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View Full Version : Accuracy of Crown Graphic Top Rangefinder



Frank Petronio
3-Nov-2007, 18:00
So I've been experimenting with a Crown Graphic in addition to my Technika for handheld 4x5 photography. My work is mostly medium length portraits, from 6 feet to 15 feet away, shot wide open (f/5.6) without movements. And I am thinking the Crown might be a nice alternative that is lighter weight and cheaper for rougher conditions. I've had several Speeds and Crowns before, with Kalharts and top rangefinders.

Anyway, this one I have is quite nice and clean, and I have it set up as properly as I know how.... I chose a top rangfinder model figuring that the cammed rangefinder would be more accurate and reliable over time (not jiggling out of true from vibration).

Yet, even though I can set infinity on the ground glass and with the infinity stops.... it doesn't stay in track down to 15 or 8 feet. The focusing is close... the difference to getting perfect focus is maybe an 1/8 of an inch (3mm) of a turn at the closest (6 feet)... so is it normal for a cammed top rangefinder to be this amount off?

I am 99% sure the cam is correct for the 135 lens, as the camera is all factory stock.

My Technika has been to Martin's twice and it focuses very accurately... I notice that the Graphic cams are quite a bit smaller than the Linhofs' -- so are Graphic rangfinders going to be a little sloppier in general?

If I didn't habitually shoot wide open all the time, I am sure it would do fine for general work at f/11 or f/16 covering up the slight mis-focusing. But I really need this to track better --

Wayne Crider
3-Nov-2007, 19:19
I had a top rangefinder on a Super that was out for short distances when set for infinity. You might want to set it up for close focusing and mark the rail for infinity. Even set for closer focusing you need to check at 8ft and 15ft distances as they can be different. Also remember that there were lot's of cams for different lenses with different back focus distances because there more then one lens supplier. From what I remember I had a list once. With Graphics its always a work around.

Frank Petronio
3-Nov-2007, 20:06
I know the Super cams are larger too, and I am starting to think the larger cams must be more accurate...?

Jim Jones
3-Nov-2007, 20:25
It's easy to change cams and lenses in the Crown, and this might have been done sometime, somewhere. A list of cams and the lenses they fit is at http://www.graflex.org/speed-graphic/top-rangefinder-cams.html

Asher Kelman
3-Nov-2007, 20:49
It's easy to change cams and lenses in the Crown, and this might have been done sometime, somewhere. A list of cams and the lenses they fit is at http://www.graflex.org/speed-graphic/top-rangefinder-cams.html

Jim,

That's really great information. Now can these cams be used with many lenses of the focal length stated, how available are the cams and where is a good set of instructions.

Thanks,

Asher

Frank Petronio
3-Nov-2007, 21:21
Getting at those top RF cams is quite the PITA. Any guides or quick tips? It is like a dark cavern in there...

Jim Jones
4-Nov-2007, 06:06
http://graflex.org/articles/oakes/ has a little information on changing and making cams. The entire site, graflex.org, is the first online place I look for information on graflex/graphic cameras. It has much information that even Morgan & Lesters fine Graphic Graflex Photography series doesn't cover.

Wayne Crider
4-Nov-2007, 15:18
From what I know, Super cams and Crown cams are different. Check Graflex.org

Bill_1856
4-Nov-2007, 22:25
Super camera are larger, more accurate, and can be easily changed in the field. To change the Crown/Speed cams I have to be sitting down at a table, tilt the front standard all the way back, then remove it from the track and shove it back into the camera body so I can get at the cam. The focusing track should be run forward to take tension off the spring which zeros the cam. Then you can slide it off the keeper, and turn the camera upside down and shake it to loosen the cam from whereever it has landed. To replace it you just reverse the proceedure, including two or three times of overturnng and shaking the camera to get the cam back.
Remember -- if it doesn't slide out easily, you're doing something wrong, and stop right there before you make a mess of it and can't get it out or the new cam back in.

Kuzano
9-Nov-2007, 02:27
I've had a half dozen Graphics and a couple of Super Speed Graphics. The Super speeds both had th 135 rodenstock. Seemed to focus well at the distances you describe. However, I seem to recall that all the Crown Graphics I owned had 127 lenses (ektar?). It's been a while, but could that be the difference, if your cammed for a 127 and using a 135?? Just pondering the possibilities. Seems like you could dial it in at one distance and it would go out of register as the front plane moved from that dialed in point.

Michael Roberts
9-Nov-2007, 03:42
Frank,
Here are a couple of tips from the graflex.org site:
1. The rangefinder did not quite match the ground glass, but adjustment was easy: a small bracket on the left focusing rail governs how far the cable (from the top rangefinder) extends. Loosen one small screw on the bracket, and nudge it back and forward until the superimposed RF images merge where the ground glass says they should.

2. The top and bottom does not line up.--IS that horizionally? Cam not installed; balls and spacers in tube need cleaning; plunger not contacting bed guide.
IS that vertically? Remove battery cover and batteries, remove two screws in the top of the RF cover and lift it off. Mount camera on tripod and focus. From rear (normal shooting position) note the movable mirror on the right, it has an adjustment screw, carefully turn to achieve correct image. Reinstall top cover and check RF image. Remove cover and readjust if needed. Repeat until image stays correct. DO NOT TURN ANY OTHER VISABLE ADJUSTING SCREW with cover off.

I've had a couple of Crowns; my current one does not have the rangefinder as it was stripped off before I got it. I use the scale on the bed which I have also modified (added more marks). Takes a little practice but it works once you develop your eye for estimating short distances. Since you shoot a lot between 5 and 15 feet I would think you could develop this pretty quickly with some practice and using the gg for instant feedback. You could do this before your next shoot. Of course you may just prefer the rangefinder once you get it adjusted.