Jump to content

MR or MR-4 meter?


Recommended Posts

Advertisement (gone after registration)

I usually use my M7 or MPs but want to use my M3, 2 and 4s as well. The Leica meters are the only ones that are coupled from what I've read on the internet. What exactly does that mean and were is a good source to get accurate or overhauled ones in the USA?

 

I have used a handheld meter, a Voigtlander VC II and even used the iPhone app Fotometer Pro which has both reflective and incident capability but they all require more steps than the built in meters in the more contemporary M's. Can a coupled meter be quicker?

Link to post
Share on other sites

The MR is coupled because it connects to the shutter speed dial, so as you change the speed (by the larger dial on the MR) it changes the camera shutter speed and the f-stop then reads out directly (as the aperture scale on the meter moves with the speed selection).

The needle is captive: that is you view through the finder, and the meter area matches a 90mm lens. you find the zone to meter, press the button and release it, and it traps the needle so you can then lower the camera, read the meter, and set the lens or shutter as you want.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

It is convenient. I also have the VCII for my IIIf, and you have to turn dials on it to null the LEDs in order to see the reading, where the MR reads directly.

It's similar to the difference between the Luna Pro and the Luna Lux; where the pro reads a scale with a needle and the lux must null the LEDs.

I have both the MR and MR4, and you can use either on all the M3 & 4. The rapid rewind crank on the 4 may interfere with the button on the MR, but only while rewinding. I haven't had a problem either way.

It's common for these to have intermittent operation as the unplated internal switch contacts are usually dirty/corroded. I've opened and cleaned my own with contact enhancer, but there are tricks and some parts break easily. (don't ask...) But you can often buy the non-working ones cheap, and I've bought a few and come out with 2 good meters for low cost.

Gus Lazzari does a great job on repairing, but I imaging DAG and others can do so too.

Edited by TomB_tx
add photo
Link to post
Share on other sites

I used an MR-4 meter for a number of years on my M4, and it was handy when I either didn't have my incident meter handy, or was unsure of the light to not use the sunny 16 rule. Finally I sold the meter, and honestly, don't miss it one iota. You asked, "Is it faster", I'd say not particularly, but it good for a reflective meter.

Link to post
Share on other sites

I like the idea of an MR style meter and have used them in the past, but I can estimate the exposure most of the time through experience. And for the rest of the time when I can't guess what the exposure is I want a guaranteed accurate reading which the MR meters don't give in extreme situations like heavy shade etc. So my prefered walk around meter is a Sekonic Twinmate, a meter conveniently so small and light I am now on my second, after misplacing the first!

 

Steve

Link to post
Share on other sites

Make sure you adjust the three little screws in the foot of the meter correctly otherwise you will scratch the top of your camera. Note there is a spring in there which will allow the meter to press down on the camera even if there is a gap.

Link to post
Share on other sites

The other thing with these meters is they were designed to take PX625 1.3v mercury batteries which are long since out of production. 1.3v zinc-air (hearing aid) batteries can be fit by the use of an adapting washer, but these batteries are quite short-lived.

 

To read accurately with a 1.5v battery these meters need to be properly recalibrated. The effect of the voltage mismatch is not linear. so a simple ISO (or to be correct, ASA :D) compensation isn't enough. To further complicate things, alkaline batteries drop voltage as they discharge, so the calibration is good only with a fresh battery. I have several MR4 meters which I rebuilt and recalibrated, and I use MS76 silver-oxide batteries in adapting washers. Silver batteries maintain a straighter discharge curve, almost like mercury.

Edited by bocaburger
Link to post
Share on other sites

Advertisement (gone after registration)

The other thing with these meters is they were designed to take PX625 1.3v mercury batteries which are long since out of production. 1.3v zinc-air (hearing aid) batteries can be fit by the use of an adapting washer, but these batteries are quite short-lived.

