Tamron 17-50 - Comments sought after a comparative test

Discussion of lenses, brand or independent, uses and merits
Forum rules
No more than three images or three external links allowed in any post or reply. Please trim quotations and do not include images in quotes unless essential.
Alan Shaw
Acolyte
Posts: 22
Joined: Fri Aug 01, 2008 9:17 pm

Tamron 17-50 - Comments sought after a comparative test

Unread postby Alan Shaw » Wed Aug 12, 2009 12:36 am

Some time ago I was ruminating about wanting to rationalise my lenses now that I had bought a second hand 7D. Based on the high praise on many review sites, I bought the Tamron 17-50 f2.8 as a general walk-round lens, and hoped it would allow me to replace my Minolta 28 f2.8 and Minolta 50 f1.7 lenses with little appreciable loss of image quality – and to then sell them to part fund the Tamron. A few people here and in other places told me I’d need to keep the primes, while others said the Tamron should be a more than acceptable replacement.

Well, I finally got organised to do a simple comparison of the lenses.

Here is how I did the test. Tripod mounted, with a focus on a cityscape with plenty of detail, and in excellent late afternoon light. I expect focus was effectively infinity, although I left it to the autofocus to sort it out. After all, this is how I would typically do my shooting. All shots were at ISO 100.

Firstly I tested the Tamron at 28mm and then 50mm, at a full range of apertures starting at f2.8 running out to f22. I then repeated the process with the Minolta 28mm lens and then the Minolta 50mm lens.

To do the comparison, I put together test sheets with pairs of crops from each subsequent file for each focal length and aperture of both the Tamron and the relevant Minolta. The sheets are laid out so that the comparable Tamron and Minolta crops are placed directly side by side. Rather than draw conclusions from screen images, I then had the files printed at my local processor as 10 by 8s, and did the comparison from the print. No post processing was done on the individual files. I also had a print made of each test sheet with some moderate sharpening applied – this should mean that all crops had exactly the same sharpening applied.

My conclusions, from both the sharpened and non-sharpened sheets, are that at 50mm in particular, the Tamron is significantly softer and lower contrast than the Minolta until f8, which is a worse performance than I had anticipated. I was not expecting a performance as good as the primes, but I was expecting a little better than I actually get.

The shop manager agreed with my conclusions and generously sent the files on to the local Tamron supplier who responded by saying there is nothing wrong. He also suggested I should have tested on a calibrated camera using test targets – which kind of missed the point that I wanted a comparison on my equipment doing the sort of shooting that I do.

Anyway, I’ve put compressed versions of the tests here:

http://www.railgrafx.id.au/Shaw/Sundries/Lenstest28mm.html
http://www.railgrafx.id.au/Shaw/Sundries/Lenstest50mm.html

A guide to reading the comparisons is on the left of the page when you open it.

I’d be interested in your views – maybe this is all the lens is capable of and these results are what should be expected (and so perhaps my expectations were too high), or maybe despite what Tamron say I do have a dodgy copy.

The issue for me is less that the Tamron performs worse then the primes (which I expected) but whether the results should be regarded as acceptable at all.

It’s also possible I have a focus problem, maybe associated with the camera, but I tend to doubt that as the subject was effectively at infinity and at lower apertures depth of filed would have more than covered it.

It is also possible that my test procedure is completely invalid!

As it is though I am now having second thoughts about using the Tamron to replace my primes and may need to continue searching for a suitable walk-round lens.

Thanks in advance.

Alan
Brisbane, Australia
Alan Shaw
Brisbane, Australia
-------------------------------------------------------------------
Visit my Railgrafx rail photography site:
http://www.railgrafx.id.au

Visit my Moreton Bay Model Railways Site:
http://home.iprimus.com.au/mbmr/index.html

David Kilpatrick
Site Admin
Posts: 6248
Joined: Sat May 19, 2007 1:14 pm
Location: Kelso, Scotland
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby David Kilpatrick » Wed Aug 12, 2009 1:36 am

I could not get the full 50mm test page to load, but what I see is typical of zooms of this type. It is what you expect. You appear to have a good 28mm f/2.8, not all are that sharp at the edge wide open. But the Tamron results are fairly much as expected - a good level below prime lens results. That's what zooms do unless you spend £1500.

