Tamron AF 17-35mm f2.8-4 Di LD Aspherical

Does anyone have any opinions on this lens? I've narrowed my options down to the Tamron AF 17-35mm f2.8-4 Di LD Aspherical or the Canon 17-40 f4L. I do take a lot of low light shots, and the price difference is a factor, though not a huge one.
I'd appreciate any feedback, especially regarding the Tamron lens.

There is something about it in here. About having 2.8: Canon 17-40 is sharp at 4, I'm not so sure you can get same result with Tamron wide open so 2.8 may be a moot point.

Big apertures are mainly for shallow depth of field. High ISO settings are better for low light shots, unless you also happen to want a shallow DoF, in which case you've got the best of both worlds.

The Tamron 17-35 appears to have a good reputation for sharpness and value, but I wouldn't expect brilliant results at full aperture. However, it might well outperform the Canon 17-40 one stop down at f4, depending on quality control variability.

If you are using a camera with a crop factor (10D etc), I'd go for it. The cheaper lenses often suffer from poor corner resolution but can be very sharp in the centre.

Thanks, Pekka, Rayz. I'm currently using a 300D... so Rayz you're saying the crop factor will bypass the main advantage of the higher quality L lens (the corner sharpness)? And the resolution of the remaining area of the Tamron would be comparable to the Canon L?

And, Pekka, as far as the 2.8 vs. 4: sharpness suffers with the Tamron wide open, such that the 2.8 is not terribly useful? Is this a general problem with less expensive lenses?

I think Rayz is saying that, because of the crop factor, the Tamron might approach the L for sharpness. One thing to remember - although we often talk about lens performance at the center and at the corners, there is a transition zone, not an abrupt cut between the two. So if a lens is poorer than another at the corners (full-frame), it's likely going to be somewhat poorer as you move toward the center as well even if the center performance is equal.

Popular Photography tested the Tamron as actually slightly better than the Canon. Quality control variations between samples of each are probably greater than overall differences between the two designs (and yes, the Canon lens is subject to significant quality control sample-to-sample variation, although perhaps less frequently than the Tamron).

With the advent of computer lens design 20 years ago, good optical quality became available to anyone willing to spend the money for it--it was no longer an arcane art available to only a few gifted individuals. The major difference between Canon and Tamron is in the mount--the Canon is an L lens with environmental sealing (which doesn't help much without the complementary sealing on a 1D series camera) and USM. Also, the Tamron's focusing ring turns as it autofocuses, which does annoy me.

You may not shoot at f2.8 very often, but if you have a 20D and use the central focusing mark, remember that the 20D can use its high-accuracy focusing mode all the time with the Tamron--but not at all with the Canon. That alone can erase any optical advantage of the Canon in most cases.

I have a Tamron that is as sharp wide open across its range as my Canon 24mm f2.8 prime. On my 10D and 20D, it's sharper than the Canon at the corners of the format. It resists flare just as well as the Canon prime lens.

Someone said that wide apertures are mainly to get shallow depths of field. After 30 years of photography, I have to respone with ? to that. Personally, I mainly use large apertures to get a higher shutter speed. I've found raising the shutter speed another notch normally does more to increase sharpness than any other factor, as long as you can focus accurately. With a 20D, as I said, that f2.8 aperture makes even focusing that much more accurate.

If you do get the Tamron (and are shooting with an APS-C format DSLR), get the Tokina BH775 lens hood (designed for the Tokina 28-80mm f2.8 ATX-Pro lens). The Tokina hood bayonets perfectly onto the Tamron, and is the perfect length and diameter for the APS-C format. B&H and Adorama both sell the hood for about $40.

Thank you for that information. I have been toying with buying the Tamron lens. I have the 28-75 Di F2.8 and like it well enough. I own the 70-200 F4L and it is okay though I think the Sigma F2.8 version would do me just as well (my local shop did not have the Sigma when I needed the range, hence the F4L version).

