Deklari
Well-known
Thanks Michael,
My have more space ..
Just as idea.. remove tension mechanism from any Kiev/Contax II
drill hole for axle adapter and holding bolt
My have more space ..
Just as idea.. remove tension mechanism from any Kiev/Contax II
drill hole for axle adapter and holding bolt
Deklari
Well-known
Deklari
Well-known
Deklari
Well-known
Sorry for confusion (picture what I have used for speed I took from internet). My Y. 33### not a last version
Deklari
Well-known
On your picture 1 it is a tensioning device. I wondering why you have many bolts on second picture..I couldn't resist taking a quick look at the 'dimple' camera.
Seen from the back.
Left hand side. This is not a tensioning device, it is simply a bearing.
IMG_2849 by dralowid, on Flickr
Right hand side. This, I guess, is the tensioning device, hidden behind the cover over the sprocket rollers. Not immediately obvious how it works
IMG_2850 by dralowid, on Flickr
I will put it back together now.
Erik van Straten
Veteran
Yes, on my v4 it is the same. On the other cameras it is covered by the outer shutter housing, that is why I didn't see it at once.
Erik.
Deklari
Well-known
This is size of Kiev/Contax roller on Contax I
As you can see if drill a hole at right site for axle adapter if will fit as original. Only question how to fit left site? The hole in left tensioning device in Contax I a little larger then diameter of left end of Contax II/Kiev axle.
As you can see if drill a hole at right site for axle adapter if will fit as original. Only question how to fit left site? The hole in left tensioning device in Contax I a little larger then diameter of left end of Contax II/Kiev axle.
Dralowid
Michael
I know it looks like a tensioning device but it isn't, I have had a look. There is no cross pin or groove in the bearing for the pin to sit in. The tensioning device must be on the other end in picture 2.
That is the first curious thing I have noticed about the dimple camera.
Deklari
Well-known
On your first pictures (pic. 4 and 5) in this forum you have already show this left site.. this exactly how tensioning device looks on Contax I. You have to rotate this "pin" (what installed at the left end on axle) and tight two screws.
Dralowid
Michael
AH! Sorry to confuse you Deklari, that is another camera!
To clarify: The camera I have been dismantling and photographing is a V4 as per Erik's classification. The first version with slow speeds. These are the pictures you are referring to. The flat circular plate on the tensioning device is bare metal in the pictures.
These last two pictures posted today are of my 'dimple' camera, no slow speeds, V2 I think. The flat circular plate is black.
Apologies,
Michael
To clarify: The camera I have been dismantling and photographing is a V4 as per Erik's classification. The first version with slow speeds. These are the pictures you are referring to. The flat circular plate on the tensioning device is bare metal in the pictures.
These last two pictures posted today are of my 'dimple' camera, no slow speeds, V2 I think. The flat circular plate is black.
Apologies,
Michael
Deklari
Well-known
I see now. Thanks
But if your tensioning mechanism on the right, you may be able to use Kiev/Contax II roller without any modification. ?
Erik van Straten
Veteran
Thank you, Brett! Great article, makes fascinating reading. Slowly the eye of our ignorance is filled.
At the end another article is mentioned: by Fridolin Bertel in Zeiss Historica from Fall 2000. Do you have any access to that?
Erik.
Hopefully, yes, I think. Many issues are available there to read. I will link to the parent directory, momentarily.
Cheers
Brett
Here is the link to the uploads made by Zeiss Historica which include a number of journal issues, and some other documents.
And here is the Autumn 2000 journal edition.
There are a number of other Contax related articles in various journal editions, covering things such as the no name Contaxes, the Jena Contaxes and sundry other items of interest. Also some talk about the Contax I. They're worthy of a few evenings quiet contemplation, I think. As a fan of the Contaflex and Contarex SLRs as well as the Contax, there is no shortage of absorbing information about those, too, and many other Zeiss-related precision instruments.
Cheers,
Brett
And here is the Autumn 2000 journal edition.
There are a number of other Contax related articles in various journal editions, covering things such as the no name Contaxes, the Jena Contaxes and sundry other items of interest. Also some talk about the Contax I. They're worthy of a few evenings quiet contemplation, I think. As a fan of the Contaflex and Contarex SLRs as well as the Contax, there is no shortage of absorbing information about those, too, and many other Zeiss-related precision instruments.
Cheers,
Brett
Dralowid
Michael
Brett,
Many thanks, very interesting read. I had completely misunderstood the function of the 'lifting heel'!
Michael
Many thanks, very interesting read. I had completely misunderstood the function of the 'lifting heel'!
Michael
Michael, until reading that, so had I. It had never crossed my mind, but after reading it, it makes perfect sense. The way the slit of the Contax shutter is pre-formed at the fast speeds is ingenious. But with any focal plane shutter, if you want the exposure to be even across the gate, you have to keep the velocity constant (possible with electronics I expect, but easier said than done with mechanical spring powered shutters). Otherwise you need to vary the gap to compensate. It's for this reason that when working on more conventional focal plane shutters with separately driven curtains, you're generally better off setting the tension so the first curtain gains on the second slightly, rather than the other way around. You're generally looking for an even slit across the gate, but the lesser of two evils will usually be a slightly increasing gap. If both the curtain velocity increases, and the gap decreases, the two may well combine to underexpose the far side of the gate.
The Contax curtains running off together at their pre-formed slit, assuming the clearance at the clutches is good, there's no question of the gap changing across the gate. It's prevented by the shutter design. Hence, the leather heel to increase the curtain gap slightly to counter the increased velocity near the bottom side of the gate.
This was all new to me until I read the linked article. I had, in the past, pondered the implications of varying velocity. But the Contax shutter is unique, and certainly one of the earlier vertical travel ones too. I'd reasoned (obviously, now, incorrectly) that either the velocity change across the shorter dimension of a 35mm gate was of less consequence than it would be over the more conventional horizontal, or that Zeiss had managed to stabilise the velocity across the gate enough that it was not a problem. Of course, even Zeiss are not immune from the laws of physics, and their way of managing the tapering of the exposure that would otherwise occur without the leather piece is elegantly simple (it may be the only aspect of these cameras that is!).
What it all boils down to is that the conventional wisdom which dictates that the Contax slit width does not vary at the high speeds because it's pre-formed isn't quite correct, because the leather is included to widen the gap so that exposure will remain constant. There you go. Fascinating stuff.
Cheers,
Brett
Erik van Straten
Veteran
Makes perfect sense and works perfect. From the first shot with a Contax I I was surprised how even the exposure is.
Contax I v7, Jupiter 8M 50mm f/2, 400-2TMY.
Erik.
For a focal plane shutter over eighty years old it's very impressive, isn't it? They're complicated blighters, but between the sheer beauty of the mechanical and optical design and the performance of the lenses, it keeps me committed to them. I can't ever see myself wanting a Leica. The Ms represent genuine progress but by any objective assessment the II and III were more advanced, sophisticated instruments than any screwmount Leica. I was shooting some shots at an outdoor concert today with one of my IIs, and loving it.
Cheers
Brett
Cheers
Brett
Hatchetman
Well-known
Looks like you guys are doing a hell of a good job figuring this thing out! I don't have the patience or coordination (or eyesight) to do that stuff myself, but I admire those who do.