Een mooie Linhof Press Compur 1:4,5/150 sluiter, maar defect
De werking werd niet duidelijk, nog minder wat er fout was
Met hulp van Oom Google deskundige Rick Oleson gevonden
Contact opgenomen en dat hielp:
Hi Rick,
my name is Toon Brok, I’m from the Netherlands and I like old way photography.
On my old wooden 5×7″ camera I like to use a Linhof Press Compur 1:4,5/150.
One problem: it’s shutter is not working.
Years ago I tried to repair without success, maybe I made it even more bad.
Do you have any advice how to get it to work again?
A good drawing should be very helpful, to see were and how parts belong.
With kind regards, Toon Brok.
Hello Toon!
I have attached some notes, which I hope may be of some help. The Linhof shutters are made by Compur, so the two sets of Compur view camera shutter sketches hopefully will be similar to yours although there may be some differences in details depending on the shutter size and when it was made. Although there are a number of detail differences, all leaf shutters operate on similar principles, so it may be possible for you to work out how a mechanism in your shutter may look different but performs the same function as a detail in my notes.
I have also attached my general leaf shutter repair notes, which are broad and generic to cover a variety of types but will hopefully help you get it working properly.
Please look these over and see if they help; I will be happy to try to answer questions if these are not enough to make it clear.
Best wishes, rick
Hello Rick,
thanks for all these information.
It gives me already a good view in the Compur shutters.
With that knowledge I try to identify the parts of mine one.
Most parts I can localize, but how it has to work together is still a miracle for me.
Problem is that maybe not everything is mounted well or even parts are missing.
Let me tell what I think to recognize in my shutter (see also my drawing).
On “A” I see the cocking rack, a ring around the center of the shutter.
“B” is the shutter release, but the shutter time is always on T.
Part “C” hooks up the cocking rack “A” and on the other end “B” will release the shutter.
Point “D” is direct connected to the three shutter blades.
On “E” is a rather strong spring, but with nothing in contact for some pressure or so.
Also the function of part “F” is not clear for me.
Now (writing to you) I realize that the shutter speed cam is needed for the timing.
Problem is how to mount this cam, e.g. in which position?
And for sure some pins in the mechanism has to communicate with that cam.
Can you give me some instructions/advices how to mount the shutter speed cam?
Further I think I see on “G” the timing gear for longer exposure times (> 1/4 sec.?).
There is no self timer and I think “H” is the empty case for the missing selftimer.
I hope you have some extra information for me.
And I hope also my English good enough to understand each other well.
It should be nice if we can repair such a small instrument on such a big distance.
Thanks so far, Toon.
Toon!
I just spent half an hour answering your question and your email blocked it!
How can I get my answer to you?
rick
hopefully this will image come through!
rick
Rick,
maybe you send only an image without any text?
In your next try you wrote some text and it was successful.
After that I received two times your half an hour answer.
So our communication is going well; no problem.
Today I go on with your answer and see how far I come.
You get my findings and maybe new questions soon.
Toon.
Thanks Toon!
Glad it got through.
Hopefully that will be enough information for you to get the shutter working.
Best wishes, rick
Hello Toon!
You have given a very good description of the workings. I can fill in a few blanks, although unfortunately I don’t have an identical shutter handy and my notes do not include all of the details that they should for this conversation.
You are quite correct on A, B and C.
You are also correct on D. I think you may find that this little piece is involved in the B / T function.
Just to the left of D, on the opposite side of F, there appears to be a small tab. Can this be moved left to right?
The T and B functions do not use the timing escapement system. Usually they are controlled by 2 levers near the shutter release, that look rather like fingers or the blades of a small scissor. When set to B, one of these levers shifts into position so that its tip blocks the movement of the ring attached to the blades, holding them open until the shutter release returns to its rest position. When set to T, the second of these levers also shifts into the same position, so that after the shutter release and the first lever return to their rest positions, the second lever remains in the way, blocking movement of the blade ring. It only returns to its rest position when the shutter release is pressed a second time.
These levers may be hidden underneath part F.
