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Old 29th August 2017, 10:23 PM
Mike O'Pray Mike O'Pray is online now
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Join Date: Oct 2008
Location: Daventry, Northants
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Default Hanimex CdS PR-65 Light Meter - Help Needed

I have obtained the above secondhand meter. I got it off a stall holder at an antiques fair who knew little about it and there were no instructions. Here's what I know.

It is a CdS meter with High(H) and Low (L) buttons. I tried it before I bought and in sunny early afternoon conditions I pressed the H button and the needle moved to between 12 and 13 on the almost straight set of figures at the top of the meter. When you move the fixed black pointer on the round dial to almost the square labelled 13 you get an EV reading of nearly 15 in the opening on the rim of the dial. This is the classic sunny day EV reading so I am reasonably confident that it works pretty well as it should. I'll qualify "pretty well" in a moment.

There are ISA figures on the opposite edge of the fixed metal dial which is attached to a movable clear dial which has the black arrow and against ISA 100 there is a red dot. Reading the shutter speed against this red dot gives you the shutter speed required for f16 for that EV value. So if you have a 100 speed film and use f16 then things are simple. Even if you decide to shoot at other apertures things remain simple as the other f numbers give the shutter speed for those numbers.

The other ISA numbers are slightly cramped so reading the correct shutter speed for say a 400 speed film is a little more difficult but possible. If you use a film speed other than 100 and an aperture other than f16 then some metal gymnastics are required or you can set the red dot corresponding to f16 against the new speed and then read off the new shutter speeds against the the other aperture numbers.

So I think I have worked out how the meter works and how to decide on the correct shutter speed and aperture for the film speed being used

If you have followed all of the above so far, well done, because I am looking for confirmation that my interpretation of how this meter works is correct.

Secondly I need to come back to my phrase "pretty well" in terms of where the needle ends up on the light scale after you press either the H or L button. I have noted that if neither button is pressed the needle sits a little to the left of the 0 EV and does not sit on the zero. However on the back of the meter there is a screw with the word "zero " above it.

I assume that this is a calibration screw. If I am right then the question is: Should it be set so that the needle remains at zero on the scale when neither button is pressed and NOT as at present to the left of the zero? I presume that if this is the case, then when either button is pressed the needle for any given light level will rise to a slightly higher level and this will give a more accurate reading.

Finally there is a large screw on the back which looks as if it is designed to be unscrewed by a small coin. I assume that underneath this screw is a compartment for a button type battery which powers the CdS meter? Is this the case and can the right size and power of button battery still be obtained?

Of course most of this lengthy thread would probably be unnecessary if anyone has the instructions for the meter. Here's hoping


Thanks for your perseverance in following my thread

Mike
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