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11-13-2011, 05:12 AM   #1
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Tamron 17-50mm XR DiII f/2.8

any opinion regarding this lens? for indoor work i have the FA 50mm 1.4 lens. this Tamron is good enough for some stock work? i wish too buy an F 28mm 2,8, but in this case i don/t want to have two prime lenses with close focal lenghts. maybe this tamron is a real (and good) choice for me, to replace the 50mm? ... thanks

11-13-2011, 08:50 AM   #2
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I have this and it seems like an excellent piece of kit for the price. Very sharp (for a zoom). One complaint that I have seen often enough to mention it would be some copies front/backfocusing. Hence getting yours from a reputable dealer is a good idea so that if this happens the lens can be exchanged / fixed without hassle.

Check out:

Tamron AF 17-50mm F2.8 XR LD Aspherical IF SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database

Last edited by jolepp; 11-13-2011 at 10:40 AM.
11-13-2011, 10:35 AM   #3
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QuoteOriginally posted by piskota Quote
any opinion regarding this lens?
This is probably one of the most popular aftermarket lenses, if not THE most popular, and as such there are tons and tons of reviews of this lens. Just do a Google search for "Tamron 17-50mm review" and you'll find so many professional reviews it'll make your eyes bleed. You will also be able to find hundreds of user reviews by searching for the lens on sites such as Amazon, Abe's of Maine, B&H, Adorama, Newegg, etc.

I owned this lens briefly, but returned since it seemed to have an actual max aperture of only f3.3 or 3.4, even though it said f2.8 on my camera.
11-13-2011, 12:16 PM   #4
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thank you for your opinion. my question is if this tamron could match in performance my prime lens, the FA 50mm 1.4.
or in the 28mm focal area the F 28mm is the sure winner against this lens.
and yes... i know the google solution....

11-13-2011, 03:54 PM   #5
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QuoteOriginally posted by piskota Quote
my question is if this tamron could match in performance my prime lens, the FA 50mm 1.4.
I have both Tamron 17-50-2.8 and FA50-1.4... They both perform, but I don't think I can answer your question as I wouldn't be without either...

My K-x comes out of the bag with the Tamron bolted on and is my general use lens.... The fifty goes on for specific shots or when I have time to mess around, but it's to narrow for a general use lens...






QuoteOriginally posted by Edgar_in_Indy Quote
I owned this lens briefly, but returned since it seemed to have an actual max aperture of only f3.3 or 3.4, even though it said f2.8 on my camera.
How'd you work this out? Intriuged...
11-13-2011, 06:03 PM   #6
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QuoteOriginally posted by DaveHolmes Quote
How'd you work this out? Intriuged...
I have a home studio, and when I first got the 17-50mm I switched out from the 28-75mm to the 17-50mm midway through a shoot. Lighting, camera settings, etc. all stayed constant, with the only change being the lenses. When processing pictures later, I was surprised to find that all of the pictures from the 17-50mm were underexposed by a full stop.

Further testing revealed that my 17-50mm was underdeveloping by about half a stop when it was wide open (which is why I say it's actually only a f3.3 or 3.4 lens), and gradually underexposed more as it was stopped down. In the studio I was shooting at f10, by which time it was underdeveloping by almost a full stop. Here are two samples from that shoot:



I later compared exposure at given apertures between all of my lenses, and they were all identical except for the 17-50mm. I concluded that there is some error in how much the aperture is opened on the 17-50mm. I don't know if this was just a problem with my lens, or is common to the 17-50mm. If you're interested in more, I started a thread at the time about the issue that contains a lot more detail and discussion:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/124013-tamron-...-k-x-pics.html

Despite this issue, I still think the Tamron 17-50mm is a great lens for the money, and is probably the best value in a replacement for the kit lens.
11-13-2011, 06:22 PM   #7
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Might also find this interesting:
DA* 16-50mm vs. Sigma and Tamron 17-50mm Comparison - Introduction

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11-13-2011, 06:31 PM   #8
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Piskota: If the aperture problem I experienced is common to this lens, then you may want to avoid it for studio work. If you ever change out lenses throughout a shoot, then you would have to adjust your lighting and/or exposure settings to compensate for the aperture error.

11-14-2011, 08:31 AM   #9
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well, excellent details, but in the studio maybe a can compensate the underexposure characteristics of this lens. but the overall optical quality is good enough? sharpness, bokeh ... i wish to use it mostly in the 28mm area. how does he perform? thanks
11-14-2011, 10:37 AM   #10
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QuoteOriginally posted by Edgar_in_Indy Quote
I have a home studio, and when I first got the 17-50mm I switched out from the 28-75mm to the 17-50mm midway through a shoot. Lighting, camera settings, etc. all stayed constant, with the only change being the lenses. When processing pictures later, I was surprised to find that all of the pictures from the 17-50mm were underexposed by a full stop.

Further testing revealed that my 17-50mm was underdeveloping by about half a stop when it was wide open (which is why I say it's actually only a f3.3 or 3.4 lens), and gradually underexposed more as it was stopped down. In the studio I was shooting at f10, by which time it was underdeveloping by almost a full stop. Here are two samples from that shoot:



I later compared exposure at given apertures between all of my lenses, and they were all identical except for the 17-50mm. I concluded that there is some error in how much the aperture is opened on the 17-50mm. I don't know if this was just a problem with my lens, or is common to the 17-50mm. If you're interested in more, I started a thread at the time about the issue that contains a lot more detail and discussion:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/124013-tamron-...-k-x-pics.html

Despite this issue, I still think the Tamron 17-50mm is a great lens for the money, and is probably the best value in a replacement for the kit lens.
Have you tried to perhaps utilize another copy of 17-50?
11-14-2011, 10:49 AM   #11
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QuoteOriginally posted by dr_romix Quote
Have you tried to perhaps utilize another copy of 17-50?
At the time, I heard enough people say that they had also experienced exposure anomalies with their 17-50 that I figured it probably wasn't worth my time to try sending it back and hoping for a good copy. I ended up just returning it and using the money towards the Sigma 50-150mm f2.8 EX HSM II. I'm glad I did, since that is an incredible lens, and it was discontinued shortly after I ordered it and is no longer available.

