Archived posting to the Leica Users Group, 2001/02/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Sal, How do you *really* feel about it? What I found interesting about the test (if it was done accurately) is that the M6 failed to put the 75 in the same place it put the other two lenses. This is the whole accuracy/precision thing. Of course, this close-in testing requires that you only turn the lens one way (usually, from what I understand, you go near to far, but here that breaks down). Wouldn't decision to put the film plane 0.01mm back (which may be optically insignificant since LTM spec is +/- .02mm or more - and if such a difference even exists) reflect a decision to induce the user to focus *closer* rather than farther? This would at least theoretically increase usable DOF. This may be a workaround for a low-magnification finder where you may be in danger of overshooting the focus point. Focusing behind a subject is disastrous for sharpness, since you always get less DOF in front than behind the focus point. If you fit different M and LTM lenses onto a Hexar, you can see how the shutter box is cut out for a 50/2 Summicron collapsible, Summar, and even the 35/2.8 Jupiter. Everything was done for a reason. If the body focus spec is different in any significant way, I would wager that it's not accidental. Dante "Sal DiMarco,Jr." wrote: > Akhil, > Sorry, I can't be of any help here.... My opinion of the Konica Hexar is > that it was a poorly made piece when compared to a real M camera and did > offer enough features over an M camera for me to consider it. > Maybe someone else can help you. > Good Luck, > Sal > ----- Original Message ----- > From: "Akhil Lal" <akhil.lal@bcc.cuny.edu> > To: <leica-users@mejac.palo-alto.ca.us>; "Dan Honemann" <ddh@home.com>; > <TTAbrahams@aol.com>; "Erwin Puts" <imxputs@knoware.nl>; <leica@topica.com>; > "Sal DiMarco, Jr." <sdmp007@pressroom.com> > Sent: Sunday, February 04, 2001 6:29 PM > Subject: Re: Min. focus accuracy of Leica lenses and the Hexar RF > > > Recently, there was a thread regarding the Hexar on the Rollei list. > > > > Bob Shell, former editor of Shutterbug, stated that Konica have > > intentionally set the Hexar's back focus to be 0.01mm/0.01inch (it was > > not clear which) longer than the Leica M's. I assume he got this > > information from official sources. > > > > Another list member stated that Konica UK have acknowledged this > > difference and, upon request, will adjust the backfocus of the Hexar > > body to Leica M specs. Then the Hexar lenses need to have their infinity > > stops adjusted to focus properly on the readjusted Hexar body. > > > > Please note I have no firsthand knowledge of this - I'm only reporting > > what was posted on the RUG. > > > > Tom A., Erwin, Sal D., LUG'ers/LEG'ers with "inside" info, can you shed > > further light on this issue ? > > > > Regards, > > Akhil > > > > Dan Honemann wrote: > > > > > > When shooting some test slides (velvia, if it matters) with my new Hexar > RF > > > and 35/1.4 asph, 75/1.4, and 50/2, I noticed that all three lenses focus > > > closer than their min. focus mark on the lens. I also noticed that the > > > Hexar rangefinder does not register the last 1/8" turn toward the > closest > > > distance. My .72x M6 TTL rangefinder does move through the entire > range, > > > however. > > > > > > The results of my first test--a ruler and newsprint at a 45 degree > angle, > > > widest f-stop and min. focus distance for each lens, focused on the 6" > mark > > > on the ruler (shot with tripod and cable release, of course)--show that > the > > > 35 and 50 are right on the money with the M6, but the 75 consistently > > > focuses on the 4" mark instead. The Hexar RF, on the other hand, is > > > consistently off by 1.5" (too close), with sharpest focus at the 3 1/2" > mark > > > with each lens. (By the way, I often shoot wide open, and very often at > > > min. focus, so these aren't just trivial tests for me.) > > > > > > I performed the first round of tests with the SF 20 flash, and the Hexar > > > slides were a bit overexposed, so I just did a second round with natural > > > light. That's when I noticed that the Hexar rangefinder does not engage > > > with the last small twist of the focus ring toward closest distance. > I'll > > > shoot a few frames with the lens set at the closest distance mark > tomorrow > > > as well, to see if this makes a difference. I should have results back > by > > > Thursday. > > > > > > I'm left with the following questions for now: > > > > > > 1. Does the fact that the lenses turn past the 2.5" (or min. focus > distance > > > mark) printed on their barrels mean that anything closer than this mark > is > > > up for grabs? Should I consciously keep from turning their focus > ring/tab > > > all the way? > > > > > > 2. If only the 75 mis-focuses on my M6, does that mean I should have the > > > lens calibrated instead of the rangefinder (not even sure how they would > do > > > this)? Would having the M6 adjusted for the 75 mean that my 35 and 50 > would > > > now mis-focus up close? > > > > > > 3. Do those of you who own the Hexar RF notice that your RF cam stops > > > engaging beyond the .7m mark on the lens, with the last small twist not > > > affecting the rangefinder at all? Or is something amiss with my Hexar? > > > > > > Dan > >