Re: [Leica] Question: R8 and lenses without ROM

[Pascal <cyberdog@ibm.net>]

On 02-02-1998 04:07 TEXWORKER@aol.com wrote:

(snip)
>Until last week I believed the main information transmitted to the camera 
>from
>the ROM lens was the focal length of the lens or in  the case of the zoom the
>apparent focal lenght being used.  HOWEVER, in discusion with dealer and
>leica, as to whether to ship new  lens or add the ROM chip to misshipped 
>lens,
>Leica admitted that if they added the chip in N. J. it would not transmit as
>much information as a factory installed ROM would.  No other explanation was
>given and  I chose a new one rather than  having N. J. add the chip. I am not
>sure what this means.  
>
>Any ideas anyone??
>
>clifton (texworker@aol.com)
>

Brian Bower said in his book "Leica R photography" (latest edition) that 
the electrical contact strip transfers information from a ROM chip in the 
lens through the contacts in the R8 body. The contact strip provides 
information for dedicated flash guns and also to enable more precise 
stopping down of lenses when the camera is in automatic shutter speed 
priority or programme operating modes.

Check your R8 manual: it will say that, in addition to mechanical control 
of exposure, an electronic one is carried out with ROM equipped lenses, 
but only in P and S mode. This would ensure that, in the event of some 
mechanical malfunctioning, exposure would still be OK. When fitting ROM 
chips onto lenses (new, but also old ones), each lens is tested and the 
ROM is so adapted to each unique lens that it also contains information 
on it's unique capabilities or slight differences.

This was confirmed to me by an E-mail from the Leica Solms technical 
department.

Pascal

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