monopix
Cam repairer
<<<<NOTE>>>>
I've been informed the pictures associated with this post and the one further down the thread have gone missing. As I seem to have lost the originals, I've retaken the pictures and rewritten the text. It's all posted on my Web site at http://www.z0g.eu/zi/zi_align.htm
_____
Well I couldn't resist doing some further investigation and decided to lift the lid of my ZM to see exactly what screws did what. This is what I found. Some of my conclusions haven't been confirmed as I don't want to make any unecessary adjustments to my ZM but I'm pretty sure what I'm saying here is correct.
In the other thread on this subject it was determined by several people that some adjustment screws could be found under the accessory shoe. I also added that some more screws could be found under the shutter speed selector.
Let's start with the ones under the accessory shoe...
To explain what these do requires some understanding of the rangefinder layout and I've done a couple of diagrams that I hope will help. First the general optical path.
On the far right is a prism which rotates when the focus is adjusted. Next to it is a glass block then some surface mirrors then finally the prisms that combine the images in the viewfinder. This is pretty standard stuff but the main point is that we have a prism that has to be rotated a little as the lens is focussed.
To achieve the linkage between the lens cam follower and the prism there is a series of levers thus...
The lens cam follower moves in and out and causes lever A to swing around point Q. Lever A engages the cam end of lever B and causes lever B to move back and forth also. Lever B is rigidly fixed to lever C which is hinged at P where the prism is mounted.
Now, look more closely at the join between levers B and C.
This is what you can see if you look below the accessory shoe. There are three screws that I've labeled X, Y and Z. X is the black, cross head, locking screw and Y and Z are slotted adjustment screws. In the centre we also have two fixed studs which are located in the curved slot in lever B. The two adjustment screws Y and Z are eccentric screws - that is, their heads are offset. If we unlock the locking screw X and adjust Y, lever B slides back and forth as the eccentric head of Y pushes it. The movement is controlled by the two fixed studs so lever B can only move in a slight arc.
If you look back at the previous image, you will see that moving lever B in this arc will alter the pitch of the edge along which lever A operates. The overall effect of this is that adjusting screw Y will change the amount that the lever B and C assembly moves for a given amount of movement of lever A. (with me so far???)
So what of screw Z? Well this isn't an adjustment screw as such. What it does is to keep lever B in close contact with the two fixed studs. If you look at the following pic you'll see that lever B is held tightly up against these studs so there is no slop in the movement. As far as I can see, that's all screw Z does.
You might also note in this picture the sealant on the locking screw. I think it's also worth noting that any attempt to adjust screw Y without first unlocking the locking screw will probably result in damage (I guess there's some people who didn't want to hear that). Similarly, if screw Z is adjusted you will either introduce slop into the system or you will cause damage by pushing lever B up against the fixed studs.
My conclusion to the above, and this is based also on what follows, is that screw Y is to adjust the close focus of the rangefinder.
So now, moving across to the screw I noted under the shutter speed selector. Here's what it looks like with the shutter speed dial removed.
The prism is located under the metal disk that can be seen near the screw. If you look either side of the black crosshead screw you can see two slots which is the slot of the adjustment screw. The crosshead fits down the centre of the adjustment screw and locks it. If the locking screw is loosened, and the adjustment screw turned, the prism will rotate slightly in it's mount. The adjustment screw is another eccentric type and rotating it moves the prism mount slightly. The effect of this is easy to understand and it will adjust the horizontal alignment of the rangefinder image.
Here's another pic of the arrangement with the camera cover off so it can be seen more clearly.
Also note the glass block next to the prism. We'll deal with that in a minute.
