Question on focussing on Tachihara 4x5

[gemdiverstation]

Hi everyone,

I recently decided to explore LF photography, and I am just getting started learning the ropes. So, apologies if my following questions seem to be rather rudimentary.

I had acquired a Tachihara 4x5 and a Sinaron S 150mm f/5.6, and was fiddling around with the operation of the camera and lens. The basic setup seems to be fine, but I noticed I couldn't focus any image onto the ground glass except for very close distances (around 0.2m?). I realize that Sinaron S is capable of taking landscape shots, so I was wondering if I might have done anything wrong. Any comments, suggestions, and help would be much appreciated!

Thank you, and happy holidays to all!

Bernard Chan

[Richard Wasserman]

You have the bellows extended too far. Try moving the front of the camera back until the lensboard is about 6 inches from the ground glass, and try again.

[Leigh]

You can pre-set the focus on any view camera by moving the front standard to about the infinity focus position.
That will be with the distance from the front of the lensboard to the film about equal to the focal length.

I say about because the proper value is from the rear lens node to the film. It can be difficult to determine the exact position of the rear node*; using the diaphragm position is pretty close.

To focus the camera at closer distances, the lens moves forward, away from the film**. The maximum movement equals the focal length, at which the image on film will be the full size of the subject.

In all cases, it's best to find the real infinity focus using the ground glass and a magnifier on a distant subject.

- Leigh

*NB: The rear node is near the diaphragm in lenses of "normal" design, generally around the focal length of a lens for normal use. Lenses at either extreme, i.e. wide-angle or telephoto, may have rear nodes that are at very different positions, even outside the physical lens body. For example, the rear node on telephoto designs is way out in front of the front element. The rear node of a wide-angle may be significantly behind the rear element.

**NB: For work where the magnification is critical, the lens to subject distance does not change. Focusing in such situations is done by moving the rear standard (the film) forward or back. The camera must be designed for this.

[Ken Lee]

I have a Tachihara.

For lenses like the 150, you have to move the rear standard forward first. Otherwise you won't be able to focus at infinity or long distance.

[gemdiverstation]

I'm grateful for your help, Richard, Leigh, and Ken.
It was a moment of exhilaration when I finally got the camera to focus.

Leigh: it took me some time to take in what you wrote, but I appreciate the information.
I'll be keeping that in mind for future reference, as I continue exploring this.

Thank you, all!

Bernard

[Richard Wasserman]

Glad you got it working!

[Leigh]

Hi Bernard,

Glad you got it working.

- Leigh

[Michael E]

Hi Bernard,

I guess you moved the front standard all the way to the front of the bed. For shorter focal lengths (I use mostly 120 and 90mm), that is too far to focus on infinity. I simply use the screws that connect the metal rails to the wood frame as a guide.