winfried_buechsenschuetz1

Yes, the diaphragm diameter cannot be measured directly, you always have to take into accout the magnifying factor of the lens. The thing about the f/2 and f/2.8 of the Retina is no myth. I think Rick Oleson described the method of removing the stop on one of his fabolous camera repair pages - if they still exist, must be a decade or so since I last visited them.

I am sure it s 0.5mm. All older german cameras (and most, if not all, japanese ones) use metric threads, and I have reshaped a lot of filter threads with a 0.5mm pitch thread chaser.

I am owner of a PF2 (and former user). I cannot help you with this specific problem, only thing I knew that there were a lot of modifications during the manufacturing period (and sometimes even left-overs of older parts were used), so it s hardly possible to check by the s/n how your camera was assembled. There is a forum on Foca cameras. It s in french only but I think some of the members will understand english, so you might post your question there. http://opl.foca.free.fr/index.php

Actually the 7s has some kind of CLC. The CdS cell is divided in two halfs, and light comes in through a small window. So a bit similar to a camera obscura, the upper half of the scene is projected on the bottom half of the CdS cell and vice versa. Since the higher resistance part of the CdS - the less illuminated one - dominates the exposure, it will compensate somewhat for a "darker half" of the scene.

It seems as if you succesfully turned the locking nut when disassembling. So when assembling you have to turn it just the other direction. I agree that this is simetimes difficult as the last fold of the bellows sometimes covers the locking nut partially. First, place the shims on the "stud" of the shutter assembly. Then hold it against the lens standard and make sure it peeks out on the back a few mm. If you cannot reach the slots of the locking nut, unfold the bellows halfway. Sometimes it is not easy to place the locking nut on the shutter thread, it is a "fine thread". In case you manage to rotate the locking nut freely (i.e. without interference with the last bellows fold), place it evenly on the end of the shutter thread and rotate it clockwise, it will "catch" the thread by itself. Holding the bellows half opened during this procedure sometimes requires three hands, maybe you find someone to help you holding the camera. As mentioned by others, the shims are necessary for adjusting the focus. With front focussing lenses, it might be possible to adjust the focus (there are DIY methods) WITHOUT the shims but then the front lens will not in the optimum distance to the other lenses, i.e. picture quality will suffer a bit. (Am not sure whether this will be visible though.)

Be careful with heat guns, they might affect the glue between lens elements. Heat is one factor, time is another. With front lens focussing, try to remove the focus ring (you need a really hard and good material screwdriver, the ones sold by El Cheapo tools can destroy the tiny set screws very fast), and drip some drops of household alcohol or lighter fluid into the small gap of the focussing thread. Let it rest over night. With helicoid focussing, on many cameras (I do not know the Solinette in detail) the top of the helicoid is visible through the film window. Apply some drops of alcohol/lighter fluid and wait.... To regrease, it is the best to take things apart and regrease with special "photo equipment grease" or light silicon grease. If you do not dare to do so, apply some tiny drops of gun oil to the focussing thread/helicoid.

My first guess would be the double exposure latch, too. On many cameras this latch is located under the bottom plate. Remove the bottom plate (and check for parts falling out - keep the camera with the bottom plate on top). Check whether there is a lever with a cam which blocks a groove on the main advance shaft (in many cases, it s a a rather big cog wheel, maybe it moves slightly as you try to move the advance lever). Maybe the return spring of this lever is blocked or broken. In some cases, the bearing of the lever is stuck. Apply a drop of lighter fluid to the bearing and try to move it. You can add a tiny (I said TINY) drop of gun oil (or silicon oil) to the bearing. In case of a broken hairspring, in most cases you have to replace it. With some practice, it is not too difficult to bend a new hairspring from thin springy wires. In the era of computer diskettes you could cannibalize the spring from the cover covering the case slot. In most cases, "strength" of this hairspring is not critical.

The quick loading system of the QL is quite simple. There are two rubber pads on spring-loaded arms on the wind shaft. They press the film against the wall of the film chamber and push it forward as you advance the film. Make sure the rubber pads are intact and clean the surfaces of the pads and the inner polished surface of the film chamber with household alcohol.

Maybe your make of foam is somewhat more suitable, but I (living in mainland EU) always had good results with foam rubber (Moosgummi) from a DIY store. It takes some time until it settles and until the backdoor can be closed again smoothly but worked on all my cameras including the 500G.