David

User avatar
KevinBarrett
Emperor of a Minor Galaxy
Posts: 2562
Joined: Wed Aug 13, 2008 5:32 pm
Location: Seattle, Washington, USA
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby KevinBarrett » Wed Aug 12, 2009 5:53 am

These results are to be expected, honestly. I have a Tamron 17-50/2.8 as well, and have compared it to my Minolta 50/1.7 and 24/2.8 RS. Both primes are superior. The more relevant test would be to compare the Tamron to other walk-around zooms.
Kevin Barrett
-- Photos --

01af
Imperial Ambassador
Posts: 504
Joined: Sun May 20, 2007 2:44 pm
Location: Germany

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby 01af » Wed Aug 12, 2009 8:50 am

I'd say at 28 mm, the Tamron is performing just the way that is to be expected from a good (but not stellar) zoom lens. You can be happy with that. At 50 mm however (where I can see only the top row of your images), it is disappointing indeed ... still I don't think you got a particularly poor copy. You really should check auto-focus accuracy carefully; with the focus slightly off you'd get this kind of result exactly. Anyway, most zoom lenses are at their worst at their long ends. You may want to try several copies, test them all, and eventually keep the best performer. You may end up with a better performer than you currently have ... or maybe not.

In my experience, fast standard zoom lenses usually don't deliver ... with the possible exception of those with four-digit price tags. I feel in a standard zoom lens, wider zoom range is more useful than faster lens speed. I guess you'd be happier with an SAL DT 16-80/3.5-4.5 ZA for example, or an SAL DT 16-105/3.5-5.6. Then, of course, in available-light situations you'd have to resort to your prime lenses.

-- Olaf

Alan Shaw
Acolyte
Posts: 22
Joined: Fri Aug 01, 2008 9:17 pm

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Alan Shaw » Thu Aug 13, 2009 12:32 pm

OK – thanks for these observations. It sounds like the Tamron’s performance is about what I should expect to get from it. I’m still some way away from deciding though whether that performance is actually good enough. I am not an especially demanding photographer but the ability to produce a 10 by 8 print which is consistently sharp across the image at a reasonably wide aperture does not seem like an unreasonable expectation to me.

I will endeavour to take Kevin’s advice and “audition” some other walk-round zooms if I can find them – the obvious alternatives at the lower-price range are the Sigma 17-70 and the Sigma 18-50 – although from what I read I doubt they will be any better.

As hinted by David and Olaf though, I guess I may need to have a look at the Sony 16-80, which would have been my first choice anyway apart from price. I’ve re-read David’s article on this lens and it does seem like something I should at least test on the 7D. If it performs closer to what I like then a purchase may have to be made – fortunately I hope my tax refund might be significant enough this year to contemplate it!

However, my enthusiasm is tempered by this quote from Photozone about the Tamron: “The Tamron AF 17-50mm f/2.8 XR Di II LD Aspherical [IF] is a very serious performer and an obvious alternative if you can't get warm with the Sony standard zoom lenses. In terms of resolution it is easily able to match the Zeiss ZA 16-80mm f/3.5-4.5 DT for instance - that is technically.” Indeed, I have to confess it was this statement that convinced me about the Tamron in the first place.

The other alternative may be to stick with primes and forgo the convenience of zooms, although I’m not sure how I’ll get on at the 28mm (FF equivalent) end of the range.

This transition to digital is altogether full of more compromises than I’d expected!

Alan
Alan Shaw
Brisbane, Australia
-------------------------------------------------------------------
Visit my Railgrafx rail photography site:
http://www.railgrafx.id.au

Visit my Moreton Bay Model Railways Site:
http://home.iprimus.com.au/mbmr/index.html

User avatar
KevinBarrett
Emperor of a Minor Galaxy
Posts: 2562
Joined: Wed Aug 13, 2008 5:32 pm
Location: Seattle, Washington, USA
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby KevinBarrett » Thu Aug 13, 2009 5:06 pm

I must have missed the part where you were shooting on a 7D. I was about to say that your results look slightly softer than mine do, but given that you're shooting on 6 MP rather than 12, I must say that your results look a LOT softer than mine. In my comparisons it took 100% pixel level peeping to spot the differences from primes, but most of it was seen in distortion and the appearance of diffraction at the smallest apertures.

