[Brightcolours]

[quote name='Frank' timestamp='1311950095' post='10310']

I don't understand why photozone does not test Tamron 200-500 again (on FX body). In certain sense this is a charming lens since it has an attractive focus range, it is not expensive but has a good IQ, and in addition it has a very light weight in the class.



Frank

[/quote]

The reason for longer lenses not being tested, is that the longer the lens is, the bigger a distance is needed between camera and focus charts. The focus charts are designed to fill a certain amount of the image... so the longer the focal length, and the higher resulting magnification, the bigger the distance between camera and subject needs to be.



And you do need to have the room indoors to be able to test that like you test the other lenses...



Suppose the test charts are designed to be 51x the distance of the focal length from the camera. 500mm would then need 51 x 0.5 = 25.5 meters. Add some space behind the camera too. I certainly do not have the space (26 meters minimum!).



The biggest space i have available is a bit over 7 meters, and that is without a blind wall on either end!

[SRoyC]

After a lot of research I could dig out the following which I would like to share with the experienced members for their thoughts, which are very important to me.



1) Reviews- not exactly a direct comparison, but one can draw a comparative study:



[url="http://www.ephotozine.com/article/tamron-sp-af-200-500mm-f-5-6-3-di-ld--if--interchangeable-lens-review-13558"]Tamron SP 200-500 f5/6.3 LD IF Lens Review[/url]



[url="http://www.ephotozine.com/article/sigma-150-500mm-f-5-6-3-dg-os-hsm-interchangeable-lens-review-13621"]Sigma 150-500 OS HSM Review[/url]



[url="http://www.ephotozine.com/article/photographing-nature-with-tamron-lenses--the-sp-af90mm-f-2-8-macro-and-sp-af200-500mm-f-5-6-3-di-ld--if--13057"]Additional article on Tamron 200-500 (2nd part of the Article)[/url]



Conclusion that I drew: Tamron 200-500 wins all hands down in Sharpness as well as CA (both Center and Corners) at 500mm end. Now I think for bird and wildlife photography the IQ at the 500mm end is most important.



Please share your thought on this matter.







2) Feature Comparison:



-----------------------------Tamron 200-500 ------------------Sigma 150-500 OS------



Max Aperture (wide): ----------f5 -------------------------------------- f5.6

Min Focus: ------------------2.5m ---------------------------------220cm ------- Interesting to note,

Weight: ---------------------1237g -----------------------------------1910g ------- Interesting to note

Stabilization: --------------------X -----------------------------------------Y

AF Motor: ----------------------- X ----------------------------------------HSM

Min Aperture: ----------------32 -----------------------------------------22

Lens Elements: -------------13 ----------------------------------------- 21--------- is it lesser the better?

Lens Groups: ---------------10 ------------------------------------------15---------- is it lesser the better?







As I ponder over the above comparison the following questions come to my mind:

1. Less number of elements and groups in Tamron, does not this mean better and consistent Optical Quality?

2. Does the better Close Focusing distance really matters?

3. For bird photography, should OS be the deciding factor? Considering the above articles outcome clearly showing better IQ for Tamron!

4. Sigma though sports a HSM, will it really AF that fast? How good the AF speed of Tamron?







Please help me with this further more so when two members using either of the lenses have kindly decided to come out and help me. I think you, the users (past/present) are in best position to help me out as well as other experienced users.



Thanks again, you people are really great.

[arvydas]

Hi,

dcwatch have reviews on both lenses ([url="http://dc.watch.impress.co.jp/docs/review/date_lens/20100428_364184.html"]Sigma 50 - 500[/url] and T[url="http://dc.watch.impress.co.jp/cda/lens/2007/09/04/6918.html"]amron 200 - 500[/url]), however on different bodies, and Tamron on Nikon D200, so bit outdated. Anyway they are good for real life examples. Google translate might help also <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />.



A.



P.S. they have and [url="http://dc.watch.impress.co.jp/docs/review/date_lens/20090625_296051.html"]Sigma 150 - 500mm[/url].

[SRoyC]

[quote name='arv' timestamp='1312275777' post='10340']

Hi,

dcwatch have reviews on both lenses ([url="http://dc.watch.impress.co.jp/docs/review/date_lens/20100428_364184.html"]Sigma 50 - 500[/url] and T[url="http://dc.watch.impress.co.jp/cda/lens/2007/09/04/6918.html"]amron 200 - 500[/url]), however on different bodies, and Tamron on Nikon D200, so bit outdated. Anyway they are good for real life examples. Google translate might help also <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />.



A.



P.S. they have and [url="http://dc.watch.impress.co.jp/docs/review/date_lens/20090625_296051.html"]Sigma 150 - 500mm[/url].

[/quote]



Thanks arv for the links, as you rightly assumed, I could not understand anything and unless I know about the language, I cannot use Google Translate effectively. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='' />

Are these pages is Korean?



EDIT: Ok, figured...it's Japanese, at least Google Translate thinks so, and I'm happy as long as I can see English as a result of translation <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />