Issues with Bronica GS-1

PhotoTexan · Nov 6, 2022

I’m testing a Bronica GS-1. I’ve been having issues with the shutter firing. I could see clearly through the view finder well at first. Then it was intermittent and now I can’t see through it at all. I think that issue might be the lens. I’ve read the manual front to back. I’ve looked up videos and looked for articles. Not finding much on this camera. I’ve made sure the crank is fully advanced, slider out, film lock lever in vertical position as well as the double exposure lever. I’ve taken the lens off and the mirror is down and seems to work well. I purchased a brand new battery and properly installed it. I’m stuck. Any advice would be much appreciated.

MattKing · Nov 6, 2022

Welcome to Photrio.
I've moved this thread to the Medium Format Cameras sub-forum, because the "Feedback sub-forum is for discussions about how Photrio is functioning. No problem, hopefully you will soon be familiar with our setup.
Sounds to me like the shutter in the lens isn't opening when it should be open for viewing. That is an indication that the lens needs service, but it would be wise to check the body as well.
Good luck!

PhotoTexan · Nov 6, 2022

MattKing said:
Welcome to Photrio.
I've moved this thread to the Medium Format Cameras sub-forum, because the "Feedback sub-forum is for discussions about how Photrio is functioning. No problem, hopefully you will soon be familiar with our setup.
Sounds to me like the shutter in the lens isn't opening when it should be open for viewing. That is an indication that the lens needs service, but it would be wise to check the body as well.
Good luck!

Thank you! I think you are right. I’ve looked over the body multiple times and it seems to be working ok.

btaylor · Nov 6, 2022

You should be able to look through the lens when the mirror is down because the shutter should be open for viewing. If the shutter is closed something is amiss. As Matt suggested it may be a problem with the shutter in the lens. If you have another lens to try that would be helpful.

PhotoTexan · Nov 6, 2022

Thank you for the comment! Unfortunately I don’t have another lens to try.

reddesert · Nov 7, 2022

When you finish the winding motion of the camera, the mirror comes down, and the body lever cocks the lens shutter, which opens it for viewing.

The lens and body should both be cocked to unmount or mount the lens. If you have a lens off the body that is uncocked (shutter closed), you can cock it yourself by moving the lever, then mount it. If the shutter doesn't open when the lever at rear of lens is pushed, then there is something mechanically wrong with the shutter.

The camera, like many 120 SLRs, will not finish the winding/cocking motion unless there is film loaded or you have the multiple-exposure lever flipped to ME. (Unlike most 35mm SLRs where you can test-fire the camera without film loaded.) I usually test wind such cameras with a spool of 120 backing paper, so as not to waste film.

itsdoable · Nov 8, 2022

reddesert said:
The lens and body should both be cocked to unmount or mount the lens....

As I recall, the GS1was designed such that it would automatically synchronize when wound. You can remove/mount the lens in any state, with the body in any state, and winding the camera synchronizes the mechanics - it was one of it's features.

With the lens off, the lever/slider on the back of the lens controls the cocking and releasing of the shutter - you should be able to slide it one way to cock it, and slide it back to release it (at 1/500 sec only when there is no power, or "T" is the T-button is pulled). If this does not cocking or release the shutter, then something inside is stuck.

reddesert · Nov 8, 2022

itsdoable said:
As I recall, the GS1was designed such that it would automatically synchronize when wound. You can remove/mount the lens in any state, with the body in any state, and winding the camera synchronizes the mechanics - it was one of it's features.

With the lens off, the lever/slider on the back of the lens controls the cocking and releasing of the shutter - you should be able to slide it one way to cock it, and slide it back to release it (at 1/500 sec only when there is no power, or "T" is the T-button is pulled). If this does not cocking or release the shutter, then something inside is stuck.

Not really. You are supposed to have the GS/PG lens cocked to mount or dismount it. This is covered in the manual. With the lens off the camera, if it is uncocked, you can just push the cocking lever over to the green dot to cock it as you said. However, you can't push the lever the other way to uncock it.

