Camera & Equipment Design Questions

[ruben]

Hi Peter,
my fidling with old cameras many times presented me with the question "why this was designed that way".
I have several questions in my mind not relating specifically to Canon, but I hope that from your general knowledge you may be able to answer them.

OK, I throw now one of them, sorry it is too silly:
Why in pre war Contax for example (and I supposed other cameras too) the cold shoe is not positioned in a straight axis above the lens ? At the time they were supposed to mount auxiliary finders, then what had they in their minds ?
Thanks in advance,
Ruben

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AMENDED REPLY: Hi, Rubin! The answer to your question lies in the fact that the accessory shoe (what you call the "cold shoe") was mounted directly onto the cover over the VF and RF optics as well as parts of the shutter timing assembly: since the covers were made of very thin metal the shoe's screws had to go far enough to engage a solid piece of superstructure that was situated directly under the cover. Otherwise, the shoe would quickly come loose from the thin metal cover pressing with regular use. Thus there was a fundamental design question as to where the lower ends of the shoe's attachment screws and whatever firm support they engaged could be placed without getting in the way of the active rangefinder, viewfinder, and shutter speed assembly parts below the cover. The Contax was not alone with respect to offset accessory shoe location; the Leica's shoe, too, was offset, as later were those of early Canons and Nikons before the S2. Considering how inexact any optical viewfinder was (and still is), the very slight amount of horizontal parallax introduced by the offset made no practical difference to the user; thus the concerns and decisions of the designer won out. Auxiliary finders, by the way, were by and large even more inexact than the ones built into the camera bodies: neither type showed the photographer the full coverage he would get when he made an exposure.
I have changed the name of your thread in anticipation of further questions you (and others) may ask with respect to design considerations; I hope you'll forgive me!
Peter

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[ruben]

Many Thanks Peter for your detailed answer, and no problem at all with the change of topic title. On the contrary you are insipiring more trouble to come (questions).

Cheers,
Ruben

 

[ruben]

Hi Peter,

Me again, so take your time as i am in no hurry but curiousity.
Again too about the Contax design. Two questions.
1)
Many people complain about the pre-war Contax and Kievs about the very thin window contacting the eye. Personally no problem, but after mounting for my first time a Soviet 35mm finder I said "WOW", what a pleasure!
Was the reason for such thin eyewindow the attempt to avoid entrance of undesired light into the top casting ? Or perhaps to force a more correct position of the eye, i.e, centering the eye straight where it should be ?

2) Why the borders of the yellow patch of the Kievs, and I assume Contax too, are rather diffuse in contrast to those of the Leicas. I do understand the mechanism is different in each one, but what makes those diffused borders on the Kiev/Contax range finding mechanism ? After all the Contax was the most expensive camera of its time, no ?
Cheers, and take your time.
Ruben

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REPLY: Personally I've never used a Kiev, though I have one in my collection. I'm not entirely sure what you mean by "thin", but my guess is that you're saying the eyepiece is very small. On my Contax II, the view is even more restricted than on my Kiev, and both require that you place your eye directly behind and close to the finder: just wearing eyeglasses makes it almost impossible to see the entire finder coverage. This, I think, is a necessary factor imposed by the long-base rangefinder of the Contax-type cameras; if you didn't look absolutely straight through the eyepiece, the rangefinder area would disappear.
The "yellow patch" is the area in which the rangefinder view is superimposed over the viewfinder area. It looks about the same on my Contaxes and on my Kiev, and its border is somewhat diffuse, although that in no way hampers one's ability to do rangefinding. The diffusion is again, I believe, simply a concomitant of the long-base rangefinder design: the finders are meant to be seen through, and there is no necessity for seeing their outlines as being sharply delineated. This is not a defect in design, it's simply a result of the way the finders are engineered, with no real effect on the user's ability to work them properly.
And the TLR Contaflex was much more expensive than the Contaxes, by the way -- and never worth the price as a "user" camera!
Thanks for revisiting; I'm sorry I took so long to get back to you, but I wanted to check out the finders. Peter

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[ruben]

Many thanks Peter,

Nunca es tarde cuando la leche es buena!

Cheers,
Ruben

 

[John Shriver]

The Leica M finders have a crisp-edged RF patch because that edge is formed by the mask for the framelines. Through complex optical design, that plane (framelines and RF mask) is in focus.