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How Film Develops

Lesson 21 from: Introduction to Black & White Film Photography

Daniel Gregory

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Lesson Info

21. How Film Develops

Lesson Info

How Film Develops

The advanced black and white, like I said, is kind of like a catchall 'cause there's a bunch of things that I think make black and white photography amazing in terms of the aesthetic, the look, the feel. And we've covered a lot of, I'll say the basics, and some of the advanced stuff and we've done it at a pretty big clip. But in this segment, like I said, I want to backup a little bit and explain how some of the things work. With how film works and how film processes. And then I wanted to talk a little bit about some of the things you need to really consider if you're shooting film that's different than digital that can really help make I think the ... the images you ultimately create be that much more satisfying. So one of the first things I wanted to talk about is I get asked two questions a lot. I get asked "How does film actually develop? "How's it actually work?" And then, like I said, "how do we know what zone is what?" How did we determine zone three other than I point at some s...

tuff on a screen like, "that's zone three, and that's zone seven, "and you will all trust me." So beyond that, how do we get to that? So, what we've got here is a negative, for those of you who are location driven, this is Death Valley, castle in Death Valley. When we look at a negative the lighter parts are the shadow detail, the darker parts are the highlights. So, it's because it's inverted. What happens is less exposure occurred over here, more exposure occurred over here 'cause it was brighter. So, what's actually happening in this process is the photons of light are coming in and there is more light hitting that part of the film than is hitting this part of the film. Because of that, the developer is able to respond differently to the film because there's more stuff for the developer to chomp on over here, "chomp, chomp, chomp, chomp, chomp, chomp, chomp, chomp." And over here it's like, "chomp ... "chomp ... "chomp." So it's a slower process in the eating of the silver over here. When we look at the negative, what we're looking for is, like if I look here I can see detail down in here, but up here there's a little bit less. So if I look down here I'm like "oh, I can print "and get some detail there, "I can see some detail back in there." This is pretty bright, so that tells me I'm up in that zone seven, zone eight, nine range. So I'm starting to look at that and think about, "oh huh, if I print that, "that's going to be really really bright. "So if I want that darker I might need "I might need to burn that a little bit." So, as I'm thinking about those tones I'm kind of looking at that. But these relative values are all determined by exposure here... developer here. So, how does that actually work? So, what I've got here is a chart that simulates the various zone. Now remember, when we talk about the zone system of paper we talk about zones one through 10. We're out, we've gone to Mount Rainier. Up here, in the Pacific Northwest, we've gone to Mount Rainier, beautiful site. We've got these big puffy clouds. We take our photograph, we get back, we scan it, we're in the analog darkroom, it doesn't really matter, I get down there and those clouds don't show up. And so I start to burn, so I add more light, and all of the sudden the clouds appear. Well, if the cl-- if there's only 10 zones, where did those magic clouds come from? Okay, they came from zone 11, 12, as we applied more light they got burned down. So we are going to talk about that more in a second, but that's why there are zones here. These are the zones that are moving beyond the paper, these are on the film. Now, when I put that film in the developer, the first minute it was in that developer, zone one fully developed. Zone two almost fully developed. So that first minute I told you is critical we get that agitation going. Zone three, zone four, zone five was the equivalent of a zone two. So if I pull the developer out at that point and I look at it, zone five was zone two. 'Cause it hasn't gotten the time for the developer to hit. At 4 1/2 minutes, zone three, zone four are almost completely developed. Zone five, not quite. Zone six is actually a zone five. Zone 13 at 4 1/2 minutes is a zone eight. So this is that question of "oh, if I'm going to compress," So, we had that question in the first session about what happens if my range is eight stops. I start to shorten the development time, I start to pull those down. 'Cause you see, I don't have ... you know, zone three is getting pretty close at 4 1/2 minutes. If my normal development time was seven minutes, all the zones are where they're supposed to be respectively. Now, what really happens is we develop normally and these start to race up. You start to see this effect, even at normal, above about zone nine and they start to raise. And what's happening is, remember we had all sorts of "chomp, chomp, chomp, chomp, chomp, chomp, chomp, chomp," a lot of data over here. So there's a lot of information for those highlights to work on, so that developer just goes to town. (chomping noises) And it's starting to move the zones. So, anyway I'm building and I forget, and I develop for 11 minutes. What happens at that point is that zone seven is actually an eight, zone 10 is actually a 12 1/2. So, the amount of time in the developer, now ... 11 minutes, zone 10 is a 12 1/2 but what's zone three? A 3.2. Remember, "chomp ... "chomp ... "chomp." There's not enough action over here in that exposure for the developer to extend those zones in the same way. So, because it doesn't have enough exposure, it's completed, for all intents and purposes, as developer. So, even if I left it in another seven minutes, I only get about another two 10ths of a stop there. But, zone 10 is now zone 14. Because that highlight has all that information. So that's how the developer's really ripping up in those upper zones to move that and that's also why setting the exposure is so important because I can't develop, say "oh man, I missed my zone three, "I'm going to develop it for 18 minutes." Great, you went to 3.4. And meanwhile, zone 10 became 14 and is almost unprintable at that point. You almost exceeded the ability to actually get the detail down from the print, and on the scan you're gonna be hard pressed to pull that down and that low level. So, that's what's actually going on with how film develops. That's why we talk about expose for shadow, develop for highlight 'cause I can manipulate all of this by a function of time in the developer.

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Ratings and Reviews


I am really fond of Daniel Gregory as a teacher. He does a great job. To me, his enthousiasm, his passion for and his dedication to film photography are infectuous. It's great that CreativeLive makes place for film photography and for such a pro teaching it. It can never do so enough for me. Thanks. I am a fan.

Texas Beauty Photography

Great class!! It's jam packed with usable information for anyone wanting to shoot, process, and print black and white images. There is so much detail presented in this class, I can practically guarantee you'll come back to it again and again. I successfully used this class to capture b/w photographs, process the negatives, capture them digitally, and finally, produce beautiful prints that I'm proud to show my friends and clients. This may well be one of the best classes on all of CreativeLive. Highly recommended!


This is an excellent course and Daniel is a great teacher! I'm coming back to shooting film and darkroom work after 20 years away. I have some wonderful film cameras sitting in my cabinet and I decided I wanted to use them--so I have decided to shoot BW with film, and shoot color with my digital cameras. I will develop the BW film myself and scan and print digitally. This class is perfect for me!

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