Shooting B&W roll of film through camera

[leica M2 fan]

and since I'm using a K2 Yellow filter I am exposing the Neopan 400 at 200 ASA. My question is : can I shoot say a portrait without the filter? Do I leave the ASA on 200 or shoot at 400? I am not developing the film myself. TIA.

 

[drewbarb]

If your camera has an internal meter, it will automatically compensate for the filter, so you should leave the ISO setting the same for the whole roll, regardless of whether you have a filter in place or not. If you're using and extrenal meter you will have to adjust the E.I. if you take the filter off, or you'll get too much exposure. One stop over exposure certainly won't hurt, though. Especially if someone else is processing your film, I'd shoot 400 speed film at 320 or 250 normally, and add a stop for the filter from there. Tell the lab to process normally.

 

[NickTrop]

My apologies if this is too basic, but you really only need a yellow filter if you're shooting a scene where a blue sky is prominent, expecially if there's "puffy clouds" in the scene because the blue will translate to white and the clouds will blend into the sky without one. Yellow is the complementary color of blue and improves contrast.

 

[Bryce]

Another take- the yellow filter only costs 1/3 of a stop anyway. You can shoot the same with or without it, since the difference in exposure is negligible. Also, you can shoot portraits through it. K2's don't do anything really awful to people anyway, with the possible exception of rendering blue eyes a little dark.
So I guess you can't really lose.