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Posted (edited)

It's funny how Leitz, still towards the end of the era of the famous "5 letters" codes, and after hundreds of codes invented, still struggled to give a bit of "sense" to the codes... M3 with Elmar was IMARO ... and with the Summicron was ISUM😄 

(for the oldest and long lived items it was easy... Elmar 5cm 3,5 was always ELMAR , and the long lived RF was always FOKOS 😄)

Edited by luigi bertolotti
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2 hours ago, luigi bertolotti said:

It's funny how Leitz, still towards the end of the era of the famous "5 letters" codes, and after hundreds of codes invented, still struggled to give a bit of "sense" to the codes... M3 with Elmar was IMARO ... and with the Summicron was ISUM😄 

(for the oldest and long lived items it was easy... Elmar 5cm 3,5 was always ELMAR , and the long lived RF was always FOKOS 😄)

Hello Everybody,

And the reflex housing that makes a noise when you release it is PLOOT.

Best Regards,

Michael

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On 7/8/2021 at 11:59 PM, thomas_schertel said:

yours sincerely
Thomas

Hi Thomas,

May be it's a stupid question but what about the scratches in the upper rangefinder housing? I'm always tempted to get one of those light meters (specially the battery operated) but I'm concerned about the possibility of scratching the top.

Best wishes,

Augusto

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Hello Augusto,

The scratches sometimes come from a slide on light meter where the meter is not properly adjusted to the specific camera that it is mounted on it. There is sometimes some degree of variation when the same meter, set the same way, is moved from camera to camera.

If you look at the underside of the mounting shoe you will see 5 screws: 3 with larger heads & 2 which are headless. These allow the adjustment of the meter to clear the camera AND also allow the meter to be directed so that it covers the frame area in the viewfinder window appropriate for its angle of coverage.

For example: So that the meter cell in MR and MR4 meters cover the angle that the 90mm lens frame covers AT 1 SPECIFIC DISTANCE. For example: Infinity. Or to cover the 50mm lens frame with an MC meter AT 1 SPECIFIC DISTANCE.

To do this the camera should be on a tripod. With an appropriate target light or dark at the appropriate distance to fill the frame line.

Then the 5 shoe screws loosened.

Then they should be tightened little by little: The 2 small headless screws lifting the meter up from scratching the camera & the 3 screws with heads moving the meter around to:

Align the meter on top of the camera in a horizontal position. With the bottom of the meter parallel to, but above by a few millimeters, the top of the camera.

Have the cell on the meter which is collecting the light aligned so that it fills the proper frame line: When there is a lens mounted on the camera which is set to the distance you want the meter to measure ALWAYS. Infinity is a good choice.

Make sure that the little pin at the bottom of the shutter speed wheel falls into the slot in the middle between the "2" and the "5" or closer to the "4" between the "2" and the "4".

Easier to do than it is to write.

Best Regards,

Michael

 

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Posted (edited)

Hello Augusto,

If there are any "complexities" while you are doing this please come back here. These are very handy, easy to use & good meters.

For example: An MR or MR4 meter will measure from EV 2 to EV18 with a film of ISO 100/21. A good range for a lot of photographic situations. Especially for such a small meter.

Best Regards,

Michael

Edited by Michael Geschlecht
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Posted (edited)

Hello Everybody,

Just a thought about MR & MR4 meters:

These meters were built to take either PX13 or PX625 mercury "button" batteries  of 1.35 volts, which are no longer being manufactured because of their mercury content. Because of the adverse effects of mercury in the waste stream. This is a good thing to stop manufacturing.

The alkaline batteries that are made to replace them sometimes act in an erratic manner & are not always accurate.

What I have done with an MR meter as well as a Metrastar meter & a Minolta 101 camera, all of which operate accurately when compared to my neighbors Minolta Flash Meter IV, is as follows:

I will be back:

Best Regards,

Michael

Edited by Michael Geschlecht
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Posted (edited)

Hello Everybody,

I'm back.

I measured the diameter of the button battery/battery opening. Which, if I remember correctly, might be 15mm? Please measure the diameter to check.

Then I went to the hardware store key making section & got a HIGH QUALITY STAINLESS STEEL split ring of the correct size to fit in the space SNUGLY but not tightly. It cost a few cents.

Then I bought an SR44, the same as a 357 SILVER OXIDE battery of 1.5 volts.

Then, back home,  holding the ring horizontally with my fingers: I pulled 1 end where it "split" in to the center partially. Making it look like a watch balance spring. I did this until there was a circle A LITTLE BIT smaller in diameter than the battery is wide.

So that the battery fit SNUGLY inside the swirl. And the combination, plus (+) side up, fit SNUGLY into the battery compartment.

I'll be back.

Best Regards,

Michael

Edited by Michael Geschlecht
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Posted (edited)

Hello Everybody,

I'm back again.

Then, THIS IS IMPORTANT, set the meter to DIN +1.5 more than the film speed that you are USING. This is easy to do because there are NO "click" stops on the ASA/DIN dial. Just set the marker in the middle between 2 DIN number lines. DIN is a good film speed system.

This means that if you are USING Portra 160/23 at the box speed: Set the meter at 23 + 1.5 = 24.5.

THE  + 1.5  IS IMPORTANT.

Now, when you push the meter test button (A separate circuit from the scene measuring  circuit.) the needle will go a little past the meter test measuring "dot".

Don't forget to "0" the meter with your finger over the meter cell.

When you measure the scene to be photographed within the 90mm finder frame, the meter measures the exposure between EV2 and EV18 correctly with NO FURTHER ADJUSTMENT/COMPENSATION.

Easier to do than it is to write.

Best Regards,

Michael

Edited by Michael Geschlecht
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Posted (edited)

Hello Everybody,

1 small clarification:

When I wrote that the range of sensitivity of the MR meter is from EV2 to EV18 it was correct but confusing because I did not explain the context. Context is important.

Years ago different meter manufacturers used a variety of different ASA/DIN speeds when describing the sensitivity & range of operation of their specific meters. Then, less years ago, many (Not all.) manufacturers more or less standardized on ASA 100/Din 21 as the standard speed that they would describe the EV range possible with their meters with.

Today that would be written ISO 100/21.

It is important to know what the sensitivity of a film/sensor is in order to understand the range & usefulness of a meter.

Because an EV number is the added combination of lens opening added to shutter speed. Without knowing the film/sensor speed/sensitivity the EV number is NOT a useful measure of the sensitivity of the meter.  And MAY only tell you the range of useful exposures sometimes.

Because EV numbers are simply numbers reflective of various lens openings & various shutter speeds which are ADDED together to determine exposure, etc.

Example: f Stop of f1.0 = EV0 and shutter speed of 1 second = EV0

EV0 + EV0 = EV0

If you double or halve a lens opening you add or subtract 1 EV

If you double or halve a shutter speed you add or subtract 1 EV

A lens/camera set @ f1 + 1 second = EV0

A lens/camera set @ f2 + 1 second = EV2

A lens/camera set @ f16 + 1/1000 second = EV18

When you take an MR meter & set the film/sensor speed to ISO 100/21:

And then see where the range of movement of the needle travels to, using both ranges, you find that the range of sensitivity from the lowest reading in the low range to the highest reading in the high range is EV2 to EV18. Leaving out the most extreme ends of both the lowest low & the highest high. As should be done with ALL meters from ALL manufacturers.

Best Regards,

Michael 

 

Edited by Michael Geschlecht
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