I also really like the Rollei/Maco film, though I haven't done a head-to-head comparison with the Ilford or anything. It's a little bit high-contrast, though nothing like litho film---I tend to shoot it at EI 50 and develop it in Diafine, which produces an interesting combination of high midtone contrast and highlight compression.
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_
I've gelled strobes to get the ortho look w/ Tri-X, but if you don't like filters, I'm guessing you don't like a bunch of strobes with Gels. I've had some luck getting continuous tones out of Ortho Lith, but (because I'm fairly inexperienced) I'm not sure exactly how or why one negative will have mega high contrast and some will not, I use relatively similar dilutions of Rodinal pretty much in every batch.
"Ortho" film usually means it IS spectrally sensitized (with sensitizing dye) for green wavelengths, in addition to blue. Non-sensitized emulsion is blue-sensitive only. Those are also available for some special purposes such as copy films as mentioned before in this thread.
All emulsions are UV sensitive also, unless there is UV absorbing overcoat.
If you like the "look" of ortho film, you can use cyan filter with pan film, but of course you still lose the ability to develop in red safelight.
But why bother as there are ortho films available? What we really lack is a medium-speed ortho film (ISO 200 or 400), but OTOH those were not available "in the old days" either.
You have also Orthopan films, Acros 100 (Fuji), Efke 25, Retro 100 TONAL (Rollei-Maco). At least iso 100 and in daylight you can use the TONAL for iso 200 speed with a speed enhanced developer.
This has come up several times. People have posted the spectral curves of the film and my observation is that these are just poorly sensitized pan films with low red sensitivity. They are red sensitive, just not as much as other films, so the manufacturers had to come up with a name to describe them.