5D Mark 3 and Canon 100mm f2.8 Macro

[unclened]

I'm not quite sure why this happens and the manual doesn't seem to offer any help, but whenever I attach my Canon 100mm f2.8 to the 5DMK3, only the middle 21 af points become available. I know that 21 af points seems like a lot, but there all in a rectangle and bunched together.

I have my camera set to only cross type points, but on my other lens I see the normal grid with 21 in the middle and 8 on either side.

This makes macro work a lot harder and I can't figure out any logical reason why it does that! :bonk:

 

[modchild]

Have a look at page 78 in the manual and it'll explain. The outer 8 points are Cross-type focussing for f/4 horizontal and f/5.6 vertical and your 100 L macro is f/2.8. I have the same lens and camera and get the same pattern when I use mine. It's just to give you more accurate focussing ability.

 

[lostsoulal2]

Assuming your lens is the USM version it will fall into Group E and because you have restricted your camera to cross type points it will restrict you to the 21 central points - Turning off the cross type point selection (page 99) presumably gives you access to all 61 AF points?

Looks like you may need to upgrade to the 100mm F2.8L IS version in order to access additional cross type points - this lens falls in Group C and will give you the central 21 plus a bank of 10 cross type points either side - interestingly the older 100mm F2.8 non USM len also falls into this category.

 

[Byker28i]

Have a look at page 78 in the manual and it'll explain. The outer 8 points are Cross-type focussing for f/4 horizontal and f/5.6 vertical and your 100 L macro is f/2.8. I have the same lens and camera and get the same pattern when I use mine. It's just to give you more accurate focussing ability.

This: On page 78 it says:

Depending on the lens attached to the camera, the number of
usable AF points and AF pattern will differ. For details, see pages
79 to 84.


http://ecx.images-amazon.com/images/I/E1e-92xRLBS.pdf if you haven't a copy

 

[unclened]

Assuming your lens is the USM version it will fall into Group E and because you have restricted your camera to cross type points it will restrict you to the 21 central points - Turning off the cross type point selection (page 99) presumably gives you access to all 61 AF points?

Looks like you may need to upgrade to the 100mm F2.8L IS version in order to access additional cross type points - this lens falls in Group C and will give you the central 21 plus a bank of 10 cross type points either side - interestingly the older 100mm F2.8 non USM len also falls into this category.

Thank you for that. It was never an issue on my 1ds mk3!