Colour Neg/Zone System?

[Stephen Vaughan]

Does anybody have any advice regarding contrast control with colour neg?

Is it possible to alter tonal range with changes in exposure/development - and how does this affect colour balance?

Any thoughts? Many thanks......

[Ellis Vener]

With C-41 materials and process the subtle contrast controls are minimal and there are color shifts which are more evident if you shorten the processing time.

The best approach is to really get to know your film and make the best possible negative and then (and you may not like this answer) do your manipulation work in Adobe photoshop or a similar program.

[William Marderness]

A related question: Is the EI for color film determined the same way as with black and white? Is Zone I .01 over film base + fog? Could the density be read with a black and white densitometer? If a color densitometer is needed, what channel would be used?

[Enrique Vila]

Hi...

For B&W you "expose for the shadows and develop for the highlights". For Color "Expose for the highlights, and fill the shadows".

This have worked pretty fine for me, at least when flash use is suitable. I use this even when developing in a prolab.

[David Kaufman]

Enrique is completely wrong. For colour negative you also must expose for the shadows and let the highlights fall where they may. This will give you a good rich negative with lots of choice for printing emphasis and full detail in shadows for scanning if you so choose. And colour negative contrast can be manipulated somewhat in development, perhaps by as nuch as the equivalent of a full grade in black and white, but (and this is an important but) colour printing materials have a very limited range compared to black and white printing materials so that contrast manipulation by development of the negative has a limited usefulness. Extending development slightly, perhaps ten to fifteen percent, if you do your own colour neg processing will raise the highlight density relative to the shadow density significantly and give a snappier print but in making such a print you are bound to lose some shadow detail, which because it is present in the negative can be restored to some degree by careful dodging. Of course, the best contrast control for contrast reduction is using a form of unsharp masking, but that is a lot of work. So to sum up: Expose for the shadows, expose genrously. You will get lots of shadow detail and nice tight minimal grain. For very low contrast subjects, moderate extended development can provide a useful contrast increase with minimal colour shift. Experiment and have fun!

[Stephen Vaughan]

Thanks David - that confirms the way I have been working so far. There seems to be a good deal of latitude with the highlights so long as you expose for shadow detail. I think Enrique was answering for Transparency film not neg..... Thanks........

[neil poulsen]

For color transparency film, you definitely want to expose for the highlights and let the shawdows fall where they may, although one has some control after the negative's been exposed. You lose the highlights in transparency film, and you're dead.

I realize that Stephen was referring to color negatives, but perhaps this that to which Enrique was referring.

[Henry Ambrose]

For sure, give color negative film plenty of exposure. For low contrast scenes g ive a bit more. Ellis is right about using digital tools to extract all the info rmation you pack into the film. Its pretty amazing what you can do by these tech niques and not need much if any filtration or messing with processing times. NPS rated at 100-125 is gonna give you loads of scene information, holding shadows and highlights as well.

[Thilo Schmid]

Stephen,

there is a way to increase contrast, but I know of no way to decrease ist. Increased Contrast C-41-Development requires a seperate bleach process as it was defined in the original C-41-Process. It will not work with a bleachfixer. The steps are as follows: 1. develop (normal time/temperature) 2. fix (normal time/temp) 3. bleach (normal time/temp i.e. 6:30) 4. intermediate exposure (white light) 5. develop (normal time/temp) 6. bleach (normal time/temp) 7. fix (normal time/temp) 8. rinse

You may repeat the steps 2-5 to further increase contrast. You may gain up to one f-stop (resembles a Push Process). Bleach and Developer do exhaust faster, because of repeated activity. On the other hand, the fixer will be effective as normal, because the total amount of silverhalogenides do not change.

Regards,

[Scott Walton]

I feel that if you manipulate c41 to much you will get cross overs that are nearly impossible to correct for. Process normally (exposing for the shadows) and print on a higher saturated paper. Kodak has NC and also VC and of course there is always Fuji papers that are a bit more saturated... You really don't have that much control as yopu do with B/ W! Cheers