One of the things that drives me nuts is washed out shadows. When my film is underexposed, my scans come back from the lab with shadows that are dark gray instead of black. I can fix this in post-processing of course, but it’s a drag. And what’s more, it means I’m not getting the full dynamic range out of my film.
So why are those shadows washed out anyway? If you underexpose your film, it would make sense that the subject would be less bright, but black should still be black, right? But what happens is the lab scans so that the subject of the image is at the proper density. If your subject’s skin tones are too dark, they get bumped up. And so does the minimum shadow density.
While ideally I would expose my film properly all the time, that’s just not possible in the real world. I shoot weddings! Sometimes you have to sacrifice proper exposure in exchange for a shutter speed that won’t blur your subject. Poor exposure is often more acceptable than a blurry bride. But it’d be nice if I had a film that could handle underexposure a little more gracefully.
I had never used Ilford’s XP2 Plus, which is a ‘chromogenic’ film. It uses the C41 color-film processing, and is in effect a single-layer color film. Upon reading the literature, I took special note where it said the film works well even exposed at ISO 800 (i.e. One stop underexposed). So I thought I’d better try it!
Where I experience problems is during receptions, which are often very dark. Very little light, large rooms, and often the available light is an ugly mix of tungsten and fluorescent. So to simulate this, I placed my sun under a tungsten recessed light in our living room’s ceiling, and turned the rest of the lights off. This would give me plenty of dark shadows, but with lighting that was consistent with the temperature I might find in a reception. I then pitted Kodak Tri-X 400 vs Ilford XP2. Tri-X is of course a traditional black and white film.
I did several tests to compare the film, shooting each roll in matching Nikon N90s bodies, and switched the same lens (and flash, when applicable) between the two. Here’s what I found:
XP2 does really well maintaining good contrast when shot at ISO 800. Tri-X, not so much. Look at the images above. XP2 maintains that solid black shadow very well. But the ISO 800 on the Tri-X is noticeably ‘gray’ compared to the ISO 400 version. In fact, comparing the histograms of each image in Lightroom, the XP2 ISO 800 frame about matches the blacks in the ISO 400 version of the Tri-X.
One of the other things I tested was overexposure latitude. I took an incident-meter reading outdoors in direct sunlight, and then shot a light brick wall with a white rose in front of it. I exposed at ISO 400, 200 and 100 (zero, one and two stops overexposed). Both films performed very well under these circumstances, so I wouldn’t pick one or the other on that basis alone. I didn’t test anything more extreme than that, but C41 process film is known for its overexposure latitude.
Before doing this test, I primarily considered C41 black and white film to be merely a convenience. You could have a local mini-lab process it if you want. You could also take advantage of dust removal technology that scanners offer, which don’t work on traditional black and white films. XP2 is about twice as expensive as Tri-X however, and hasn’t seemed worth it. However with the underexposure latitude XP2 offers, I’m rethinking that math.
So why didn’t I test Kodak BW400CN instead? It too is a C41 process black and white film. However it is no longer made in medium format, only 35mm. XP2 comes in both varieties, and I shoot both formats of film.
One other thing to consider is that Tri-X pushes better than XP2. In fact, the literature recommends that you don’t push XP2 at all, because no benefit would be gained (haven’t tried it myself). However a lab will usually charge extra to push film, and you run into other problems. If I needed to go to ISO 1600, I’d probably choose Tri-X. But for ISO 400 and 800, I think XP2 is my way forward.
You might want to see my film use in action, on my client-centric site here.