Hey Evan, I'm having spacing/advancing issues, but I also have an issue where the advance knob locks up, and the only way to get to the 1 position is to fire the shutter and repeat this until it gets to the 1 position. I also noticed on the faulty film back it doesn't have a little pin sticking out, like the others. Would this be the culprit?
Thank for the video. It is very informative. I have Mamiya M645, a old one. My issue with camera is uneven film advancing. Sometimes it overlaps frames and sometimes it has large gaps between frames. Do you have any ideas why. Your is the first video that i have found about film advance issues in the the 645. Any guidance would be helpful
Hi, unfortunately I'm not familiar with the older M645, so I'm not sure what could be causing your issue. If you can find a shop that repairs Mamiya camera equipment, I bet they would be able to fix your camera for a reasonable price, since this seems to be a common issue with those cameras. Good luck!
It sounds like your system might have dirty electrical contacts. Clean all the gold contact points on both the back and the body. Isopropyl alcohol (IPA, rubbing alcohol) is not technically proper contact cleaner, but in my experience it has worked just fine. Make sure the contacts are dry before testing. And while you're at it, you might as well clean the contacts for the prism on the body and prism side as well. The electronics in the back are extremely simple so it's unlikely the problem is internal. Please report back!
Thanks for the video! I recently purchased a mamiya645 super, and while mine stops at 1 once I load the film to begin shooting, film count doesn’t advance with the lever (all the while I’m able to take photos). Would this method of fix still apply to my case?
Your problem is a bit of a puzzle, so I'm not sure if the fix in this video is relevant. The only explanation that makes sense to me is that the frame counter on the camera back you're using is just broken, but that's not entirely satisfying to me. And then I don't think this fix would help. But if you answer these questions I can help you diagnose: 1. Does the camera "click" when the frame counter stops at frame 1? 2. Since you state you can take photos, I'm guessing that means the advance lever cocks the shutter normally and stops advancing after about a full turn - is this correct? 3. Is the camera body in multi exposure mode? I just want to confirm since that would explain the shutter cocking without the film advancing. But it wouldn't explain the fact that the back advances properly to frame 1. The multi exposure dial is on the right side of the camera. If the white dot on the dial is next to the yellow MULTI label, the body is in multi exposure mode. You can also narrow the issue down more by trying to reproduce it with the camera back removed from the body.
@@EvanDorsky oh my goodness.. it was the multi exposure setting.. the manual advised to put it on while operation testing and i forgot to put it back on. Thanks so much for the above steps! I'll def be capturing this troubleshooting methods for future reference :)
Hey! I’ll pass this question here because this is one of the few videos that I have seen when somebody is disassembling the film back. Do you happen to know which element inside the film back is responsible for how much film gets moved between each frame? I’m thinking of trying to build a panoramic film back and the idea I have is to fabricate a custom part so that the film advancement works correctly with a different film aspect ratio. Obviously, I’d also add a mask just to expose a smaller part of film. Still I’m wondering if it’s even feasible to adjust it inside the feedback itself. Thanks!
Hi, yes, I believe I know the part that determines the frame spacing on these backs. EDIT: see comment below Note: You may be able to achieve what you want by modifying the film insert cassette instead of the internal ratchet mechanism (along with the mask you mentioned). -Increasing- DECREASING the diameter of the rubber roller in the film insert should decrease the frame spacing. I'm not sure if there's enough room in the back to actually do this, but if it's possible, it would be easier than taking apart the back - and inserts are cheaper than backs. Increasing the diameter of a 120 spool could also work in theory, but you might end up with a fat roll that's not light-tight. To your original question: The frame spacing is set by a ratchet mechanism containing a ratchet wheel with wide square notches. The pawl is just barely visible in this video, but the ratchet wheel is easy to see. It sits under the film counter indicator wheel, on its lower right (when the film plane of the film back is facing to the right). At 4:08 it is visible, spinning clockwise as I turn the advance lever. I did take apart the back more than shown in this video, but I never removed the ratchet wheel. That said, it's probably possible to do it nondestructively. If you fabricate a different ratchet wheel (for your purposes you will probably want to decrease the space between the notches to get more "shorter" frames in a roll), just beware: the pawl of the ratchet is tensioned into the edge of the ratchet wheel, and it rides along the edge as the film advance lever is turned. So the edge of the fabricated part must be very smooth, or the film will never stop advancing (i.e. exactly the problem this video addresses). In fact I believe years of metal-on-metal contact from past use may have been one contributing factor in my case. I believe I have better pictures of the inside of the camera back, and I'm happy to answer more questions - feel free to contact me through my website: www.evandors.ky/about/ - and good luck!
