Home   Donate   New   Search   Gallery   How-To   Books   Links   Workshops   About   Contact

Mamiya Rangefinder Adjustment
© 2009 KenRockwell.com. All rights reserved.

2009     More Mamiya Reviews

INTRODUCTION

The Mamiya 6 and 7 often require rangefinder adjustment, since for some reason they often arrive new in the USA with the calibrations not quite as close as I'd like.

Don't even think about adjusting this yourself. Even if you can get it right, it will be apparent that you've been inside your camera, which eliminates any resale value it might have had. If you adjust it, you keep it as they say.

Have a professional repair shop do this for you. They won't leave tell-tale marks, or if they do, you used a sloppy repair place.

Rangefinder inaccuracies are small and not apparent unless you use the 150mm lens at f/4.5. If you do and if the rangefinder is off your images simply will be focused at a distance a little different than you intended. If you have shallow depth-of-field this inaccuracy could lead to a lack of sharpness. Stopped down or with shorter lenses this isn't a problem.

This is so prevalent that there are people who sell specialized "Mamiya 7 Rangefinder adjustment" kits over the Internet. Just search for them.

I had to have my new Mamiya 7 adjusted at a reputable camera repair shop before I could get the spectacular results of which the 150mm lens is capable. My Mamiya 6 was fine when I bought it used.

When focusing on something a couple of miles away or more you need to get a perfect focus indication when set to the infinity stop on the lens. If you have even the slightest misalignment then you will likely be out of focus and see this with the 150mm lens at large apertures. This has to be exact. Even the slightest visible error in the viewfinder can lead to a lack of sharpness if you really know how to look for it.

Most cameras and lenses are rock solid and when set to the infinity stop actually are focused exactly at infinity. The trick is to get the indication in the rangefinder to agree. The lenses and camera lens flanges don't budge once set at the factory unless some bonehead messes with them. On the other hand the rangefinder is delicate and can drift with use and time.

When getting more lenses check them for correct performance at infinity. Adjusting lenses should not be required. Select your lenses to focus identically. In other words, if you've checked your current body (by shooting film at infinity), rangefinder and lens at infinity and it's OK, avoid buying other lenses that don't indicate proper focus at infinity. You may have to pick and choose, and if you do you can get a set that's right on. If your lenses give different rangefinder indications at infinity you now have to go have the lenses adjusted. Just buy a set that match each other and save yourself the hassles.

Regardless of the rangefinder indications, most people won't see any of this on film unless shooting at full aperture with the 150mm lens. With the 75 mm and 80 mm lens even the usual amount of misalignment is not often a problem, and with the wider lenses not a problem at all. I'm just picky.

Stopping down the 150mm lens as one would on a tripod also allows you to ignore any misalignment.

Always ensure the camera's rangefinder roller follower and the mating surface on each lens is clean. The slightest contamination will lead to errors, and if you readjust the system and then clean it you'll have errors again! These adjustments are more precise then the thickness of a hair, so make believe you are Swiss when doing this. The lens' mating surfaces are sturdy and easy to clean with a Q-tip. The camera's roller follower is very delicate and if you are reading this web page you are more likely to screw it up than you are to be able to clean it successfully. I've never touched my roller follower.

ADJUSTMENT

Adjusting your own camera is the best way to destroy it. Even if you get it right, a camera that's been touched by a user will have marks showing prospective purchasrers tt its been fiddled with, and since these cameras are so delicate, eliminates any resale value.

When buying used cameras avoid those with "technician tracks," which are tell-tale marks on the plastic cover over the adjustment screw. You have to use a pick to remove it, and a legitimate facility throws it away and replaces it with a new one when done. If the last adjustment was done by a three-year old it may not have been glued back in, in which case a piece of sticky tape may be able to remove it without marks.

Personally I gave up trying to calibrate my rangefinder. I just see where I need to focus on an object at infinity and then manually compensate the focus ring position for every shot. That works fine!

Mamiya USA does a careful job of alignment. Send your camera to them and check it when you get it back. They have a precise laser interferometer and know how to do this. Unfortunately they kept adjusting my Mamiya 6 to precisely the wrong value each time. I finally got out my butter knife and tweaked it myself to perfection. Beats me as to the discrepancy; Mamiya always cheerfully took back the camera to try again at their expense. Some people like me are just too picky.

If you're not skilled at precision camera work leave this to those who are.

I believe it was Marty Silverman of Mamiya posted the complete instructions in the chat sections of Mamiya USA's website at Mamiya.com in a plea to get people to stop screwing with this. Why? Because the correct procedure is rather involved and requires removing the complete top of the camera. By posting all the steps he hoped to dissuade people like me with butter knives from destroying cameras.

If you dare (and I wouldn't buy your camera from you after you screw with this) you adjust the rangefinder with a screw behind the plastic cover on the back of the camera to the right of the viewfinder. The screw you want adjusts left-right and another adjusts up-down, which should not need adjustment.

The screw is locked with glue and a lock nut. Ideally you soften the glue with solvent and then loosen the locknut, make the adjustment and then tighten the nut and glue the whole thing so it stays put. If you use a butter knife as I did you can just jam it in the hole and wrench on the adjustment screw with enough force to move it. You might destroy the rangefinder that way, but for me it worked. Don't do this. Glue a new plastic cover over it when done.

Now that you're dangerous enough to know where the screw is, here's how to set it.

First, go make photos with each of your lenses set to the infinity stop at full aperture and look at the film (NOT prints) with a 22x loupe. Your images should have their best focus at infinity. If they do, great. If not, STOP and you have a different problem. You need to mess with the adjustments inside the lenses and get them correct first. If you dropped your camera there is the slight possibility the distance from the lens mounting flange to the film plane is off, but this is the rarest.

Knowing your lenses are calibrated after you've gotten your film tests back, go find something like a ridge of trees at least a few miles away. The Mamiya rangefinders are so precise that if you get lazy and adjust them to infinity for a subject only a few thousand feet away you will wind up having miscalibrated your system.

Ideally when you set each lens to its infinity stop the rangefinder should show perfect alignment on those trees 10 miles away. If not, get out your butter knife and wrench on your delicate camera till the rangefinder shows perfect alignment. Note also that you will see different alignment depending on the position of your eye.

Again, don't do this. I've seen too many cameras destroyed by people who thought they were camera technicians just because they were skilled at some other profession. I'd advise sending it to Mamiya, your local repair guy or just manually compensating for errors.

Good luck!

Help me help you         top

I support my growing family through this website, as crazy as it might seem.

If you find this as helpful as a book you might have had to buy or a workshop you may have had to take, feel free to help me continue helping everyone.

If you've gotten your gear through one of my links or helped otherwise, you're family. It's great people like you who allow me to keep adding to this site full-time. Thanks!

If you haven't helped yet, please do, and consider helping me with a gift of $5.00.

The biggest help is when you use any of these links when you get anything. It costs you nothing, and is this site's, and thus my family's, biggest source of support. These places always have the best prices and service, which is why I've used them since before this website existed. I recommend them all personally.

Thanks for reading!

Ken

Home   Donate   New   Search   Gallery   How-To   Books   Links   Workshops   About   Contact