automatic mode with old lens

[mrlast]

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Hi guys.

 

I have a question regarding the M10. How does the automatic mode work

with old uncoded lenses? How does the camera know what aperture I selected?

I do not mean the EXIF data but the automatic mode.

 

Thank you. All the best, Severin

[jaapv]

It will never know which aperture you selected, irrespective of the age of the lens, there is no connection.

Old and new lenses are the same.

It will know which lens it is if you have it coded, or if you select it in menu.

The camera will estimate the aperture from exposure values, but it will not be recorded in EXIF.

 

The A setting will use the amount of light entering the camera, not any aperture  or lens data.

[UliWer]

Sorry, I am not sure what you mean by "automatic mode".

 

Automatic metering works with old and new lenses independantly from coding. The camera never knows which aperture you choose because there is no technical link between the lenses aperture and the camera. Automatic meterering reacts only indirectly on your aperture: smaller aperture - less light - longer shutter time. But the automatic metering does not know whether the low light comes from your aperture or from dark surroundings otside.

 

You can use Auto Iso dependant on the focal length of your lens, if you want to assure that the camera always uses a release time  2* or 4* of your focal length (e.g.90mm lens - longest release time 1/180 or 1/360). With a coded lens the camera "knows" the focal length from the code.

 

For an uncoded lens, you can choose an appropriate  lens detection for a certain - also older - lens from the Menu: "Lens Detection" - "Manual M" - you get the list and choose the lens you want. Then you have the same effect as if the lens was coded.

 

There is one problem for old screw mount lenses which need an adaptor described here: http://www.l-camera-forum.com/topic/268492-m10-fw-requestsbug-reports/?p=3236351

 

(Edit: jaapv was quicker)

[AlanJW]

Auto mode means the camera selects the shutter speed.   You select the f stop manually.   The camera measures the light coming through the lens at whatever aperture you have selected and chooses a shutter speed for a "correct' exposure.  The camera never actually knows the f stop, just how much light is coming through.  You know the f stop because you picked it.   It is all pretty simple.

I put "correct" in quotes because you may want to countermand what the camera selects, and that is pretty easy too. 

[mrlast]

Thank you guys a lot!