On second thought, my first reply had a mistake. You'd need to make the rubber roller in the film insert smaller, not bigger. So it would definitely be possible. And I think that's all around a much cleaner solution, especially if you were already planning on modifying some hardware. Hope this helps!
@@EvanDorsky Yeah, you're right, that should work. Basically the gearing for advancing the film will work with the same speed, but the rubber wheel with smaller diameter would roll quicker, so the back would indicate the next frame(and stop advancing the film) at a shorter distance change. The only issue I'd think is that it will reach the 15th indicated frame with pretty much half of the roll still good to go. I think I'll check what makes the filmback identify the insert as 220, and triggrer that. With 30 frame counter being used I think would be almost a perfect solution. Thanks for the idea! I'll try to modify one of my inserts and I'll share it online if it works!
@@DARTHMAUL1994 Yes exactly, and modifying the 120 insert to make the back count 30 frames should go perfectly with the wheel mod. Making the camera back think that a 120 insert is a 220 insert is also quite easy. 220 inserts have an extra tab on the sidewall opposite the wall with the hinged metal tabs for inserting film. This tab depresses a lever inside the back, which is easy to see when the insert is removed. 120 inserts have two empty screw holes for this tab in a vertical line (when the insert is sitting on the pressure plate). I've used a scrap piece of plastic to stand in for this tab, the options are endless. Best of luck and I'm interested to see your results!
I have the regular Mamiya 645. Discovered that an exposure overlapped another. Sent it off today for an exchange. Seems to be a common thing with some.
Sorry to hear you had issues with your Mamiya 645. I'm curious how similar the film advance sensing mechanisms are between the M645 and M645 Pro, which was released almost 20 years later. The issues likely have different root causes since in this case, the frames were ending up too far apart. I hope you end up with a working camera!
I believe it's possible to remove a plastic piece from a 220 magazine to tell the back to stop advancing after 15 frames instead of 30 (compare a 220 magazine to a 120 magazine to see where this piece is), but I don't think it's possible to shift the pressure plate. So running 120 film through a 220 magazine might scratch the film. But I've never tried so I'm not sure.
@@EvanDorsky Hello and thanks for the reply. I looked at the difference between 120 and 220. It only changes for that piece that can be removed. Other than that I don't see any difference. They are identical. I go to the photo market on Sunday and go to see the warehouses for sale. HI!
@@GiacomoAlbertini I believe the 120 and 220 pressure plates are in *slightly* different positions - the 220 plate being closer to the lens - since 220 film has no backing paper between the film and pressure plate. That's why I was worried that running 120 film through a 220 magazine might scratch the film, or cause film transport issues, since there's less space. You would only be able to detect the difference in pressure plate position with calipers. It might make no practical difference, just something to keep in mind. I hope you find a solution that works for you!
Hey man I have a problem with my Mamiya 645 pro could you help me to fix please sometimes work somestimes not the mirror lock and I can’t shoot and then I have to switch manually to orange button to make it setup again but it’s wasting me a shot
Hi, happy to help. It sounds like sometimes the mirror gets stuck in the up position after shooting (viewfinder blacks out) and you need to waste a shot to get it to come back down? First thing I would do is check to make sure the battery in the camera body is fresh. Hold the B.C. button on the front of the body and make sure the red light above the PRO label on the front of the body lights up solid red. Even if it does, I would recommend replacing the battery anyway unless you remember replacing it fairly recently, just to see if that solves the issue. I have a vague memory of an M645 Pro body that wouldn't shoot, and it ended up just being a dead battery. Maybe yours is almost dead, which could explain why it still works sometimes. After checking the battery: are you using a motor winder? If you have access to a hand crank, I'd test and see if you can replicate this behavior without the motor winder. I'd also check the batteries on the motor winder. I've never experienced this issue so I don't have any insight beyond that - maybe jiggle the M.UP knob and multiple exposure knob and make sure they're both set where they should be? I hope it's just a low battery. Good luck!
Hey Evan, I'm having spacing/advancing issues, but I also have an issue where the advance knob locks up, and the only way to get to the 1 position is to fire the shutter and repeat this until it gets to the 1 position. I also noticed on the faulty film back it doesn't have a little pin sticking out, like the others. Would this be the culprit?