There is a little catch behind one of the bayonet flanges that you can depress, which then allows you to uncock the lever, closing the shutter, but doesn't really fire the shutter (close-open-close sequence). This little catch is depressed by the body when the lens is mounted. The ETR, SQ, and GS systems all work this way.

I agree that automatic synchronization was a noted Bronica feature, but I think it was for the backs. IIRC you can mount and dismount a back from the body without regard to whether the camera and back are both wound, and winding will advance the film or cock the body as needed. I think that's different from Hasselblads where the back can be cocked or not (but I don't have a Hasselblad to experiment on).

PhotoTexan · Nov 8, 2022

From what you all are saying… I’m pretty certain the lens needs servicing. The shutter will not open for viewing by moving a the lever on be back of the lens.

I’m testing this camera out to see if I want to buy it. It comes with this one lens, original case, several filters for this lens, a camera bag, and a partial tripod. I mostly take landscape shots and with the bulkiness of this camera and the lens issues not sure it’s the right fit for me. I’ve looked for other lenses for this camera on keh and a couple other sites. Looks like the filters won’t work for 50mm and looks like the 100mm are harder to find.

Thank you all for the feedback!

reddesert · Nov 8, 2022

On the rear of the lens toward the bottom, there is a pin that moves sideways. It should slide freely to the position marked with a green dot, opening the shutter. If it doesn't slide freely or the shutter doesn't open, then something is wrong with the lens. (Could be a broken link or spring between the cocking pin and the shutter?) There is an A/T switch near the front of the lens that controls whether the shutter does normal or T-mode operation, but I think it doesn't affect the cocking lever.

The GS-1 is a good system and probably the least bulky of all the 6x7 SLRs - to get less bulk in a modern system you may have to go to a rangefinder (eg Mamiya 7, but very expensive) or scale down to 6x6. It has to work though obviously, and I'd be cautious of buying in with an outfit that already shows problems. The wide angle and tele lenses do use somewhat enormous filters, though that's true of many MF SLRs.

There were not that many GS-1 produced compared to other systems, so one has to be patient to find used gear. Lenses come up sometimes at KEH or other dealers, and there are usually some on ebay from sellers in Japan, though there you have to read the descriptions and feedback carefully as some of these sellers are quite conscientious and others are less so.

itsdoable · Nov 8, 2022

reddesert said:
Not really. You are supposed to have the GS/PG lens cocked to mount or dismount it.... <snip>

Thanks for pointing that out, it's been a while, but I do remember going through the process to see what synced automatically. So I pulled out my GS1.

The lens cocking lever slides right to the green dot to cock. sliding it back closes the shutter, and the last 2 mm will trigger the lens at 1/500 or "T" (if the T-lever is set), which are the mechanical speeds. From the green dot, the lever is locked by an accessible catch in the lens mount next to it, so it does not inadvertently trigger when the lens is off the camera. So it's easy to check the lens mechanical operation at the 2 mechanical speeds. All other speeds have the closing delayed by the electronic timer.

You cannot remove the lens uncocked as the release lever on the body is blocked.

You can mount an uncocked lens onto the uncocked body.

You can mount a cocked lens onto an uncocked body, and it will sync.

You can mount an uncocked lens onto a cocked body, but the pin needs to be a few mm from the triggered position to match the body, the pin only has ~2mm of play anyways, so it's not that hard to do, and the lens will not mount until the pin is in place. When you trigger the shutter, it will not physically open until you re-cock it and sync the system, so you have to remember to use the multiple exposure lever, or loose a frame.

Clearly it's better to keep everything cocked in use, but it's nice to see that they made sure it would eventually autosync and not jam (like H). And f you are the type to store thing uncocked, you can't really ef it up when you want to use it.