The 500G is a nice little shooter. The lens is quite sharp and contrasty. As often with these old things, the light seal foam is deteriorated. The 500G uses a back door design quite different from other cameras and the light seal foam is also shaped different. With some practice, you can cut the whole light seal from a single piece of 1.5 black foam rubber. Light seal strips (as often used on other cameras) cannot be used.

I have tinkered a lot on the Yashica Electro 35, and I think I still have a Hi-Matic E sitting around somewhere. The Hi-Matic E shutter and its control have nothing in common witih the shutter control of the Electro 35. Actually, the Hi-Matic E even does not have aperture blades - the shutter blades act both as aperture and shutter blades. For small apertures, they just open a little, and they can do this quite fast - I think the Hi-Matic E max shutter speed is specified at 1/1000. The "program" is quite simple: under good lighting conditions, it operates at high shutter speeds and small apertures, on low light it acts with the shutter opening fully (slow speed) and "full" aperture. On the Electro 35, there is a real aperture and you can pre-select an aperture value. As mentioned, with the Hi-Matic E, you never know which aperture and speed it selects. The shutter of the Hi-Matic E is much more advanced, I think it was completely made by Seiko, and also appears on a (rare) Petri camera of same era.

The blueish (or otherwise coloured) bloom on old lenses is not necessary fabricated on purpose. Some types of optical glass tend to corrode (very slightly), i.e. the glass changes it s structure. This may lead to changes of the refractive index, but only of a very thin layer. This might have a similar effect as anti-reflective coating, which depends on a similar physical effect (coating with a layer with very little but well-determined thickness, of a material with a refraction index lower than the "base" glass).

It's true that the Novar is not the best lens ever made (and not the best triplet design - to me, the best of these is the Meyer Trioplan) but it is far from being the worst. Stop it down 1 or 2 steps and you well get decent pics. As far as I know, Zeiss outsourced manufacturing Novar lenses to several other companies - I have heard of Rodenstock, for example. This might be the reason that the Novars usually do not have serial numbers - would have been difficult to organize a sequence of serial nos. across several companies.

Many years ago I was looking for a 28mm lens for my Leica/Canon7 bodies but did not want to spend $$$$- So I bought a M42 28mm f/2.8 as cheap as M42 lenses are. Back then, there was a used equipment store in the (german) town where I work, and in one of his grab boxes we found a M42 to M39 adaptor with suitable length to compensate for the back focal length. With 28mm you can easily "guesstimate" focussing. This, however, will be difficult or practically impossible with longer focal length. You can use one of the (expensive) adaptors with a rangefinder coupling mount (you have to set the focus on the lens separately), or use an old rangefinder accessory.

First thing to check are the contacts of the battery tray. Contacts and wires which are close to (former) mercury cells are prone to corrosion. You can clean the contacts with a glass fibre eraser pen. Second, these cameras are a bit tricky. I had a sample with a broken light meter cell. On another one, almost all the wiring was severly corroded and even the electronic board inside the shutter assembly was affected. Also, they are everything but simple to repair... So try to clean the contacts and maybe you are happy then. The V lever sets the self timer (V = Vorlauf in german, which translates into delay)

The shutter seems to be a clone of a german Prontor shutter. Anyhow, if you are new to camera repair, you should not try yourself. Usually these shutters are opened by removing the front lens element by unscrewing it and lifting the "nameplate" ring. Beneath it, you will probably see a thin ring with notches around the opening, held in place by a tiny screw. After removal of the screw, you can screw off the ring and CAREFULLY lift the shutter dial. It seems your shutter is gummed with corroded lubricant. The Prontor shutter and its clones can be set to any speed before or after cocking. In the link, you can find some hints for a similar shutter (with added slow speeds). prontors1

My experience with the Moskvas is that it mostly depends on the general shape of the camera. Obviously there are many worn out samples around, with bend struts, scratched lenses, worn bellows etc. Sometimes you have to buy two or three of them to assemble a decent one. Once you get them to work, they are not too bad. The lens does not compare to a post-war Zeiss Jena Tessar but is far better than most 3-element designs. The shutter can be reasonably accurate once it is cleaned and adjusted properly. The rangefinder is a bit difficult to adjust but works nice. The built-in viewfinder is more handy than the frame finder on the Ikontas (and earlier Moskvas) but its image is much smaller. So I would recommend to buy one on a camera show, not by mail order. You will pay more than when buying from a russian or ukrainian dealer, but, as mentioned, you might two or three buys to end up with something that compares with a nice sample from a camera show.