Thanks to this video I repaired all of the Mamiya 645 Pro backs that I own
Wow that's so great, how many Mamiya 645 Pro backs do you own?
Thank for the video. It is very informative. I have Mamiya M645, a old one. My issue with camera is uneven film advancing. Sometimes it overlaps frames and sometimes it has large gaps between frames.
Do you have any ideas why. Your is the first video that i have found about film advance issues in the the 645. Any guidance would be helpful
Hi, unfortunately I'm not familiar with the older M645, so I'm not sure what could be causing your issue. If you can find a shop that repairs Mamiya camera equipment, I bet they would be able to fix your camera for a reasonable price, since this seems to be a common issue with those cameras. Good luck!
can you make do a fix for the super back where the light meter always says over and after rotating to a different ISO it wants you to LT exposure
It sounds like your system might have dirty electrical contacts. Clean all the gold contact points on both the back and the body. Isopropyl alcohol (IPA, rubbing alcohol) is not technically proper contact cleaner, but in my experience it has worked just fine. Make sure the contacts are dry before testing. And while you're at it, you might as well clean the contacts for the prism on the body and prism side as well. The electronics in the back are extremely simple so it's unlikely the problem is internal. Please report back!
Thanks for the video! I recently purchased a mamiya645 super, and while mine stops at 1 once I load the film to begin shooting, film count doesn’t advance with the lever (all the while I’m able to take photos). Would this method of fix still apply to my case?
Your problem is a bit of a puzzle, so I'm not sure if the fix in this video is relevant. The only explanation that makes sense to me is that the frame counter on the camera back you're using is just broken, but that's not entirely satisfying to me. And then I don't think this fix would help. But if you answer these questions I can help you diagnose:
1. Does the camera "click" when the frame counter stops at frame 1?
2. Since you state you can take photos, I'm guessing that means the advance lever cocks the shutter normally and stops advancing after about a full turn - is this correct?
3. Is the camera body in multi exposure mode? I just want to confirm since that would explain the shutter cocking without the film advancing. But it wouldn't explain the fact that the back advances properly to frame 1.
The multi exposure dial is on the right side of the camera. If the white dot on the dial is next to the yellow MULTI label, the body is in multi exposure mode.
You can also narrow the issue down more by trying to reproduce it with the camera back removed from the body.
@@EvanDorsky oh my goodness.. it was the multi exposure setting.. the manual advised to put it on while operation testing and i forgot to put it back on. Thanks so much for the above steps! I'll def be capturing this troubleshooting methods for future reference :)
@@cloudy_note9502 Glad it was something simple and your camera is operational!
Hey! I’ll pass this question here because this is one of the few videos that I have seen when somebody is disassembling the film back.
Do you happen to know which element inside the film back is responsible for how much film gets moved between each frame?
I’m thinking of trying to build a panoramic film back and the idea I have is to fabricate a custom part so that the film advancement works correctly with a different film aspect ratio. Obviously, I’d also add a mask just to expose a smaller part of film.
Still I’m wondering if it’s even feasible to adjust it inside the feedback itself. Thanks!
Hi, yes, I believe I know the part that determines the frame spacing on these backs.
EDIT: see comment below
Note: You may be able to achieve what you want by modifying the film insert cassette instead of the internal ratchet mechanism (along with the mask you mentioned). -Increasing- DECREASING the diameter of the rubber roller in the film insert should decrease the frame spacing. I'm not sure if there's enough room in the back to actually do this, but if it's possible, it would be easier than taking apart the back - and inserts are cheaper than backs. Increasing the diameter of a 120 spool could also work in theory, but you might end up with a fat roll that's not light-tight.
To your original question:
The frame spacing is set by a ratchet mechanism containing a ratchet wheel with wide square notches. The pawl is just barely visible in this video, but the ratchet wheel is easy to see. It sits under the film counter indicator wheel, on its lower right (when the film plane of the film back is facing to the right). At 4:08 it is visible, spinning clockwise as I turn the advance lever.
I did take apart the back more than shown in this video, but I never removed the ratchet wheel. That said, it's probably possible to do it nondestructively.
If you fabricate a different ratchet wheel (for your purposes you will probably want to decrease the space between the notches to get more "shorter" frames in a roll), just beware: the pawl of the ratchet is tensioned into the edge of the ratchet wheel, and it rides along the edge as the film advance lever is turned. So the edge of the fabricated part must be very smooth, or the film will never stop advancing (i.e. exactly the problem this video addresses). In fact I believe years of metal-on-metal contact from past use may have been one contributing factor in my case.