So, what we have are two adjustments of the horizontal alignment. My conclusion is that the first one, that can be found under the accessory shoe, is, as I said, the close focus adjustment while the one next to the prism is the infinity adjustment. I have spent some time pondering this as, at first, I wasn't sure which was which but I finally decided it was this way around when I thought of them as being a Gain and Zero control (something more familiar to the electronic guys amonst you of which I'm one). The adjustment under the accessory shoe effects the degree of movement of the prism for a certain amount of movement of the lens cam follower. I interpret this as a gain adjustment. The movement of the prism will have equal effect over the full range of movement so this is more like a zero of offset control. The question then is, at what point of the range do you adjust the zero control. In this case, I'm guessing that the arc through which lever B moves when screw Y is adjusted is centred on or about the position where lever A will contact lever B when the lens is on infinity. This is the only fixed or known point so it would make sense. If this is so, then adjustment of screw Y when the lens is set to infinity would have no effect so this must be the control for close focus and adjusting the prism is for infinity adjustment. Those people who have tried adjusting the screws under the accessory shoe and noted horizontal movement of the rangefinder image may disagree with this but, unless the locking screw was loosened before making the adjustment, the resultant effect is unpredictable as it would probably result from distortion or damage of lever B.
So how about vertical adjustment.
Look at this picture of the way the prism is mounted. Note especially the two strips of metal below it.
The lower of these two strips is the end of lever C. The prism is actually mounted on the upper strip of metal and, between the two, where I've put the red circle, is a small adjustment which moves the upper strip up and down. Although it's difficult to see in the picture, this adjustment has a pair of flats on it so it can be rotated and it also has sealant on it to lock it in position. This is obviously an adjustment and it alters the vertical alignment of the rangefinder image. The thing to note here is that this is not accessible without removing the top cover - but read on...
In the picture here you can see again the prism and the glass block next to it. In front of the glass block is an adjustment screw. This is another eccentric screw sitting in a slot.
The holder of the glass block is pivoted on the pivot that can be seen next to the screw. The effect of rotating the screw is to tilt the glass block on this pivot. Now this will effect the vertical alignment of the rangefinder image but it is quite a crude adjustment and I'm guessing this is not intended to be moved once assembled. I assume this because the mechanism has been very firmly sealed by the gunge that can be seen across the top of the mechanism above the screw. This gunge is set hard and there's no way of removing it easily. However, I did try turning the screw and, even with everything sealed up, I did get some vertical movement of the rangefinder image. This screw is accessible without removing the top plate, though it's difficult to get at, but it is a possible solution to vertical alignment problems. But an altogether, possibly, easier way to adjust the vertical alignment is to bend (yep I said bend) the end of lever C up or down. This end of lever C with the prism mounted on it is not supported at all by the body of the camera, it's only attached to the rangefinder assembly, so it will flex up and down a little. I found just by putting a little pressure on it either up or down, I could make small adjustments to the vertical alignment. It should be possible, I think, to do this via the shutter speed selector hole in the top plate so, as long as any error is small, this may be a quick and dirty solution.
So, that's pretty much it. I'm going to do another post with some more practical details of how to get at and do these adjustments for anyone who wants to have a go, but I thought I would keep this one to the theory.
Edit: Just to make it clear, I didn't adjust the screws I labelled as X, Y and Z as I didn't want to upset my own camera any more than I needed to to find out what does what. I have, however, tried adjusting everything else and I've no doubt about what they do. There is just a small question still about the actual effect of adjusting screw Y. It may be that there is more to it than I'm thinking. But if anyone else can throw more light on to it, please post it here. But please don't email with comments suggesting it's unsafe for me to be posting this...
I've been informed the pictures associated with this post and the one further down the thread have gone missing. As I seem to have lost the originals, I've retaken the pictures and rewritten the text. It's all posted on my Web site at http://www.z0g.eu/zi/zi_align.htm
_____
Well I couldn't resist doing some further investigation and decided to lift the lid of my ZM to see exactly what screws did what. This is what I found. Some of my conclusions haven't been confirmed as I don't want to make any unecessary adjustments to my ZM but I'm pretty sure what I'm saying here is correct.
In the other thread on this subject it was determined by several people that some adjustment screws could be found under the accessory shoe. I also added that some more screws could be found under the shutter speed selector.
Let's start with the ones under the accessory shoe...
To explain what these do requires some understanding of the rangefinder layout and I've done a couple of diagrams that I hope will help. First the general optical path.
