Quote Originally Posted by AgX View Post
Don't forget that with your examples the opacity of the filter (though limited) and the high in-sensitivity of the emulsion add up.

(maybe weird wording; but I guess very understandable for a geek...)

By the way, you refered to colour conversion filters. Colour separation filters are much steeper.
Fair enough. I'm not familiar with color separation filters, but it makes sense that they would be steeper given their function. I just used an 80A as an example since it is generally available in a variety of sizes.

I just looked at the Ilford site and the response dies around 570nm for Ortho and 650 for Delta 100. I think the folks who are saying to try Ortho Plus are on the right track if the OP can use 4x5. That combined with a blue filter (separation if you can find it, 80A otherwise) might be the best in the end.