MUST SEE... sigma VS tamron VS nikkor

[phatkid77]

well i went to test the sigma at another store...from the first shot.. i could tell i wasnt smoking crack...

heres the 100% tamron AF


manual focused


sigma 18-50 EX f2.8 100%


nikkor 17-55 f2.8 100%


on my D200 the sigma was sharper than the nikon... but looking at my monitor i think the nikon acually wins..

Regardless, i showed the pics to the guy where i bought my Tamron, and he agreed it was the pits, and was surprised at the sigma... said it must be an EXCEPTIONAL copy... he was surprised it ran with the nikon.. so they are ordering me the sigma, but i went to the other store and put that copy on hold in case the sigma i get is questionable...

also, i think the AF is inaccurate on the tamron, thus the issues, as others stated the tamron wont change AF is the distance is similiar, and i did notice this....when i moved side to side it didnt change..... but the sigma seemed to AF way better..

anyway, i am not nots and the nikon and sigma where tested handheld too... 1\160 at ISO 400

thanks for all the input, and feel free to comment on what u see here..

mals

[Mr. Pickles]

I normally like Sigmas more than Tamrons anyway. And these images are varying sizes, so hard to tell if your one shot with the Sigma is or isn't on par with the Nikkor. Of course, I'm not sure I know which lens each of these actually is though.

[phatkid77]

yeah im an idiot... although im not sure why my crops are different sizes?

Tamron 17-50 XR Di-II f2.8

Sigma 18-50 EX f2.8

Nikkor 17-55 AFS f2.8

[Mr. Pickles]

I would think that they should all be pretty close to the same quality wise. One would think the Nikon woul dbe better, but sometimes that just isn't the case. Of course, in this case, I think you got a bum Tamron model. One would think they aren't all like this, but.....

And just because you are posting on PhotoCamel, does not make you an idiot, so you should take that back. If you was a PhotoCamel moderator, nowing you don't get paid, well, then we can talk....

[cyclohexane]

Optically, the three seem to be pretty similar. My guess is that color and contrast would be best overall with the Nikkor, and the Sigma and Tamron would be close, if not the same. Now, in regard to build quality, there's no comparison... the Nikkor's going to win.

[scoundrel1728]

I don't know whether you really got a bum copy of the Tamron or the box surface just wasn't quite perpendicular to the lens axis. In the manually-focused image, the left side of the image is sharp, whereas in the autofocused image the right side is. I would also guess from the blur pattern that the right side of the box is closer than the left. After all, at the distances you are working, any such misalignment could easily put part of the box outside the depth of field.

[Mr. Pickles]

Scoundrel,

That was what I was wondering, but I thought he didn't move the box or the the tripod in any of these. But, now I don't know where I got the tripod idea. In looking at the one Tamron AF shot, the EXIF says the F-number was 28/10, which seems odd, but maybe Nikon D200's do it that way. Assume it is 2.8, but is that a narrow band for the camera's DOF to be off?

[cyclohexane]

It shows up as f/2.8 in my EXIF Viewer (Opanda iEXIF), so I don't know where you're getting 28/10, though it's correct. It sounds more like something an old Leica M camera would write if they were electronic, LOL

[scoundrel1728]

Some numbers are stored as fractions in EXIF, including aperture and shutter speed/exposure time. Some EXIF readers leave the data as a fraction while others convert to more familiar floating point.

[scoundrel1728]

If these are all taken with the same camera and are 100% crops as advertised, the focal length settings or the lens-to-subject distance must have varied a lot between pictures to have caused such a variation in image size. In either case, the variables haven't been well-controlled enough to make meaningful comparisons. The test was especially hard on the Tamron because it was required to focus closer or at a longer focal length, which is more difficult for a lens to focus close and the depth of field would be shallower. My Tamron 28-75mm f/2.8 shows traces of chromatic aberration when focusing extremely closely at full telephoto that is not in evidence when the subject is farther away, so there is no guarantee that the image quality at close focus will be the same as that nearer the design center of the lens.