On the far right is a prism which rotates when the focus is adjusted. Next to it is a glass block then some surface mirrors then finally the prisms that combine the images in the viewfinder. This is pretty standard stuff but the main point is that we have a prism that has to be rotated a little as the lens is focussed.
To achieve the linkage between the lens cam follower and the prism there is a series of levers thus...
The lens cam follower moves in and out and causes lever A to swing around point Q. Lever A engages the cam end of lever B and causes lever B to move back and forth also. Lever B is rigidly fixed to lever C which is hinged at P where the prism is mounted.
Now, look more closely at the join between levers B and C.
This is what you can see if you look below the accessory shoe. There are three screws that I've labeled X, Y and Z. X is the black, cross head, locking screw and Y and Z are slotted adjustment screws. In the centre we also have two fixed studs which are located in the curved slot in lever B. The two adjustment screws Y and Z are eccentric screws - that is, their heads are offset. If we unlock the locking screw X and adjust Y, lever B slides back and forth as the eccentric head of Y pushes it. The movement is controlled by the two fixed studs so lever B can only move in a slight arc.
If you look back at the previous image, you will see that moving lever B in this arc will alter the pitch of the edge along which lever A operates. The overall effect of this is that adjusting screw Y will change the amount that the lever B and C assembly moves for a given amount of movement of lever A. (with me so far???)
So what of screw Z? Well this isn't an adjustment screw as such. What it does is to keep lever B in close contact with the two fixed studs. If you look at the following pic you'll see that lever B is held tightly up against these studs so there is no slop in the movement. As far as I can see, that's all screw Z does.
You might also note in this picture the sealant on the locking screw. I think it's also worth noting that any attempt to adjust screw Y without first unlocking the locking screw will probably result in damage (I guess there's some people who didn't want to hear that). Similarly, if screw Z is adjusted you will either introduce slop into the system or you will cause damage by pushing lever B up against the fixed studs.
My conclusion to the above, and this is based also on what follows, is that screw Y is to adjust the close focus of the rangefinder.
So now, moving across to the screw I noted under the shutter speed selector. Here's what it looks like with the shutter speed dial removed.
The prism is located under the metal disk that can be seen near the screw. If you look either side of the black crosshead screw you can see two slots which is the slot of the adjustment screw. The crosshead fits down the centre of the adjustment screw and locks it. If the locking screw is loosened, and the adjustment screw turned, the prism will rotate slightly in it's mount. The adjustment screw is another eccentric type and rotating it moves the prism mount slightly. The effect of this is easy to understand and it will adjust the horizontal alignment of the rangefinder image.
Here's another pic of the arrangement with the camera cover off so it can be seen more clearly.
Also note the glass block next to the prism. We'll deal with that in a minute.
So, what we have are two adjustments of the horizontal alignment. My conclusion is that the first one, that can be found under the accessory shoe, is, as I said, the close focus adjustment while the one next to the prism is the infinity adjustment. I have spent some time pondering this as, at first, I wasn't sure which was which but I finally decided it was this way around when I thought of them as being a Gain and Zero control (something more familiar to the electronic guys amonst you of which I'm one). The adjustment under the accessory shoe effects the degree of movement of the prism for a certain amount of movement of the lens cam follower. I interpret this as a gain adjustment. The movement of the prism will have equal effect over the full range of movement so this is more like a zero of offset control. The question then is, at what point of the range do you adjust the zero control. In this case, I'm guessing that the arc through which lever B moves when screw Y is adjusted is centred on or about the position where lever A will contact lever B when the lens is on infinity. This is the only fixed or known point so it would make sense. If this is so, then adjustment of screw Y when the lens is set to infinity would have no effect so this must be the control for close focus and adjusting the prism is for infinity adjustment. Those people who have tried adjusting the screws under the accessory shoe and noted horizontal movement of the rangefinder image may disagree with this but, unless the locking screw was loosened before making the adjustment, the resultant effect is unpredictable as it would probably result from distortion or damage of lever B.
