Certo Box, box...

[Quincy]

Hello,

I have Certo Box and i'm thinking about his "M" time, i don't know what time it is. I think that is 1/10 or 1/20 or something like that. What do you thnik about it?

 

[moki]

All box cameras have a very simple shutter that's everything but accurate and can differ a bit from camera to camera of the same build. They usually have something between 1/30 and 1/50.
If you have another camera at hand, you could compare the sound. You may not be able do tell 1/500 from 1/400, but there the difference between 1/30 and 1/60 is very clear or at least clear enough for a good guess.

Don't know about the Certo Box, but for most box cameras, it's a safe bet to use 100ISO film for bright sunlight, 200 for cloudy and 400 at dawn or indoors. With the great exposure tolerance of modern color negative films, it works pretty good.

 

[macrorie]

Usually "M' on old shutters refers to a setting for a sync with flashbulbs, but I don't know if that would be the case with a box camera.

 

[Nicholas Lindan]

Google for shutter speed testing methods using two, rather obsolete, items: A CRT television and/or an LP record player.

There are also methods that use your computer's sound card microphone input.

 

[2F/2F]

I don't know specifically, but in general, an M setting synchs a class M flash to the shutter opening.

 

[moki]

Box cameras usually only have two different shutter settings. It's a very simple mechanism, probably a rotary shutter with a fixed spring.

One setting keeps the shutter open as long as you press the release, like a bulb-setting (sometimes labeled "Z" for "Zeit", that's german for time)
The other's "M" for "moment", as in "short amount of time". That's your 1/30 or whatever it is. I don't think, the Certo Box even takes a flash.

 

[AgentX]

Put 100 speed film in it and shoot it in sunlight...tends to work for all box cameras I've owned, but may vary with vintage of camera. Adjust film speed if you're consistently over or under throughout the range. The actual shutter speed ceases to matter when you've only got one of them.

 

[Quincy]

Put 100 speed film in it and shoot it in sunlight...tends to work for all box cameras I've owned, but may vary with vintage of camera. Adjust film speed if you're consistently over or under throughout the range. The actual shutter speed ceases to matter when you've only got one of them.

and this is the good idea, i've made photos on acros in sunny day, probably it will be a little bit overexposed but this is no problem. Thanks all.