The Wein zinc-air have good capacity, but only last about a year whether used or not. I use the CRIS 625 adapter, that takes a 386 silver cell and reduces the voltage to 1.35. The adapter is size-shape of the PX625 so fits directly. The 386 cell doesn't have the A-H capacity, but only discharges when used, so for me lasts longer than the zinc-air batteries.

If you get the CRIS adapter, be sure to use a 386 cell. The more common 357 cells look the same but are thicker and may damage the battery compartment.

Link to post
Share on other sites

Hello Everybody,

 

Always set the camera shutter speed dial to "B" before you put on or take off your meter.

 

Always pull up the meter dial which you have set @ "B" & turn the dial until it reads "120" before putting it on or taking it off the camera. Pulling it up & rotating it is how you read exposures longer than 2 sec (B) when it is on the camera.

 

When you are adjusting the 3 larger screws underneath the shoe remember there are also 2 small headless screws which may also need adjusting. Also remember: When you are done the meter body must clear the camera underneath by @ least 1mm everywhere even if it is not exactly parallel. (More later.)

 

Before you begin to tighten down the screws after making adjustments make sure the meter field being read is aligned correctly within the 90mm frame. Where? I set mine @ Infinity. Remember the 1mm.

 

Once you think the adjustments are correct & the meter clears the camera by @ least 1mm & the 90mm frame accurately shows where the meter is pointing: Try to put the meter set @ 120 on the camera which is set @ B. Make sure the bottom of the meter clears the top of the camera by @ least 1mm everywhere. If everything clears front & back: Slide the meter all the way in checking it while you are sliding it. If it does not clear appropriately: Repeat above.

 

Next:

 

Turn the meter dial back from 120 to B. When the meter dial pops down check to see if the connecting pin has come down far enough to engage the mating slot in the shutter speed dial. If it does not come down enough to engage @ B you should remove the meter & repeat the steps above to readjust the meter to lower the entire body & dial. The reverse if it is too tight. When the connecting pin is properly engaging the shutter speed dial the meter should also be clearing the body by @ least 1mm @ its closest point even if the meter body is not exactly parallel to the camera body.

 

When the meter set @ B is on the camera & the meter clears the body all over by @ least 1mm & the dial pin is properly engaging the shutter speed dial which is also set @ B:

 

Turn the shutter speeds to 1000 & back watching between the meter & the camera all around to make sure the dial on the meter does not rub against the camera shutter speed dial & also that the dial pin does not pop out of the slot. If the dials rub or the pin pops out @ any point: Go to the top of this Post & begin again. Repeat until the meter dial pin engages properly & the meter dial does not rub against the shutter speed dial.

 

Everything should be OK.

 

What I have done for years is: Get a 16mm stainless steel spring ring for a keychain. This is the same diameter as a PX-13. Grab part of the outside loop w/ a needle nose plier. Grab the inner loop w/ another needle nose plier. Pull the inner loop inward making it look sort of like the curl of a balance spring on a watch or clock.

 

Do this until you have created a smooth curve which makes an enclosure slightly smaller than a 357 silver oxide cell. They work very nicely. Pop the battery into the curl making sure the spring ring touches the wall of the battery all of the way around & it is midway between the top & the bottom of the side of the battery all of the way around. Put the ringed battery into the meter "+" side up. The door closes very neatly.

 

Important: Set the meter to the DIN you are using for that film + 1.5

 

This also works just fine on my SL3 - aka: Minolta 101 + appropriate adapters.

 

Best Regards,

 

Michael

  • Like 1
Link to post
Share on other sites

  • 2 weeks later...
The Wein zinc-air have good capacity, but only last about a year whether used or not. I use the CRIS 625 adapter, that takes a 386 silver cell and reduces the voltage to 1.35. The adapter is size-shape of the PX625 so fits directly. The 386 cell doesn't have the A-H capacity, but only discharges when used, so for me lasts longer than the zinc-air batteries.

If you get the CRIS adapter, be sure to use a 386 cell. The more common 357 cells look the same but are thicker and may damage the battery compartment.

