Leica CL can't use larger then f/3.4 with lens Leica 60mm f/2.8 ASPH

[andben]

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I tested a Leica 60mm f/2.8 ASPH with my Leica CL. I used A setting and when I adjusted to the largest aperture setting it wouldn't go no larger then f/3.4. I have the latest 4.0 firmware. I suspect the camera didn't read the lens metadata correctly. Anyone else seen this?

Edited January 23, 2021 by andben
spelling

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[lct]

Welcome to the forum . I have no experience with this lens but does it happen only at short focus distance? If so it could be normal.

[Leon Sung]

Hi, Andben

 

  As i know, this lens has two working modes: Macro mode (max aperture: f/3.4) and normal mode (max aperture: f/2.8).

  The mode is selected automatically based on the focus distance.

  Please try to focus to infinity and check whether the aperture can be set to f/2.8.

[Gregm61]

Yep, you have to get really, really close before the lens switches to f3.4. It stays f2.8 up to a really close distance.

[wda]

13 hours ago, andben said:

I tested a Leica 60mm f/2.8 ASPH with my Leica CL. I used A setting and when I adjusted to the largest aperture setting it wouldn't go no larger then f/3.4. I have the latest 4.0 firmware. I suspect the camera didn't read the lens metadata correctly. Anyone else seen this?

Welcome. What aperture is recorded is an educated guess. There is no communication between lens and processor.

[LocalHero1953]

2 minutes ago, wda said:

Welcome. What aperture is recorded is an educated guess. There is no communication between lens and processor.

Er....isn't that just with the M series? In L-mount there is full digital communication.

[wda]

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3 minutes ago, LocalHero1953 said:

Er....isn't that just with the M series? In L-mount there is full digital communication.

Sorry. I thought  he referred to an R lens. 

[andben]

On 1/23/2021 at 4:56 PM, Leon Sung said:

Hi, Andben

 

  As i know, this lens has two working modes: Macro mode (max aperture: f/3.4) and normal mode (max aperture: f/2.8).

  The mode is selected automatically based on the focus distance.

  Please try to focus to infinity and check whether the aperture can be set to f/2.8.

I see, I didn't know that, then it would make sense. I don't own the lens just tested in store as I wanted to get it! Thanks so much for the answer

[andben]

I think the behavior I saw might stem from the distance as some people pointed out. Time for another trip to the store to test theory. Thanks for your feedback!!!

Edited January 26, 2021 by andben

[michali]

6 hours ago, andben said:

I think the behavior I saw might stem from the distance as some people pointed out. Time for another trip to the store to test theory. Thanks for your feedback!!!

I have this lens & Leon in post #3 above is correct. At macro distances, I guesstimate @ a distance of approx. 15cm to 20cm from the front of the lens it defaults to f3.4 & as you move further back it goes to f2.8.  The lens is designed this way & does this on both the CL & SL2.

 

[Forestier]

It could be, that the f3.4 reported at short distances is the effective aperture. As the distance sensor - object gets shorter, (increasing aspect ratio) the distance lens - sensor gets bigger. This yields in an decrease of the illumination on the sensor. Leaving the aperture mechanical unchanged, to calculate the correct exposure time, a smaller aperture (higher f-stop) must be assumed: the 'effective' aperture. I know, that some Nikon macro lenses transfer the effective and not the 'real' aperture to the camera.