Music1537 · Dec 24, 2022

Hello all..I’m new to this forum.. but not new to medium format, having owned a Bronica ETR for 20 years and loved it. Recently returned to,film and purchased a beautiful GS-1. I have two issues now. It was working fine, but I tried to remove the AE FINDER and am having difficulty. I pushed down the finder removal button and try to slide the finder off, but to no Avail. I also did this with the 120 back removed. Does anyone have any suggestions? Also I was having focusing problems with the finder, removed it to test out the waste level finder, which proved that focusing was fine. So I figured it must be a diopter issue. But how does one test which diopter they need? Thanks for any help you can give.

reddesert · Dec 25, 2022

I'm not near my cameras at the moment to check, but you should just need to push the removal button down and slide the finder back. If this isn't working then perhaps the lock pin isn't retracting all the way, or is under tension from the finder, or the finder is hung up on something inside (loose focusing screen?)

If you have the wrong diopter then everything may look a little blurry. The manual for the AE prism (available on Mike Butkus's camera manual website) shows how to remove the diopter, basically just remove the eyecup and then the small flathead screw next to the eyepiece. The diopters are labeled on the back, the side you can't see when installed. The default is -1.5.

Music1537 · Dec 25, 2022

Thanks for the help.. I thought the diopters were inserted with label side on outside. It just seemed to slide in better

wiltw · Dec 25, 2022

I have owned an ETRS system for about 30 years, and know the mechanism of the ETR/SQ/GS quite well

You should be able to look thru the eyepiece and clearly see any etched lines on the focus screen...such as the circular edges defining the fine focus area centered in the focus area...if you cannot see the focus screen and edges of the frame clearly thru the eyepiece, you have a not-standard eyepice that was installed by a prior owner, to adjust for their near vision!
You should be able to press the finder release button and slide off a prism or waistlevel finder attachment, without having to remove lens or film back, and regardless of the status of any interlocks on the film back (darkslide, film-advanced interlocks)...the finder should slide back freely when the release button is pressed.
To remove or mount a lens on the Bronica ETR/SQ/GS, the swing arm and green dot on the back of the lens should be swung (and locked) at the other Green Dot on the back of the lens. Similarly, the pair of green dots visible within the lens mount sof the body hould be aligned.
You should NOT be able to remove lens from body if the shutter is not cocked!
After firing the shutter, (assuming you have speed grip, or without a speed grip, the first HALF rotation of the winder)_ one stroke of the film advance should begin to lower (half way) the reflex mirror and fully lower the blind so the film is protected from light, the second stroke of film advance (or second HALF rotation without speed grip) of the winder will lower the reflex mirror the rest of the way down and the shutter should open fully.

The same behaviors should apply regardless of the presence or absence of film back on the body. Interlocks between film back and the body will prevent the shutter from firing if

the film is not advanced to a fresh frame (unless a multi-exposure lever is actuated)
the dark screen is insert ed in the film back

Music1537 · Dec 25, 2022

wiltw said:
I have owned an ETRS system for about 30 years, and know the mechanism of the ETR/SQ/GS quite well

You should be able to look thru the eyepiece and clearly see any etched lines on the focus screen...such as the circular edges defining the fine focus area centered in the focus area...if you cannot see the focus screen and edges of the frame clearly thru the eyepiece, you have a not-standard eyepice that was installed by a prior owner, to adjust for their near vision!

You should be able to press the finder release button and slide off a prism or waistlevel finder attachment, without having to remove lens or film back, and regardless of the status of any interlocks on the film back (darkslide, film-advanced interlocks)...the finder should slide back freely when the release button is pressed.

To remove or mount a lens on the Bronica ETR/SQ/GS, the swing arm and green dot on the back of the lens should be swung (and locked) at the other Green Dot on the back of the lens. Similarly, the pair of green dots visible within the lens mount sof the body hould be aligned.
You should NOT be able to remove lens from body if the shutter is not cocked!

