Leica meter MR-4 accuracy.

JoaoF

JoaoF

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Hello.
I just bought a Leica M2 and it came with a meter MR-4. Explendid machine indeed. My question is: how is this meter accuracy? Is it good if proporly calibrated
And with a new battery. Just curiouse before I use it.
Oh, and a 50 Summilux type I, very nice combo IMO. Never will forgive myself from selling my M6, so I bought this one. 10 times better. Ehehehhehe
Thankx to all in advance.
 
dunno about the MR-4, but I have a chrome MR and I don't really trust it much. but then again, I don't usually trust reflective meters.

it works okay for negative film in my experience. but I have noticed that the high end of low scale and the low end of the high scale don't always lign up (ex. the high scale will read f/3.5 and 1/250 and the low scale will read f/2.5 and 1/250 when measuring the same thing).

oh well, it's better than guessing.
 
I have one on my M3. Use a zinc-air hearing aid battery with one air hole open (same as a wein cell basically), as the mercury batteries are no longer available and the usual silver-oxide adapters are a little bit too thick for the battery compartment. When in clean and calibrated condition they are just as good as any other reflected-light meter. The convenience of the shutter-speed coupling makes it much quicker than a separate meter.
 
mooge said:
dunno about the MR-4, but I have a chrome MR and I don't really trust it much. but then again, I don't usually trust reflective meters.

it works okay for negative film in my experience. but I have noticed that the high end of low scale and the low end of the high scale don't always lign up (ex. the high scale will read f/3.5 and 1/250 and the low scale will read f/2.5 and 1/250 when measuring the same thing).

oh well, it's better than guessing.
Click to expand...

There's a certain point of the day where I get a reading at the very end of one scale and the very beginning of the other. I always have trouble with that. Gotta get me a Sekonic L-308s soon. But under most circumstances the MR-4 seems to give me decent exposures even on my DSLR.
 
JoaoF said:
Hello.
I just bought a Leica M2 and it came with a meter MR-4. Explendid machine indeed. My question is: how is this meter accuracy? Is it good if proporly calibrated
And with a new battery. Just curiouse before I use it.
Oh, and a 50 Summilux type I, very nice combo IMO. Never will forgive myself from selling my M6, so I bought this one. 10 times better. Ehehehhehe
Thankx to all in advance.
Click to expand...

In fact all second hand MR-4 meters need a CLA.:cool:

After that it is a fine and reliable meter.


In helping my friend secure an MR-4 for his non-metered M's, I've gotten hold of several of them in working/accurate condition and discovered something interesting:

Checking the readings at the low, mid and high ends of the brightness range, I have found no variation between the following (voltages tested on a meter):

a new (never used) PX625 1.3V Mercury battery

a new PX625-A 1.5V Alkaline battery

a new MS76 1.55v Silver-Oxide battery in a CRIS MR9 1.3v adaptor

a new MS76 1.55v Silver-Oxide battery in a washer-spacer (left over from a Wein cell).

I did not have the same results when I tried this with a Leicaflex SL, M5 or CL, all of which required compensation with a 1.5v and then would still not read accurately at both ends of the brightness range.

Could it be that the MR-4, made by Metrawatt, has a built-in voltage regulator that nobody knows about? I'm reluctant to open these meters since I don't own them, and wouldn't know what I was looking at if I did. Just curious if anybody else has checked an MR4 with different battery types and found the same thing. I don't mean the readings are close, they're *identical*. BTW for using the MR9 adaptor I would recommend a 386 vs an MS76 because the latter is thicker and pushes the battery door open a little--and those battery doors don't look like they're too strong.

http://www.l-camera-forum.com/leica-...s/2/50437.html
 
The MR-4 meter has a rosette bridge which automatically compensates for voltage variations. It is a very accurate meter. Also easily calibrate by a screw on the bottom. I shot thousands of rolls of Kodachrome 25 with it and never doubted it. Like all reflective meters you need to know how to use. Works slick, pick your shutter speed, read the aperture, set same and shoot. The 90mm frame lines delineate the meter view.
 
A MR-4 meter (my copy at least) is most accurate down to around EV4 (the minimum I can shoot hand held with 400ISO film and fast lenses). Recently I found one in BP (but it was sold only in combination with an original BP M4 so I had to pass ....)
 
Any MR/MR-4 meter is a very good reflected light meter if properly calibrated. It's worth remembering that the metering area when attached to a Leica M body is supposed to be the same as the field of view of the 90 mm viewfinder frame, which makes using it very easy.
 
I use an MR-4 with my M3. I check it occasionally against my metered M's and it is fairly accurate. I am shooting Tri-X almost exclusively with the M3, so there is plenty of latitude anyway. I don't worry about exposure.

It is quite useful to have a coupled meter right on the camera. I typically only meter when the light changes.

I have not run out of Mercury batteries yet, so I don't know about other options and how they work with the meter. I will probably use a Gossen adapter when I do run out of PX-13's, like I have done before on my Luna Pro meters.
 
Hilm3 said:
I have not run out of Mercury batteries yet, so I don't know about other options and how they work with the meter.
Click to expand...
You'll find that MS76 batteries work just as well. The MR-4 has a Rosette (or Wheatstone) electrical bridge to compensate voltage and temperature variations. Mercury batteries where originally used because of the universal use (easy to find) and cheap price. Other cameras (like my SL-2) also work fine with MS76 batteries. On some meters the meter needs to be re-calibrated for the different voltage output but this is easily done by using the calibration screw on the bottom of the meter.

Being an old film guy (an and Engineer) I'm always amazed that people automatically assume that some jury rig is required when the battery type is changed. Many meters do not have rosette bridges to save costs and because of size (esp. the fixed RFs). However many meters and cameras do use them.
 
I miss my MR4. It died after taking a swim with my M4 and I in the Bay of Cadiz, February, 2005.
I loved that meter. It was always quite accurate. I wish I could stick one on my M9...

Phil Forrest
 
Beemermark said:
You'll find that MS76 batteries work just as well. The MR-4 has a Rosette (or Wheatstone) a new MS76 1.55v Silver-Oxide battery in a CRIS MR9 1.3v adaptor

Mercury batteries where originally used because of the universal use (easy to find) and cheap price. Other cameras (like my SL-2) also work fine with MS76 batteries. On some meters the meter needs to be re-calibrated for the different voltage output but this is easily done by using the calibration screw on the bottom of the meter.

Being an old film guy (an and Engineer) I'm always amazed that people automatically assume that some jury rig is required when the battery type is changed. Many meters do not have rosette bridges to save costs and because of size (esp. the fixed RFs). However many meters and cameras do use them.
Click to expand...

In my opinion the Leicaflex SL (2) and the Leica M5 needs ,when used a new MS76 1.55v Silver-Oxide battery a CRIS MR9 1.35v adaptor .
Because these cameras have no electrical bridge to compensate voltage and temperature variations.... :cool:
 
If you are not sure of the calibration of the meter, or you want to have it adapted for a modern battery, send to Quality Light Metrics for repair. I got an MR meter for my M3 from QLM, and find it very trustworthy. I recently sent a Gossen Lunasix 3 for calibration, and I am very happy with he results. Price is reasonable, and turnaround time is fast.

(George Milton runs the shop, and I see positive references to him and his work everywhere.)

Randy
 
Another thing - Wien cells are modern replacements for mercury batteries, and provide a constant 1.35 volts. They are available from Freestyle.

Randy
 
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