Any good alternative to AF-S DX 17-55mm f/2.8G IF-ED ?

[nikkie]

Yah. he explained what I was lazy to say.

You know how to check image-focal plane difference? You have to use another lens to get the 1st accurate reading. Then, you use the Tamron to get a 2nd reading.

If both readings show a difference in subject-camera focal plane difference, that is the true, and correct test. If both readings show roiughly the same result (give or take a few mm) then I have to say your Tamron is correct.

Right now your test.. I have no idea how you conducted it. Seems like it was with the same lens all the time. TTL and TTL-BL will not affect subject distance-focal plane readings. The only way you will know the CORRECT subject-focal plane distance is with another lens. Then you can compare with your present Tamron. The other lens, in science, is called a "constant".



Anyway if you are happy with your lens good for you.

checking error between TTL mode and TTL-BL mode la..
get another lens to test for what?

 

[chanjyj]

checking error between TTL mode and TTL-BL mode la..
get another lens to test for what?

See if the lens got inherent problem reporting correct subject-camera focal plane data

 

[psychobiologist]

actually its not easy to test for TTL-BL, there are scenarios where TTL-BL will under expose, and TTL will blow. after all TTL-BL is to fill.. not as a main subject flash.

taking a picture of an object in TTL and TTL-BL, at close enough distance, good enough background lighting, there wouldnt be much issues. but if one's shooting something crucial, like an AD, and needs spot on accuracy, well there's only one choice.

else if you dont feel nor sense/experience that TTL-BL distance issue on the tammy, the tammy's a fine lens.

i use manual lenses, and AF, non D lenses, and currently dont have the luxury of distance reporting for flash photography. still surviving well on TTL, but with diffuser, i.e. omnibounce/light sphere, at times on slow front sync.

 

[chanjyj]

actually its not easy to test for TTL-BL, there are scenarios where TTL-BL will under expose, and TTL will blow. after all TTL-BL is to fill.. not as a main subject flash.

taking a picture of an object in TTL and TTL-BL, at close enough distance, good enough background lighting, there wouldnt be much issues. but if one's shooting something crucial, like an AD, and needs spot on accuracy, well there's only one choice.

else if you dont feel nor sense/experience that TTL-BL distance issue on the tammy, the tammy's a fine lens.

i use manual lenses, and AF, non D lenses, and currently dont have the luxury of distance reporting for flash photography. still surviving well on TTL, but with diffuser, i.e. omnibounce/light sphere, at times on slow front sync.

TTL buddy