So how about vertical adjustment.
Look at this picture of the way the prism is mounted. Note especially the two strips of metal below it.
The lower of these two strips is the end of lever C. The prism is actually mounted on the upper strip of metal and, between the two, where I've put the red circle, is a small adjustment which moves the upper strip up and down. Although it's difficult to see in the picture, this adjustment has a pair of flats on it so it can be rotated and it also has sealant on it to lock it in position. This is obviously an adjustment and it alters the vertical alignment of the rangefinder image. The thing to note here is that this is not accessible without removing the top cover - but read on...
In the picture here you can see again the prism and the glass block next to it. In front of the glass block is an adjustment screw. This is another eccentric screw sitting in a slot.
The holder of the glass block is pivoted on the pivot that can be seen next to the screw. The effect of rotating the screw is to tilt the glass block on this pivot. Now this will effect the vertical alignment of the rangefinder image but it is quite a crude adjustment and I'm guessing this is not intended to be moved once assembled. I assume this because the mechanism has been very firmly sealed by the gunge that can be seen across the top of the mechanism above the screw. This gunge is set hard and there's no way of removing it easily. However, I did try turning the screw and, even with everything sealed up, I did get some vertical movement of the rangefinder image. This screw is accessible without removing the top plate, though it's difficult to get at, but it is a possible solution to vertical alignment problems. But an altogether, possibly, easier way to adjust the vertical alignment is to bend (yep I said bend) the end of lever C up or down. This end of lever C with the prism mounted on it is not supported at all by the body of the camera, it's only attached to the rangefinder assembly, so it will flex up and down a little. I found just by putting a little pressure on it either up or down, I could make small adjustments to the vertical alignment. It should be possible, I think, to do this via the shutter speed selector hole in the top plate so, as long as any error is small, this may be a quick and dirty solution.
So, that's pretty much it. I'm going to do another post with some more practical details of how to get at and do these adjustments for anyone who wants to have a go, but I thought I would keep this one to the theory.
Edit: Just to make it clear, I didn't adjust the screws I labelled as X, Y and Z as I didn't want to upset my own camera any more than I needed to to find out what does what. I have, however, tried adjusting everything else and I've no doubt about what they do. There is just a small question still about the actual effect of adjusting screw Y. It may be that there is more to it than I'm thinking. But if anyone else can throw more light on to it, please post it here. But please don't email with comments suggesting it's unsafe for me to be posting this...
Last edited:
ClaremontPhoto
Jon Claremont
Well done mate; this is the wackiest thread here for a long time.
You must be a dedicated fiddler to have done this to your ZM.
And such detailed photos and instructions too.
I love it, I really do.
Thank you.
Mind you, I once bought a workshop manual for a VW even though I didn't have a car yet, but the book was a good read!
You must be a dedicated fiddler to have done this to your ZM.
And such detailed photos and instructions too.
I love it, I really do.
Thank you.
Mind you, I once bought a workshop manual for a VW even though I didn't have a car yet, but the book was a good read!
monopix
Cam repairer
Want to have a go? Read this.
Want to have a go? Read this.
<<<<NOTE>>>>
I've been informed the pictures associated with this post have gone missing. See http://www.monopix.co.uk/zmadjust.shtml
_____
So here's some practical info about geting the ZM apart and making the above adjustments.
Removing the accessory shoe (this has been covered elsewhere but I'll include it anyway). Lift up the accessory shoe clip by getting a very small screwdriver under the edge as shown. There's a little recess to help you.
Pull the clip out...
Then remove the four screws.
Easy peasy eh?
Removing the shutter speed selector. For this you really need the proper type of wrench to undo the screw.
Slacken the screw in the middle of the selector. Note that the dial starts to lift as there's a big spring underneath. Hold down the dial with your fingers while you take the screw completely out then carefully remove the dial and all the parts from the shutter speed selector shaft. Note how they go together. These are all the parts in order.
Wasn't too bad was it?
