust the distance so the area photographed is roughly the same. I position beer bottles (I found that they work better than soda cans) in the corners, and on an electric box in the middle. The labels work well for evaluating contrast and resolution.

A tripod is must, and the camera has to be absolutely level, and perpendicular to the brick wall. Especially with UWA lenses the latter is critical. I then take pictures at ISO 100, and at a couple of different appertures, and (if zoom) focal lengths, using a remote release, and mirror locking. Note you should do any focus adjustments first.

I now have a "library" of these pictures, so I can compare results. The Tamron, for example, is weaker in the middle than the extremes.

Not very scientific, but when you compare your results to online tests, it gives you (IMO) a better appreciation for those "numbers" mean

Be careful though. When I first tested my DA* 16-50mm I thought I had gotten a bad copy, but it turned out I had not aligned the camera prefectly, causing one side to look soft (I have a hard time distinguishing between out of focus, and just soft - maybe someone could enlighten me on how to distinguish???)

Like I said - others may have a more comprehensive/accurate method.

[normhead]

As far as I know the Pentax 1.7 will work with anything, even manual lenses. You have to manually focus your lens, it has it's own auto-focus sytem, that will finish focussing for you, regardless of what you have mounted to it. It's not like an auto-focus lens exactly, but I find it quite workable.

As for testing this lens.. the biggest problem seems to be a sticky aperture. Be sure you run enough shots through it to make sure it's not jamming, there's lots of good info in the lens review section, 33 different users who have owned the lens. They all have different experiences, but, they'll what you know what the problems they've had are, and what they did to over come them. At least that's what I'd do. I'd paraphrase, but better to read it in their own words.

Click here

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Last edited by normhead; 02-02-2012 at 11:25 AM.

[dgaies]

FWIW, I have the Tamron 70-200/2.8 and bought a Tamron-F 1.4x TC to use with it. Well, when i switch to MF and disengage the AF clutch ring, the motor does not disengage and my turning the focus ring grinds the gears and is sluggish. I contacted Tamron and they said their TC's are not compatible with that lens. Just be aware in case you are buying both to use together. I wish I knew which TC will work with this lens because i love the lens.
YMMV.

Mike, if you flip the AF/MF switch on the body, can you MF without any issues? I wasn't sure if what you meant was that disengaging the AF clutch on the lens isn't enough to be able to MF.

I used the Tamron 1.4 and 70-200/2.8 (although always as an AF combo, never used MF with it) and I didn't recall having any issues.

As far as I know the Pentax 1.7 will work with anything, even manual lenses. You have to manually focus your lens, it has it's own auto-focus sytem, that will finish focussing for you, regardless of what you have mounted to it. It's not like an auto-focus lens exactly, but I find it quite workable.

The AF-A 1.7x will indeed work with anything you put in front of it as all of the focusing takes place in the 1.7x itself. Whaterver lens you put on the adapter effectively acts like a MF lens at that point as there is no screw drive coupling, nor SDM contacts. As stated above, you basically prefocus close and then engage the AF to finish the job. Depending on the specific lens and how far away your subject is, you can often leave the focus ring of the lens in one position and the range of the 1.7x can often be enough that you don't have to pre-focus. Once you play around with it for a little while, it becomes pretty easy to work with.

[HenrikDK]

I used the Tamron 1.4 and 70-200/2.8 (although always as an AF combo, never used MF with it) and I didn't recall having any issues.

Same here. Works for me with a Tamron-F Pz-AF 1.4x. To manul focus w/o TC you have to disengage the lens AND the body. Does that not work with the TC??? I haven't tried...

[mikeSF]

when testing a new zoom, be sure to also check AF at several focal lengths, and at a given focal length, test the AF of near objects as well as near infinity objects; I have found it possible for a lens to exhibit front focus on distant objects but backfocus on close objects, making in body AF adjustment impossible. good luck.

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Last edited by mikeSF; 02-03-2012 at 02:13 PM.

