A Coding Question

[lars_bergquist]

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The manual of my M8 states, in no uncertain terms: "When using a lens without 6-bit coding, the recognition function of the camera must always be turned off to prevent malfunctions."

 

This means, if we may believe the warning, that dire consequences will ensue if we change between coded and uncoded lenses without accessing the main menu and switching off lens recognition. These malfunctions are not specified. The question is: Are they real? If so, what are they?

 

I understand that it is in the corporate interest of Leica Camera to keep independent lens manufacturers (read: Cosina and Zeiss) away. Even at the price of getting old M users to send in droves of Leica lenses for coding, even in cases, such as 50, 75 and 90 mm lenses, where the benefits of the procedure are extremely marginal. However, if this means that every change of lenses from a wide-angle to a longer lens and vice versa, means a visit to the main menu, then to me this sounds like a good argument against coding, period. Especially if you have over a dozen lenses ...

 

The old man from 1936 B.C. (Before the Computer)

[marknorton]

Manual writers are a cautious bunch what with lawyers breathing down their neck and there's always scope for something being lost in the translation.

 

They're obviously thinking that any old lens mounted on the camera without a code may be incorrectly recognised but in practice, I haven't found there's a problem. If you keep the bayonet ring clean (you DO keep your bayonet rings clean, don't you?), the lens should be recognised as type 0 which means "None".

 

As for the consequences, the worst that could ever happen would be that the camera applies image correction inappropriate for the lens mounted and - shock, horror - might put the wrong focal length in the EXIF header.

 

Seen in the context of the risks we all face - and I speak as someone who has just cut his finger while prepating melon for breakfast - these potential problems are at the "fairly benign" end of the spectrum...

[lars_bergquist]

Well, Mark, if you're willing to take the risk, I am too. I have risked my life at times (not always voluntarily), so even if it's an M8 ... And you know, the C/V 75 mm is a really nifty little lens.

 

The old man from the Bad Old Days

[steve_l]

and if you want to ensure that you don't get incorrect lens correction, you can avoid the main menu by setting up two user profiles that are identical except for lens detection, then just switch using the SET button

[carstenw]

This is a real risk, but the worst-case scenario is simply that a lens like a Zeiss 21/2.8 would be mis-recognised as something else, because it has a screw-hole in the mount exactly over the sensor. Try all your code-less lenses, look through the EXIF and see if any of them registered as something.

[jaapv]

The Biogon 21 needs a drop of white correction fluid on the screw.