Re: [Leica] Zzzzz... OT: Hexar RF focusing

[Dante Stella <dante@umich.edu>]

[Should we start a FAQ on how to test rangefinders and lenses...?]

Ernst --

It sounds like a simple linear adjustment.  Take it into a local shop and have the infinity point and near point checked.  Then send it to Konica.  There has been a lot of discussion about how to check RF alignment yourself.  If it focuses "past infinity" (how far?) and focuses "short of" close distances, it is probably just a simply misalignment.  But it could be your eyes.  The 0.6 VF makes it harder to finely focus close-up.  I know it's a lot tougher than an M3.  How do your pictures look wide-open at infinity?

It doesn't sound like there is a registration problem with the mount (unless it got bashed and the mount is off-alignment).  Konica USA has the equipment and expertise to correct any impact-oriented problems (as I learned the hard way - and let's not talk about how a well known delivery service later destroyed the camera, necessitating its replacement...)  Watch the weight of the lenses, too, and how you hold them.  If you exert too much pressure on any body, it can flex.  The Noctilux is a very heavy lens, even for an M.

Konica is very cooperative about fixing the RF (and it doesn't take 3 months - more like 10 days), and if you can document the problem, they may just exchange the body.

As an aside, the recurring Hexar focusing "problem" is kind of an amusing thread:

(1) 	Konica won't guarantee Leica compatibility - why?  Trademark infringement, for one.  More practically, think of the vast number of lenses you can plug into a Hexar RF body - that's about 150 or more, from Leica, Canon, Nikon, Zeiss, Komura, KMZ, Steinheil, Voigtlander, etc.  If you plug lenses from all of those manuacturers into an M3, you'll discover that the infinity point *doesn't* always line up.  That has a lot to do with manufacturing tolerances used in rangefinder cams.  

If you warranted that your camera would work with any M or LTM lens, your warranty costs would be out of sight.  General Motors does not warranty the performance of its wheel studs with aftermarket wheels.  Leica does not warrant the operation of its bodies with Canon LTM lenses.  This is for a reason.

A lot of this has to do with system tolerances.  Sometimes everything is within spec and it just adds up wrong.

(2)	It is more than reasonable to expect that the flange-film distance is identical.  Leica's figure is public, and duplicating to Leica's tolerances it is not  much more difficult than making a K-mount body with the proper distance.  I have heard conflicting stories about how the flange-distance is achieved on the Hexar (USA indicated that it was done by hand), but in most Japanese cameras, the film rails are ground to assure perfect alignment.  

(3)	A 0.6 finder is always going to be harder to focus precisely than a 0.72, a 0.85 or a 0.91.  While theoretically capable of the same accuracy, a lot of people on this group have poor eyesight.  Let's hear about how well M6 0.58 users do with the same lenses.  You have to work within the parameters of what the camera is designed to do.  Both the RF and the 0.58 are designed for wide-angles up to moderate-aperture telephoto.

(4) 	A lot of "infinity" testing falls short of the mark.  I haven't seen anything from anyone who has had the RF on a collimator.  I have had two RFs so far, and on casual inspection both looked like they focused past infinity.  Testing independently at a local repair shop (very interested in the outcome) and at Konica USA (also interested in the outcome, but in the opposite way) showed that it was on - and the negatives have agreed with both bodies.

I have seen a lot of used Ms where the infinity point had been reset to 100 feet or so, which while within a hyperfocal distance for an f/2 lens, is probably not appropriate for a 1.0 or 1.2.  It also has a disastrous effect close-up with long lenses.

The camera-store "it doesn't line up" is a self-fulfilling prophecy.  Walk outside of a New York store, and you can't see a half-mile in any direction.  Go to the top of the Empire State building, point it at New Jersey, and go.

(5)	I have never seen this problem in my own testing, which admittedly only goes down to a 50/1.2 and an 85/2 (four different examples from three different manufacturers).  With a 90/2.8, there is no RF reading difference between my M3 and my RF at 1m, which I think is pretty damn good.  As far as the flange distance, it should have been an acute problem with the 35/2 Summicron, but it's not.  (BTW: my 35/2 4th-gen - and only that lens - requires a huge distance to infinity with the M3... hmmm.)

The only way to tell is to take pictures - and if they present a problem, to have someone look at it.  



On Saturday, November 18, 2000, at 07:56 AM, Ernest Nitka wrote:

> I know this has been discussed but I got on this "train" a bit late. 
>  
> Anyway I bought my Hexar and really love it's features.  Was bothered by the 
> comments about possible rangefinder inaccuracies.  This drove me to test it 
> against my M6. 
>  
> Just comparing rangefinder readings and image separation my Hexar is off: 
> It doesn't register infinity when it should and focuses short of where the 
> M6 does ( I think this is what other people have said?). 
>  
> Well I can probably live with that but then I did a test actually taking 
> pictures and I selected a 90/2.8 @2.8 and my 50/1 @1 as the two most 
> gruelling tests of shorter distances.  Again both lenses on the Hexar seem 
> to Focus short of the M6 and it does make a difference when shooting wide 
> open under the loupe. Taking the same lens putting it on the M6, 
> re-focussing and then taking that lens with the new reading and shooting the 
> Hexar the images are sharp. 
>  
> Now to my question - can this be corrected with a rangefinder adjustment or 
> is this a problem In the hexar mount that no adjusting will ever fix.  If it 
> can be adjusted who can do this work given that I purchased the Hexar in US 
> and there is the dicey problem of not using Konica lenses and therefore 
> would Konica of USA even get involved?  Any help would be appreciated. 
>  
> On a positive note my tesing revealed that every instance of rangefinder 
> patch flare on the M6 was gone when I used the Hexar! 
>  
> Thanks ernie nitka 
>  
>