View Full Version : Minimum focus distance with Crown Graphic and Xenotar 150 using side RF?

28-Jun-2012, 19:15
I'm just adjust my Kalart side RF on my Crown Graphic to work with my Xenotar 150mm f/2.8 lens. Seems like the minimum focus distance that I can get with the rangefinder is about 8ft. Should I bother trying to tweak my rangefinder adjustments to get closer focus? I'd sure like to, but I have no idea what this camera/lens combo is capable of.

Frank Petronio
28-Jun-2012, 19:21
You do better using a string tied to the camera, marked at a pre-focused spot and having your subject park themselves at the end of the string. I am not trying to be funny, I'm completely serious and it works. Far better than that sketchy rangefinder that isn't accounting for several inches of parallax error even if you could get it to accurately focus.

28-Jun-2012, 19:26
I know you're not trying to be funny, and honestly, I'm with you on that concept. I've actually done this with my Aero Ektar. I used a laser rangefinder in conjunction with the GG, mark a distance on the camera track and then tape out a mark for my subject. It helps to have worked in the theater as a kid!

I'm open to all suggestions!

28-Jun-2012, 19:27
I've also been working on my own electronic rangefinder.....mainly because I like diy engineering, not because it makes a whole lot of sense....

The idea is that I pre-focus the camera to a distance on the GG, or via a mark on the focus track, say 5ft, and my diy rangefinder is pre-set to tell me when I have a subject at that distance +/- some degree of accuracy. Then, blam, take the photo. Sounds funny, but it's no different than the press photos using a blinding flash and f/22. Right now, it works, using the Arduino because of the number of sensors available and it's all battery powered. Just need to figure out a mounting solution to get accurate alignment between rangefinder and film plane.

Kevin Crisp
28-Jun-2012, 19:29
I thought the Kalart would focus to 4 feet accurately. That is the minimum distance when you are setting one up. For close up work I would use the gg if that is an option. Or you can use a tape measure and the bed scale.

28-Jun-2012, 19:33
Well, I've read all the Kalart adjustment manuals, and they all talk about a 4ft adjustment, but mine is 8ft. Minimum. No matter what lens I use. Perhaps there's something wrong with my rangefinder.

Kevin Crisp
28-Jun-2012, 20:36
I think the error is often in not having the camera properly set up for infinity.

If you open the bed, with the focus racked in all the way as it should be when you fold it up, then pull the front standard out to the focus stops, you should be at infinity right there. Makes sense when you think about it for press photographers -- open the camera and you're good to go. Drop the bed, pull out the front standard, and you're set for infinity.

There are other ways and places where the camera could be in focus at infinity. For example you could set it up with the stops further back and it would be necessary to rack out the focus a bit to get infinity in focus on the film plane. If you set the camera up that way it throws everything off. Every Speed or Crown I've had has been off this way.

So try this if your camera is not set up this way. You have to deal with that annoying cam/slotted adjustment on the right side, but it tends to stay put once you get it right.

28-Jun-2012, 23:32
I'll double check the infinity adjustment again. I thought I had setup so that the rails are racked all the way back, but, it could be off. Thanks for the help.

Ivan J. Eberle
29-Jun-2012, 08:00
If the Kalart has ever been removed or reassembled, it may be "clocked" incorrectly with regard to the input/thru shaft, and then readjusted to work (somewhat) from there.
Most elusive Kalart Synchronized RF adjustment is probably the one behind the mirrored prism-- Jo Lommen's page addresses this.
Another possibility is the RF needs lubed, or perhaps it isn't moving freely with the light spring pressure that happens at shorter focusing distances.

I have a Kalart adjusted to work down to 8 feet with a 210mm, (though not on a Speed/Crown); same camera with a 135 when adjusted properly goes down to about 4'.

Dan Fromm
29-Jun-2012, 08:28
Folks, my little 2x3 Graphics' Kalarts all sense the bed's position with a lever that is spring loaded to bear on a cam that's firmly attached to the inner bed rail. The lever will follow the cam until the bed rail is moved around (guesstimate, I didn't measure) 15 mm forward from the infinity position. Move the bed farther forward and the lever won't follow it. This is what limits the RF's close focusing ability. The shorter the lens, the closer a Kalart can focus it. To rewrite Yogi Berra a little, if you look you can observe a lot.

Oh, about that cam. Its for fine-tuning the RF's infinity position, not for adjusting the RF for the lens' focal length.

29-Jun-2012, 12:22
Thanks for the input.

I've double checked my infinity setting, so I'm taking the rangefinder off the camera as per Jo Lommens instructions.

Since the rangefinder arm loses contact with the cam at 8ft regardless of lens, I'm going to adjust that.

Dan - I've found the instructions for adjusting the cam, and the rangefinder. Given that the instructions call for a 4ft focus with the standard lens, and mine is only capable of 8ft with the standard lens, it seemed like there was something wrong!

29-Jun-2012, 13:10
Ah, you're all going to laugh. The rangefinder arm inside the camera body was hitting the slide rails for the bed! I slid the arm over on the rod connecting it to the RF, and then had to do some minor surgery. Final upshot is I can adjust the RF properly for the 150 mm Xenotar!

My mistake assuming the rangefinder was operating correctly at all. The funny part is that this camera looks brand new, none of the screws look like they ever been touched. So, I get the feeling this rangefinder was never used.