If you're going to attempt to adjust the rangefinder, you probably won't need to go any further but removing the whole top plate is pretty easy and it makes access to the rangefinder much easier. Note that if you decide to remove the top plate, there's no need to remove the accessory shoe.
To remove the top plate completely. Remove the shutter speed dial then the wind on lever.
To remove the wind on lever, remove the screw in the middle of the wind on lever (the black disk you can see). It has no slots or method of getting hold of it and there's insufficient clearance between it and the shutter release to get the usual sort of clamp on it. So, a pair of pointed nose pliers with rubber sleeving covering them is the only option. Once the screw is off, lift off the other parts. Here's all the parts in order.
It's not neccessary to remove any other parts to remove the top plate so now, remove the two screws at the back of the top plate then the two hidden screws at the front (why do they always do that?). The two hidden screws at the front are just under the edge of the leathers.
Now the top cover will just lift off but be careful of the wires connecting the flash sync socket or you will end up with this...
It's possible to remove the flash socket without desoldering the wires and I suggest you do. If the wires do break, when you fix them, put some heat shrink sleeving on them to give them some extra strength.
Ok, you should now be seeing something like this.
(Note: the f/1.5 Sonnar is an optional accessory).
Now, if you refer back to my previous post, you should be able to have a great time tinkering. I think the only thing to watch out for is if you try to adjust the prism. The locking screw will probably be sealed with something and I suggest you start by removing all the sealant before trying to undo the locking screw. This will allow the locking screw to turn without the risk of upsetting the present setting of the adjustment screw underneath. Also, just slacken the locking screw the absolute minimum as the screw also holds the prism assembly together and if you take the screw right out, it all comes apart.
Hope this is of some help. If anyone has any questions, I'll do my best to answer.
Oh, by the way. I meant to say don't try lifting the rangefinder assembly to look underneath as I did. It's only four screws and very tempting but, if you do, you'll upset the rangefinder and you'll have to calibrate it whether you want to or not.
Want to have a go? Read this.
<<<<NOTE>>>>
I've been informed the pictures associated with this post have gone missing. See http://www.monopix.co.uk/zmadjust.shtml
_____
So here's some practical info about geting the ZM apart and making the above adjustments.
Removing the accessory shoe (this has been covered elsewhere but I'll include it anyway). Lift up the accessory shoe clip by getting a very small screwdriver under the edge as shown. There's a little recess to help you.
Pull the clip out...
Then remove the four screws.
Easy peasy eh?
Removing the shutter speed selector. For this you really need the proper type of wrench to undo the screw.
Slacken the screw in the middle of the selector. Note that the dial starts to lift as there's a big spring underneath. Hold down the dial with your fingers while you take the screw completely out then carefully remove the dial and all the parts from the shutter speed selector shaft. Note how they go together. These are all the parts in order.
Wasn't too bad was it?
If you're going to attempt to adjust the rangefinder, you probably won't need to go any further but removing the whole top plate is pretty easy and it makes access to the rangefinder much easier. Note that if you decide to remove the top plate, there's no need to remove the accessory shoe.
To remove the top plate completely. Remove the shutter speed dial then the wind on lever.
To remove the wind on lever, remove the screw in the middle of the wind on lever (the black disk you can see). It has no slots or method of getting hold of it and there's insufficient clearance between it and the shutter release to get the usual sort of clamp on it. So, a pair of pointed nose pliers with rubber sleeving covering them is the only option. Once the screw is off, lift off the other parts. Here's all the parts in order.
It's not neccessary to remove any other parts to remove the top plate so now, remove the two screws at the back of the top plate then the two hidden screws at the front (why do they always do that?). The two hidden screws at the front are just under the edge of the leathers.
Now the top cover will just lift off but be careful of the wires connecting the flash sync socket or you will end up with this...
It's possible to remove the flash socket without desoldering the wires and I suggest you do. If the wires do break, when you fix them, put some heat shrink sleeving on them to give them some extra strength.
Ok, you should now be seeing something like this.
(Note: the f/1.5 Sonnar is an optional accessory).
