Inconsistent exposure with a 2x TC
I've never been a fan of teleconverters, but when I recently spotted a Tamron-F PK-A (KR with the Ricoh pin removed) 2x MC4 TC for $4, I had to pick it up. I thought if nothing else, I'd de-glass it & use it as an "A" extension tube. I tried it out on a couple of lenses & it's actually not bad. Surprisingly sharp & relatively free of PF. Better than I expected.
Anyway - I've noticed that it exposes differently with different lenses. On the Pentax A 50/1.7, it consistently underexposes by about 1.5 stops. On the Tamron SP 60-300 model 23A, it consistently overexposes by a stop.
Anyone else used a TC that exhibited this behavior? Just curious...
Cheers,
Bob :-)
| 
Similar Threads 