E is a booster spring for the 1/500 speed. The timing escapement delays all shutter speeds from 1 second through 1/125. At 1/250 there is no delay, the blades open and immediately close as fast as the main coil spring on A (visible behind C) can move them. For the 1/500 speed, there is also no delay, but the spring at E is engaged, increasing the speed of the entire system for the faster speed. You may notice that it is harder to turn the speed ring to 500 than to the other speeds – this is the force of charging the spring at E. In some shutters, it is not possible to set the ring to 500 after the shutter is cocked.
F is the operating lever for the cable release. Just above E you can see a rectangular block with a single screw through it – this is the cable release socket, the threaded hole for the cable is in the outboard end of the block. The end of the cable pushes into the block, moving lever F clockwise, and the opposite end of Lever F then rotates shutter release B counter-clockwise to release the shutter.
G is the timing delay escapement. The escapement itself is the star-shaped wheel just above your “G” label, and the 2-toothed rocking pallet just above it that engages one tooth of the star wheel at a time. To rotate the star wheel to the next tooth, the pallet must swing out of the way, in which position its other tooth engages the star wheel so it must rock back again to release the wheel for one more tooth of rotation. This rocking back and forth and engaging and releasing one tooth at a time is what makes the buzzing sound in the shutter (this is also what makes the ticking sound in a clock, the only difference is the speed of operation). Just above the star wheel is small lever, which can pull the pallet out of engagement with the star wheel. The faster speeds run without the pallet engaged, the slower ones run with the pallet engaged. One of the stepped slots in the speed cam moves this lever in or out. Below and to the left of your “G” label, you will see a partial gear with a pin sticking p from it – shutter ring A is resting against this pin. “A” is not quite in the correct position here, it should be just slightly clockwise from where it is. so that the part that is resting against the pin would be instead resting against the left-hand flat edge of the partial gear, such that movement counter-clockwise of ring A would tend to rotate the partial gear clockwise, moving the pin to the right into the U shaped slot in the escapement frame. To set the ring A into its proper position, push its handle slightly to the right while pressing the ring downward into the shutter – once it is clear of obstructions it will drop into position against the left side of the partial gear, and you can let it come to rest in that position.
You are correct about H – it is the empty shell of a missing self timer escapement. I don’t know if the shutter would have been made this way, or if someone removed the self timer gearing because it was causing trouble.
I have attached a copy of your photo with markings to show which parts of the shutter go into which slots of the cam. Be careful to ensure that these pins/levers are actually in the slots, as they can be damaged if they are trapped behind the cam when you reattach the front panel to the shutter. If you look closely at the cam, you will notice that the inboard edge of the bottom slot (at the red dot) is tapered, gradually becoming closer to the center of the circle as you move from left to right along the slot. This taper moves the initial position of the pin on the partial gear, which changes the amount of distance that it has left to move before the tab on ring A can move past it to close the blades. This – plus the engagement of the pallet for the slower speeds – is what creates the different speeds of the shutter.
I hope this helps! rick
Hello Rick,
everything you wrote is clear for me and very helpful.
A few issues come up now.
You talk about shutter speed up to 1/250 and 1/500.
On my shutter speed cam I see only T, B, 1/1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100 and 1/200. Has this to do with age and is spring E already needed for the time of 1/200?
There is a ring with at the bottom an indication of the aperture 4,5 to 32.
At the top a space has been saved for the shutter speed indication (see image).
On the position of the aperture lever I can see how this ring must be mounted.
Therefore the position of the shutter speed cam is also known; the numbers must appear in the hole at the top.
But that is not the position you suggested the shutter speed cam has to be mounted.
Can it be that the shutter speed cam 120° CW of your suggestion must be mounted?
Following your instruction shutter ring A is now in the right place down into the shutter.
You wrote about a pin where before the shutter ring A was resting against.
Should this pin (where you pointed your red line) also be operated by the shutter speed cam?
In that case I have the idea that the contact between the pin and the cam is very poor.
On the new image this pin is moved into the U shaped slot in the escapement frame.
The lever F for cable release I have removed now and I see the two levers witch take care for T an B times.
