Bronica S2A focusing problems

bronica-s2a-nikkor-h-50mm Bronica S2A focusing problems

Bronica cameras usually are very sturdy. You can find them in excellent condition, despite their considerable age. But unfortunately, any complex mechanism has weaknesses. Many users complain that they are having trouble focusing. Lens doesn’t reach to infinity and on the finale negatives there are quite a lot of misfocused frames. The problem lies in the fact that the sealing foam loses its properties over time, turning into a sticky mess. In this short article I will explain to you how to solve this problem. Also I’ll describe the option of replacing the standard focusing screen to a brighter one with a split image.

We’ll need:
1. Flat-blade screwdriver
2. New seal. Here you can improvise. Personally, I have used self-adhesive sealing for windows (it’s useful, no need to mess around with glue, easy to cut). You can take an ordinary household sponge, foam from cases or other sufficiently dense foam material.
3. Glue (for non-self-adhesive seal)
4. Household cleaner


 So, let’s begin. Remove the waist level finder:
bronica-s2a-focusirovka Bronica S2A focusing problems
Unscrew the four screws that secure the metal frame. Under the two screws holding the metal bracket that secure the waist level finder there are two brass washers and small steel pads. Be careful, don’t lose them. Caution! The screws are made of a very soft metal. It is easy to damage them. Use a well sharpened screwdriver of the correct size:
bronica-s2a-focusirovka-2 Bronica S2A focusing problems
Now we see the camera body, the waist level finder bracket, the Fresnel lens, the ground glass and the metal frame that fixes all these parts together:
bronica-s2a-focusirovka-3 Bronica S2A focusing problems
1. Body 2. Waist level finder bracket 3. Fresnel lens 4. Ground glass 5. Fixing metal frame
Here’s a close-up:
bronica-s2a-focusirovka-4 Bronica S2A focusing problems
1. Fresnel lens 2. Ground glass 3. Fixing metal frame
On the back side of the frame, we will see the old sealing foam. Most likely, a matte screen is firmly glued to the frame. Our goal is to remove the old seal and clean the matte screen. Carefully separate the matte screen from the metal frame. Try not to touch the matte surface! Simply, put it in a weak solution of water and household cleaner. Then rinse it with clear water. It is very important not to touch the matte surface of the screen! You can damage it. Now clean the metal frame with any alcohol-containing cleaner. Let it dry.
Do the same thing that you did with the matte screen with the Fresnel lens. Try not to touch the surface with concentric circles. If dirt gets between these “ribs” it will be almost impossible to remove it.
Then apply the new sealant on the frame. Make a thicker layer than is needed to make sure it will give enough pressure:
bronica-s2a-focusirovka-5 Bronica S2A focusing problems

If desired, you can black paint the seal with a permanent marker.
Do not be amiss to slightly bend up the top edges of the metal springs. This will provide a more secure fit of the Fresnel lens to the matte surface:

bronica-s2a-focusirovka-6 Bronica S2A focusing problems
Putting all this mess in the reverse order. First, put the Fresnel lens on springs. Important! Put it with the ribbed side up (the smooth side facing the mirror). The lens is a rectangular shape, so setting it in the correct position will not cause any difficulties:bronica-s2a-focusirovka-7 Bronica S2A focusing problems
Now we come to an interesting part. At this point, you can install the original matte screen, or use a brighter screen with a split image, which you can purchase on Ebay for example. Since the locking system of the focusing screen is simple and flexible, the thickness and the size of the new matte screen are irrelevant (within reason). The important thing is that the new matte screen should be without the Fresnel lens on the upper surface (there is no need in two Fresnels lenses)So, put the matte side of the screen to the mirror (the smooth side watching us):
bronica-s2a-focusirovka-8 Bronica S2A focusing problems

I also tried to put the matte screen directly, bypassing the Fresnel lens. But unfortunately, the focus became completely misaligned and needed some serious readjustment. I have postponed this option until better times.

