I bought the Tamron SP 10-24mm f3.5-4.5 and use it on Sony Alpha A580. I noticed that when I mount this lens to my A580, I cannot change the AF method from phase-detect to contrast AF. Doesn't this lens support contrast AF? or is my copy of this lens defective? I am also planning to buy the Tamron SP 70-300mm USD (for sony), and I am wondering if this lens, like the 10-24mm doesn't support contrast AF either.
Would appreciate information from anyone who has knowledge of or experience with these lenses...thanks.
[quote name='rommel' timestamp='1312901127' post='10554']
I bought the Tamron SP 10-24mm f3.5-4.5 and use it on Sony Alpha A580. I noticed that when I mount this lens to my A580, I cannot change the AF method from phase-detect to contrast AF. Doesn't this lens support contrast AF? or is my copy of this lens defective? I am also planning to buy the Tamron SP 70-300mm USD (for sony), and I am wondering if this lens, like the 10-24mm doesn't support contrast AF either.
Would appreciate information from anyone who has knowledge of or experience with these lenses...thanks.
[/quote]
Contrast AF on the A580 does work with SSM or SAM lenses only. For 3rd party implementations of SSM (USD, HSM) I would check with the supplier first as there are confirmations for SIGMA HSM not to work with contrast AF.
Therefore, Tamron 10-24 does not enable contrast AF, Tamron 70-300 USD should, but I have no confirmation.
[quote name='fotorrhoe' timestamp='1312967844' post='10570']
Contrast AF on the A580 does work with SSM or SAM lenses only. For 3rd party implementations of SSM (USD, HSM) I would check with the supplier first as there are confirmations for SIGMA HSM not to work with contrast AF.
Therefore, Tamron 10-24 does not enable contrast AF, Tamron 70-300 USD should, but I have no confirmation.
[/quote]
Well it's a relief to know that the reason why Contrast AF doesn't work in the Tamron SP 10-24 is because it doesn't support Contrast AF and not because I got a bad copy. As for the Tamron SP 70-300 USD, I have made up my mind that I will buy it whether it supports Contrast AF or not. It would be nice if you have a choice between using Contrast AF or phase - detect AF, but since the 70 - 300 's main use would be sports or birds in flight shooting, the faster phase - detect AF would probably be the preferred AF method for this lens. Thanks for the information..