For B one of these levers is pushed a little bit away by the shutter speed cam.
This also gives an indication for the right position of the shutter speed cam.
You asked for the small tab on the opposite side of F can be moved to the right.
That tab is on one of the levers that serve the T/B function and I think it can be moved a little bit.
Thank you so far again,
Toon.
Hello Toon!
Oops! I guess you’re right. I had mistaken the shoulder on the cam where I placed the blue dot for the one on the next cam below it. This is the bit that will engage spring E when you set the shutter to its fastest speed.
I would guess that this is a fairly large shutter. The booster spring is generally used to power a top speed of 1/400 or 1/500, but in larger shutters the maximum speed is reduced because of the greater mass and the greater distances to travel for the shutter blades.
Yes, the pin that is now in the U shaped slot in your latest photo would ride in a slot in the cam. At faster speeds, the cam holds this pin outward, so that the ring A will not have to move the partial gear very far before passing by – at the fastest 2 speeds, 100 and 200, the pin should be held fully outboard so that the tab on ring A never touches the partial gear, thus there is no delay in the shutter blades’ travel. At slower speeds, the cam slot would be a bit wider, allowing the pin to rest farther inboard, so that the tab on ring A has to move the gear farther before passing. At the slowest speeds, the lever at the green dot engages the escapement, which creates resistance to the movement of the partial gear and requires a longer time for the tab on ring A to push it out of the way.
I think you’re very close now to getting this back together and working. If all of these levers, gears etc are clean and move without resistance, the shutter should run. It should not need much lubrication, it may run well completely dry – if any oil is needed it should be very thin, and used sparingly, just a drop or two on the teeth and shafts of the pallet and star wheel should be all it would need.
rick
Hello Rick,
yes I think too a working shutter is close now.
Today I’ve put the shutter speed cam without problem in place. But things are not moving as smooth as I like.
Could the spring of the cocking ring “K” be a problem?
I think this spring restrict lever “C” in its moving around “M” (image).
Around point “L” on lever “C” is another small spring with two “arms”.
The arm left fits behind a screw, but the right arm is jammed between spring “K” and lever “C”.
I thought to turn spring “K” 90°, so it comes lower; there is room for it.
Shall I remount the spring on “A” turned 90° or simply force the spring in the “right” way?
Then there is another small stronger spring under “C” around point “M”.
I can’t see this spring has any use, but maybe you know more about it?
B.t.w. “J” is the handle for setting the aperture.
This position is F 4.5, biggest opening.
The size of the shutter is outside ø68 mm; opening is ø29 mm.
Is that a large shutter in your opinion?
No problem if it’s working it gives more light on my 5×7″.
I hope you still like this job.
Toon.
Hello Toon:
There should be a spring forcing lever ‘C’ in a counter-clockwise direction, so that the hook at its right hand end would be pressing against ring ‘A’. It should not just rest in the position that it is in in your photo, it should require pressing the shutter release’B; to force it into this position against spring pressure. I see what looks like a groove in the bottom face of ‘C’, just below the pivot at ‘M’. Would it be possible for the small spring at ‘L’ to fit into this groove? Or, does it appear that the free end of that small spring is broken? If you look at it under magnification, if it is broken it will generally break at an angle and leave a sharp edge at the tip. I’m not sure whether that spring, or the stronger one under ‘M’ is the one that should be forcing ‘C’ counter-clockwise, but something has to do that for the shutter to work.
I would not modify any parts (such a ‘K’) or install them in an unnatural orientation, unless you find signs of wear, damage or tampering in the shutter; sometimes you can modify or move a part to make a particular operation function, but often then you will find that you have put some other function out of order by the modification. If the shutter is not damaged, it should only need cleaning and getting the parts back into their original positions to make it work.
rick
Hello Rick,
on the attached picture you can see the mystery spring.
As you see one end of this spring is fixed in the groove you mentioned.
I don’t think this spring is broken (I’ve tried to make a detailed picture).
Now I’ve put the parts, as far as I know, on their original positions.
And yes, it’s working a little bit; i.e. 1/25 and 1/50 sounds OK.