Give the information here, I may just end up treating myself this weekend.

Thanks again,

I have taken several shots with it and it performs very well. I am not sure against the Canon 17 to 40 but I think ti will hold it own at half the price.

Here is an inside shot with it at F4, I have not tried f 2.8 yet but I will.

at 17mm
http://www.pbase.com/p​hili1/image/35932350&e​xif=Y

at 35 mm
http://www.pbase.com/p​hili1/image/35930684

at 18mm
http://www.pbase.com/p​hili1/image/35932358

Hope it helps you.

Interesting! I usually raise ISO a notch when I want a faster shutter speed. But that's probably because I shoot aperture priority most of the time. However, in situations where the ISO setting is likely to cause unacceptable noise (800 on my D60 and perhaps 1600 & 3200 on the 20D), I'll sacrifice DoF and reduce the F stop #.

However, I agree that in all cases it's necessary to use an adequate shutter speed to get a sharp hand-held shot. Balancing the trade-offs between lens performance at a particular aperture, camera shake at a particular shutter speed and noise at a particular ISO setting, can be tricky. For example, if the Tamron 17-35 is noticeably sharper at f5.6 than at f2.8 (which I think it probably is), having selected an appropriate shutter speed to ensure maximum sharpness (say, double the 1/focal length rule), one might then be faced with a choice of f2.8 with ISO 100 or F5.6 with ISO 400.

Supposing DoF is not an issue, ie. the pros and cons are about the same, esthetically. Would you not choose F5.6 for a sharper result?

Well you are in a way right about F2.8 but that is a perceptional sharp. If you focus at F2.8 and have a shallow depth of field then everythng else will be out of focus and your subject will take on a sharper look. In fact it should not be any differnt then at F 4 or F 5.6.

It is a fact that each lens has it F stop that it is sharper at but that is hard to tell visually.

I normally shoot aperture priorty myself--wide open--as it will give me the highest possible shutter speed. If I weren't such an old fogey, I might shift ISO a bit more readily--high ISOs are certainly more usable in digital than in film (I have to chuckle at people who are aghast at ISO 3200 20D noise--they must never have tried to boil fujichrome to 3200)

TANSTAAFL is the only unbreakable rule in photography. But the Tamron's quality barely changes as you stop down. It's pretty much at maximum sharpness at maximum aperture. And DoF is pretty good at all focal lengths, too.

As above, it's not significantly sharper with the Tamron--I have zero fear of working at maximum aperture with it.

Hey someone who remembers golf balls. When I hear all this chatter about noise, I say I remember when.

ISO was asa and you couldnt go above 64 or you had god I almost forgot what we called it ( Grain)

Manual Focus was the best we had and we had to anticipate action. NOw if auto focus isn't fast enough we do not know what to do.

Shutter speeds hey 1500 was fast now we have 8000.

Match needle metering was an inovation now its matrix, evaluative.

Fill flash was manual and we had to adjust for it, now put it on and you get perfection, so when someone complains that its to dark what should I do? ADjsut the Camera we had to.

Thanks it was fun brining up the old days when we had it so hard, unlike now when it is so esay.

Hey its made me a better photographer and I am lovving it.

This Tamron 17-35 sounds like a very fine lens. I'd get one myself were it not for the fact I'd be duplicating focal lengths I already have.

One should also bear in mind that 17mm on a 1.6 crop DSLR is equivalent to 27mm on full frame 35mm, and if one steps back to get the same field of view as 17mm on FF 35mm, then F2.8 has the same DoF as 17/F4.5 on full frame.

My experience is, generally most 35mm lenses are sharpest at f8, very slightly softer at f11, noticeably softer at f16 and obviously softer at f22.

At f stop numbers below f8 there's a similar deterioration, but for different reasons, and a marked worsening of corner and edge performance, especially with the cheaper lenses.

There are always exceptions, of course.