An observation about exposure of color film and RA-4 printing vs B&W.

[rpavich]

I think I've observed something about exposing color film vs B&W when it comes to darkroom printing.

It appears to me that when exposing color neg film with the intent to print in the darkroom the exposure really plays a big part of how things come out. If the shot is underexposed, then to get the correct looking print, you are forced print it so that the max black cannot be obtained. The results really do look much better if the exposure is correct in the first place. I realize that B&W is the same and I'm not saying that you can do whatever you want with black and white, but not being able to add contrast to try and make the blacks look better when making the print lighter really exposes my shooting faults.
I made a contact sheet where I exposed for just barely getting black on the rebate portion of the film and sure enough, the frames that were correctly exposed look a LOT better when printed than the frames that I had to monkey with during printing because they deviated from that.

Just my observation from the short time I've been printing color.

 

[RPC]

Yes, proper exposure as well as lighting and color temperature are key ingredients to getting a technically good shot.

The basics may take a while to learn but it pays off.

 

[trendland]

In general one could say : The exposure of bw film compared with colour negative film or compared with slide film is the same.

You may have a corect adjustment of exposure. There is no other way.

But with exeptions - if you want an incorrect exposure. One can say the correct exposure is that you will
prefer to your oppinion - not to the opinion of the others.

Exept you are not able to have any corect adjustment due to experience - thats not a good way ( to say: " But I like this " )



Here are the differences from different Films modern color negative 4-7 stops exposure tolerance

modern bw negative 7-10 stops exposure tolerance


slide film old or new 1/3 stop exposure tolerance


Thats indeed enormous - see that tollerance of modern films !!!


But it is very relative due tho the quality you want to have. For having a sufficiency qualtity never underexposure color negatives over 1 or max. 1 1/2 stops
and evoid overexporure outside a maximum of 5 stops entirely.

The same procedure for bw will give you a very good quality on bw. And what is meant with " good quality " ??? That depends on you - i would say.

But notice , if you want the absolute max. quality were modern films are designed for - the laboratory design for an emulsion with very many tests and lots of

science research at least over many decades ago " YOU HAVE TO EXPOSURE THE FILM WITH CORRECT ADJUSTMENTS " and that means you have a tolerance of 1/3 stop

for any kind of film.

With other exeptions of cause - for example when you want to chance the charactaristic of your film in viev of contrast aso.


with regards

 

[Berri]

yes that is true. Producing contact sheet prints as you describe, is the best way to judge the exposure and those frames are always a lot easier to print

 

[rpavich]

yes that is true. Producing contact sheet prints as you describe, is the best way to judge the exposure and those frames are always a lot easier to print

I found that any frames on the contact sheet that were exposed the same could be printed one after another with the same enlarger settings and they would come out great and the "basic" Y and M settings would suffice. The farther they got away from optimum the more trouble they seem to be.

 

[BMbikerider]

Colour negative film has a very wide lattitude as much as 2-3 stops over and 1-2 stops under. It is much more tollerant of over exposure. Under expose and you will start to get muddy shadows. Over expose, it becomes tricky to handle the extra contrast/density and you may have to fiddle with the filtration.
The film development should remain the same whatever, or you are going to start to get "crossed curves" which is where you are going to get difficulties. It is also a good idea to standardise everything. Film, C41 Developer, Printing paper and RA4 developer. Print development is not so fussy though, it can stand a little over development. That way you will get an easy road to successful printing

 

[chassis]

I like to think about balance with color negative film. While exposure and overall contrast are important, color balance is an additional complexity with color negative vs. black and white film.

Given the exposure latitude with color negative film, I would say there is also a tolerance regarding acceptable color balance. To me this implies the notion of "latitude" less than what is being talked about here. Useable latitude to me represents acceptable shadow exposure, overall contrast and color balance. More factors in play than with black and white negative films. Useable is admittedly a subjective criteria. "It can all be fixed in post..."

 

[Berri]

Colour balance greatly depends on the subject. Known colours such as skin tones have to be precise while unknown colours like flowers could be pleasant with many different colour balances.

 

[BMbikerider]

Printing RA4 has many significant differences to B&W. . Development of the film can have a lot of liberties taken with it and still get a printable image. Secondly B&W printing may need areas where burning in and dodging to hold back the light has to be done. With colour you MAY get away with this if you are lucky, but excessive use of both methods will significantly alter the colour balance of that particular area.

Having said that, C41 film has such a wide latitude, plus a greater tolerance of tonal range or exposure so it is not needed so often and after an accurate colour balance has been obtained for one set of negatives, providing the camera exposure is correct, then there will be less darkroom exposure difference between each frame. Colour paper has only one contrast grade, unlike B&W paper. But once you get the colour balance correct the tones and colours are more or less spot on and the print will actually look very good.

Once you get a darkroom set up where everything is more or less as you wish it, and you re comfortable when using it, colour printing is actually quite easy. You must however be consistent! Use the same film, The same C41 developer, The same RA4 developer and rigidly stick to the times and temperatures for each particular bath in both negative development and print development. You can get away with a small amount of over development of the print, nominally 45 seconds at 35C. But no more than 10 seconds over or the paper will degrade in the whites.

The temperature of the development is the greatest problem. This is why I much prefer to use a deep tank processor so the chemicals are kept within =/- half a degree. When using the roller drum method the drum has to be washed out after each print, dried thoroughly and then allowed to get up to the operating temp. This slows the whole process down and leads to inaccuracy and colour balance drifting off.