[mikeSF]

Mike, if you flip the AF/MF switch on the body, can you MF without any issues? I wasn't sure if what you meant was that disengaging the AF clutch on the lens isn't enough to be able to MF.

Same here. Works for me with a Tamron-F Pz-AF 1.4x. To manul focus w/o TC you have to disengage the lens AND the body. Does that not work with the TC??? I haven't tried...

I am saying that when the camera body switch is set to MF and the lens clutch is pulled back (blue ring exposed), if I turn the focus ring on the tamron it is sluggish, as if the motor gears are still engaged. When I remove the TC, the lens manually focuses normally. I have much experience shooting with this lens, with both AF and MF.

Here is the response from Tamron customer svc:

From: Custserv@tamron.com
Sent: Monday, November 28, 2011 11:21 AM
To: MikeSF
Subject: Re: Customer Service Form

Hi MikeSF,

The teleconverter is not compatible with the 70-200 F/2.8 lens and we cannot provide support for its use. I would recommend discontinuing use of the teleconverter with that lens as they are not compatible.

Regards,

Customer Service
Tamron USA, Inc.
10 Austin Blvd.
Commack, NY 11725
631-858-8400

[HenrikDK]

I am saying that when the camera body switch is set to MF and the lens clutch is pulled back (blue ring exposed), if I turn the focus ring on the tamron it is sluggish, as if the motor gears are still engaged. When I remove the TC, the lens manually focuses normally. I have much experience shooting with this lens, with both AF and MF.

I tried it, and I do have the same problem. I very seldom switch to Manual Focus on any of my lenses - rather relying on focus lock - so it doesn't bother me, but it is nice to know.

[Marc Sabatella]

I have a K5, a couple small primes (15mm and 40mm Limiteds), a 18-135 DA (which I really like), but no real longer glass.

I had a 55-300, but somehow it didn't seem "right" for me

I'd consider the possibility that your tests of the 55-300 were flawed (or your copy of the lens was). By any objective measure, it's at least as good as the 18-135, and certainly better than anything else remotely close to it in price or in size/weight, such as the 18-250. Moving up to something like the 60-250 approximately quadruples the costs, and similarly increase the size and weight.

[HenrikDK]

I'd consider the possibility that your tests of the 55-300 were flawed (or your copy of the lens was). By any objective measure, it's at least as good as the 18-135, and certainly better than anything else remotely close to it in price or in size/weight, such as the 18-250

I agree with the latter part of your statement. Gotten thousands of pictures with my 55-300 (i have had two copies). However the Tamron 70-200/2.8 is in a different class, and the results are VERY visible better (not just test results). I suspect the 60-250 would show a similar improvement. And yes - you are lugging around a HUGE piece of glass. When I first got it my first inclination was to return the lens - that was until I saw the difference in IQ. I recall the 55-300mm performs similar to my DA* 16-50 wide open, but what stood out compared to the Tamron was the much lower contrast.

I do suspect the smaller size and the lower aperture of the 55-300mm will cause you to have more borderline pictures due to low shutterspeed/shake, which of course is not the fault of the lens. I know a lot of my first pictures were out of focus and showed blur.

[GDRoth]

I found a almost new copy of the Tammy 70-200 2.8 here on the forum a couple of days ago and snapped it up.............It's in transit now.............I know it's going to be big and heavy and I plan to use it almost exclusively with a tripod....I shoot lots of landscapes and was in the rut of thinking all landscapes must be shot with a WA like my 15mm Ltd............however I have 2 DVDs by Tony Sweet watching him go thru the process of composing many beautiful landscapes and nature type images(including waterfalls) and he was using a 70-200 (Nikon, of course) to better compose images................he still uses WA, but touted the versatility of a 70-200.........so I'm planning to incorporate that lens into my thinking.............links to Tony Sweet below..................these were great videos!!
Tony Sweet Fine Art Photography, Workshops and Instruction

Dave