Filters with 400CN

[mesh]

One of those questions I've always been too embarrassed to ask... ;-) Do filters like Yellows and Oranges work with chromogenic B&W films like 400CN? Any differences to real B&W?

Thanks.

 

[markbarendt]

Yes.

No.

 

[mesh]

Thanks ;-)

 

[xwhatsit]

How panchromatic is 400CN et al.? I know all modern films are pan (apart from the weird Efke KB25 that just arrived but I haven't spooled up yet to try), but to different degrees; red sensitivity drops off somewhat, although not anywhere near with ortho film. Is 400CN more panchromatic than silver pan?

 

[danegermouse]

no idea about red sensitivity but i have found that yellow and yellow-green and green filters work well with this film. orange and red filters lose a lot of detail in the shadows if you want to keep the highlights in check. could be a statement about the user rather than the film and it is not a film i use that much but the results i have had have been consistent.

dane.

 

[markbarendt]

How panchromatic is 400CN et al.? I know all modern films are pan (apart from the weird Efke KB25 that just arrived but I haven't spooled up yet to try), but to different degrees; red sensitivity drops off somewhat, although not anywhere near with ortho film. Is 400CN more panchromatic than silver pan?

There is some "personality" to each film but generally they are all fully "pan".

Here are links to a few PDFs

Delta 400

HP5Plus

TMax 400

XP2Super

BW400CN

 

[Ian Grant]

Remember that it's just a B&W emulsion with a colour coupler added although unlike XP-2 it has a n orange mask for printing at Minilabs. Any B&W film can be processed Chromogenically in a C41 developer as long as you add a coupler to the developer, you may need to work at a lower temperature depending on the films hardening.

Ian

 

[srs5694]

Any B&W film can be processed Chromogenically in a C41 developer as long as you add a coupler to the developer, you may need to work at a lower temperature depending on the films hardening.

That's an interesting idea. Do you have any pointers to what would be required? (What chemicals to add to the developer, timing, etc.?) Any broad statements about the results? (Grain, film speed, etc.?) It could be interesting to play with this, if it's not too much hassle....

 

[Ian Grant]

You can make up a very simple Colour developer, as there's just one emulsion & it' B&W there's no no cross curves to worry about.

Look at (there was a url link here which no longer exists), these are the formulae I used to use in the late 70's & 80's. You can mix the couplers to get a desired colour.

You can bleach the silver after processing to leave just a dye image. While the process is ideal for Dye toning, and there have been commercial kits it's also similar to how Kodachrome works.

So yes you can process a B&W film in what is essentially a super fine grain developer and by judicious choice of couplers achieve a dye-coupled image that has better printing density (due to it's colour) and which gives much finer grain images.

Ian

 

[srs5694]

Thanks for the pointer, Ian. I'm filing that away for experimenting on some rainy day....