Actually I never stumbled across the unit designator "cmp" although I was raised in a metric country where pond was used as a physical unit. But I can imagine that "cmp" stands for "centimeters x pond". Usually the designator for torque units had the unit of power first and then the designator for distance from center, like kpm (kilopond * meters). Maybe the usage in the 1950s and 1960s was different. You can find conversion tables for torque unit on Einheitenumrechnung für Drehmoment - Lorenz Messtechnik GmbH . I entered the value 160 in the "pond zentimeter" field and the result was 0,14 inch-pound. Hope this helps. PS. On Convert units - Torque (τ, M - Moment of Force, Moment) ... CALCULAND I found the unit "centi-pond * centimetre" (cpm), this conversion table yields the same result.

It will not be possible to solve this problem without disassembling the focus mount. To get it loose again, you should warm up the lens mount with a hot air gun and try to turn the focussing ring. As soon as it is somewhat loose, disassemble the focus mount and dip both parts into household alcohol over night. This will remove any residues in the threads. To regrease, there are special greases available but I had good results with silicon grease. DO NOT use any mineral oil based grease.

Hello, sorry this was years ago, I don't know where I got the CdS resistor from. I faintly remember that it was a standard item from an electronic parts shop. These days CdS resistors are harder and harder to get. If you find some (some surplus shops still sell them) you should try those with a "!bright light" resistance as low as possible. I thinki most camera manufacturers used CdS with custom specs so it's always a matter of luck to find a suitable replacement.

Over the years I had had many cameras in my hands and fixed quite a few of them. Also, I have a degree in precision engineering. And all this experience tells me that this concept will never make it to real. How will you compensate for different distances between cartridge axis and film window? And how do you want to transfer the advance mechanism to the cartridge and tell it that there will be a new pic? There are several different concepts of film advance in mechanical cameras. Some of them turn the cartridge axis (via a friction coupling) and stop it as soon as the sprocket wheel turned by the pulled film has made one full turn. Some make it the other way round and turn the sprocket wheel a full turn and the cartridge axis is loosely coupled to that drive. I do not remember how many times this subject has appeared during the last decade ... but noone has ever seen a digital film cartridge yet and probably noone will ever do so.

As far as I know there were just a few zoom lenses available from VEB Pentacon in M42 and/or Praktica B mount towards the end of production of the Praktica line in the late 1980s. Most if not all of these lenses were manufactured in Japan. I have never heard of any zoom lens originally made for Exakta mount in the GDR, or at least marketed by GDR companies. Also, Exakta never was a company but a camera designator. You cannot expect an Exakta zoom lens being manufactured by a company which never existed under this name. All these Exakta lenses are of far-east origin and were marketed by western companies. BTW there are also some newer lenses with an "A. Schacht" designator. Production of original Schacht lenses was stopped somewhere in the 1970s so all these lenses are also re-branded far-east lenses and have nothing to do with the older Schacht lenses.

<p>Just a warning: Sometimes even the normal shutter mechanism (or blades) are stuck and the shutter does not fire at all. Some people think that the self timer can do magic and try to operate the shutter via the self timer - and,as mentioned, due to poor usage the self timer mechanism will be stuck too. So DO NOT try the self timer when the shutter does not fire via the shutter button! Things only can worse that way. </p>

<p>A "press focus lever" makes sense only on cameras where you control the focus on a ground glass. Like some others, I rather think this is the selftimer lever. And this is a common issue ... since the self timer mechanism usually is not used very often it is prone to gumming. Release the shutter, hold the release button and push the lever gently. And DO NOT operate it anymore unless the shutter has been cleaned!</p>

<p>All the leaf shutters I had in my hands (and there were quite a few) did not have any kind of interlock for keeping them open. The blades are simply swivelled around by an actuating ring which is driven by the shutter spring. After completing this movement, they are driven backwards by a closing spring and it is the escapement mechanism or a solenoid which determins the fully open period.</p>