M3 focussing problems. Help!

[skibeerr]

Guys help me.

I have a very nice M3 realy love it, and I use it in combination with the Nokton 50mm and a Hexanon 90mm.

The problem:

I noticed on foto's that the focus was never where I intended. Example in a close up at about one meter and the nokton wide open I focus on the eyes and then the plane just behind would be sharp, say temples and ears. This problem repeats itself in other foto's.

Then I did a test:

Took my Pentax lx with 50mm1.4 and 100mm 2.8
Took my Leica m3 with 50mm 1.5 and 90mm 2.8 and an old summitar 50mm 2

With the same roll of Ilford 50 I photographed a wooden plate with inlaid ivory, a lot of detail, on tripod with remote. On the LX i did the mirror up.

Distance was 1m for the 50mm and 2m for the 90mm.

The Pentax LX lenses where much sharper than the Nokton and Hexanon etc.
This, I thought, is not normal, I used to have a Hexar rf and with that camera the focus was always spot on despite the smaller rf base.

The m3 whent to the repair shop in Antwerp for rf allignement together with the Nokton. When it came back the problem was the same.
After some thought I checked the pressure plate and to my feeling it did not connect tight to the guiding rails of the body. So I took the pressure plate of and twisted the springs a little to get more tension.

The foto's thereafter where better qua focussing.

After that I compared the M3 with the newly arrived Bessa r3a, same set up same lenses. And the Bessa gives a slightly better result. Wich worry's me, normally one should be able to focus the M3 better than the Bessa r3.

Questions:

Am I doing anything wrong or missing something?
Am I right assuming that filmflatnes is the problem?
What can I do to regain accurate focus and confidence in My only Leica?
Dante Stella said he had to take his M3 3 times to the repair shop before it was ok,
what where his problems?

Thanks for reading all of this and also for any help.

 

[mfunnell]

Well, your thoughts about the film plane seem sensible. As I understand it, when people try to align lenses with RF camera bodies, they often do so by using a ground glass where the film should be. But if the film isn't being positioned correctly then that's obviously a procedure which aligns the RF correctly but doesn't do much for your photos 🙁 Having no experience of this, all I can say is that your diagnosis of the problem seems rational. Perhaps your best bet is to send it off to an expert repair outfit with a detailed outline of where you think the problem lies.

...Mike

 

[Sonnar Brian]

Have you loaded the camera, taken the lens off, set to "B" and looked at the film? If anything strange is going on, it would be nice to see the film is not curled. also: set up a tripod, use a tape measure to an object, and then focus using each camera. The distance scales should all agree. If the M3 is off, then the RF alignment is the problem. If not- both cameras agree with the tape measure, you are back to film flatness.

 

[Dante_Stella]

There is another thing. Have the body focus measured. There is a possibility that the alloy body casting of the camera has been impacted (or has shrunk very slightly over time).

 

[skibeerr]

A quote from Tom A

A quote from Tom A

Quote
Sometimes a lens that works fine at 1m, will through focus at 2m or even 5 meter. You have to check, shoot, realign and pray that everything stays fine. The only time I really set myself to do this rather boring task is with fast lenses, Noctilux, Summilux 75, Nokton 35f1.2. Of course, you also have to dedicate a camera body to it for these lenses as even miniscule shifts in filmplane/lens will affect it.
Ow, to hell with it and stop down or get f2 -f2.8 lenses instead!

Borrowed this from payasam's thread.