We come to the last step. Install the frame and fasten all the screws back. The seal, which stands out from under the frame can be easily tucked by using any wooden or soft plastic stick (or something like that).

bronica-s2a-focusirovka-9 Bronica S2A focusing problems
Checking the quality of work is very simple. Press slightly on the focusing screen. Particularly along the edges. If there is no backlash, congratulations! The seal tightly presses the entire structure. Now you can shoot!
Bronica S2A focusing problems

31 thoughts on “Bronica S2A focusing problems

  1. Eugene says:

    Thanks for this useful information. Do you know if the focusing screen of an EC TL can be used in a S2A?

    1. I don’t think that you can use the focusing screen of EC-TL on S2A model. They a little bit different. But if you lost or damaged your S2A screen there is a lot of 3rd party screens form china on ebay which are actually not that bad.

  2. Hello Alexander,

    I am waiting for my Bronica to arrive, but I am afraid the camera will have a focusing problem as well. I am browsing/searching the net and found your splendid article, but after i found this one:

    But it seems Peachel (the person on flickr) replaces the foam under the mirror and his metal frame doesn’t look the same as yours:

    1/ Am I correct or is it another camera?? I haven’t got mine yet.
    2/ Which thickness would you recommend for the foam??

    Kind regards,

    1. Hi, Barry!

      ideally, you should replace foam both from the focusing screen and under the mirror. To replace foam under the mirror you should remove focusing screen also. So its a wise idea to do it all in one go. It is not that difficult.

    1. Of course you can replace a ground glass. But the trick here is to much a thickness of a new glass to the old one. It will help you to avoid futher alligment.
      And you can also find a used options on Ebay.

  3. Hallvar Hauge Johnsen says:

    Can’t thank you enough for sharing this guide. Now I’m able to infinity focus. Even did some general cleaning down there whilst I was at it!


  4. I got the foam replaced. Ran a roll through it on a shoot(haven’t scanned yet) but the negatives seem to be soft where I need it to be focused. I’ve looked at the negatives with a magnifying glass and my subject seems to be completely out of focus. The rocks behind the subject show definition. Getting frustrated. Could there be an issue with the lens itself?

    1. The easiest way to check your focusing in this case is to try to focus to infinity. If your lens seems to not reaching infinity even by a tiny bit that means that you still have problems with a foam. But in this case you need to replace it under the mirror. Check this video, its in chinese but pretty self-explanatory:

      Hope it helps

      1. Mark says:

        Thanks for this post. I just received an S2A in excellent condition but haven’t shot a roll through it yet. When I focus to infinity it’s a bit soft but reasonably close. I haven’t disassembled it yet, but I can see that the foam seal under the focus screen/metal frame looks new like it’s been replaced recently (the seller on ebay didn’t know much). The focus screen and metal plate are firmly in place. I can’t really see under the mirror, so I’m wondering whether the softness I’m seeing at infinity is just normal for this camera or whether I should disassemble and check the mirror seal…? Or perhaps just shoot a roll through it first…

        1. If you not sure than I supose that the only way to find it out is to try! Try to take pictures on a different distances and on a wider aperture. If there is any consistent missfocus than its time to do some repairing.

          1. Mark says:

            Thanks mate. I’m still waiting on film, but decided to take apart the mirror and found that the foam underneath had deteriorated, so I replaced it. Now the camera focuses slightly PAST infinity (previously it wouldn’t quite reach infinity). I compared the distance on the focusing mount when focused on a subject at different distances I measured myself, and from distances of 2 to 10 m it is spot on, but at close distances of 1.5 m or less it seems to be off slightly by 20 cm or so. I’m not too worried about infinity being slightly off, as I don’t really expect to focus on distant subjects at large apertures. But the close distances I’m more concerned about, so I’ll have to test with film. Having everything secured with new foam, I’m not sure what else I could do though if it’s off.

