Contaflex Lens Crap

[drgoose]

Hello everyone, I recently purchased a Zeiss Ikon contaflex with a Tessar 2.8 Carl Zeiss lens on a compu-Shutter. I love the little camera and the image quality is not bad. The lens has a rim of "crap" on its outer edge. The center of the lens is clear. I am trying to find out if this lens can be cleaned from the back somehow without a very involved proccess. I don't see how to take it off. I am attaching a picture of the lens. Thanks in advance.

 

[richard ide]

I could be wrong but that looks like element separation and would need to have the two elements separated, cleaned and recemented.

 

[rjbuzzclick]

I just took one of these apart recently. You need to completely remove the two grub screws on the distance scale ring, and then THROUGH those screw holes loosen the three grub screws that hold the knurled focus ring to the front lens element. When those three screws are loose enough, you can lift the knurled ring off, and then unscrew the front element all the way. Take note of where the front element comes off as there are a multiple thread paths that it can go back on. Only one is correct. There are little painted indentations where the grub screws from the knurled ring sit on the front lens element ring. Check it at infinity with the split-screen on the ground glass before you put the knurled ring back on. With the knurled ring back on, the lens should "stop" at infinity. Good luck!

EDIT after seeing Richard's post above, I believe that the front group in a Tessar formula is a single element, not a cemented pair, so it shouldn't be lens separation. I could be wrong as well however.

 

[bernard_L]

Does not look like separation. Looking closely at the pic (full magnification) one can see that the damaged ring extends in streaks towards the center (look near the 1:2.8 marking). Would suggest someone has over-enthusiatically cleaned the lens, insisting on the periphery, and degraded the AR coating to a state where is is "milky". Maybe (just maybe) the way to rescue that lens is to remove uniformly the AR coating on the front surface, using Cerium oxide (found as a supply for stone polishers).

Or, find yourself another cheap "for parts" compatible Contaflex, with (e.g.) a dead shutter and scavenge its front element.

 

[shutterfinger]

Light travels the arrow direction.
The 45mm f2.8 was used on the Contaflex I and II. It is a fixed lens. It does not have interchangeable front elements like the later models.
It should clean up once disassembled.

 

[drgoose]

Repair manual

View attachment 89747
Light travels the arrow direction.
The 45mm f2.8 was used on the Contaflex I and II. It is a fixed lens. It does not have interchangeable front elements like the later models.
It should clean up once disassembled.

do you know if there is a way to get a repair manual or an exploded diagram for this camera?

 

[elcabezagrande]

do you know if there is a way to get a repair manual or an exploded diagram for this camera?

You might ask Jon Goodman, I'm pretty sure that he is well-versed in Contaflex repair.

 

[shutterfinger]

http://benoit.suaudeau.perso.neuf.fr/manuels_rep/obturateurs/Compur-shutter-repair-manual.html
shows a Compur MXV CN-1110-543 shutter which is an adaptation of the CS-1110-020 shutter, the 543 variant is not shown. Lens cells screw into the shutter from the front and rear. Once a cell is removed from the shutter then it can be disassembled into its component parts.

Use a rubber sink stopper that just fits the inside of the lens opening without touching the lens itself. While pressing down hard turn the stopper counterclockwise. Lens become stuck with age and are sometimes difficult to remove. You may need special tools to open the front cell once removed from the shutter to access the space between the two front elements. Spacing between the two elements is critical.

 

[rjbuzzclick]

On mine, it was easier to remove the rear lens element with the whole shutter out of the camera, but that opens up another can of worms. One of the tricky bits with this camera is that there is a spring that applies pressure to stop down the aperture blades. Looking inside the shutter box from the rear you'll see a star wheel in the lower left. There is a set screw that you remove and then the star wheel will unwind to release the spring tension. See some of Jon Goodman's and Rick Oleson's info linked below.

Here is a good flickr set that illustrates going in from the front:

https://www.flickr.com/photos/7699588@N07/sets/72157634432827967

More helpful info:

http://photo.net/classic-cameras-forum/008A7Z

http://www.rangefinderforum.com/classics/forum/messages/6900/3878.html?1121692303

The middle element can be unscrewed from the front with the front element removed. This will change the "starting point" for the threads on the front element though during reassembly, so there will be a little trial and error there. Again, I found it much easier to work with the shutter completely removed from the body. With my moderate skill set, several of the steps took a few tries and much patience. There's a lot that needs to happen when you press the shutter on these things.

 

[AgX]

EDIT after seeing Richard's post above, I believe that the front group in a Tessar formula is a single element, not a cemented pair, so it shouldn't be lens separation. I could be wrong as well however.

The first thought I had when seeing that photo was "That is up front." And the Tessar has its cemented group at the back.