Tamron 17-50mm TTL-BL problems revealed

[chanjyj]

http://dptnt.com/2007/10/over-exposed-flash-shots-with-tamron-af-17-50-f28-xr-di-ii/

http://www.bythom.com/1750lens.htm (At the bottom of the review)

Glad I never bought this lens
Imagine using flash compensation for this lens.. then you change to a NIKON telphoto/wide angle.. and then you forgot to change flash compensation value - bye bye to your picture.. and if it's an important event good luck to you

[chanjyj]

http://forums.dpreview.com/forums/re...ssage=25697386

Seems like this is not the only Tamron lens with the problem. The 90mm macro seems to be plagued with the same problem too.

In a long stretch, maybe all Tamron lenses have this defect.

[SolBadGuy]

Hmm, wonder if I'd get the same problem on an old body like S3 Pro, with an old flash like SB 80, which uses D-TTL.

[chanjyj]

Originally Posted by SolBadGuy Hmm, wonder if I'd get the same problem on an old body like S3 Pro, with an old flash like SB 80, which uses D-TTL.

I don't think so. D-TTL uses the preflash. Doesn't bother with subject-camera distance. So it would not be affected.

I-TTL would also not be affected. So far I believe only TTL-BL would be affected. (And possibly CLS too)

[chanjyj]

http://www.nikonians.org/cgi-bin/dcf...wmode=threaded

http://forums.dpreview.com/forums/re...ssage=23424733

Seems like it is not bad copies or what. Rather, a design flaw in ALL Tamron lenses (they do not give correct subject-camera distance to the camera)

[ortega]

i'll test

but now i can think of 2 work arounds

1. bounce flash
2. change to A mode on your flash

[chanjyj]

Originally Posted by ortega i'll test but now i can think of 2 work arounds 1. bounce flash 2. change to A mode on your flash

No lah. Using TTL will solve your problems because TTL doesn't use distance info transmitted by the flash,

The problem starts when you use TTL-BL cause that mode uses distance info.

[smtan24]

I'm using a Tamron 90mm on a Dynax 5D and it over expose with flash about 2EV. I resolve the problem with advise from one of CS member by diabling the ADI funtion and use TTL only. Could other brand camera have the same issue?

[chanjyj]

Hey.. I thuoght I posted this in Nikon forum because the problem deals mainly with TL-BL,,

Who shifted it to this "Others" forum?

[ortega]

Originally Posted by chanjyj Hey.. I thuoght I posted this in Nikon forum because the problem deals mainly with TL-BL,, Who shifted it to this "Others" forum?

this is a tamron issue and not just for nikon, so i guess that is the reason it was moved here.
it is good to have feedback from other camera brands as well

[psychobiologist]

so how about nikon AF lenses?

there are quite many happy users of the tamron though.

do you use head on flash or diffused?

[chanjyj]

Originally Posted by psychobiologist so how about nikon AF lenses? there are quite many happy users of the tamron though. do you use head on flash or diffused?

I never buy the lens.. heng ah
But when I use fill flash it is in TTL-BL mode with SB-800 diffuser. Since I use matrix in that mode, it is quuite likely I will suffer from the Tamron's ill effects.

[lsisaxon]

Originally Posted by chanjyj I never buy the lens.. heng ah But when I use fill flash it is in TTL-BL mode with SB-800 diffuser. Since I use matrix in that mode, it is quuite likely I will suffer from the Tamron's ill effects.

That's why I always say, don't buy third party because they do not have the full electronic communication protocols. They just reverse engineer the communication and implements what they think how Nikon lenses communicate with the body. They will get something right but definitely not everything.

[chanjyj]

Originally Posted by lsisaxon That's why I always say, don't buy third party because they do not have the full electronic communication protocols. They just reverse engineer the communication and implements what they think how Nikon lenses communicate with the body. They will get something right but definitely not everything.

Give me a cheap f/2.8 normal zoom then
I have no cash to go round on a 17-55mm.. already I buy 18-200mm my brain protest