[Leica] Konica Hexar RF body / Leica Lenses Compatibility Survey LONG

[Cummer Family <cummer@asiaonline.net>]

Dear Luggers
Here is what I have so far. Twelve people representing experience with 15
Hexar bodies and a big variety of Leica glass have responded.
SUMMARY: Of fifteen Hexar RF's fourteen have no back focus problem with
high speed Leica lenses and one doesn't know as camera was used for
close-ups only.  The less than 0.7 meters decoupling problem was mentioned
in four of the twelve cameras - this is to be expected since RF's minimum
focus spec is 0.7 meters. Focus past infinity was mentioned for four cameras.
DETAILED REPLIES (quoted with permission)
Reply # 1"I have used a decent variety of M and LTM lenses with the Hexar
and a Leica M3, most often shooting in the 1 meter-or-less range (usually a
tiny bit longer than the bare minimum focus - but not much).  Ones used
less exhaustively (but tested nonetheless) are starred.
Canon: 35/1.8(2), 35/2, 50/1.2, 50/1.5, 50/1.8, 100/3.5, *135/3.5(3)
Konica 50/2, 90/2.8
Leica: 35/2 (4th gen), *50/2 Summicron-M (1st gen), 50/2 Summar, *50/2
Collapsible Summicron,
*90/2.8, *90/2.0 (not ASPH)
Nikkor 50/1.4, 50/2, 85/2, 105/2.5
Soviet 35/2.8(3), 50/1.5(3), 50/2(4), 85/2(many)
For LTM I have pretty freely mixed and matched Leitz, Bower, Gandy and
Kobalux LTM adapter rings.  Some are all chrome; some have brass backs.
Some are matte; some are mirror-polished.
In a couple of instances I had focus or RF problems with the Soviet
stuff (most notably the 85/2 Jupiter), but when I used a "real" (and
completely calibrated) M body as a control, these problems manifested
themselves identically.  So I concluded that there were bugs in the
lenses themselves."
Reply #2 "my Hexar works fine with the 35/1.4 , and since that 
is the lens I use most on it, it looks like I'll be OK. The 90APO is 
hard enough to get dead on consistently with the .85 bodies, let 
alone a shorter base rangefinder. My camera has no such 
discrepancy, and that any discrepancies I've noticed are within my 
limits of error. It'll not replace my Leicas, but it's a fine 
addition."
Reply #3 "my RF did not have parallax compensation down to the minimum
focus distance with all Leica lenses I used (21/2.8 ASPH, 29/2.8, 35/2
ASPH, 35/1.4 Aspherical)." When asked if there was a focus problem at
infinity #3 replied that he had used the camera only for closer pictures
and couldn't say.
Reply #4  "My RF works fine with all my M lenses: including the Noctilux
and 135/4. I have not used the Konica 50 on all my Ms but it works fine on
one M6."
Reply #5 "On my Hexar I've used the 24/2.8, 28/2.0, 35/1.4, 50/2.0, 75/1.4 and
the Tri. … I've used the 28 and the 35 wide open at closest focus with no
problem but I have not used the 75 in any configuration more challenging
than 2.0 at 1.5 meters….I've never noticed any focus problems of any sort
No missed planes of focus, no RF decoupling below .7m."
Reply #6 "All my three RFs focus without any problems, including the APO
90/2.0 and 75/1.4 wide open at minimum focusing distance. However, all
three of them focus a touch beyond infinity…. Also, all my RFs focus down
to 0.7m only.  With Leica lenses that focus a bit closer than 0.7m, you get
this 'decoupling' issue.  I do not regard this is a problem, since Konica
state that the RF focuses down to 0.7m, not closer."
Reply #7 "I measured the optical register (the English term for the 
flange-to-film plane distance) using a machinist's depth gauge with a 
double-arm standard placed across the flange and the measuring point lightly 
contacting the center of the pressure plate (shutter held open).  The gauge 
reads in 1/1000'ths of a millimeter (5X the sensitivity of 0.02mm quoted as 
Leica's tolerance) and my Hexar is within 0.008mm of the 27.800 ideal. My 
camera was second-hand and varies significantly from Konica's 
official tolerances.  It does prove that a Hexar *can* be set up to Leica 
specs, but then would be out-of-spec for the Hexanon lenses."
Reply #8 "I have a Hexar which I like and use as a backup to the M6 - ie
not that often. I have used it with a wide open Noctilux at about 4m at a
concert and am happy with the results. Its only shortcoming IMO is that the
meter area
is less defined ( or known by me!) and I get more exposure inaccuracies
than with my M6"
Reply #9" I have used the Konica with the pre-asph 35 Summilux
wide open. One has to be careful (due to the .6x magnification) but it
focuses. - and it's a cinch with 50 Summicron.
Reply #10"My Hexar RF focuses a little past infinity, so I tested it very 
carefully closeup at F2 with both the Konica 50 and the 50 Summicron. with 
basically no depth of field, the focus was dead on, i.e., the pictures 
were sharp. Yes it is annoying, but for all practical purposes, it works
just fine. I have now shot about 30 rolls of film with it and no problems."
#11"My Hexar RF seems to focus properly at one meter and at infinity with a
50mm Summicron."
#12 "My experience: No problems with the 35 Aspherical 1.4 or any other
Leica lens wide open at maximum aperture, but focus decoupling below 0.7
meters (Hexar's limit of focus anyway) and  "old eye problems" focussing
the 90 APO wide open." 
CONCLUSION: It is always safe to say more sampling is needed. From what has
been reported, there is inconsistency between actual in-the-field use and
what Erwin extrapolated from Konica's numbers about focussing
incompatibility between Leica lenses and the RF. Fourteen of 15 cameras
reported no soft focus problems with Leica lenses, 35 /1.4. 75/1.4 even the
Noctilux 1.0., Are Leica and Konica, as Dante Stella suggests, measuring
distances from flange to film plane in different ways? It seems so.
Whatever the answer, the suggestion that Leica lenses will not focus
accurately on the RF because of a difference in back focus is not borne out
by this little survey. Thanks to all who took the time to reply. Enjoy your
RFs!  
RECOMMENDATION: If you are contemplating buying an RF to use with Leica
lenses take a high speed normal / wide Leica lens to the dealer and shoot a
short roll wide open at infinity and closeup, develop it.  If there are no
focus problems, buy the camera if you like it. Eleven of 12 users like the
camera. One user sold his.  
Howard.