Also 1/100, but I have to force the shutter speed cam in that position.
1/200 is not possible, while the booster spring “E” isn’t touched by “A”.
With the longer shutter times the shutter only opens.
The timing delay escapement “G” should do something, but it remains silent.
That is the situation you see on the “Actual shutter” picture.
I have to push the lever “N” on “G” , to close the shutter.
When I push “N” to the right it gives the buzzing sound, but not 1 sec. if set so.
Has the fascia plate a roll in the working of the shutter?
Toon.
Hello Toon!
It sounds like your timing escapement is not working. When the cam is off, and lever N is to the left as shown in this photo, can you push the pin on the partial gear at the bottom of G and move the gear outward? And when you do, does it move smoothly but with a small resistance, and does the escapement buzz as it moves? And when you release it, does the partial gear return to the left to its original position without you pushing it back in that direction?
And when set at a slow speed: if you hold the lever N to the right while releasing the shutter, does the shutter fire? And does it buzz, or does it just operate without buzzing?
And, what speed is the shutter set at in this photo?
And can you send a photo of the BACK side of the cam ring?
The shutter should operate normally without the front panel, as long as all of the levers and pins are in their correct positions – sometimes when the front panel is off, it’s possible for the cam ring to move forward slightly and allow a pin or lever to get out of position, which can prevent it from operating correctly.
:)=
Rick,
with the cam off and “N” to the left resting against “A” it’s not possible to move the pin on the partial gear, cause this pin is blocked by a tab on the cocking ring “A”
(image left).
When I push the cocking ring “A”, the pin on the partial gear comes in a free position (image middle).
Then it is possible to move the partial gear into “G” and when I release it the partial gear go’s back in the original position.
But while it’s moving (in both directions) the escapement is not buzzing, it is not moving at all.
When I now release the shutter slowly, also the blades already open slowly; that’s no good I think (image right)
Now I put the shutter speed cam in its place on 1/5 sec. and bring the cocking rack in tense (image left).
As you can see the lever “N” is already pushed to the right.
After releasing the shutter, the shutter opens quickly, without any buzzing (image middle).
If now I push the lever “N” to the right, the shutter close with a short buzzing sound and “N” goes back to the left (image right).
In the photo you asked for the shutter speed is set on 1/5 sec. one of the slower speeds.
My answers has to be done a bit quickly cause this evening I am not at home.
We have a meeting about the upcoming photo exhibition in April with my photo club.
They will be wondering about all my effort for an old lens.
They are all new, modern and digital and will simply order a new one on the internet.
Thanks again, Toon.
Hi Toon!
I’ll have to look at these later and get back to you, but just a quick note about the pin on the partial gear and the tab on cocking ring A: This tab should never be in a position to block the pin. The flat back face of cocking ring A should rest directly on the front face of the gear, so that the tab engages the left edge of the gear and pushes it out of the way… the pin should always be some distance away from the cocking ring. With the cam and front cover off, it is possible for the cocking ring to float forward, allowing the tab to ride up on top of the gear and strike the pin, but the shutter will not operate properly if this happens.
More later……rick
Hello Rick,
first my short reaction on this mail.
You wrote, the tab on cocking ring A should never be in a position to block the pin on the partial gear. But when the cocking ring is in the rest position (up) then the tab is simply in the position it blocks the pin.
Then you wrote: The flat back face of cocking ring A should rest directly on the front face of the gear, so that the tab engages the left edge of the gear and pushes it out of the way…
I do not understand that correctly. I think the flat back face of cocking ring A is always away from the front face of the gear G.
Or do you mean with this that without the shutter speed cam there is never a normal situation?
Your next mail cost me some more time I’m afraid, but I’ll be back.
Toon.
Hi again Toon!
I don’t know how much help this will be, but I’ve taken your back view of the speed cam and marked the functions and proper control positions on it (see attached).
The red and green dots indicate the position of the pin on the partial gear at every speed setting. Red dots indicate that the pallet is engaged (pallet lever toward lens, shutter will buzz) and green dots indicate that the pallet is disengaged (pallet lever pushed away from lens, shutter will not buzz).