I believe I have better pictures of the inside of the camera back, and I'm happy to answer more questions - feel free to contact me through my website: www.evandors.ky/about/ - and good luck!
On second thought, my first reply had a mistake. You'd need to make the rubber roller in the film insert smaller, not bigger. So it would definitely be possible. And I think that's all around a much cleaner solution, especially if you were already planning on modifying some hardware. Hope this helps!
@@EvanDorsky Yeah, you're right, that should work.
Basically the gearing for advancing the film will work with the same speed, but the rubber wheel with smaller diameter would roll quicker, so the back would indicate the next frame(and stop advancing the film) at a shorter distance change.
The only issue I'd think is that it will reach the 15th indicated frame with pretty much half of the roll still good to go. I think I'll check what makes the filmback identify the insert as 220, and triggrer that. With 30 frame counter being used I think would be almost a perfect solution.
Thanks for the idea! I'll try to modify one of my inserts and I'll share it online if it works!
@@DARTHMAUL1994 Yes exactly, and modifying the 120 insert to make the back count 30 frames should go perfectly with the wheel mod.
Making the camera back think that a 120 insert is a 220 insert is also quite easy. 220 inserts have an extra tab on the sidewall opposite the wall with the hinged metal tabs for inserting film. This tab depresses a lever inside the back, which is easy to see when the insert is removed. 120 inserts have two empty screw holes for this tab in a vertical line (when the insert is sitting on the pressure plate). I've used a scrap piece of plastic to stand in for this tab, the options are endless.
Best of luck and I'm interested to see your results!
I have the regular Mamiya 645. Discovered that an exposure overlapped another. Sent it off today for an exchange. Seems to be a common thing with some.
Sorry to hear you had issues with your Mamiya 645. I'm curious how similar the film advance sensing mechanisms are between the M645 and M645 Pro, which was released almost 20 years later. The issues likely have different root causes since in this case, the frames were ending up too far apart. I hope you end up with a working camera!
question: I have a 220 magazine, can it be converted into a 120 magazine?
If yes, how do you do it? Thank you
I believe it's possible to remove a plastic piece from a 220 magazine to tell the back to stop advancing after 15 frames instead of 30 (compare a 220 magazine to a 120 magazine to see where this piece is), but I don't think it's possible to shift the pressure plate. So running 120 film through a 220 magazine might scratch the film. But I've never tried so I'm not sure.
@@EvanDorsky Hello and thanks for the reply.
I looked at the difference between 120 and 220. It only changes for that piece that can be removed. Other than that I don't see any difference. They are identical. I go to the photo market on Sunday and go to see the warehouses for sale. HI!
@@GiacomoAlbertini I believe the 120 and 220 pressure plates are in *slightly* different positions - the 220 plate being closer to the lens - since 220 film has no backing paper between the film and pressure plate. That's why I was worried that running 120 film through a 220 magazine might scratch the film, or cause film transport issues, since there's less space.
You would only be able to detect the difference in pressure plate position with calipers. It might make no practical difference, just something to keep in mind. I hope you find a solution that works for you!
Hey man I have a problem with my Mamiya 645 pro could you help me to fix please sometimes work somestimes not the mirror lock and I can’t shoot and then I have to switch manually to orange button to make it setup again but it’s wasting me a shot
Hi, happy to help. It sounds like sometimes the mirror gets stuck in the up position after shooting (viewfinder blacks out) and you need to waste a shot to get it to come back down?
First thing I would do is check to make sure the battery in the camera body is fresh. Hold the B.C. button on the front of the body and make sure the red light above the PRO label on the front of the body lights up solid red. Even if it does, I would recommend replacing the battery anyway unless you remember replacing it fairly recently, just to see if that solves the issue.
I have a vague memory of an M645 Pro body that wouldn't shoot, and it ended up just being a dead battery. Maybe yours is almost dead, which could explain why it still works sometimes.
After checking the battery: are you using a motor winder? If you have access to a hand crank, I'd test and see if you can replicate this behavior without the motor winder. I'd also check the batteries on the motor winder.
I've never experienced this issue so I don't have any insight beyond that - maybe jiggle the M.UP knob and multiple exposure knob and make sure they're both set where they should be? I hope it's just a low battery. Good luck!