( 9 reviews )
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Posted: 07-27-2009
First let me say my first copy of this lens was totally bad, soft at just about every everything under f/8.0. My second copy behaves very well. I'm using this lens on A Pentax K2000 (K-m in Japan), that has the same sensor as the Pentax K200. I have several other lens but my best lens is a Pentax SMC-FA 50mm f/1.4 and I define sharpness, color and contrast in light of the quality of this lens (one of the better 50mm primes). at f/2.8 it is soft, at center or corners depending on the focal length. Still, testing also shows potential for smaller images after sharpening, especially at the shorter end. My Pentax SMC-FA 50mm f/1.4 gives much better images at f/2.8. at f/4.0 everything improves a great deal, especially center sharpness but there are still signs of some softness at the extreme corner at some focal lengths. My Pentax SMC-FA 50mm f/1.4 is still better at f/4.0. at f/5.6 this lens can go "mano a mano" with my Pentax SMC-FA 50mm f/1.4 and at times I think the Tamron does better. I suspect that both lenses are exceeding the resolution of the camera sensor at this aperture. The fact that this quality at this aperture is so consistent across the full focal length gives the Tamron many points. at f/8 the lens acts a little strange. At some longer focal lengths it is as almost as good as when used at f/5.6 while in the shorter end we get lost in quality. Totally usable and still good at f/8 but the lost of quality is unexpected on the short end, better than f/4.0 at center with no corner softness on the short end but not the same quality as f/5.6. at the longer end sharpness is excellent from f/5.6 - f/7.1, very good from f/8-f/11 and still good from f/13-f/16 with little distortion to talk about. Macro is very good at 75mm f/8. My biggest issue with the lens are as follows: my first copy was bad and too many people write similar experiences. That is not good quality control. My second issue is that from an expectations point of view, at least on my Pentax K2000 camera, the lens seems like a good constant f/4 lens with a f/2.8 in case of emergencies. I would avoid using the f/2.8 aperture if possible (remember, I have a Pentax SMC-FA 50mm f/1.4 lens and used to very good quality at f/2.8). Now, since I paid $400 for the lens and that is more or less what Sigma would charge for a similar lens and 2/3's of what Pentax would charge for their Pentax SMC-DA 17-70mm f/4 AL SDM (that is a little soft at the long end but wider on the short end) this is a good buy. Were it not for the quality control issues getting this lens would be a simple "YES". As it stands, I'm like, think about it and be ready to test and return if necessary. If you get a good copy you will find it a good value. If I could I would give this lens 4.5 and not 5 stars for the quality control issues. On the other hand the pictures look really once yo get a good copy.
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Posted: 07-16-2009
Just bought from AllAboutElectronics through Amazon. Never touched it before, chose based on on-line search and my foto needs. Not as bulky and heavy as I was affraid it would be. Nice feel, good balance with Pentax K2000d. About 1/2" longer than kit 18-55mm lens and a bit wider. I was shooting very fast running pets, haven't noticed much noise during focusing. One needs to get used to slight resistance of the zoom ring but the controls layout is very user-friendly. Very fast focusing, excellent colors even under cloudy conditions at 5-6 pm, SHARP! First impression that the image quality is close to 1:1.9 43mm Limited... Not cheap but worth every penny!
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Posted: 07-10-2009
likes: feels very solid, well constructed. constant 2.8 aperture. when sharp, its very very sharp. dislikes: front focus/back focus issues. fortunately the k20 has lens microadjustment capability, which helps very very much. very heavy. nitpicking, but i wish it zoomed out to 18mm. 28 is inconvenient for group shots. Bought for wedding purposes, and it's definitely helped. When its sharp, its amazingly sharp. The "bokeh" is great. Some shots at 2.8 (set to center point focus) were about 10 feet off (closer to me), which is completely ridiculious, but when they were nice it was worth it. I wouldn't buy this for a camera that doesn't allow you to adjust the autofocus settings.
