Tamron 17-50 and Sigma 18-50

[Reportage]

The tamron is 67mm, the sigma is 72mm.

would you give up the wider end for a larger diameter lens if their performance was similar.

[pinholecam]

Don't quite understand. How is larger dia. better? I only know its going to be more $$$ for the filters.

[chalib]

I would go with tamron....

Based on review, IQ from 17-50 is much better

[FireZ]

since TS started question on the diameter...er..
is it true the bigger diameter enable more light to go in which gives a better final result?..
coz tat's wat i was told by 1 wedding photographer...

cheers!

[screamingsnapshots]

i MIGHT be wrong, but i've seen a couple of my friends with the tamron 17-50, and the AF tends hunt around abit (even in decent lighting conditions) and isnt accurate sometimes? i use the sigma 18-50 and it doesnt face the problem.. Not too sure about IQ, but i think they're pretty similar, unless you start pixel peeping, which i dont.

but i do agree that you're gonna hafta spend more on the filter, and if you're using a d40/d40x/d60 body with the sigma, the weight distribution is gonna be a little weird at first but you'll get used to it.

[Edwin Francis]

Originally Posted by FireZ since TS started question on the diameter...er.. is it true the bigger diameter enable more light to go in which gives a better final result?.. coz tat's wat i was told by 1 wedding photographer...

Absolutely not. Larger aperture lenses (f2.8 is pretty large, esp for a zoom) do let more light in, but:
- both lenses are f2.8 (there might be slight variation, but hardly significant)
- filter diameter is not the same as objective lens diameter (in photos, the Sigma looks like it has more 'housing' area)
- more light doesn't equal better photos -- the photographer was probably over simplifying things

Originally Posted by screamingsnapshots but i do agree that you're gonna hafta spend more on the filter, and if you're using a d40/d40x/d60 body with the sigma, the weight distribution is gonna be a little weird at first but you'll get used to it.

Don't own either, so can't comment on AF performance, but aren't both Sigma and Tamron abt the same size and weight? Why a weight distribution issue? Unless you mean the Sigma extends out a lot when zooming?

[screamingsnapshots]

Quote: Don't own either, so can't comment on AF performance, but aren't both Sigma and Tamron abt the same size and weight? Why a weight distribution issue? Unless you mean the Sigma extends out a lot when zooming?

http://www.sigmaphoto.com/lenses/len...28&navigator=6

http://www.tamron.com/lenses/prod/1750_diII_a016.asp


i've toyed with both, and definitely the sigma is heavier. the diameter itself is larger and the sigma weighs about 100grams more. anyways i googled the two links above. hope it helps!

and no, it doenst really extend out that much to me.

[PrimePhotog]

Tamron for me.Noticed that many copies of the 18-50 Sigma lens have back/front focus issue.I have owned the Tamron before and I have nothing bad to say other than lousy build quality.

[Legoz]

Originally Posted by FireZ since TS started question on the diameter...er.. is it true the bigger diameter enable more light to go in which gives a better final result?.. coz tat's wat i was told by 1 wedding photographer... cheers!

Dont trust wedding photographer nowadays. Most of them are small time part timers out to spoil a couple's big day.

By the way, does anyone in the thread know what is a f stop and how it derived?

Regards

[Reportage]

Originally Posted by Legoz Dont trust wedding photographer nowadays. Most of them are small time part timers out to spoil a couple's big day. By the way, does anyone in the thread know what is a f stop and how it derived? Regards

know what f2.8, f4-f6.3 and so on stands for?

F Number http://en.wikipedia.org/wiki/F-stop#...f-number_scale

[FireZ]

Originally Posted by PrimePhotog Tamron for me.Noticed that many copies of the 18-50 Sigma lens have back/front focus issue.I have owned the Tamron before and I have nothing bad to say other than lousy build quality.

back when i purchased my tamron last mth, i tried out 3 copies and all quite equally sharp...i assume now tamron has improved tat issue of front n rear problem...bought at IP...

as for the build quality..lousy meh?!... personally... i feel tat..if u love your equipment..you will sure take gd care of it...n as for the tamron....perhaps i can say tat if u gif ur 50% care to it...there shdn't b any issue..

haha...jus my 0.0001cent worth of comment..

cheers!

[Yoricko]

A lot of Sigma lenses have issues. If you plan to get the Sigma, make sure you really test out the lens well before buying.

[Legoz]

Originally Posted by Reportage know what f2.8, f4-f6.3 and so on stands for? F Number http://en.wikipedia.org/wiki/F-stop#...f-number_scale

Yup. My point is... if we all know what F stop is.. then the diameter really doesnt matter.

And both Tamron and Sigma (at one point of time or another) has front back focus issues with many of their lens. Its really dependent on the QC.

Regards

[Reportage]

Originally Posted by Legoz Yup. My point is... if we all know what F stop is.. then the diameter really doesnt matter. And both Tamron and Sigma (at one point of time or another) has front back focus issues with many of their lens. Its really dependent on the QC. Regards

so the Canon 24-70 L doesnt really have to be 77mm diameter...hmm.

[Legoz]

Originally Posted by Reportage so the Canon 24-70 L doesnt really have to be 77mm diameter...hmm.

The price of the lens is a function of the way it is made. The way it is made is dependent on how the designers (and company) wanna market the lens.

Technically, you can have a 24-70 lens with just 52mm in diameter.. the only diff is that compromises would have to be made. The F stop is but one of the variables.

Regards

[Octarine]

Originally Posted by screamingsnapshots i MIGHT be wrong, but i've seen a couple of my friends with the tamron 17-50, and the AF tends hunt around abit (even in decent lighting conditions) and isnt accurate sometimes? i use the sigma 18-50 and it doesnt face the problem.. Not too sure about IQ, but i think they're pretty similar, unless you start pixel peeping, which i dont.

Not only the lens is focusing. It's the body that gives the respective commands to the lens after evaluating the image delivered from the lens and analyzed by the AF sensor unit. Hunting can happen even in decent light conditions if there is not enough contrast for the AF sensors to determine the status of the lens (how much off focus) and therefore how much the focus unit has to move to achieve focus. In such case the lens starts hunting. It' simply the last resort to check for any setting that gives a focused image. I have had focus hunting also with Canon kit lens. If it happens just check the way you try to focus, you'll find the mistake.

[LukaviZ]

i've heard of issues with Sigma much too often, though I was also told that the service centre is efficient in rectifying focusing issues.

hmm... i chose the tamron though, because it's well received by many, and the bonus is that it offers 1mm more of wide angle

[XenoPhoto]

tamron for me. just that it is noisy.