Now, if you refer back to my previous post, you should be able to have a great time tinkering. I think the only thing to watch out for is if you try to adjust the prism. The locking screw will probably be sealed with something and I suggest you start by removing all the sealant before trying to undo the locking screw. This will allow the locking screw to turn without the risk of upsetting the present setting of the adjustment screw underneath. Also, just slacken the locking screw the absolute minimum as the screw also holds the prism assembly together and if you take the screw right out, it all comes apart.
Hope this is of some help. If anyone has any questions, I'll do my best to answer.
Oh, by the way. I meant to say don't try lifting the rangefinder assembly to look underneath as I did. It's only four screws and very tempting but, if you do, you'll upset the rangefinder and you'll have to calibrate it whether you want to or not.
Last edited:
peripatetic
Well-known
Fantastic work!
It makes me really glad I didn't try to figure this out for myself and sent it in to Zeiss.
Maybe when my camera is old and dusty I'll try to do this for myself.
Maybe the mods can make this thread sticky?
It makes me really glad I didn't try to figure this out for myself and sent it in to Zeiss.
Maybe when my camera is old and dusty I'll try to do this for myself.
Maybe the mods can make this thread sticky?
mfogiel
Veteran
Good work, but I have a warning...
I have tried to adjust my horizontal alignment, using a 1.33 magnifier on the VF and a Nikon matte screen on the film plane. I have been very careful, and tried to be as precise as possible.
The result ?
My focus got acceptable BUT at 1m distance i got more than 3cm backfocus of the sharpest plane with the 50/2 Planar, while originally the camera was PERFECT - the error was not exceeding 2mm which was certainly caused by human error while focusing...
So eventually, I have sent the camera to Oberkochen, and am now waiting to see the results... My impression is, this RF is SO precise, you really need specialized optical tools to set it right...
I have tried to adjust my horizontal alignment, using a 1.33 magnifier on the VF and a Nikon matte screen on the film plane. I have been very careful, and tried to be as precise as possible.
The result ?
My focus got acceptable BUT at 1m distance i got more than 3cm backfocus of the sharpest plane with the 50/2 Planar, while originally the camera was PERFECT - the error was not exceeding 2mm which was certainly caused by human error while focusing...
So eventually, I have sent the camera to Oberkochen, and am now waiting to see the results... My impression is, this RF is SO precise, you really need specialized optical tools to set it right...
monopix
Cam repairer
So, if I understand this correctly. Your focus was fine before you started but was then out at close distance and ok at infinity after you adjusted it. Is that right? So which screws did you adjust? From the other thread it looks as if you were adjusting the screws below the accessory shoe. In which case, I'm not surprised at the results as my conclusion was that these screws are for adjusting the near focus. If I've interpreted what you did correctly then that sort of confirms what I thought so it would be interesting to hear the details of what you adjusted and how. Could you enlighten us further?
mfogiel
Veteran
No, monopix, the camera was perfect after I bought it new, even if apparently the "infinity" distance was not aligned well (It was, when I looked at the stars...) but after a year of intensive use, including some bumps against my car door and a couple of hard landings on a Milan-London plane... the rf went out of alignment by several cm at the 1 m mark. I gave it to a local (Milan) reputable technician, and it came back with a 6cm error... I was able to trim the error down to 3-4 cm, but for my taste this is not enough considering the kind of dof I have available when shoothing the 35/1.2 Nokton or the 50/1.5 C Sonnar wide open (3-4 cm at most)... so I gave in and sent it to Germany... Will tell you if the result has been good... This is what they told me when I was asking about a competent service center:
"Adjusting a rangefinder is a very sensitive topic and needs special measuring equipment and long-time experience.
To get your camera´s rangefinder adjusted accurately, please send it directly to us."
"Adjusting a rangefinder is a very sensitive topic and needs special measuring equipment and long-time experience.
To get your camera´s rangefinder adjusted accurately, please send it directly to us."
bennyng
Benny Ng
monopix,
You have my respect! And thanks for sharing. Now to find the balls to do it myself!
