"FSV" - Horseman Exposure Meter

[matt_chroust2]

Greetings,

 

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I bought a used Horseman exposure meter and was able to find a battery for it, but I'm confused about the meaning of "FSV" (full scale value? something else?) and what the indicated shutter speed corresponds to in the context of aperture.

 

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I don't have the manual, but I gather that I'm supposed to set the ISO, take an FSV reading and use the dial to translate this to a shutter speed. But what aperture does this correspond to? How / when do I use the zero adjust control.

 

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Many thanks. This is my last resort as I can't find any data online.

[howard_slavitt3]

The aperture is the one set on your lens when you take the

reading. Pretty simple, huh? I had the same problem when I

first tried to use one.

[audidudi]

I've already responded to Matt privately but am reposting it here for

the benefit of archive searchers everywhere...

 

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"FSV" stands for "film speed value" and appears to be roughly the same

thing as the EV scale. The first thing you do is set the film speed

with the rotating dial; then you insert the meter under the

ground-glass, open the aperture and take a reading by rotating the

knob on the side until the meter needle falls within range of the

visible scale. Then you rotate the clear plastic dial on top of the

film-speed dial until the thin green line lines up with the FSV shown

by the meter ... since you've already picked your aperture, this

indicates the correct shutter speed. If you want to use a specific

shutter speed and let the aperture fall where it may, you simply work

backwards; i.e., you select your preferred shutter speed on the scale,

see what FSV is indicated and then adjust your aperture accordingly

until you're getting the correct reading on the scale.

 

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BTW, the zero adjust control is used to compensate for changes in the

battery voltage ... set the scale to the battery check position, push

the test button and use the adjustment screw to center the pointer in

the wider band opposite the "0" mark.

[audidudi]

I was just flipping through the copy of the owner's manual that I made

for Matt and realized that I erred in my post above regarding the zero

adjustment provision. Oops!

 

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It turns out that it's NOT for the battery voltage but for zeroing the

meter needle if it somehow gets knocked out of adjustment. It is done

by turning the meter off, placing it on a flat surface facing upwards,

and twisting the adjustment screw to or fro until the needle indicates

zero.