Anyone Double-Developed with Colour+B&W?

After experimenting and fudging around I have formed a hypothesis and a few ideas.

I did an experiment of developing some C41 film in xtol, (used an offcut thats been directly exposed to light) and cut that up into pieces, that nor undeveloped c41 doesnt appear to clear in tetenal superfix odourless (my b&w fixer - acetic acid + sodium metabisulphate), but clears in its own fix (thiosulphate) - as does developed b&w, the developed film clears but stays dark, the undeveloped clears

Where as the bleach completely clears both developed (using xtol) and undeveloped C41 indentically.

Which leads me to the fact that b&w developer only affects the silver, doesn't mess with the dye (hopefully).

This gives me a hypothesis - and sneaky idea of developing correctly BW400CN in C41 dev, then developing in another bath of xtol - which hopefully should only affect the silver and not the dye, and doing a bleach bypass and fixing only in thiosulphate.

Thereby theoretically increasing the contrast range captured, effectively increasing the exposure latitude.

Hopefully it wont turned into a big mess though.. thought of trying it on colour C41 too.. but -if- it works, i think it might give an overall desaturation - not a deal breaker as can be increased in digital darkroom if needed, and the monochromatic image on the silver may have a different tonal range which may increase subtleties - esp on intense films like kodak ektar 100 - but pushing the monochromatic image past the colour image i think would give monochromatic deep shadows where the dyes had clipped.

I think that it may give some interesting images however.


Has anyone tried this before?

What results did you get?

Well...... There's only one way to find out!




Steve.

It is a motion picture trick called skip bleach processing, with the added option of ENR, or black and white 2nd development prior to normal completion of the process. The black and white step allows you to control the intensity of the skip bleach look. After C-41 dev. then b/w dev., you finish the C-41 process as normal, starting with bleach. You can vary time, temp., and dilution of the b/w developer to control the amount of silver you wish to retain.

It will certainly change tonality and saturation, but the word "subtle" is nowhere near an accurate description for the effects you will get. It will not increase your exposure latitude. (How could it?) In fact, it will make it more narrow. It will simply increase your contrast.

It would be something that I think you would enjoy most with color film, not b/w C-41 film. That way you don't just get extremely high contrast, but you get color effects as well. It could still be really neat with the b/w C-41 film...however, there would be little reason to use the color developer at all in that case. I'd just run the film through a normal b/w process instead. Lord knows enough beginning students have done it on accident at my school...

(there was a url link here which no longer exists)
http://www.jpgmag.com/stories/1228
I haven't tried it though as i've not been doing my own c-41 lately.

Yeah, I am familiar with bleach bypass.

Thanks for the links Akki14 sounds interesting.

if you develop B&W C41 process films in B&W chems, you are getting an image on the silver and not on the dye like it was designed for.

Here is why I think it could be used to increase latitude:

Correct development of the monochromatic dye using C41 chemical.
Wash, then second development in B&W developer, the B&W developer doesnt affect the dye (not in my preliminary testing in anycase with xtol), and a fix, no bleach.

Therefore, it seems quite logical you can push the image on the silver using B&W developer, while keeping the image on the dye at its correct level as its not affected (theoretically).

Thus, the pushed image will see more into the shadows and blow the highlights.

What I am thinking is this will result in what looks like a higher contrast neg, with denser highlights and darker over all (on the neg before reversal/inversion in post), ie: blown highlights on the silver against non-blown highlights on the dye look darker than non-blown highlights if you did bleach, but not as dark as blown against blown, so the detail would be able to captured digitally (perhaps might be a bit hard for scanners, but for dSLRs on a copystand where "multiexposure"/bracketing works - it should be fine, i dont think youd need to multiexpose either since most normal negs dont even fill up half the histogram).

That is basically my thought on it - by being able to further develop (overdevelop/push) the silver independantly of the dye - you are effecively sandwiching two different exposures together.

So since the image on the silver will be monochromatic, this would theoretically work best for B&W C41 films.

Perhaps there is higher contrast range on the neg, with extreme tail and head curve than can be traditionally reproduced/optically printed etc? Which would mean that the clipping on either end would result in a high contrast re-production that has only recreated a portion of the curve, which would represent the typical contrast ratio of a neg, instead of compressing the entire curve/contrast ratio back into a normal one.

In any case, I will give it a go, I have a roll of BW400CN and C41 chems and xtol in my laundry, I'll deliberately try to shoot a high contrast scene with deep blacks that should get burned out by exposing for the highlights.

Dev it in C41, wash then xtol, and fix it, and skip stabiliser, digitise it, then bleach to remove the silver layer, then stabilise, and digitise again and compare.

