Darker filter question

[grooski]

I had this question about darker filters (such as polerizer, red filter, and filters that just mack the frame darker). If you put on a polerizer on your lens your lightmeter makes up for it and makes it look like it like you would. But if you dont have a filter and the seen is just darker than you just have what is there, you cant really make it like the polerizer or other darker filter. So why does the your ttl lightmeter makes up for the darker shade but if the seen is just dark you cant do much about it? Thanks, and it would be great if you could give me as much aswers, if you understand the question, that would be great.

 

[voodoocat]

Hrmm... I'm not really understanding what you're asking.

TTL stands for through the lens. Your meter is behind the lens, so anything you put on the lens will change what the meter sees. So you don't have to calculate exposure in your head.

 

[ksmattfish]

If you are using ISO 400 film on a sunny day, aiming at a generally middle gray tone, you will find that your meter reads something along the lines of f/16 at 1/250th sec. If you have the exposure set on some sort of auto, and stick a polarizing filter on it which subtracts 2 stops of light, then the meter reading will change to something equal to f/16 @ 1/60th. If you are not using a filter, but the sun goes behind a cloud (subtracting 2 stops of light), then your meter should also read approx f/16 @ 1/60th.

The meter cannot tell the difference between a filter and a dark scene. It can only measure the light that hits it.