Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Sony Alpha dSLR / Konica Minolta dSLR, Sony SLT

Reply
 
Thread Tools Search this Thread
Old Jan 27, 2008, 7:00 AM   #1
Junior Member
 
Join Date: Jan 2008
Posts: 3
Default

Can somebody tell me whether the alpha 100 auto-focusses via theflash unit's infra-red or is ADI a better way? How fast is the autofocus with the flash gun? I have a 3500xi at present which I know doesn't involve the flash unit in the focussing and sometimes in very low light focus is forever.

Thanks

Philip
flip43 is offline   Reply With Quote
Sponsored Links
Old Jan 27, 2008, 12:45 PM   #2
Senior Member
 
Join Date: Nov 2006
Posts: 323
Default

Welcome to the forum Phillip.

I just ran a quick test with my A100+KM 28-75mm f/2.8+Minolta 5600HS (D). I would say that the AF speed is the same in dim light as it is in bright light with no flash.

ADI is used for controlling flash exposure (with 'D' lenses) and I don't think that it affects AF speed.

Good luck.
FrankD is offline   Reply With Quote
Old Jan 27, 2008, 1:08 PM   #3
Senior Member
 
Join Date: Feb 2006
Location: California
Posts: 2,295
Default

Hello Philip and welcome to the forum.

I agree with Frank concerning the ADI and focus speed. One other observation I've made is how with "D" type lenses (especially the kit lens 18-70) when I have my 5600 mounted the focus seems to be more accurate.
lomitamike is offline   Reply With Quote
Old Jan 27, 2008, 3:30 PM   #4
Junior Member
 
Join Date: Jan 2008
Posts: 3
Default

I have the Zeiss 16-80 - is that what you refer to as a "D" lens?

Overall how does the speed of focussing compare say with a Nikon D2 with matched flash gun or a Canon equivalent which I think uses the infra-red focussing system taking the measurement off the gun?

Many thanks for such quick responses too.

Philip


flip43 is offline   Reply With Quote
Old Jan 27, 2008, 9:52 PM   #5
Senior Member
 
Join Date: Nov 2006
Posts: 323
Default

flip43 wrote:
Quote:
I have the Zeiss 16-80 - is that what you refer to as a "D" lens?

Overall how does the speed of focussing compare say with a Nikon D2 with matched flash gun or a Canon equivalent which I think uses the infra-red focussing system taking the measurement off the gun?

Many thanks for such quick responses too.

Philip

The Zeiss is a "D" compatible lens (and a very nice lens too!). The "D" series lenses were first introduced by Minolta when they introduced the ADI (Automatic Distance Integration) festure. ADI compatible lenses send focusing distance information back to the camera body so that it can more accurately control flash exposure. A simple way to identify if you have either a "D" or "non-D" lens is to count the number of electrical contacts there are on the lens mount. Non-D lenses have five contacts and "D" compatible lenses have eight contacts. I think that most of the current Sony/Ziess lenses are "D" comaptible. Many of the older Minolta lenses are not.

I don't know if many people in this group can offer a comparison between Sony/Canon/Nikon. You may get more response if you post that question on the Canon dSLR and/or Nikon dSLR forums.

Regards.
FrankD is offline   Reply With Quote
Old Jan 28, 2008, 3:12 AM   #6
Junior Member
 
Join Date: Jan 2008
Posts: 3
Default

Thanks for your help.

Philip
flip43 is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:38 PM.