Cheers,
You have my respect! And thanks for sharing. Now to find the balls to do it myself!
Cheers,
ClaremontPhoto
Jon Claremont
You should be able to do it in the dark with one hand tied behind your back.
Parsival
Newbie
Thank you so much Monopix!
I bought my ZI used from Matsuiyastore and it seemed to backfocus 4-5 cm @ 1 meter with my Hexanon lenses (50 mm and 90 mm) and infinity focus was clearly off.
After I tried in vain to send my camera without receipt for repair under warranty to Oberkochen I decided to try adjusting the horizontal focus of the rangefinder myself.
I found out that you don't necessary have to open locking screw X, it didn't nudge and I didn't want to remove the sealant. I found out that screw Y indeed adjusts more close focusing and the tiny two-slotted screw under crosshead locking screw (near the prism) adjusts infinity focus. However minute adjustments to infinity focus seemed to make a huge diference so one has to be very careful and precise trying to find the right position for infinity.
Both adjustments also affect each other (as zero and gain) so I first got the infinity right, then the close focus @ 1 m, then again the infinity... I had to do the cycle about 4-5 times before I got it absolutely right. It was not easy, but with patience and right tools it's doable even if you're not Swiss clockwork engineer
Word of warning: You have to be really careful not to scratch the accessory shoe and the shutter speed selector. I wasn't careful enough and got a few hairline scratches but cameras are made for using and they will scratch anyway so I don't care.
Juho
I bought my ZI used from Matsuiyastore and it seemed to backfocus 4-5 cm @ 1 meter with my Hexanon lenses (50 mm and 90 mm) and infinity focus was clearly off.
After I tried in vain to send my camera without receipt for repair under warranty to Oberkochen I decided to try adjusting the horizontal focus of the rangefinder myself.
I found out that you don't necessary have to open locking screw X, it didn't nudge and I didn't want to remove the sealant. I found out that screw Y indeed adjusts more close focusing and the tiny two-slotted screw under crosshead locking screw (near the prism) adjusts infinity focus. However minute adjustments to infinity focus seemed to make a huge diference so one has to be very careful and precise trying to find the right position for infinity.
Both adjustments also affect each other (as zero and gain) so I first got the infinity right, then the close focus @ 1 m, then again the infinity... I had to do the cycle about 4-5 times before I got it absolutely right. It was not easy, but with patience and right tools it's doable even if you're not Swiss clockwork engineer
Word of warning: You have to be really careful not to scratch the accessory shoe and the shutter speed selector. I wasn't careful enough and got a few hairline scratches but cameras are made for using and they will scratch anyway so I don't care.
Juho
monopix
Cam repairer
Hi Parsival and thanks for the extra information. I do, however, think that adjusting screw Y without first loosening the locking screw will cause damage. Lever B is quite thin and, I imagine, easily bent and, if screw Z was properly adjusted in the first place, then the only way lever B can move as a result of turning screw Y, without loosening X first, is by deformation - it can't possible slide in the way it's intended with screw X still locked.
Anyway, I'm glad the information was useful and thanks for the feedback.
Anyway, I'm glad the information was useful and thanks for the feedback.
awilder
Alan Wilder
Wow, that's some wonderful thread! It looks like the Leica M series is a bit easier to adjust the rf and the Hexar RF is somewhere between the two cameras based on my personal experience adjusting the Leica and Hexar RF. The bottom line however, is how resistant is the ZI's rf mechanism to going out of adjustment with typical use? Any takers on this question?
italy74
Well-known
Kudos for the time and the work you did, my friend!
rxmd
May contain traces of nut
One of the best threads I've seen in a while.
I don't have a ZI but you get a beer nevertheless when you''re in the area.
I don't have a ZI but you get a beer nevertheless when you''re in the area.
monopix
Cam repairer
Bump bump.
monopix
Cam repairer
I've been informed the pictures associated with my posts in this thread have gone missing. As I seem to have lost the originals, I've retaken the pictures and rewritten the text. It's all posted on my Web site at http://www.monopix.co.uk/zmadjust.shtml
willie_901
Veteran
Peter,
Thank you so much for taking the time to share your valuable explorations of the ZI-M innards.
