[Solved ] 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

[U-Type]

I understand that the 5Dm3 AF system will have different sensitivities on its AF points depending on the maximum aperture of the lens.

I got a Tamron 28-75 f2.8, and while selecting AF points, it looks like I expect to, something like the first pic where the black dots are solid and the grey dots are blinking

However when I mount my Canon 100 f2.8 (non L) on it, ALL of the AF points on the left and right groups are blinking. (refer to second pic)

Does anyone know why that is?

 

[Mt Spokane Photography]

Re: 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

I just tried mine, I had to change the setup to allow all 61 points, and then it worked like your top image with just the gray dots flashing. My 24-70 was the same way.

If you have enabled all AF points, try a camera reset. Sometimes a 3rd party lens can play havoc when a Canon lens is subsequently mounted. I've had to reset my camera for that issue. Third party lenses tell the camera that a Canon lens is mounted, and then the trouble begins if you try to mount the same Canon lens as the 3rd party was emulating. If resetting the camera doesn't fix it, and the obvious contact cleaning, then your lens may have a problem.

OOPS, I have the "L" version. The non L works as stated.

 

[GaryJ]

Re: 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

I think Neuro discussed this,the Macro 100mm L f2.8 ,is a different grouping than ordinary lenses,this means the focus points don't react as they would with another 2.8 lens that was not a macro.

 

[Loswr]

Re: 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

I think Neuro discussed this,the Macro 100mm L f2.8 ,is a different grouping than ordinary lenses,this means the focus points don't react as they would with another 2.8 lens that was not a macro.

Correct. The 100mm f/2.8 Macro (non-L) is in Group E, so it behaves like a typical f/5.6 lens for AF point selection on the 5DIII/1D X (all 61 points available, 21 cross-type points, like your bottom pic). FWIW, the 100mm f/2.8L Macro IS is a little better - it's in Group C, meaning it behaves like a typical f/4 lens (all 61 points available, 41 cross-type points like your top pic, but no dual crosses like most f/2.8 lenses), while the 180mm f/3.5L Macro is worse…it's in Group G (only 33 points available, 15 cross-type points).

For the 100mm Macro non-L:

 

[U-Type]

Re: 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

ooo, I understand now. thanks for all your guys' input and help

I guess it's cause the macro has built in extension tubes for achieving 1:1 magnification? Thus the bellows factor causes it to be registered as a f5.6?

 

[Loswr]

Re: 5Dm3 Not Recognizing 100mm 2.8 Macro as f2.8?

I guess it's cause the macro has built in extension tubes for achieving 1:1 magnification? Thus the bellows factor causes it to be registered as a f5.6?

Maybe…although both the 100mm macro lenses (L and non-L) achieve 1:1, but they're treated as different groups. So possibly a combination of bellows factor and some empirical performance testing by Canon...