Photoclubalpha

I have had this lens for a while , it has a tendancy to underexpose pictures when I us a flash. It has been back to SIGMA and they say it is working fine. Any suggestions? Should I 86 it and get somehthing else?

It's not a terribly expensive lens but I see the few reviews that there are of it aren't screamingly favourable none of those are D lenses either. theres lots of lenses inthat range from used minolta to brand new sony so you have a lot of choice. I was intrigued by your flahs under exposing with the lens attached does your copy have a distance encoder? 8 contacts on the back.. have you tried your flash in TTL mode too ?

I set the flash to TTL and it works perfectly. Thanks for the input.

wow thats good to hear. I'm a little surprised though I thought the cameras would default to TTL automatically if a lens without a distance encoder was attached. maybe that info is wrong.

ruthless wrote:I set the flash to TTL and it works perfectly. Thanks for the input.

Javelin wrote:wow thats good to hear. I'm a little surprised though I thought the cameras would default to TTL automatically if a lens without a distance encoder was attached. maybe that info is wrong.

According to the A700 manual, no, it won't automatically switch. It only reverts to TTL automatically when you switch to wireless, plug in a PC cable, or attach the twin macro setup. If you use a non ADI lens and don't change to TTL, you can get some weird effects as the camera tries to use the non-existent distance information as a friend of mine found out the hard way. You must also change to TTL manually when you are using a diffuser, any filter that changes exposure (Like ND's), wide panels, or close up lenses. Basically anything attached to the flash head or front of the lens. As much as I like some of my older lenses, if I am going to use direct flash, then I only use my ADI lenses. Of course I seldom use direct flash, prefering diffusers, wireless setups and the like, so it's rare for me to need ADI. Still, it's nice that it's there.

well thats good to know. I think it's been a pretty common misconception then because I see it quoted a lot.