            Another thing — I did manage to strip one of the screws on the metal frame above the focusing screen. I can still get it on and off if I’m careful, but worried this screw won’t last through many more disassembles. Do you happen to know if these can be replaced with a standard screw (e.g. from a camera or computer hardware store)? Obviously best to avoid trashing screws, but if it happens, it’d be good to have a backup set of screws.

          2. Yes, this little screws is very soft. The only thing you can do in order not to strip it off is to use a very sharp screwdriver. I’m pretty shure that finding a replacement will not be a huge issue.
            I have an old Zorkiy camera that I tried to disassembly and service and failed to assemble it back again. So I used it for infinite amounth of little screws, springs, washers etc.

  5. Hi! I just wanted to point out that the focus problem in the S2 is not entirely … or even primarily … due to the foam above the screen. There is another set of foam pads, behind the mirror, which also degrade and allow the mirror to settle back out of its correct position. Movement of the mirror results in a focus error of about 1.4x the actual amount of settling due to the angle of the mirror, so a little error there can be too much to try to correct at the screen. I have some notes on replacing the mirror foam which I’ll be happy to email to you if you like.

    1. Grant Watson says:

      Hi Rick,

      About to perform this repair – can I please get your notes on replacing the mirror foam ?

    2. Phasit. says:

      I totally agreed with you. Pushing down the screen would solve a minor off focus. But replacing the foam behind the mirror will help lifting up a mirror to its proper position. Your answer emphasized my solving the back focus issue. Thank you.

    3. Chris Wilson says:

      Good evening Rick Oleson.

      If you could let me have your instructions for replacing the mirror foam, I’d be most grateful. Thanks, Chris.

  6. Dimitris Papadopoulos says:

    Hello ! Congrats for this info ! I own a Bronica S. Is this model (the S ) in need for a foam change ? As I can see there is not any foam…

  7. Massimo says:

    Hello, I have an issue, I cannot screw up again the two screws of the finder bracket side. They seem too short… what would you suggest to do? Thanks

  8. David Wilson says:

    Alexander, perhaps you can help me.
    I’m looking for any information on dismantling the old Bronica S2 75mm f2.8 and the S2 50mm f3.5 lenses in order to clean the aperture blades. My old lenses are sticking and changing the aperture is next to impossible. I am shooting wide open all the time because of this issue.
    I see the screws and I could probably dismantle the bottom most section of the lens and access the blades, but I don’t want to do that without some level of insight. I could use a video or a PDF outlining the procedure so I don’t screw something up.
    I’m trying to contact anyone who has some knowledge or access to some written material about doing this.

    Thank you for anything you may have to share.


    1. Hi, David!

      Unfortunately, I don’t have any experience of fixing Bronica lenses. And to be honest with you I always try to stay as far as possible from this kind of work. Because chances higher to screw something up rather than fixing it…

  9. Nick says:

    Hey Alexander, just wanted to say thank you for the instructions, they worked perfectly for me!

    In case anyone else out there is thinking of doing this, but is nervous about taking their Bronica apart, it’s not too difficult at all. Go for it!

    In case anyone’s interested, I filmed myself following the above instructions and you can watch it here –

    Hope that helps someone.


  10. David Wilson says:

    Alexander, do you know of any information (instructions) on dismantling the back end of an S2 lens and cleaning the aperture blades? I have oil on two of my S2 lenses and changing the aperture is next to impossible. Any information or links you have would be wonderful.

  11. Mike says:

    any suggestions on getting the 2 screws out from the metal bracket at the back? Mine appear to be stuck in there and I cannot get them out. I have tried to carefully (with a tiny eyedropper) put a tiny bubble worth of WD-40 to see if it would loosen the screw, but I have not had luck. I don’t want to try more WD-40 because I don’t want the oil to run through the the rest of the body. Any tips would help. The first two in the front came out very easily. These two…are very irritating.


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