Leica R question

[henry_ting2]

I have a R8 and the exposure has not been consistent. I tracked the

problem down to the camera's inconsistent aperture close down while

tripping the shutter. The cam that trips the lens aperture flips to

about 8'O clock position (looking from the front). However, when I

use the pre-release, I see the cam swing to about 11'O clock

position. I suspect this is the cause of exposure discrepency. Can

someone confirm their R8 to see if this is also the case ? I'm trying

to isolate the problem whether its the camera or the lens. Yes, I

tried the "peek" through the camera back while tripping the shutter

and the lens aperture seems to stop down in variable degrees.

[xavier_dalfort]

Hi Henry,

 

Some R8 have developped a failure with the spring back command of the diaphragm.

Why don't you join the Leica Reflex Forum on http://www.topica.com ?

 

Cheers.

[ray_moth]

Henry,

 

I had an R8 with exactly the same problem. Leica R lenses have a built in spring which tries to close down the diaphragm to the selected aperture. In the camera is a rotating aperture control ring, which interacts with a lever on the lens that controls the movement of the diaphragm. Until you fire the shutter, the aperture control ring is held in a fixed position and opposes tension of the lens's diaphragm spring, thereby keeping the lens aperture wide open until you fire the shutter. (There is also a cam, sometimes known as the "third cam" or "R cam", which interacts with a different lever on the lens so the camera knows what aperture has been selected. This cam has nothing to do with your problem).

 

When you fire the shutter, the aperture control ring is released and should be able to rotate freely, in a clockwize direction, under pressure from the lens spring. The lens should thus be able to close down to its taking aperture for the actual exposure. The farthest the cam on the aperture control ring can move is to about the 11 o'clock position, as you have observed, in manual (m) or aperture priority (A) mode, when the lens is free to stop down fully to the selected aperture. In shutter priority (T) or program mode (P), the aperture control ring will be free to rotate only to a position corresponding to the taking aperture the camera has calculated, which will usually be before it reaches 11 o'clock. It's obviously better to test the aperture control ring operation in the more predictable m or A mode.

 

During the exposure sequence, there is very little time for the lens to close right down. If things don't run smoothly, the lens may not reach the target aperture before the aperture control ring comes back into play, following the shutter action, and opens up the lens once again. A problem arises if the aperture control ring sticks (as was the case with my R8) or the lens spring is weak. In either case, the stopping-down action of the lens can become sluggish and erratic; sometimes, it may not even move at all.

 

FWIW, I tried to get my R8 corrected by the Leica distributor in Hong Kong, but they didn't seem able to fix the problem. For that reason, I gave up with Leica R and changed over to M. Let's hope your problem is just a weak lens spring, which Lecia should be able to repair easily.

[henry_ting2]

Thanks Ray. I think the Leica R's Archilles heel is the complexity of its aperture cam. When triggering the lens aperture, this cam does not seem to close down at a pre-determined position. In fact, I tried manually triggering the shutter and observed that this cam seems to rotate at a random angle. I would imagine if the lens close-down spring is touchy, it leads to a chain-reaction and it all happens at a mil-second timeframe. I'm not too sure whether to give it up or to have a repair depot look into it. I've heard fixing the R8 is a hit or miss ordeal.

[doug_nelson1]

Problems like these are inexcusable in a camera of this price range. No wonder SL2's and R6's are so expensive. Of course, this is sour grapes on my part, as every piece of gear I own is not worth what an R8 body costs. A good SL and a couple of 2-cam lenses are more likely to turn my head.

[jay_.]

Henry, you must be making up stories. You must have walked under a ladder or let a black cat cross your path. You need to post some of your work so we can rip it apart and prove that you must not know what you're talking about. R bodies are perfect, they never malfunction. You must be a terrible photographer. Yup, that's it. I know because all 3 of my R8's had the same problem, and that's what the R experts on the forum convinced me the real problem was.

[henry_ting2]

Jay, good thing I learned my lesson with only one R8, not three :):)

[Robin Smith]

Henry

 

I have no idea how long you have had the lenses, but if they are newish then should not happen, however, like everything, springs will age and when this happens the apertures do not stop down all the way. So far I have had to have 50 and 90mm Summicrons fixed at Leica, but considering they date from 1972 and 1978 respectively I don't consider this bad. I anticipate that my 80mm 'lux is likely to be next on the list as the blades have the furthest to move. It is a pretty routine fix and not very expensive. If it is the camera then that is something else, but I have never had a problem with this on my SL and R6/R6.2. Auto apertures are clearly more prone to need fixing than the simpler M lenses in this regard. This applies to all reflex lenses not just Leica.

[doug herr]

I had a problem like this on my R4s after using it for 15 years or so. A simple CLA fixed it.<P>

BTW, Leicaflexes are not immune to this kind of problem. Earlier this year my SL2's aperture release lever stopped working - it wouldn't open the lens aperture because a spring that links this lever to the mirror action had broken. Given that this particular camera body had been submerged in water at one time and is now about 28 years old I consider it just one of those things that happens with old cameras. For the simple task of letting the lens stop down to the aperture set on the lens, the Leicaflex design is inherently more reliable than the ring used in R bodies but I suspect the R design was required to incorporate T and P modes.

[kens]

I had that problem with one of my R8s. Sticky aperture control ring. Leica NJ corrected the problem and I've had no trouble since. My other R8 has shown no sign of the problem...(yet!).

[henry_ting2]

"I have no idea how long you have had the lenses, but if they are newish then should not happen, however, like everything, springs will age and when this happens the apertures do not stop down all the way. So far I have had to have 50 and 90mm Summicrons fixed at Leica, but considering they date from 1972 and 1978 respectively I don't consider this bad. I anticipate that my 80mm 'lux is likely to be next on the list as the blades have the furthest to move. It is a pretty routine fix and not very expensive. If it is the camera then that is something else, but I have never had a problem with this on my SL and R6/R6.2. Auto apertures are clearly more prone to need fixing than the simpler M lenses in this regard. This applies to all reflex lenses not just Leica."

 

 

Robin, I know that all cameras need maintenance. But I've only had my R8 for 2 years and for the last six months been having this problem. Now my beatup Nikon F2 being working without missing a beat for the last 30 years. I don't expect Leica to be any different. Besides, aren't durability and reliability been Leica's publicity motto ?