Battery for Leica Meter MR

I'm looking for a Leica Meter MR, for my M4, but I would like know

if the battery for this lightmeter is 1.5V or the old model 1.35V.

If it's the old model, what is the best solution, air-zinc batteries

ot the tension reductor to 1,35V?

Anyone have this lightmeter? What battery use?

Thaks.

Juan.

As manufactured, it was designed and calibrated for a 1.35 volt mercuric oxide/zinc cell.

 

Using a zinc-air cell, such as a hearing aid battery, or a Wein cell, eliminates the need for recalibration. But don't forget about the battery in the meter, these cells are much more likely to leak and corrode the device they are in than the old ones.

 

Alternately, there are schottky diode droppers (either internal, or using a CRIS MR-9 adapter) for a silver-oxide cell, or you just have the meter recalibrated for a silver-oxide cell.

Juan,

I have an MR-4 meter (taht is the one you will want too) and asked a similar question a month ago. There is a link to that thread: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00DSUc

 

I use Wein Zinc-Air cells for now. I purchased a few and will use them before I decide what to do with the meter. Here is an alternative: http://www.rolleicamera.com/sales-batt-adapt.htm

 

Cheers,

Carl

Juan... I don't know where you live, but if it's in the US, send your meter to George Milton in Quality Light Metric in California, and he'll calibrate it for PX625 batteries.

Thaks to everybody.

I live in Spain.

I bought two or three years ago a zinc-air cell for a Rollei 35-S, but the cell falls down in one year.

Juan.

Hi Juan,

I have an adapter for 1.5v silver cells in my Rollei 35 S, and its still going strong aftera

couple of years in there (the camera doesn't get regular use, mind). The adapter fits fine in

there, but is a tight squeeze in a Leicameter - think I mentioned as such in Carl's thread.

 

IMHO, the recalibrating for 1.5v cells would be the best bet. WeinCells are fine, but they

don't last long at all, which makes them poor value for money.

#675 zinc air cells are cheap compared to the cost of film and processing. They are less than $1 each and should last 2 or 3 rolls. You do have to remember to change them however.

Please correct me if this is incorrect, but my impression was that it was the sale not the use of mercury cells that was now prohibited in the USA. The 1.35 v mercury cells are still manufactured and available all over the world. I have a stock to last me a decade.

The C.R.I.S. adapter works great. You get good voltage regulation unlike having the MR recalibrated and then using alkaline batteries, which lose voltage as they run down. I would never recalibrate an MR meter for that reason. You never know if your reading is correct or not. With the C.R.I.S. adapter, you know.

If you are at all handy and have about an hour to spare, and have another meter or metered camera you can use as a standard, it is not that hard to calibrate the MR meter for the 1.5V battery. I did 4 of them. However there's one very big caveat: CdS cells lose efficiency over time. Some meters that appear to work are inaccurate even with the 1.3v. Some have faded to the point they've actually by coincidence self-calibrated to 1.5v, but at the other extreme some are so far gone it isn't possible to set the variable resistors far enough to get the meter into calibration. I bought 6 of them for $100 advertised as non-working. Of that, I got 4 back to life but 2 were beyond resussitation without major expense. So be sure you can return any MR for a refund.

One more recomendation to get a CRIS adapter. I use one on a Canon F1 (sorry, not a Leica, but it uses the same 625 mercury batteries) and the exposure is spot-on. Also, I had had a Canon FTb's meter recalibrated, but as the battery got used, the voltage went down and the exposure readings went off. A silver oxyde battery (the one you put in the CRIS adapter) has a very stable voltage.

 

Also, contrarely to a strong belief, USA is not the only country to have banned mercury batteries. In fact, most of "the West" (America, Europe, Australia, etc...), plus Japan and other asian countries have banned it. Sometimes, you will be able to get mercury batteries, but they are most likely old stock.

CRIS adaptor+battery is thicker than PX625, it puts a lot of strain on the thin slide-over battery cover on the MR meter, which are a known weak spot that breaks. Using one would be at your own peril.

I don't want to change your plans on buying a MR-4, but, -just out of curiosity- what

accuracy do you expect from such an old meter? I don't think that 1.35 or 1.50 volts will

be

your main problem. Anyway, these meters are not very accurate any more. Even if they

look

accurate in -say- overcast light, just try them in strong daylight or indoors and you will

see

that they are not so accurate in every situation. Maybe I am just not lucky, but I have not

find even

one MR-4 that is always accurate. And I have all the kinds of fresh batteries, 1.35v , 1.50v

,

mercury, venus , adaptors , etc , etc. Today, we are used to very accurate modern meters,

it

was not so easy 30 years ago... But, you can still enjoy a MR-4 ! Buy it and don't bother

too

much about absolute accuracy :O)

Kindly quote any law saying the United States has "banned" mercury batteries.

Tri, all 4 of my resurrected MR meters read accurately (compared to the Sekonic L308B I used as a standard)from one end of their range to the other. It took quite a bit of back and forth trial and error with the 2 pots in each meter to get them that way, and I did have to split the difference but it wasn't more than a half of a stop. Knowing that I can use them accurately even with slide film and compensate, and for print film they are well within tolerance. The thing that makes them difficult is following the needle to the black or silver bar and estimating whether it's 1/2 or 1/3 stop from a marked f-stop. When you compare the functionality of an M3 with an MP they're very close, but when you look at the meters, the advancements in technology during those nearly 50 years do stand out. And when you compare either of their meters to a digital handheld meter, you see another techno leap. The most disconcerting thing to me about the MR meters is I just don't ever fully trust that they won't give up the ghost for good, so I've always got a handheld somewhere in reach.

Ben Z, how do you do for calibrate de MR?

First you take out the batteries, press the battery check button to release the needle, and zero it with the screw on the bottom of the meter. Then you take the top plate off (2 screws on the end, a tweezer in the 2 dimples on the center of the ISO wheel to remove it, 2 more screws underneath, then you _must_ hold the battery-check switch in the "on" position while wiggling the top plate up and off). Then you put back the battery. There are 2 variable resistors inside (see photo) which you turn slightly with a small screwdriver, that you adjust in combination with each other until the meter reads the same as another meter you trust (involves putting the top plate and ISO back on loosely, and removing, each time to test it). This has to be done in very dim light using the LO scale, and very bright light using the HI scale. It's a drag and takes a long time, but eventually you get there _if_ the cell is in good shape. If not, you find that you hit the end of the resistor adjustment and still can't get an accurate reading.<div></div>

The silver oxide cells are similar to the old mercury cvells in that the output voltage is nearly constant as the cell ages.

 

Quality Light Metric can recalibrate most light meters for silver oxide cells. The service there is quite fast; two weeks total round trip including shipping is common.

 

You can use the very common SR44 cells ($5 for three at Walmart) with an o-ring as a spacer to center the smaller SR44 in the 625-sized battery compartment or buy the 625-sized 625S silver oxide cells from Photobatteries on the web.

Ben Z, I must calibrate the two resistors? They do the same effect over the arrow? Firts I must calibrate one of these and after the other one?

The "calibration" instructions may not be accurate.

<p>The port on the left is for high light switch to high light then adjust, the port on the right is for low light switch to low and in an indoor dim lighting condition to adjust.</p>