Athiril said:

Thanks for the links sounds interesting.

if you develop B&W C41 process films in B&W chems, you are getting an image on the silver and not on the dye like it was designed for.

Here is why I think it could be used to increase latitude:

Correct development of the monochromatic dye using C41 chemical.
Wash, then second development in B&W developer, the B&W developer doesnt affect the dye (not in my preliminary testing in anycase with xtol), and a fix, no bleach.

Therefore, it seems quite logical you can push the image on the silver using B&W developer, while keeping the image on the dye at its correct level as its not affected (theoretically).

Thus, the pushed image will see more into the shadows and blow the highlights.

What I am thinking is this will result in what looks like a higher contrast neg, with denser highlights and darker over all (on the neg before reversal/inversion in post), ie: blown highlights on the silver against non-blown highlights on the dye look darker than non-blown highlights if you did bleach, but not as dark as blown against blown, so the detail would be able to captured digitally (perhaps might be a bit hard for scanners, but for dSLRs on a copystand where "multiexposure"/bracketing works - it should be fine, i dont think youd need to multiexpose either since most normal negs dont even fill up half the histogram).

That is basically my thought on it - by being able to further develop (overdevelop/push) the silver independantly of the dye - you are effecively sandwiching two different exposures together.

So since the image on the silver will be monochromatic, this would theoretically work best for B&W C41 films.

Click to expand...

What?

Be more specific with what you dont understand about my idea?

Athiril said:

Be more specific with what you dont understand about my idea?

Click to expand...

I do not understand how blowing highlights and increasing contrast could increase latitude.

I do not understand why do you call it two exposures sandwiched together. There is only one exposure. There are two negative images: dye and silver.

I've done some BB on few color C41 negs myself and all end up with high dmin big grain and high contrast. What you propose is to increase it even further.

there is two images, exactly right, and by pushing one of them, they would be effectively at two different exposures, one being of an effectively higher film speed.

The entire negative would be overall darker/denser, which could give problems scanning or traditionally printing.

But not a problem for copy-stand style copying & stitching with a macro lens and dSLR in which you can control the exposure, and expose it for longer to compensate for the density increase, you can even take multiple exposures if need be, which does work mind you (unlike with scanners), unless the most dense part of the negative is so dense absolutely no light gets through (which of course light does get through).

If highlights are blown on the silver but not on the dye, then when you put the two together - there will be detail there, you will need more exposure to pick up that density - but it is there.

When the shadows are burned on the dye, but not on the silver - there will be detail there too obviously, as the combination of a clear part of the negative (if it was bleach) with an image of silver over the top will give differentiation, instead of a flat nothing.

Even though you'd more exposure to pick up the highlights region due to density, this should still capture shadows as well with one exposure on the copy stand - since negatives at worst case use half the available histogram on the typical dSLR when copied with a macro lens and backlight.


I think the range is there when you push the silver, and I think the trick is being able to extract it.

Athiril said:

there is two images, exactly right, and by pushing one of them, they would be effectively at two different exposures, one being of an effectively higher film speed.

The entire negative would be overall darker/denser, which could give problems scanning or traditionally printing.

But not a problem for copy-stand style copying & stitching with a macro lens and dSLR in which you can control the exposure, and expose it for longer to compensate for the density increase, you can even take multiple exposures if need be, which does work mind you (unlike with scanners), unless the most dense part of the negative is so dense absolutely no light gets through (which of course light does get through).

If highlights are blown on the silver but not on the dye, then when you put the two together - there will be detail there, you will need more exposure to pick up that density - but it is there.

When the shadows are burned on the dye, but not on the silver - there will be detail there too obviously, as the combination of a clear part of the negative (if it was bleach) with an image of silver over the top will give differentiation, instead of a flat nothing.

Even though you'd more exposure to pick up the highlights region due to density, this should still capture shadows as well with one exposure on the copy stand - since negatives at worst case use half the available histogram on the typical dSLR when copied with a macro lens and backlight.


I think the range is there when you push the silver, and I think the trick is being able to extract it.

Click to expand...

??????????(!!!!!!!!!!!!!!!!!!!)

You are totally ignoring contrast (and/or confusing it with "density"), and your idea that you are getting two exposures and more latitude is just dead wrong. How could this possibly be the case? Making something more contrasty does the opposite to latitude. I suggest that you just try it out. You have all the info you need from us. Knock yourself out. You will get cool results if you pick the right subjects and the technique supports your concept, but you will certainly not get more latitude or more dynamic range.