I'm shooting Kodak 160NC color neg film, and have been experimenting with pre-ex posure to lessen the contrast a little. I place a white card in front of the len s on location, place it on Zone II or III, and pre-expose the film before making the main exposure. Two questions:

1. Anyone have a suggestion for making sure the whole frame will be filled with the white card? I only use wide-angle lenses, so the 20x24 card sometimes misse s --- obviously I can compose perfectly in the ground glass, but without an assi stant I may move the card slightly before the actual exposure and not know it. P erhaps some sort of clamp affair on the rail of the Arca? Probably a larger card would do the trick, but how do I carry that around? If it's a folding card the crease might show up. I also sometimes detect some unevenness in reflectance acr oss the card.

2. Anyone have any experience pre-exposing color negative film with a tinted ca rd to create more warmth? Or is it just better to do this in the printing stage?

Obviously I will do more testing, but I bet you all can save me a few steps. Th anks.