You would appear to have a poor copy of the Tamron, which is surprising because I've never heard of a poor copy of that lens.
Kevin Barrett
-- Photos --

Alan Shaw
Acolyte
Posts: 22
Joined: Fri Aug 01, 2008 9:17 pm

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Alan Shaw » Fri Aug 14, 2009 10:49 pm

Sadly Kevin, I think you are right. I've just re-read a number of reviews of the Tamron and simply cannot reconcile my results with the various review sites that praise this lens. I'll take it back to where I bought it with a view to an exchange, but suspect I will be out of luck.

I also hope to "audition" a Sony 16-80 at my local Sony Central - probably more out of curiosity than anything given the cost, but you never know.

Alan
Alan Shaw
Brisbane, Australia
-------------------------------------------------------------------
Visit my Railgrafx rail photography site:
http://www.railgrafx.id.au

Visit my Moreton Bay Model Railways Site:
http://home.iprimus.com.au/mbmr/index.html

Tony Meredith
Initiate
Posts: 54
Joined: Thu Aug 14, 2008 1:01 am
Location: Central Queensland

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Tony Meredith » Fri Aug 14, 2009 11:25 pm

Hi Alan,

I don't suppose your front element has come loose, as mine did a little while ago. Since i have tightened mine up the lens seems to be sharper than it was before, but this might just be a mental thing. I have no idea what effect a wrongly adjusted front element would have on focus or resolution.

For example, in the attached image, the horses mane has been resolved down to single pixels against the blue sky (evident on the full size copy). This was taken at 35mm and f5.6.

Tony
Attachments
DSC06331.jpg
DSC06331.jpg (159.92 KiB) Viewed 3443 times

User avatar
Dr. Harout
Tower of Babel
Posts: 5833
Joined: Wed May 30, 2007 7:38 pm
Location: Yerevan, Armenia
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Dr. Harout » Sat Aug 15, 2009 11:11 am

Lovely picture, Tony.
A99 + a7rII + Sony, Zeiss, Minolta, Rokinon and M42 lenses

Flickr

Mr_Canuck
Initiate
Posts: 30
Joined: Fri Jun 27, 2008 5:36 pm
Location: Canada

Tamron 17-50 vs the usual competitors

Unread postby Mr_Canuck » Tue Aug 18, 2009 8:17 pm

I started with a handful of great Minolta primes when I got my a700. I was lucky to find one guy unloading them. So this set my expectations very high. But for a year I wasn't settled on a walk-around zoom.

I tried the Tamron. It was pretty good actually, but not enough focal length, and I already shoot indoors mostly with my 35/f2.

I then in succession went through the Sigma 17-70, Sony 16-105, Minolta 28-135 and CZ 16-80.

I've still got the CZ 16-80 and the Minolta 28-135.

All of the lenses are quite good. But I found the Sony 16-105 not to be very sharp and mostly quite slow. The Sigma was decent but I found the images a little nervous and the colour just ok. I'd compare the Sigma and Sony quite equally, and both decent options. But I wanted better quality.

The Minolta 28-135 I discovered while reading various reviews. It has quite a reputation. I'd say it's the best of the lot. But its range is better suited to full-frame and it really suffers from flare. I may try a digitally-optimized filter to try and mitigate this. But I really like the shots from it. I may just hold on to it for that mystical a850 or some such full-frame body some day.

Then I finally picked up a (good used) copy of the CZ 16-80 (though it suffers from zoom creep, otherwise it's great). The optics are clearly superior to the Tamron, Sigma and Sony in my experience. No lab tests, just out there shooting.

The speed/focal length combination on the CZ are really pretty great when you think about it. And it is true, this lens is sharp pretty much across the aperture and focal length range. The colours are very nice and there is good contrast. Bokeh is good too, and you can actually get some nice out of focus elements with this, unlike with the Sony.

The Sigma is tempting only if you can get a good used copy; then it's half the price of the CZ. But ultimately, I'm in it for the longer haul and the investment in the 16-80 was worth it to me. It's a lens I feel I can trust to deliver.

I'd keep your 50/1.7 because they are so cheap and they are a great portrait and low-light lens. But I think the CZ could replace your 28/2.8 because at that length it's only a stop darker, and then you'll have all that extra reach outdoors.
a850 | 28-135 | 70-300G | 20/2.8 | 35/2 | 50/2.8M | 100/02 | 200f2.8 | HVL-20FA | 3600HS | Border Collie X

David Kilpatrick
Site Admin
Posts: 6248
Joined: Sat May 19, 2007 1:14 pm
Location: Kelso, Scotland
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby David Kilpatrick » Wed Aug 19, 2009 1:14 am

No filter can reduce flare or increase contrast - that's a Brooklyn myth. The lowest flare level will always be produced by a bare lens, with no filter fitted.

