[Leica] More M8 questions

[mark at rabinergroup.com (Mark Rabiner)]

On 4/1/07 1:57 PM, "Leonard Taupier" <len-1@comcast.net> typed:

>  From what I can see the current Noctilux is the biggest problem. It
> is made worse by a focus shift that occurs with this lens between f2
> and f2.8. The focus shift causes a more pronounced back focus
> condition then at f1. The shift remains up to f5.6 or so but begins
> to be masked by the DOF. I have seen the same problem with my film
> M's but not to the extent of the M8. I have seen the same type of
> shift with the 50/1.4 Summilux but it generally stays in focus but
> barely.  The APO 90/2 ASPH will also back focus.
> 
> The hex adjustment to the rangefinder cam is not really a fix for
> this problem. That cam adjustment is the infinity adjustment for the
> Leica rangefinder. It does pull in the backfocus problem of the
> Noctilux but will also throw off the infinity focus of the long
> lenses.  The best fix for these problems is to do what Tina did. Send
> Leica the lens and body.
> 
> Len
> 
> 


This famous focus shift on the Noctilux between such and such f stops was
brought up by some guy on the lug a decade ago. Was asked for any
corroboration on this. Was given none. And other lenses too I see.
Would love to see any kind of corroboration on this what so ever.
Some kids Blog along with the keys to utube vignettes would be a start.
But some lens expert person would be ever so much better.

Mark Rabiner
8A/109s
New York, NY

markrabiner.com