9 out of 10 points and recommendedLight weight, Excellent value for money, Very useful macro capabilityAwkward engagement and disengagement of macro function
I bought this lens about 18 months ago for use on my Nikon D80. Mine is the built in motor version, which focusses a bit slowly, but accurately.reviewed May 2nd, 2011 (purchased for $195)
I was immediately impressed with its usefulness as a nature photography lens, being able to photograph birds in flight or at rest, or switch to macro and take excellent photos of insects, small animals, flowers, etc. Being able to then switch to the macro capability is very useful in the field, with the long working distance at the maximum magnification of 1:2 being ideal for photographing nervous insects etc.
The Nikon 70 - 300 VR lense I bought subsequently does a better job of photographing birds (at a much higher cost). I also bought a Nikon 105 VR Micro lense which, while excellent, does not provide the same working distance as the Tamron lense.
The 2 Nikon lenses are also much heavier, more expensive and slower to swap over in the field.
The Tamron lense on the other hand can be converted from zoom telephoto to zoom macro quickly (see below!) before your subject leaves.
Cons: On the negative side, I would say that images taken with the Tamron lense do not have the richness of colour of the Nikon lenses, however this can be adjusted in post processing to the user's taste.
Also, the process for engaging and disengaging the macro function is fiddly and needs some practice to be used comfortably.
Conclusion: Overall, an excellent lense for the beginning photographer on a budget.
9 out of 10 points and recommendedExcellent value for money, good image quality, effective VRAutofocus not always dead accurate
I bought this lens for use with my Nikon D80 for wildlife/nature photography after reading the reviews on SLR Gear and other sites on this lense and on the Nikon 80 - 400 VR.reviewed May 2nd, 2011 (purchased for $1,200)
Compared to the Nikon the Sigma appeared to offer faster focussing speed, an equally effective optical stabiliser, longer reach (the extra 100mm was important) and adequate build quality for my purposes.
Also against the Nikon 80 - 400VR was its age. It is generally considered to be overdue for an update, and I didn't want to buy one then find it superseded by an improved version in the near future!
To guard against possible durability problems with the Sigma, I bought an extended Mack warranty.
The lense has performed fully to my expectations. Handheld, it provides sharp, richly coloured images. It did take some time to develop a technique for carrying and handholding the lense/camera combination, which weighs 2.7 kg all up.
Following the advice of SLR Gear reviewers it is used mainly at f8 and with as high a shutter speed as I can obtain and still keep the ISO sensitivity reasonably low.
I've also used it with a Sigma 1.4X teleconverter, and although focussing becomes super critical, with perseverance it provides stunning images.
As one SLR Gear reviewer noted, the Sigma produces sunstars, particularly when photographing reflections from water, however I find this an attractive feature.
Cons: In tests of the lense carried out on a tripod and with the lense set at various apertures, it appeared that focussing on my D80 body varied slightly from shot to shot. This may be more a characteristic of the camera's autofocus mechanism than any problem with the Sigma. When the focus was accurate, however, the images produced were very sharp.
On a camera with live view and the ability to magnify the image and achieve fine focus, I would expect consistently sharp images.
Conclusion: An excellent lense and very good value for money.