Assymetric Tilts

[KJK]

I know this has been gone over many times before, and I understand the theory of Assymetric tilts. But what I can't figure out is how Sinar gets them to work on their cameras becasue the tilt mechanism is entirely below the film plane and therefore seems more like a base tilt than an assymetric tilt, which I would assume should be located at some point about 1/3 the way up from the bottom of the lower edge of the film.

If a person wanted to incorporate these assymetric tilts in a camera, is there a mathematical formula for where the pivot point has to be, what the arc of that pivot has to be, and then where the focus point are on the ground glass?

[rusty71]

WHOA! It's late, and glancing over recent posts, my tired eyes deleted the "L" in your subject line....
Sorry, wish I could help you out with the Sinar. But thanks for the giggle.

[plungefrog]

The Sinar tilt axis (on the P/P2/X series) is indeed located 1/3 of the way up the focus screen.The mechanism uses a geared drive which is located in an arc described by the base of the standard.The drive is self-arresting,the tilt axis does not require a support of its own.The location of the arc is largely dictated by the size of the standard.Some models of Sinar (the Norma for example) have ordinary base tilts.

[AgX]

Actually I'm not qite sure about the term assymmetrical tilt. Could also just mean that the tilt axis does not meet the optical axis.

Anyway, the Sinar mechanism you are referring to is different in that way, that it does not employ a mechanical axle to pivot the standard, but rather a virtual axle. It does so by employing a roller-segment type of joint. You must not look at that physical joint, but rather where the axis of this roller-segment is to be found.

Furthermore, the mechanical type of joint has nothing to do with what optical kind of tilt (or swing) you gain. With both type of joints you can place the tilt axis deliberately while engineering.

There are cameras (Horseman types eg.) where a real axle is employed, but a shift mechanism is placed between the standard and the axle. Thus enabling you to place the tilt axis at your choice.

[David A. Goldfarb]

Actually I'm not qite sure about the term assymmetrical tilt. Could also just mean that the tilt axis does not meet the optical axis.

Generally, cameras that advertise "asymetric tilts" put the tilt axis somewhere on the groundglass. Base tilts are asymmetric in the general sense of the term, but in the context of describing a view camera, these are generally just called "base tilts."

[AgX]

Yes, David, in my first sentence I meant `off the optical axis but still on the groundglass´. I have to think more, before posting...

However there were constructions with central tilt but still off the groundglass. I don't know whether this has a special term to it. But the more terms, not only in English but in our very own language, the more complicated this thing gets. For instance, in my post I had it about the standard, but actually meant that frame pivoted to the standard and itself holding the filmback...

[reggie]

If Edward Weston didn't have it, do you really need it?
Spend your $$ on film and paper.

-R

[Tom Duffy]

If Edward Weston didn't have it, do you really need it?
Spend your $$ on film and paper.

-R

Don't knock it if you haven't tried it. Bet you a dollar that I can set up and take a picture in half the time you can... and get everything in focus.

[Peter De Smidt]

Yep, they're great!

[dslater]

Don't knock it if you haven't tried it. Bet you a dollar that I can set up and take a picture in half the time you can... and get everything in focus.

Hi Tom,
This is the first I've heard of asymmetric tilts. What are the advantages over base tilts and axis tilts?

Thanks,

Dan