Sorry kids, no tricks today

Well, I had done some cleaning on a Chiyoko Super Rokkor 5cm f/2 LTM lens … and I did not take any pictures.

So, I will just have to describe some things about it.

Like most LTM lenses the disassembly is quite similar … there is a ring in the back that unscrews to release the inner unit from the focus mechanism. The lens elements and groups are held in by ring screws or the casing is threaded.

What is a bit different on this lens are the “containers”. With most lenses each element or cell group is secured by a ring screw … hmm, this Chiyoko lens gave me a surprise.

Minolta decided not to do this … this lens has encased the elements into three brass tubes. The front two elements, second two (stacked), and the last three. They are secured in place by a single front (name ring) and rear screw ring.

Hmm, odd design … especially since it required very precise milling as they are not easily removed.

Got distracted

Well, it’s been a hell of a year … or two.

Not the norm, but the world is working out how to cope with a pandemic.

I have not been doing much concerning camera restoration … been preoccupied by other things. I will get back to posting some fixem stuff later on this year.

So just a plug to anyone interested in getting some nice cards from our Esty site … thought I do realize that most of of you that are paying attention to my site are probably photographers.

Pass it on if you wish.

Compur (not so) Rapid

OK, so I am going back to do the things I shudda dun when I was younger, now that I am older. You can teach an old dog new tricks.

Four years ago I posted about the Rolleicord. At the time I did not have the knowledge to dig into the shutter, so I did not touch it. Recently I ran some shutter speed tests on it. The leaf shutter is running slow … so I need to investigate.

The Learn Camera Repair course covers servicing shutters … so now that I have gone through the course material, I can dig deeper … and so can you, AFTER you read the material.

With my Compur-Rapid shutter all speeds, except the two highest, are controlled through the speed escapement pallet and retard movement. If it is gummed up or not adjusted properly … or just tired, it will affect the shutter speeds.

So time to open it up.

The shutter does not have to be taken off the body … but I did so. To remove shutter … unscrew flash wire connection … then from the back unscrew the light baffle which is also the locking, with a spanner wrench.

Take note of the black slotted spacer + shutter release/cocking lever + copper spacer ring that sit between the shutter and body.

Ok, now unscrew the front group and rear element.

This one is a Triotar, a triplet, so a two element group in front and one in the back

The cover is held on by the centre plate

Turn the semi circle then rotate the plate to the cut-outs, to pull off.

Now the speed cam …

Note that there are three points that make contact with it … turn to different speeds and you will see the movement of these.

Also note the highest speed compresses a spring.

You can see the super spring on the left that is for 1/500s.

The shutter cocking ring (main lever) main spring is attached to the end of the speed escapement. Notice that this ring contacts multiple items in the shutter.

Unhook the end of the main spring and remove the main lever.

The retard speed escapement sits on the right side. It is secured at the top and bottom.

The retard escapement (which I also call the speed escapement) is what we are after. Remove it and clean it (ultrasonic).

Note that the top and bottom holes for the securing screws are oval … meaning that the escapement has adjustable positioning.

The retard lever, on the lower section has a special shape … feel the outside for any rough edges, as I had to lightly sand it to reduce the chance of the main lever catching on it when it pushes it.

While the escapement is out you can also check the movement of the shutter blades .. no sticking or slowness. If the shutter is not moving freely then this requires further disassembly to clean everything out … meaning no flushing.

Notice in the image above the retard has moved out of engagement with the gears, which will happen when the pallet lever is moved to its inward position.

Set the retard back in as noted in the Repair Course, and put it back in.

Note how both the pallet (red) and retard (green) ride against the outside of the main lever.

The position of the escapement (both top and bottom) control how the various speeds run.

You can put the speed cam back on. Ensure that the pallet lever and retard pin are not sitting under the cam, remember that they ride along the sides of the cutouts … then check the 1 second speed … if the escapement locks up then the bottom section need to be moved more to the outside. If the shutter stays open then move the top section more to the outside.

Once you have free movement you can start adjusting. The pallet and retard are combined for speeds 1/10s and below … for higher speeds the pallet is not engaged, just the retard is used to slow the main lever … except for 1/250s.

If the ~ 1/10s speeds are all slow then move the upper (pallet) end closer to the inside. If the upper speeds are slow the move the lower (retard) end further away from the inside.

This shutter’s highest speed is 1/500s, which is controlled by a separate coiled spring. The 1/250s is controlled by the main spring and does not touch the retard.

Getting the speeds right is a delicate balance of the position of the upper and lower sections, as noted in the course material … so have patience, as it can get frustrating when you try to make a correction. It does not require much movement of the escapement to make a difference.

A leaf brief

One thing that commonly find with the many cameras that I have worked on is the shutter … the leaf shutter.

Leaf shutter

The leaf shutter that we see today first appeared in 1890, created by Voigtlander. It had four blades. Bausch & Lomb also produced many leaf shutters just after this.

Steinheil, was an optical company that got into the shutter business. Christian Bruns, in 1899, made their first 4 bladed leaf shutter.

Friedrick Deckel and Bruns got together (after leaving Steinheil) and created the Compound shutter in 1905 … the speeds where pneumatically controlled.

1910 Bruns created a mechanical retard mechanism to control the shutter speeds, and this became the Compur shutter.

When you see references to a Compur # something shutter … it refers to it’s physical size … leaf shutters were made in different sizes.

Another name in shutters was Gauthier … created by Alfred Gauthier in 1902. They are known for their many shutters, including the well known Prontor shutter.

Now the Japanese came much later to market their own leaf shutters based on both the Compur or Prontor design … in 1935 Seikosha shutters appeared and later on in 1946 the Copal shutter.

Other names in the shutter business … Wollensak and Ilex, both American companies.

The adventures of this guy who tries to restore and repair vintage photographic equipment … and wins (most of the time).

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