Modifying Summaron M 35mm 3.5 to 35mm frame line

Discussion in 'Leica and Rangefinders' started by neweditor, May 6, 2020.

  1. Hello, everybody
    Recently I`ve got the Summaron 35mm f3.5 with M mount, non-goggled version, and was surprised that it activates the 50mm frame.
    I`ve found that the bayonet can be home modified to bring up the 35mm frame. But did not see exact instruction.
    Anybody could help with it?
    What exactly should I file off?
    Thank you.
  2. Sandy Vongries

    Sandy Vongries Administrator Staff Member

    Mine has a separate viewfinder which fits the accessory shoe on my M 3. Personally, I'd look for one of those before I took a file to a Leica lens - I have seen them for sale online. That, or consult / send to one of the Leica specialists. Here's another option Link 35mm Viewfinder for Leica, Fed, Zorki Cameras
  3. This was also a common mod on the CV 40mm Nokton. I never modified mine but saw instructions on the web. A search on modification of 40mm Nokton should bring up instructions. Probably a lot more of these got modified than the Summaron.

    With the 40 I canโ€™t see the 35 lines without moving my eye around (glasses) so just go with the 50 lines and crop tight.
  4. Thanks, Sandy.
    It would be nice to have a version with 35mm frame lines. But the problem is - this Summaron was the only available for sale in my country. So I bought it :)
    Buying from ebay is too expensive (too high import fees).
    Yes, I have a 35mm viewfinder. But if I want to use the camera with a flash - it can not be used. So I`d rather modify the lens mount.

    Thanks, Glenn. I`ll look for Nokton modifications.
  5. Thank you NHSN
    Actually, I see the people from that topic filed something. But I do not clearly understand what did they filed, the top part of the lug or the side.
    If you know, could you please clarify? Maybe, with a picture?
  6. NHSN, thaks a lot!
    As far as I see, they filed the "slope" of that lens lug. On the "normal" Summaron it should be the side.
  7. I did it on a f3.5 35mm Summaron using a Dremel tool with thin abrasive wheel, about 20mm in diameter if I remember correctly. I took very particular care to protect moving parts of the lens and the rear element from metal dust and traces of the abrasive disk. If you have one or can borrow one, practise a bit on some scrap metal to get the feel of it. My job was a little rough because the Dremel tool can "grab" a bit and move, so a light touch is needed. The actual grinding took about one second or two. The geometry of the grinding was to shift the edge that interacts with the camera's feeler. Do it a bit, and if not enough, do a bit more.
  8. Sandy Vongries

    Sandy Vongries Administrator Staff Member

    Dremels are wonderful and awful - take GREAT care if you go that route. They often run away with folks.
  9. new editor, What M are you using?
  10. I'm with Sandy for sure. Buy an auxiliary viewfinder, looks cool, works great, Leitz-vf-1.jpg
    and you don't have to butcher a lens...
  11. Good advice from JDMvW and Sandy. The VIDOM finder will work for any focal length between 35mm and 135mm. Although there are lock in detents at each of the VIDOM numbered focal lengths, you can still set the mask at 40mm a little past the 35mm index mark. I use this same framing method for a 100mm Canon LTM lens.
  12. I've seen a Summicron 35/2 that brought up the 50mm framelines: it was originally a "Goggle" type lens, and the goggles converted the 50mm frame to 35mm FOV but also changed the Rangefinder response. The lens without the goggles had to be focused using the distance scale. The Rangefinder Cam itself was not indexed for a 35mm lens, had to be used with the goggles.

    Have you verified that you lens correctly focuses using the Rangefinder?
  13. For a 35mm lens I think the single focal length SBLOO is much, much nice to look through, but it's far from cheap and rather large. The modern Voigtlaender brightline finder (metal version) is nearly as good, and more compact (rather like the Leitz finders for longer focal lengths). I bought the SBLOO but would be happy with either.
  14. I guess what I'm asking is does your M have a 35mm frame line at all? M3's do not. However, the whole M3 "window" pretty closely approximates the 35mm frame line. I've used this many times on my M3 and it works well though you miss the aspect of seeing what's outside the frame, a feature I always thought was overly touted as an advantage of VF/RF cameras.
  15. I'd assumed that the original poster has a Summaron designed for the M3 (before 35mm framelines existed), but a later camera with 35mm framelines. When the earliest M Summarons are fitted to an M3, you just see the 50mm framelines that are there all the time. With a later 35mm lens on the M3, you'll also see the 135mm framelines. So to use your trick of taking the entire M3 viewfinder as an approximate 35mm frame, it's actually better to have the earlier unmodified lens as you won't see the distracting 135mm framelines. Goggled 35mm lenses behave the same way, but have extra optics to reduce the viewfinder image so that the 50mm M3 frameline can be used with a 35mm lens. Sometimes lenses designed to be used with goggles turn up with the goggles missing - as Brian suggests, these won't focus correctly with the rangefinder.
  16. Just to interject here -

    EVERY 35mm lens Leica produced prior to the M3 without goggles (these glass goggles essentially enlarged the 50mm framelines to 35mm framelines) was a screw-mount lens, which could be used on an M3 with a LSM to M adapter. Leica never produced a 35mm M-mount lens that brought up 50mm framelines that did not have goggles. Stating it clearly - EVERY 35mm M-mount lens Leica produced prior to the M2 had goggles (the flange brought up the M3's 50mm framelines). The very early 35mm lenses intended for the M2 brought up 35mm framelines.

    Therefore, there are only three possibilities here -
    1) Your lens has a screw mount with an M mount adapter fitted to it (and this adapter brings up 50mm framelines),
    2) Your lens flange was changed by a technician with an M-mount flange that brings up 50mm framelines, or
    3) Your lens had goggles originally and they have since been removed (on some lenses they were detachable).
  17. Well using a 35 Summicron on the M3, though probably because I'm just dense, but I really didn't notice the lines if I wasn't framing with them. I know the 50 frame was there, but don't remember a 135, so it apparently didn't make an impression.
  18. That's very dogmatic, but I don't think correct. According to multiple sources, there was an early M-mount Summaron 3.5 (SOONC-M) that was intended to be used on the M3 together with the SBLOO shoe-mount finder. I think the original poster has this. It will bring up the 50mm framelines on Leicas where these are selectable. It appears to have been produced from 1954, when the M3 was launched, and coexisted with the screwmount version for a few years. The goggled version (SOONC-MW) did not appear until 1956. Later there was a version for the M2 (SOONC-MT) that brings up the expected 35mm framelines. See discussion here:

    Summaron-M 35mm f/3.5 for M2

Share This Page