Next time I buy a standard zoom, it will probably be the new Sigma 17-50mm f2.8 HSM. I've been really impressed by Sigma's recent lenses.
11-14-2011, 10:57 AM   #12
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QuoteOriginally posted by piskota Quote
well, excellent details, but in the studio maybe a can compensate the underexposure characteristics of this lens. but the overall optical quality is good enough? sharpness, bokeh ... i wish to use it mostly in the 28mm area. how does he perform? thanks
I could certainly compensate for the exposure differences, but whether shooting in the studio or in the field, I'm frequently swapping out lenses. I almost always shoot in Manual exposure mode, so having to change my settings when swapping to (or from) the Tamron 17-50mm would needlessly disrupt my flow.

Besides that, I'm convinced that it wasn't actually an f2.8. This is an important point for me since I do a lot of shooting indoors with available lighting. Exposure compensation is not a replacement for a wider aperture. Exposure compensation will not allow me to enjoy the shutter speed advantage of f2.8, and will not provide the subject isolation (ie bokeh) of f2.8.

As far as the actual image quality of the 17-50mm, I found it to be excellent. Contrast was excellent and it was very sharp at f2.8 (although I believe the f2.8 was actually f3.3, in which case the lens is cheating in the wide-open sharpness test). The biggest problem was the vignetting. I was used to shooting on the Tamron 28-75mm which has almost no vignetting on APS-C. Sure, vignetting can be corrected in processing, but it's another step in the work flow and you may end up with more noise in the areas that were lightened in processing.
11-14-2011, 11:29 AM   #13
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QuoteOriginally posted by piskota Quote
but the overall optical quality is good enough? sharpness, bokeh ... i wish to use it mostly in the 28mm area. how does he perform? thanks
I only owned my 17-50mm for a few days, and I just looked through all my RAW files from those dates and I didn't have any at exactly 28mm. I do have some test shots at 35mm, which you may find helpful. The test shots are straight from the camera with no adjustments to contast, saturation, or color. I did perform a slight Smart Sharpen, since that is a normal part of my workflow. Click on the images below for the full-size 12MP image:







And this is the only real-world image I have from this lens close to 28mm. It's not what I consider a "keeper", so I had never developed the RAW file until now. It's a far from ideal image, since I was only shooting at 1/100 sec and my subject was moving, but you may still find it useful since it does a good job of showing how this lens has nice contrast and color characteristics, and you can also see a little bit of how out of focus areas are rendered. Again, this image is straight from the camera with the exception of minor sharpening. Click on the image for the full-size file.


Last edited by Edgar_in_Indy; 11-14-2011 at 11:58 AM.
11-14-2011, 01:14 PM   #14
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QuoteOriginally posted by piskota Quote
any opinion regarding this lens? for indoor work i have the FA 50mm 1.4 lens. this Tamron is good enough for some stock work? i wish too buy an F 28mm 2,8, but in this case i don/t want to have two prime lenses with close focal lenghts. maybe this tamron is a real (and good) choice for me, to replace the 50mm? ... thanks
I briefly had the Tamron 17-50 f2.8. Image quality is outstanding, IMO. It does tend to underexpose on my K-x but wasn’t really an issue since I shoot RAW. However, I must have been one of the unlucky ones who ended up with bad build quality from brand new copies, unfortunately. The first copy had some sort of substance inside the front element sitting on the inner glass. It wasn’t dust but something bigger and visible. I was surprised it didn’t show up on the images. I returned it for another copy.

The second was “clean” but had severe de-centering, where the left side of the image was practically blurred especially at f2.8. At first I thought the lens was smudged. I took dozens of sample shots of a bookcase (and other subjects) to compare with my other lenses. Taking DOF to account, I made sure book subjects are perfectly aligned and camera on a tripod is perpendicular five feet away. All sample shots taken with two-second timer. The left side of the images was just too soft stopped down, and horrible from f2.8 – f5.6 throughout focal range! Without moving the set up I took the Tamron off and mounted the 18-55mm. As much as I hate to say it but the kit-lens actually put the 17-50 to shame as far as IQ consistency across the frame.

I tried the same exact set up on other lenses (DA 18-250. A50-f2, Viv 50-f1.7, even the DA-L 55-300), all were consistent across the frame. I decided to return the Tammy and figured a third copy wasn’t necessary. My suggestion is check the return/replace policy when you buy lens your lens to make sure you have replacement option just in case. Once you get a good copy, it is an excellent lens.

Cheers!

Last edited by K57XR; 11-14-2011 at 01:36 PM.
11-14-2011, 06:06 PM   #15
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My copy needed AF adjustment and I was using it for indoor family shots. Its very sharp even at f2.8 and in my case at f2.8 it gets faster shutter than my other lenses like it's letting in more light than others. Wonderful lens for available light shots indoors.

The bad, when I used it outdoors where the subject doesn't quite fully fill the frame (but fills the sensor area, not just the dots) and are at some distance than indoors, it misses focus more than half the time. Pretty useless.

I keep it for my indoor use. When it works it will match the IQ of the F28/2.8 which I use to have.

Last edited by pcarfan; 11-14-2011 at 06:14 PM.
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