 

+1

 

I use the CRIS 625 adapter and 386 cells in the MR-4 (M3 and M4-2), Leica CL and Rollei 35. 386 cell life expectancy: years ( I have not had to replace one yet)!

 

CRIS Camera Repair and Services - Mercury Battery Adapters

 

Guy

Link to post
Share on other sites

  • 2 years later...
The other thing with these meters is they were designed to take PX625 1.3v mercury batteries which are long since out of production. 1.3v zinc-air (hearing aid) batteries can be fit by the use of an adapting washer, but these batteries are quite short-lived.

 

To read accurately with a 1.5v battery these meters need to be properly recalibrated. The effect of the voltage mismatch is not linear. so a simple ISO (or to be correct, ASA :D) compensation isn't enough. To further complicate things, alkaline batteries drop voltage as they discharge, so the calibration is good only with a fresh battery. I have several MR4 meters which I rebuilt and recalibrated, and I use MS76 silver-oxide batteries in adapting washers. Silver batteries maintain a straighter discharge curve, almost like mercury.

 

If you wish to use your Leicameter MR or MR-4 with a 'green" battery giving the correct voltage, consider this:

 

Wein EPX-625 MRB625

Link to post
Share on other sites

I have an MR on my M3 just for the sake of having one, but I've found it's really no more accurate than my best guess -- although in very low light when I have 100 ASA film loaded and start thinking I can maybe still get something, it does remind me that no, there's no chance I'll get something. Don't waste the frame.

  • Like 2
Link to post
Share on other sites

  • 7 months later...

Hi Leicameter Users,

 

I recently purchased a Leicameter 4 on eBay for my M3. It's in great condition -- except for one issue that makes it extremely difficult to use. The top disk on the meter -- the one that allows you to select the correct film speed -- is very loose. This means that it does not stay fixed at the correct film speed. So invariably it shifts and then the exposure is completely inaccurate. I have no idea how to make it "tight" again so that once a film speed is selected it doesn't wobble about. I'm also not particularly mechanically inclined. I've canvassed various forums to see if someone has come up with a solution, but have failed to find one. I love the design of the meter and the fact that it couples so elegantly with the M3. If anyone has any suggestions on how to tighten the disk, I would very much appreciate hearing from them. Thanks in advance for any advice!

Link to post
Share on other sites

Two things to try: If you have a narrow spanner, or old drafting compass you can turn the center fastener (two holes on top) clockwise to tighten. If you do not have a spanner, then try cutting a couple small slivers of paper and push them under the top disc. That should take up the looseness.

 

And by the way, many people mount the meter so that it scratches the top of the camera rather badly. You can avoid this by adjusting screws on the shoe (bottom of the meter) to level and lift it so that the meter does not touch the body when mounting.

 

Two pictures. First shows a good place to push a sliver of paper between discs. Second shows post to tighten with spanner.

Edited by pico
Link to post
Share on other sites

  • 5 years later...

Hi, resurrecting this thread - I have just acquired a MR Leica meter for my M3 and seem to be having issues with it. The battery test moves the needle over the dot, however when I try to take a reading, the needle jumps to the bottom of the meter (towards the film door of the camera) and just stays there. Pressing the battery test button centers the needle again, then trying to take a reading and the needle drops again. Just wondering if anyone has experienced this and does this mean the meter is likely dead?

Thanks 

Link to post
Share on other sites

This is unfortunately a fact, many Leicameters lost their function over the years, I also keep a defect one. You can open it and check the mechanic functionality and contacts

http://feuerbacher.net/photo/repair/Leicameter/Leicameter.html

but anything else like electronic or photo cell repair is beyond the capability of a standard photographer like me.

Link to post
Share on other sites

I used about five units of Leicameter MR4 for decades .

Some MR4 failed and "repaired" and refailed and became non-reliable with false contacts everywhere.

I don't use them anymore, I'm tired to clean those false contacts once I tried to use one of them.

Even to sell them, I'm not sure to be able to "help" the to be buyers, so ...

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...