Note that at T and B, the pallet lever is disengaged as it is at faster speeds
Note that the pin position at 1/25 is the same as it is at 1 second – the difference is the engagement or disengagement of the pallet to slow the passage of cocking ring A past the partial gear
The pin on the pallet gear must rest against the indicated cam surface until the tab on cocking ring A pushes on the side of the partial gear, which moves the pin outward away from the cam surface.
The pallet lever must also rest against the indicated cam surface, but note that the cocking ring itself pushes this away from the cam to disengage the pallet during cocking. This surface of the cocking ring goes way as the ring begins to move during firing, so that the pallet lever will be in the correct position against the cam surface before the shutter opens.
With the exception of that part of the cocking lever being in the way, if the pallet lever does not rest against the cam surface at the 1 – 1/10 speeds, something is wrong.
If you cannot easily move the pallet lever outward, or if it does not return to its inward position under its own spring force, something is wrong.
With the pallet in its engaged operating position, you should be able to move the partial gear pin outward with slight resistance, and the escapement should buzz
With the cam off, it may be possible to move the pallet lever toward the lens beyond its normal engaged position – in this case the escapement may lock up entirely. It may be possible for this to happen with the cam on, if the pallet lever has been bent or damaged.
With the pallet in its disengaged operating position, you should be able to move the partial gear pin outward with almost no resistance, and the escapement should not buzz. The partial gear should return to its original position under its own spring force when you release it.
There are only 2 operating positions for the pallet lever, either in or out. It moves from one position to the other between the 1/10 and 1/25 shutter speeds.
There are a range of operating positions for the pin on the partial gear. These establish the intermediate speeds within each of the 2 [pallet-in and pallet-out] speed ranges
The long slot across the top of the cam (from the ‘C’ in Compur to the ‘B’ speed setting) is for the T and B levers, which should rest on the inboard surface of the slot. The cam holds these out of engagement at all speeds until it gets to the B and then the T positions, where there are small steps to allow the levers to engage. Opposite that end of the slot is the shoulder that charges the booster spring for the 1/200 speed.
That should be a full explanation of all of the functions of the speed cam and the speed control levers. If any of the levers do not rest on the cam surfaces as indicated, something might be bent or damaged. If the escapement does not run freely, buzzing when the pallet is engaged and silent when it is not, and return to its original rest position under its own spring force, then something is not operating correctly. If the escapement locks up in the pallet-engaged position, it may be that the pallet lever is bent or damaged and is not correctly positioning the pallet in the teeth of the star wheel. If it goes in so far that both teeth of the pallet try to engage the star wheel at the same time, it will lock up…. it needs to be at such a position that one tooth will always engage the star wheel but never both at once.
I hope this may help you sort it out.
Best wishes,
rick
Hello Rick,
sure it’s not me who don’t like you sending these emails.
Maybe it’s a smart algorithm into a trade embargo that provides for this, afraid to lose all this interesting knowledge to a foreign power?
The marked back view of the speed cam is very clear, thanks for that. I’ve made myself a mirror view for the right projection on the shutter.
Now first I took out the timing delay escapement “G” to see what it’s doing; for it is working.
In this case I see three situations for “G” depending on pallet lever “N” (image TimDelEscG).
Lever “N” is in a rest position, pushed by his own spring, toward lens. Nothing can rotate, cause the 2-toothed rocking pallet “P” has both tooth’s in the star-shaped wheel “Q”. This is independent of the position of the partial gear “O”.
Lever “N” is pushed a bit away from lens. With the partial gear “O”, pushed by his own spring, in the position out of the escapement “G” nothing wil happen.
With the partial gear “O” in the position into the escapement “G”, “O” will slowly move out of “G” while “P” and “Q” are buzzing.
Lever “N” is pushed more far away from the lens. With “O” out of “G” nothing hapens.
With “O” into “G”, “O” move out with more speed without buzzing.
OK, this is clear for me now and I hope it is all correct. The escapement “G” is put back on its place in the shutter.
When the shutter is fired the cocking rack “A” rotate CCW back to its rest position, pulled by the cocking rack spring “K”.
