Tamron 17-50 f2.8 "Quick Test"

LightRules wrote in post #3080418
Hi Nick, the parfocal method of focusing (zoom all the way in, half press to lock focus, zoom back out, then release shutter) works on many of these APS-C standard zooms (even though they technically are not parfocal). I found this to be the case when testing the 18-125 and 28-75, among others, a while back. It seems like the 17-50 and 17-70 are the same. I suppose it's the safe way to ensure proper focusing at the wide end.

From my experience, in general, I am seeing Canon lenses to be deliver more accurate focusing than 3rd party more and more. For example, in my use with the 1785, 1755, and 1740 lenses, they were almost always bang-on at the wide end shooting a wide variety of subject distances and subject contrast. Anyway it's something I've noticed.

Thanks for the info, I thought it was a problem with my body, but I guess this is something you have to put up with, I guess while they compete on image clarity, the more money spent on Canon lenses gets things like better AF accuracy, at least now I know!

I can work around anything if I know for sure what is the cause of a problem.

Nick

LightRules wrote in post #3080610
You have a number of good options out there that are multicoated, like the B+W, Hoya SHMC, and Kenko Pro 1 MC Digital. Any one of these will do the job.

Thanks alot for the naming filter brands , I look for one of them soon .


BTW,you commented the Tamron hunts alot in low light, this surprised me since mine does not , so just wondering if you compared your copy to another?

Also , the Christian guy was requesting you to test the new Sigma 18-50macro and I think it 'd be an interesting test , if his Sigma 18-50 EX macro is so good that he prefers it to the Tamron without hesitation , then I should re-test one of the Sigma 18-50 macro

Actually, in Japan esp my home town Kobe , the Sigma is very popular among many Canon shooters and it is awarded as the lens of the year 2006 -2007 by a local paper.

But once , I rented the 18-50 maco with the 17-70 macro in Bangkok, mine was not so impressive and gave me a bad impression of entire Sigma lens selections .... also my 30mm F1.4 broke in 4 days(I think I did not break it) and now still looking for a replacement ......
I think most of Sigmas are not sharp on the left side and on the right side they are insanely sharp.

As for the 18-50 macro , although it was not great at least the copy
I tried for 4 days , still much better than the 17-70 macro , that said , I thought the 17-70 is a soft lens and slow- focusing lens, esp it is noticeable when compared with others.

The 17-70 is probably slower than the 18-200 or 18-50 and less accurate , no need to compare it to an USM lens to know this , but the 18-50 is a not slow -focusing lens.

Finally, I am not sure if what I thought about the lens was right, and if I have a couple of days off to go to a park or beach soon , I will rent another copy of the Sigma EX macro and try to compare with the Tamron.

I can't wait to see the digital picture review of this Sigma ...............

I made a big mistake my copy of the Sigma 18-50 EX was not the macro version and so I have to apologize for my mistake and my opinion on the EXmacro based on my stupid and unscientific test of the worng lens.

I relaized it while checking lens data on my computer .

DerekI wrote in post #3084467
I made a big mistake my copy of the Sigma 18-50 EX was not the macro version and so I have to apologize for my mistake and my opinion on the EXmacro based on my stupid and unscientific test of the worng lens.

I relaized it while checking lens data on my computer .

You seem to have had bad luck with Sigma lenses, the 17-70 must have been a bad copy as its anything but soft, it could have been more a focus issue, like misfocus, like Lightrules pointed out, Sigma & Tamron have more of this issue than Canon, but its easy to work around once you know, although im being VERY fussy here, 95% of shots from my Sigma are flawless without any focus issues, it only happens occasionally when wideopen when shallow DOF shows it up more.

AF probably is slow compared to others but ive been able to take split second shots out of a car window going along at 70mph with great results, faster AF might have helped but I didnt see any problems at the time, it kept up nicely.

Oops, going slightly off topic here, lets stick to the Tamron 17-50

Nick

I know this is a dumb question but I am still kind of new at this but I also would like to test my lenses. Is a 100% crop simply just doubling the size of your image and then cropping back down? How exactly do I do a 100% crop? Thanks

ben4633 wrote in post #3084560
I know this is a dumb question but I am still kind of new at this but I also would like to test my lenses. Is a 100% crop simply just doubling the size of your image and then cropping back down? How exactly do I do a 100% crop? Thanks

No, what you do is load up your image in whatever program you use, then with the zoom tool, zoom into your image until you are at 100% magnification, then use the crop tool to crop a portion of the image.

You never resize the image, you just make sure your viewpoint is at 100% then crop a little area, ideally centre & edge.

Nick

DerekI wrote in post #3084342
Also , the Christian guy was requesting you to test the new Sigma 18-50macro and I think it 'd be an interesting test , if his Sigma 18-50 EX macro is so good that he prefers it to the Tamron without hesitation , then I should re-test one of the Sigma 18-50 macro

The interesting thing about the new 1850EX Macro is this: in the May 2007 PopPhoto magazine, they tested the new Sigma 18-50mm f2.8 EX DC 'Macro' (reproduces a 1:3 image) and concluded it to be "a stellar performer." What I found interesting was that on their test-bench, the lens was actually found to be 18.80-50.55mm and the maximum aperture to be f2.99-3.03. So in effect, the lens, while a very solid optic, is more like a 19-50mm f3 lens. Some will say this is nit-picking, others might find it interesting. In comparison, PopPhoto found the Tamron 17-50 f2.8 to be actually 17.36–50.37mm and f2.74–2.93. So the Tamron is much closer to advertised "spec" than the Sigma. Nonetheless, they found both lenses to be optically comparable, almost neck-and-neck.

LightRules wrote in post #3085147
The interesting thing about the new 1850EX Macro is this: in the May 2007 PopPhoto magazine, they tested the new Sigma 18-50mm f2.8 EX DC 'Macro' (reproduces a 1:3 image) and concluded it to be "a stellar performer." What I found interesting was that on their test-bench, the lens was actually found to be 18.80-50.55mm and the maximum aperture to be f2.99-3.03. So in effect, the lens, while a very solid optic, is more like a 19-50mm f3 lens. Some will say this is nit-picking, others might find it interesting. In comparison, PopPhoto found the Tamron 17-50 f2.8 to be actually 17.36–50.37mm and f2.74–2.93. So the Tamron is much closer to advertised "spec" than the Sigma. Nonetheless, they found both lenses to be optically comparable, almost neck-and-neck.

Yep your nit-picking, hehe no that is interesting stuff... I will have to stop by that site & see what its all about.

Nick

DerekI wrote in post #3080442
Would you please tell me what brand of UV filter you recommend ? I need one for both 17-50 Tamron and 17-85IS Canon both use 67mm .

Thanks in advance.

I personally would recommend getting a Hoya regular thickness Multicoated one. I think they come with black packaging, the green/purple/gray ones are a bit cheaper but non or less coated. I've found that cheaper Multicoated filter increases flare.