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Auto iso problem on LS: help appreciated


Docderm

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I mounted my 60mm macro r lens on the SL and chose this lens in the r lens profile list

In the auto iso menu I chose: Iso range 50-6400; "maximum speed" = 1/2f; floating Iso off

 

The camera sets the value for shutter speed of 1/30th second. It alters the Iso so the exposure is appropriate. BUT it is not setting the shutter speed to 1/125th second or less. 

 

If I choose instead in the auto iso menu a fixed value for minimum speed of 1/250th second, that works. The shutter speed is 1/250th. 

 

What is going on? Any advice appreciated. 

 

DocDerm

 

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More data: 

1) I attach the R lens to the SL with a Novoflex adapter: yields 1/30th second regardless if I set 1/f or 1/2f

 

2) I attach a M lens to the SL using the Leica M to T adapter: works a treat. 

 

Could this "R" lens problems actually be a lens adapter issue? Perhaps the Leica brand adapter tells the SL to check the lens profile selection and then set the Auto Iso. 

Perhaps the Novoflex has no connectivity to the SL so the auto iso is not aware of lens selection and defaults to 1/30th

Thanks

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Docderm,

 

it seems to me that if you attach a 60mm lens and choose 1/2f the camera is doing what you ask of her: 60/2=30. Perhaps you were expecting 2*f instead of 1/2f?

Hope this helps, best

 

Vieri

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Floating ISO only works with the dedicated lenses ... for example, with the SL24-90 and the SL set to a fixed ISO setting, it uses ISO to compensate for the migration of maximum aperture from f/2.8 to f/4 if the lens is at the maximum aperture setting when zoomed. It can only work with dedicated lenses because the SL body must have specific information about both the lens aperture and zoom setting, only available with dedicated lenses. I've not found this to be a particularly useful feature and usually leave it off. Maybe I'm not running into the circumstances where it is useful. 

 

The Novoflex adapter does not provide access to the R lens codes, so the SL body does not know what lens is attached and therefore has no focal length information to work with. 

 

The AutoISO "1/2f" setting should be read "1 divided by (2 times f)" mathematically, so if the SL body knows the lens focal length, it sets the exposure time baseline (the longest exposure that it will set before raising the ISO to compensate) to 1/120 second for a 60mm lens. But if you're using the Novoflex adapter, the body has no focal length information and goes to a default of 1/30 second. 

 

So ... your camera is working normally. For adapted lenses that do not supply the focal length information to the body, set a specific exposure time baseline and AutoISO will work as designed.

 

If you want to take advantage of the R lens profiles (you get EXIF populated with lens name, focal length, a more accurate estimate of actual taking aperture, and adjustments to raw and JPEG image captures designed to optimize them for the specific lens), you need to use the R Adapter M fitted to the M Adapter T instead of the Novoflex adapter. You then manually set the lens profile for a given R lens from the SL's in-body list.

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