The escapement “G” takes care to slow down this movement.
This is done by blocking the tab on “A” by the partial gear “O”: as long as “O” is in the way, “A” can’t rotate further CCW.
At this point I have a problem. The escapement do nothing with an engaged pallet lever “N” and sometimes with the pallet disengaged.
Only if I move “N” a bit away from the lens something happens and “A” finish his CCW move.
Yes!! I’m writing this while I try things to understand.
The escapement “G” has three mounting screws; two on the left and one on the right.
I was thinking how to give “N” a little push, so I don’t have to do that by hand.
Well quite simple: with the right screw I can mount “G” a bit more in or out of the shutter.
And that was all what must be done. Now all shutter times seems to work.
A few things left now:
I doubt whether the times are right. 1 sec. is too short I think.
And 1/10 sec. sounds to be shorter than 1/25 sec.
I have to think about a method to measure the timing.
When I push “A” from its rest position I feel sometimes more, sometimes less obstruction.
But I can’t see or feel what could be the reason for it.
The lever for the T and B times didn’t go well to the T position; in that case T = B.
I wait for your answer and hope that my enthusiasm is justified.
All the best, Toon.
Great progress!
Now, things may get a bit fussy and require trial and error.
You will notice in your photo that the screw holes at both ends of the escapement are oval slots, not round holes. Because of this, the 2 ends of the escapement can be moved in toward the lens or out away from it, independently.
Moving the left end in or out will change the distance that the gear O must travel. Moving it closer to the lens will give a slower speed. This should affect all speeds except for 1/100 and 1/200.
Movig the right end in or out will change the engagement of the pallet into the star wheel in the escapement. Moving this end closer to the lens will give a faster speed, as the pallet teeth will be less deeply engaged into the teeth of the star wheel.
Both of these adjustments are a bit non-linear and will depend on a bit of guessing and trial until you get to an acceptable result.
If 1/10 is running faster than 1/25, the engagement / disengagement of the escapement pallet is not occurring between these 2 speeds as it appears from the cam shape that it should. I’m not certain exactly what would cause or correct this, but I suspect that this is also a matter of shifting the position of the escapement assembly to make lever N ride in a slightly different position along the cam. As you can see from the shape of the cam and the positions of the red and green dots along it in my earlier photo, it takes a very little change in position of these levers to cause a significant difference in the shutter speed.
One other thing to keep in mind as you go from getting it to run, to adjusting its speeds: Leaf shutters are by their design very imprecise, particularly at the fastest speeds. Consider the 1/100 and 1/200 speeds: in both cases, the blades are in constant motion, there is no pause in the full-open position; therefore, the shutter is not 100% open for any measurable duration of time, it is passing light through partially closed blades for its entire exposure time. Typically the indicated speed of the shutter represents not the total time that it is partially open, but the amount of time that a focal plane shutter would be open to pass the same amount of light that comes through the leaf shutter. Because the leaf shutter is only partially open, it takes longer than its indicated speed for it to fully open and close. At the 1/200 second setting, the shutter might take more like 1/100 second from first beginning to open until finally being fully closed, in order to pass 1/200 second equivalent of light through a fully open lens, when the shutter is perfectly adjusted. Now, consider the same perfectly adjusted shutter and lens, but this time with the lens stopped down to f/16. In this case, the shutter exposes the entire f/16 diaphragm opening almost instantaneously as its blades begin to open, therefore you will be seeing a fully open condition for the entire 1/100 second. This is the case with every leaf shutter , no matter how well designed and built, whether on a Linhof, a Hasselblad or a Deardorff. This variation of one full stop of exposure is absorbed by the exposure latitude of the film, and you never hear complaints about view cameras and Hasselblads being unable to deliver consistent exposures.
The moral of this story is, do not lose sleep over small variations in shutter speeds. Our computer age has given us expectations of precision and accuracy that are neither possible nor necessary in a mechanical leaf shutter.
Best wishes!
rick
Hello Rick,
what you already say: a bit fuzzy and trial and error work to do.
Sometimes the shutter stocked during operation.
And other things were not going very gently.
