Greetings Sage Leica Shooters,

I am new to the M6 (.85, latest 50 Summilux, 90 Summicron), but I am not new to manual 35mm cameras and high-speed lenses. I have pretty good reason to believe the 50 and/or the body are sub-par.

The ultimate question is "what to do" but that can wait. I have 3 years of passport protection after all. Rather than bore you with 6 single-spaced pages of my tests, I would ask instead, how would you go about testing a suspect body/lens? The symptoms are

1) The lens doesn't perform well wide open (great bokeh, and lots of it) and 2) It doesn't seem to focus where the rangefinder says, most apparent when wide open, of course.

How would you know, given you don't have another M6/lens to play with, whether you got a lemon body, a lemon lens, or an overdose of great expectations? Any specific films, targets, methodologies? Does Erwin Puts do excorcisms?

(Pre-postscript: I've gotten some really gratifying shots with both lenses. I lika me Leica. But for this much $$$ it should be PERFECT, no?)

Thanks for your insights, Jeff

-- Jeff Stuart (jstuart1@tampabay.rr.com), July 26, 2001

Answers

Is the 90/2 fine? If so it is probably the body. My M cameras are tough as nails 99.999% of the time. Every so often (incidents are years apart) it seems like a feather falling on the camera throws the rangefinder out. Why I do not know. I drop the camera on cement, I bang it against walls and nothing happens. I suspect that yours may have been knocked about in shipping.

Cheers,

-- John Collier (jbcollier@powersurfr.com), July 26, 2001.

Jeff: I test my cameras and lenses using a tape measure on the floor and a tripod. I focus the camera at a point marked on the tape measure, usually at about a 30 degree angle and shoot wide open. I usually shoot at minimum focus, again at about 8 feet using the tape measure and then again at infinity. I always refocus between shots. This shows me where the lens is focusing. Another way is to look at an object in the distance (infinity) and see if the rangefinder is viewing correctly. This does not check the near focus. My M6 rangefinder was off from the dealer (USA) and Leica USA fixed it in record time (6 days from my hand back to my hands). I have found ALL of my lenses are on, but the bodies needed work and were sent in.

Good luck.

Mark J.

-- Mark A. Johnson (logic@gci.net), July 26, 2001.

Jeff you don't say if your summilux was bought new (being the latest model I guess so). If it was well used, the focus cam in the back of the lens may be worn. This is the case on my 70's black summicron, a ridge can be seen at the the end of the cam. It can be corrected during a CLA.

-- Mark Wrathall (wrathall@laudaair.com), July 26, 2001.

Quick test.

Close up focus lens at 1m. Put a mark/sticker on a mirror and move camera until it's in focus. Refocus on camera or yourself. Should read 2m.

Infinity. Focus on cloud and check reading.

Also make sure you are not focusing and then rotating body plane in recomposition. ie focus on eyes of subject then recompose with eyes in the top third of frame. This will cause a shift in the plane and the focus point will move behind and the shirt will be in focus and not the eyes.

Cheers

-- Simon Wong (drsimonwong@hotmail.com), July 26, 2001.

Original poster here, thanks for the comments and suggestions. The camera and lens are new (30 days old today). I did the mirror trick, but I'm not sure what it tests. The equipment is all clean. I've run about 20 rolls of film through the camera.

They say a picture = 1KWord, so here's a picture:

http://www.photo.net/photodb/photo?photo_id=300448

This was shot on a tripod with cable release, Portra 160NC, processed by the local Walgreen one-hour ($2.15 for C-41 and you get to keep the little bits of extra crud for free) lab. The film was scanned on a Polaroid 4000, 3200 dpi, RGB linear (neagtive of course), no digital filters or corrections.

The camera was positioned above my desktop viewing down at about 20 degrees. The lens was mounted and focused so the "." of the "0.7" meter mark was top-dead-center (this is slightly "behind" the lens' close focus limit).

I laid a pencil on the desktop along the lens' axis. The rangefinder presents a view of two intersecting pencils. I assume the intersection represents the rangefinder's opinion of the focus distance. I laid a 2nd pencil pependicular to the 1st at this point. I played with the focus ring concentrating on the tip of the 2nd pencil and I kept coming back to "0.7" TDC, so I believe my assumption is correct (intersecting lines gives you an extremely precise indication where the rangefinder is "pointing" -- way better than anything else I've tried.)

