Quinn 4

The other day I made a posting about two cameras I found (See: "Cameras from Another Time") I forgot to write about light meter that came with one of the cameras. It is Dejur Amsco Model 40 Critic. It was made in 1940. I look up the manual for it. That is as far as I got. I could not get the numbers right. Has anyone work with one of them?

BebuLamar

If you can't find the manual you can post a picture of it may be we can figure it out.

rwilson1942 Loc: Houston, TX

It looks like you align the meter reading with the film speed (ISO) on the left side of the dial
and then you can use any of the f-stop/shutter speed combinations listed on the right side of the dial.

larryepage Loc: North Texas area

Older exposure meters can be a lot of fun to play with and use. The only things I have run into is that there were some adjustments to ASA (now ISO) film speed values over the years. The last that I know about was in 1960. So that means that a setting to a particular ASA value on your meter may not match up exactly with the printed speed of film that you use or the sensor in your camera. This is always true of any meter and any filmstock, of course, but these were intentional adjustments made to the system. Also...many of the older meters may be built around a base shutter speed of 1/50 second, while most modern manual cameras used 1/60 second as a base. This is much less a problem with newer digital cameras, which make an entire array of shutter speed choices available.

The biggest challenge that you may face is many of the older meters looked at a really big piece of the landscape and sky. It can be hard to interpret the reading and translate it to a setting that will give you the desired result.

A potentially big plus of the older meters is that most did not require a battery. They used either germanium (I think) or silicon photocells which provided all the power needed.

So...have fun with it.

larryepage Loc: North Texas area

I just checked and found the manual a couple of places...looks like you can buy a real one in good condition for $17.00.

This meter follows a pretty standard design in which the sensor drives a meter to display a light level indication. You as the user then set the circular slide rule to that indicated value and several valid exposure combinations are displayed. The Pentax Spotmeter 5 made 40 years later follows essentially the same design approach.

And it appears that the shutter speed scale does follow the old standard based around 1/50 of a second, but half-stop values are also provided.

lamiaceae Loc: San Luis Obispo County, CA

This http://www.cameramanuals.org/flashes_meters/dejur_critic_meter.pdf ?

It looks like it uses Weston Film Speeds, long before my day too. How might they related to ASA (ISO) I'm not sure. But they are not DIN (German), which are logarithmic.

Here you go http://www.westonmeter.org.uk/speeds.htm

DIN-ASA-GE-Weston
-----ISO
10 6 8 5
11 8 10 6
12 10 12 8
13 12 16 10
14 16 20 12
15 20 24 16
16 24 32 20
17 32 40 24
18 40 48 32
19 50 64 40
20 64 80 50
21 80 100 64
22 100 125 80
23 125 150 100
24 160 200 125
25 200 250 150
26 250 800 200
27 820 400 250

If you are good with math you can probably extend this table. Or find the old photo books with the needed equations (try Amphoto as a publisher). Good luck.

Though I'd recommend a used modern Gossen Luna-Pro or Luna-Six meter. But be sure you find a late model not with 1.35v Mercury Batteries that are no longer made. A clue, the older early model Gossen meters you don't want are likely $15-25 on Ebay, the good ones that use current batteries are more likely $80-100 used. In between it is a crap shoot. I can tell from pictures of the back of the meter showing the battery compartment, but the fronts look the same unfortunately. Or you can spend up to $400 on a new Ambient/Strobe Meter.

BebuLamar

Actually you don't need the dial. The only thing you need is to read the number of the meter and figure it out from there. The number appears to indicate EV for ISO100. If it's not is then you can just do the compensation from there.

Quinn 4

All I wanted was someone to explain to me in plain English how the thing works. I known about the manual, I found it confusing to understand. I have cameras from 1930s and 40s that have no light meter to them. I wanted to see if I could use the meter with the cameras, to see what it was like using a camera from 1930's & 40's with a light meter. P.S. It was giving to me

BebuLamar

Point the meter at the subject and note the reading the pointer is pointing at. Turn the dial so that the film speed is align with the value that you read on the scale next to the film speed scale. Use any combination of aperture and shutter speed on the 2 scales on the right.

burkphoto Loc: High Point, NC

Check your numbers. There are some typos in this list...

amfoto1 Loc: San Jose, Calif. USA

Well, back in the day, we figured out how to use our light meters by reading the manualsr:

A fairly complete user manual for your meter, 23 page PDF... http://www.cameramanuals.org/flashes_meters/dejur_exposure_meter.pdf

Looks like a supplement to a user manual (and some adverts for other products), 7 page PDF.... http://www.cameramanuals.org/flashes_meters/dejur_speed_ratings.pdf

You may need to figure out how modern film speed ratings correspond to what was used. If you search for "Weston scale versus modern ISO", you might find something. But off hand, it looks pretty similar.

BebuLamar

I would check the meter under sunny 16 condition it should read 400. Using only this scale you can figure out the light level in 1/2 stop by using the scale on the right of the pointer for the full stop and the scale on the left for half stop. At 400 reading it's EV15@ISO100.

DickC Loc: NE Washington state

I collected Weston Master Vs for awhile, must have 20, old meters are fun to fool with.