09-02-2010, 10:34 PM
[quote name='mst' timestamp='1283465563' post='2440']
Yes, but many Canon cameras (starting with the 20D) use a diamond/rhombus shaped module that leaves out some important (to me) areas. The maximum spread may besimilar to the larger and more crowded AF modules, but the area covered is definitely smaller.
I don't know if they are different or not, but they carry only slightly different names (MultiCAM 3500 DX for D300/D300s and MultiCAM 3500 FX for D700/D3/D3s/D3x).
However, the flange distance is the same for both DX and FX, consequently the position of the AF sensor is the same, too. They're usually in the bottom of the mirror box, illuminated by a secondary mirror right behind the main mirror.
-- Markus
[/quote]
I understand that some may feel the positions of AF points may lack in certain models, but that was not the point of the discussion though.
The mirror box of APS-C cameras is as far as I know always a bit smaller that the mirror box of full frame cameras. But you might be right, and maybe the bottom of the APS-C box is exactly the same distance to the optical axis as that of the FF box in cameras.
Yes, but many Canon cameras (starting with the 20D) use a diamond/rhombus shaped module that leaves out some important (to me) areas. The maximum spread may besimilar to the larger and more crowded AF modules, but the area covered is definitely smaller.
I don't know if they are different or not, but they carry only slightly different names (MultiCAM 3500 DX for D300/D300s and MultiCAM 3500 FX for D700/D3/D3s/D3x).
However, the flange distance is the same for both DX and FX, consequently the position of the AF sensor is the same, too. They're usually in the bottom of the mirror box, illuminated by a secondary mirror right behind the main mirror.
-- Markus
[/quote]
I understand that some may feel the positions of AF points may lack in certain models, but that was not the point of the discussion though.
The mirror box of APS-C cameras is as far as I know always a bit smaller that the mirror box of full frame cameras. But you might be right, and maybe the bottom of the APS-C box is exactly the same distance to the optical axis as that of the FF box in cameras.