David

01af
Imperial Ambassador
Posts: 504
Joined: Sun May 20, 2007 2:44 pm
Location: Germany

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby 01af » Wed Aug 19, 2009 9:07 am

David Kilpatrick wrote:
Mr_Canuck wrote:The Minolta AF 28-135 I discovered [...] it really suffers from flare. I may try a digitally-optimized filter to try and mitigate this.
No filter can reduce flare or increase contrast - that's a Brooklyn myth. The lowest flare level will always be produced by a bare lens, with no filter fitted.

Umm ... but filters can increase contrast. Of course they cannot reduce the kind of contrast loss caused by flare or by lens design. So David's statement is correct in the context of Mr_Canuck's musings but not true generally.

A filter often used for its contrast-enhancing effect is the polariser. Then there are edge filters (i. e. yellow, orange, red, infra-red) in black-and-white photography. Also UV-cutting filters can increase contrast but only under certain circumstances. On the other hand, filters also can be a source of flare and/or contrast loss. It's the same as with pharmaceuticals: a filter should be used only when the positive effect outweighs its (inevitable) negative side-effects.

-- Olaf

David Kilpatrick
Site Admin
Posts: 6248
Joined: Sat May 19, 2007 1:14 pm
Location: Kelso, Scotland
Contact:

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby David Kilpatrick » Wed Aug 19, 2009 9:09 pm

Of course, contrast filters in the context of isochromatic and panchromatic b/w are not what I meant (in normal English usage they are often called 'contrast filters' which is a good clue to the use!). UV and polarisers also can't increase contrast in the sense I meant, any more than changing the lighting or moving closer to a subject can do. The myth is that a filter with a multicoating can somehow improve a lens without multicoating, which is not so, and that was the basis of the reply.

A very efficient, deep, flock or dead matt lined lens hood with an exact aperture - like a bellows hood - can increase contrast with complex or inadequately coated lenses, but only by removing stray light entering the lens - scattering of picture-forming light will still be a problem.

David

Mr_Canuck
Initiate
Posts: 30
Joined: Fri Jun 27, 2008 5:36 pm
Location: Canada

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Mr_Canuck » Thu Aug 20, 2009 6:27 pm

Helpful commentary on the filter/flare issues. Fortunately, the OP's Tamron doesn't suffer from this problem like the 28-135!
a850 | 28-135 | 70-300G | 20/2.8 | 35/2 | 50/2.8M | 100/02 | 200f2.8 | HVL-20FA | 3600HS | Border Collie X

Vidgamer
Imperial Ambassador
Posts: 527
Joined: Wed Jun 11, 2008 3:37 am

Re: Tamron 17-50 - Comments sought after a comparative test

Unread postby Vidgamer » Fri Aug 28, 2009 12:35 pm

I think the bottom line is that Alan's copy looks worse than mine. I'd notice if my edges were that blurry.

The Tamron 17-50 may not be perfect, but where it fails, it seems to do so in ways that are less obvious. Or at least I like to think so. It even looks pretty good wide open. Even the 50/1.7 doesn't look good at the edges at f/2. The bokeh is pretty good on the 17-50 too, a lot better than many zooms I've seen pictures from.

The 17-50 looks close enough to my 28/2.8 and 50/1.7 primes that it's generally not worth the bother for me to carry the primes around, particularly if there's enough light to be at f/8. However, the 50/1.7 is useful in lower-light situations; it has the occasional special use, so I still recommend keeping that if for no other reason.

The 28/2.8 is a tough one. It's the least-regarded of the Minolta primes, yet it still compares well against the zooms. I like it, I just need to justify carrying it around.

I made a few comments and comparisons at f/8 at the below link, but I haven't done any extensive comparison tests. The results I get daily from the Tamron are Good Enough to justify its purchase and continued use.
http://www.computingbits.com/photograph ... rpness.htm

This photo shows how the bokeh still looks OK with a busy background:
Image


Return to “Lens Lore”

Who is online

Users browsing this forum: No registered users and 3 guests