William
Thank you so much for taking the time to share your valuable explorations of the ZI-M innards.
William
wizofz2k
Member
Thanks heaps for posting it on the website, Peter.
FWIW:
After successfully adjusting the infinity images coincidence on mine, I've noticed that it changed with some lenses.
Namely: the Leica and Minolta M lenses have a very thin focusing cam that only touches the ZM r/f roller at the edge.
With use, the roller develops a slight slack that is enough to not let it move the "A" lever completely in for infinity focus, if the roller is only touched on the upper edge by the cam.
While for example the CV lenses have a much thicker cam that has no problem contacting almost the full width of the roller.
Which lenses presented problems with infinity setting?
The thin cam ones.
What I've now done to my cron50/2 and Rokkor 90/4 is very simple: I've glued a small curved strip of plastic to the inside of the lens cams, flush with the cam itself. This is just a short curve section, matching the small arc of the cam that contacts the roller. All it does is make the are of the cam that contacts the roller a bit thicker.
The glue used was cyanoacrylate(sp?) - "super glue" - gel, which is easier to control.
Both lenses now move the roller correctly and the r/f image at infinity coincides perfectly.
The other CV lenses have of course not been affected and still coincide perfectly.
Just in case someone hits the same problem.
FWIW:
After successfully adjusting the infinity images coincidence on mine, I've noticed that it changed with some lenses.
Namely: the Leica and Minolta M lenses have a very thin focusing cam that only touches the ZM r/f roller at the edge.
With use, the roller develops a slight slack that is enough to not let it move the "A" lever completely in for infinity focus, if the roller is only touched on the upper edge by the cam.
While for example the CV lenses have a much thicker cam that has no problem contacting almost the full width of the roller.
Which lenses presented problems with infinity setting?
The thin cam ones.
What I've now done to my cron50/2 and Rokkor 90/4 is very simple: I've glued a small curved strip of plastic to the inside of the lens cams, flush with the cam itself. This is just a short curve section, matching the small arc of the cam that contacts the roller. All it does is make the are of the cam that contacts the roller a bit thicker.
The glue used was cyanoacrylate(sp?) - "super glue" - gel, which is easier to control.
Both lenses now move the roller correctly and the r/f image at infinity coincides perfectly.
The other CV lenses have of course not been affected and still coincide perfectly.
Just in case someone hits the same problem.
monopix
Cam repairer
Hi Nuno,
That's interesting. I just put on my only Leitz lens, a 90mm tele-elmarit, and it is a bit off compared with my other CV lenses. Not sure I'm going to go to the trouble you did but I'll certainly watch out for any focussing problems with this lens in the future.
By the way, I wouldn't recommend super glue be used anywhere near a camera or lens. It gives off a gas which can cloud lenses (I don't understand the technicalities of it). The only time I used it was to fit a new glass in the front of an old rangefinder. Not long afterwards I had to refit it using different glue as it had clouded in places.
That's interesting. I just put on my only Leitz lens, a 90mm tele-elmarit, and it is a bit off compared with my other CV lenses. Not sure I'm going to go to the trouble you did but I'll certainly watch out for any focussing problems with this lens in the future.
By the way, I wouldn't recommend super glue be used anywhere near a camera or lens. It gives off a gas which can cloud lenses (I don't understand the technicalities of it). The only time I used it was to fit a new glass in the front of an old rangefinder. Not long afterwards I had to refit it using different glue as it had clouded in places.
rxmd
May contain traces of nut
I'd be careful with cyanoacrylate anywhere near a lens, its fumes are quite aggressive. Modelmakers are careful with it around transparent parts because they go blind from the fumes. They might attack the lens coating, or it may polymerize on the glass surfaces.
Cyanoacrylate is used in forensics to make visible small invisible residues on glass, such as those left over from fingerprints. You don't want that to happen on your lens surfaces.