Tungsten Film/Daylight/Filter/Speed

[newcan1]

I want to shoot in daylight some tungsten film using a filter. Say the film is ASA 200, but the instructions say to rate at EI of 100 with an 85 filter in daylight.

So I put the filter on the camera, and use an external meter set at 100ASA and everything is fine.

What if I use an internal meter in the camera? Would I set that at 200 because it is metering through the filter?

My ultimate goal is to put a gel filter in front of, or behind, the lens of a point-and-shoot camera to see what it can do with this film. I would make an ISO label for the film cartridge (tin foil and electrical tape) to set the speed. The question is, what speed?

So many experiments, so little time....!

 

[holmburgers]

Yes, you're right. It just depends where the light sensor is on this point-and-shoot camera. Often times they're on the face of the camera somewhere and a filter behind the lens obviously wouldn't affect it. So, change the ISO. Other times the sensor is near the lens and will be affected by the usual placement of a screw on filter. In this case, keep it at box speed (ISO), as the meter will be looking through the filter and automatically compensate.

 

[newcan1]

Any clues on what the sensor thingy would look like? If in doubt, I guess I would assume the sensor is not through the lens, and will change the ISO. This is a good point - thanks - I hadn't even thought about sensor placement.

 

[holmburgers]

What kind of camera do you have? It's usually pretty obvious. There are only so many things on a camera.

 

[newcan1]

I actually have a bunch of them, which I intend to use as table cameras at a wedding. I looked at a few of them, and none of them seem to have anything that looks like a through the lens sensor or a sensor very proximate to the lens. So I'm pretty confident that the sensor is probably one of the several little "holes" adjacent to the viewfinder that they all seem to have. I can probably find user's manuals for them. I'll try putting a filter behind the lens of a few of them and shoot some tungsten film and see what happens.

 

[holmburgers]

Maybe it's more obvious on old school p&s cameras. Like the Nikon L35AF for instance; there's a little "eye" under the lens.