After firing the shutter, (assuming you have speed grip, or without a speed grip, the first HALF rotation of the winder)_ one stroke of the film advance should begin to lower (half way) the reflex mirror and fully lower the blind so the film is protected from light, the second stroke of film advance (or second HALF rotation without speed grip) of the winder will lower the reflex mirror the rest of the way down and the shutter should open fully.

The same behaviors should apply regardless of the presence or absence of film back on the body. Interlocks between film back and the body will prevent the shutter from firing if

the film is not advanced to a fresh frame (unless a multi-exposure lever is actuated)

the dark screen is insert ed in the film back

Thanks Should I remove the diopter? It says it’s a -1.5

Music1537 · Dec 25, 2022

PhotoTexan said:
From what you all are saying… I’m pretty certain the lens needs servicing. The shutter will not open for viewing by moving a the lever on be back of the lens.

I’m testing this camera out to see if I want to buy it. It comes with this one lens, original case, several filters for this lens, a camera bag, and a partial tripod. I mostly take landscape shots and with the bulkiness of this camera and the lens issues not sure it’s the right fit for me. I’ve looked for other lenses for this camera on keh and a couple other sites. Looks like the filters won’t work for 50mm and looks like the 100mm are harder to find.

Thank you all for the feedback!

If you get the speed grip , it greatly helps the shootabiliy of this camera and is very easily hand held. I also have a Mamiya Rz-67 pro II, with winder and grip. Now that’s a beast. But such a beautiful camera

wiltw · Dec 25, 2022

Music1537 said:
Thanks Should I remove the diopter? It says it’s a -1.5

The standard diopter is -1.5 strength! If you cannot see screeen clearly, your vision is likely the reason...Bronica screens set virtual screen distance to 30", IIRC.
OTOH, since you are having issues getting prism off, there might be some issue with its mounting that accounts for blurred view of screen!

reddesert · Dec 27, 2022

Music1537 said:
Thanks for the help.. I thought the diopters were inserted with label side on outside. It just seemed to slide in better

I'm not near my camera at the moment, but this is a little puzzling and you should try it the correct way around to see if that improves your view through the finder. IIRC, the eyepiece is secured by a screw that will only fit in properly if you have the eyepiece the correct way (label side in). Also, the lens is slightly asymmetric and it may make a difference to the effective diopter which way around it goes (though not much). As wiltw said, if you have normal vision the -1.5 should work. If you need positive reading glasses, you may need a more positive value than -1.5.

Finally, the glass is glued into the eyepiece frame on the inside (label side). If it ever pops out, if you have it the correct way around, it falls between the frame and the prism and you can retrieve it. Wrong way around, it falls on the ground and gets lost. This may seem like a trivial detail, until it happens.

skahde · Aug 5, 2024

wiltw said:
The standard diopter is -1.5 strength! If you cannot see screeen clearly, your vision is likely the reason...Bronica screens set virtual screen distance to 30", IIRC.
OTOH, since you are having issues getting prism off, there might be some issue with its mounting that accounts for blurred view of screen!

For the record: I also need a corrective lens for use on the AE-finder of my GS-1 and had a visit to my local optician today.
I already knew that the removable lens actually has a positive power as it acts as a loupe of medium to stronger power when removed from the finder. The documentation for the camera also reveals that the -1.5 means the power of the whole finder-arrangement (as already mentioned), just like e.g. Nikon does it with its finders which are nominal "-1" where your eye has to focus at 1 m to see a sharp picture in the finder. Add +1.5 (Bronica) or +1 (Nikon, the eyepiece is marked 0 in this case!) dioptrien and the groundglass is sharp with your eye focussed to infinity.
My optician accordingly measured (twice to be sure) the eyepiece marked "-1.5" as having an optical power of +7.5 dioptrien. He will try to replace it with a lens of +9 dioptrien as I'm no longer able to adapt my eyes close enough to compensate the -1.5 of the finder as from the factory. As of now I need to use glasses with +1.5 to see a sharp picture in the finder.

Issues with Bronica GS-1

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