I replaced the 1st pencil with my trusty FaberCastel ruler, turned slightly to avoid reflections on the mm scale. I took shots at f1.4, 2, 2.8, ..., 16. The focus was where it started, "1.7" TDC. I NOT refocus between shots. (I wanted my obviously inept judgement out of the equation.)

The picture shows the extreme center of the f1.4 and 2.8 shots. I observe the following:

1) The lens focuses slightly in front of the rangefinder indication. Put a gun to my head, I'd say 16mm in front. See comments below.

2) At f1.4 the lens doesn't work. Nothing is in focus, anywhere. Resolution at f2 is about in between the two examples. Closing down beyond f2.8 increases DOF but doesn't increase detail.

To answer John Collier's question, the 90mm lens is way better. Wide open it has a shallow but obvious focus, also slightly in front of the rangefinder indication, about 8mm by my eyeball estimate (but at about twice the linear distance, so I surmise the error is probably linear as well).

What got me started on all this were some attempts at handheld portaits shot with the 50 wide open. All I've ever shot is available light, mostly with 50-55mm 1.4-1.7 lenses on 35mm carcasses. I know motion blur. Motion blur is good because something has to be in focus to see it. But I was seeing nothing but fuzz.

Now, given the rangefinder may be in error, if the DOF is of the same magnitude (which at 1.4 it probably is) it is quite likely the lens was focused just in front of my subject and since there's no foreground the whole shot is bokeh. Stop down a little, get more DOF, start to see that nifty "Leica look".

I did these tests expecting to find the rangefinder is off, and I believe it is. That's not such a big deal. All focusing gadgets are wrong, all the time. (Even my friend Bob's 5x7 with the Schneider Borg-Implant loupe). It's a matter of understanding the error and learning to compensate. Maybe I'll send the camera to NJ some day, but I can live an 8-16mm mental up-close adjustment.

The performance of the 50mm at f1.4 is much more disturbing. I paid about $1000 for that extra stop. I trust all I've read about Leica's lenses and the 50 Summilux in particular, so I'm drawn to conclude I am the proud owner of a dud lens. I don't want to conclude this, so is there some other explanation?

How can I prove the lens is in- or out-side the norm? Are there any standard film/target tests which take all my judgement out of the equation and which Leica would accept as indicating the lens performance?

Thanks for your patience and advice. I didn't want to dump such a load on y'all, but there it is.

Cheers, Jeff

-- Jeff Stuart (jstuart1@tampabay.rr.com), July 26, 2001.

Quit obsessing and just send it back for adjustment. Otherwise, you'll never be happy.

-- Bill Mitchell (bmitch@home.com), July 26, 2001.

Jeff

I'm with Bill. I obsessed over a similar observation with my 75 Summilux and it turned out to be the rangefinder which was adjusted in a snap. If your gear is in warranty there'll be nothing to argue about with Leica. They'll replace whatever is defective.

While waiting for you equipment to be returned you might read the following few lines, for the record...;-)

- the DOF in the first shot (1.4) appears to be in the grain region. It is so shallow that you can't really make out the precise focus unless you use a less grainy film.

- by judging from the second shot the focus appears to sit around 16.7 mm on the ruler (rule of thumb - no pun intended - 1/3 of DOF before and 2/3 of DOF behind focus).

- IMHO non-macro lenses aren't optimized for minimum distances but for infinity. So you better don't obsess too much about lack of bite @ 0.7 meters @ 1.4. besides, I think there are reasons for Leica to restrict minimum focus to 0.7 meters - and focus optimization might be one among them. Blame me if I'm wrong.

Cheers, Lutz

-- Lutz Konermann (lutz@konermann.net), July 26, 2001.

Mark Wrathall: That ridge is not wear - it's the part of the cam that never touches the rangefinder because it's past the minimum focusing distance. Leica quits machining the cam's curve at that point, leaving a ridge.

My brand-new 21 2.8 bought 3 months ago also has the same ridge as do all my other lenses - same place/same size - near-universal Leica lens trait.

-- Andy Piper (apidens@denver.infi.net), July 26, 2001.