So I demount the shutter as far I worked on it.
I start cleaning carefully with isopropanol.
Everywhere metal on metal moves I put a tiny bit of WD-40.
Cleaned al places so there was no oil left behind.
Then it sounds already more confidence to me.
And there were no obstructions anymore.
Then I get curious how the timing will be.
I put a LED on a frequency of 20,0 Hz on a long swinging wire.
That will give a flash every 50 mSec.
With my DSLR on B, I made a picture through the shooting Compur of the moving LED.
So I get a number of flashes what is an indication for the time (image: 20Hz 19 puls).
20,0Hz is Ok for 1/1 sec. and 1/2 sec.
1/5, 1/10 and 1/25 I did with 100,0 Hz-10 mSec.
For 1/100 and 1/200 I need 1,000 KHz-1 msec. and a very fast swinging LED.
Finally this are the times in mSec.; the times I want to know:
1/1 = 940 1/25 = 54
1/2 = 460 1/50 = 21.4
1/5 = 188 1/100 = 12.8
1/10 = 62 1/200 = 5.0
This is based on five measurements for each time. With this I had to be satisfied and I think; knowing these values, I can calculate with it.
Before I can use it on my camera it must be mounted on the camera.
That will be my next challenge, cause there is nothing to mount the lens.
The lens mount of the old one is 44,5 mm and the Compur is 38,9 mm.
Maybe you have experience with this kind of mismatch?
The size of my Compur seems to be rather rare, I can’t find much information.
Best wishes, Toon.
Hi Toon!
The only speed there that I would consider to be out of spec is the 1/10. The 1/25 and 1/100 look about as close as I would expect to see in a leaf shutter. Your effective exposure time at the faster speeds will vary based on what aperture you select on the lens in any case (the full aperture is only open for a short time as the blades reach the full open position, while a small f/32 aperture will be fully exposed for the entire travel time of the blades during opening and closing …. the difference at 1/200 and 1/100 can be about 1 stop of effective exposure time between the largest and smallest aperture settings on the lens), the film has plenty of latitude to absorb these small variations.
You could make an adapter from the 38.9 to the 44.5mm thread, but it would be easier to make a new brass mounting ring with the 38.9mm opening, with the outside diameter and screw locations matching the existing ring on the lens board. This would be a very easy quick job for a machine shop, once they know what the diameter and thread pitch is on your shutter. If you plan to change lenses back and forth many times, it might be worth making a new lens board to go with the Compur. A machine shop could make the adapter easily enough but I don’t know that it would be much more work to make a new ring plus a new lens board to put it on.
rick
Hello Rick,
the shutter times are as they are, I have to deal with it; no problem I think.
And you are right, with short times the diaphragm affects also.
An old colleague of mine builds clocks as a hobby and he has made me a perfect brass mounting.
A nice piece of Dutch hardwood for the plate makes it complete.
The camera can make pictures from 25 cm distance to infinity with this lens.
Now I need some time to find out good time/diaphragm combinations.
And of course the best way to develop the sheets finally.
As soon as I have an acceptable result I will show it.
When I use the camera it is good to have some extra film cassettes.
There is one on Ebay in Ukraine, but I hope for more in the future.
That I contacted you a month ago was a good move.
Your spontaneous, extensive and responses with knowledge surprised me.
So I learned a lot about shutters, resulting in my repaired Press Compur.
I am very grateful for that and I hope I could do something in return.
It’s a pity US is not close, then I would invite you to drink a good glass of Trappist together (only if you like it of course).
So if you have plans to come to Europe again, do not forget to visit the Netherlands.
Thanks once more,
first picture is coming soon I hope,
Toon.
Hello Toon:
That’s a very nice installation! I’m sure this camera will work very well. I’m glad to hear that the shutter is working out too, I hope you enjoy shooting with this and create some new Dutch Masterpieces!
Best wishes,
rick
Hi Rick,
hat should be nice; some new Dutch Masterpieces.
But a Masterpiece is not a piece of cake as you know.
Today I started the Dutch way: with a piece of cheese.
Toon.
Well on the way, I see promise of great things
:)=