Thursday, January 24, 2013
Is Film Emulation Even Possible?
Straight From EOS 7D JPG
I've come to understand through reading much about the subject that, although colour film emulation is possible through software, and such software is available for purchase, it is not something that is necessarily self-evident or even fully possible. The software costs a couple of hundred dollars typically and is only available for Windows or Mac, and it works fairly well, although not nearly as well as B&W simulation software. So I thought I'd use the software I already have, which is not specifically "colour emulation" as in - "we make this digital picture look exactly like it was taken with Kodak Gold". Colour emulation is achieved by tweaking the colour curves, mainly, and so I thought I'd try a little experiment using the software I have (GIMP and Photivo) to determine if I could come up with anything that might make a digital picture "look like film".
First, above is a rather forgettable shot straight out of my camera - no modifications whatsoever. This represents the best my camera can do with it's own internal RAW to JPEG conversion. However, I should immediately show that's it's not necessarily the absolute best my camera can do:
RAW File Tweaked with Photivo to my own liking
The above has nothing to do with trying to look like film, but rather to show what I typically do with a RAW file to enhance it into something that looks decent (and no, I will not divulge my "secret sauce"!) Also, keep in mind that I don't have a really high regard for this particular photo - it's not bad, but I wouldn't enter it in a contest.
Now, to get down to what we're really talking about here, I can see how difficult the whole thing is. The variables with film, especially colour film, are endless. With a film camera, there is one exceptionally complex thing that happens, but with digital, there are several inter-related tightly controllable things. Let me explain it this way - with a film camera, the one thing that happens is that light comes through a lens and strikes the film - that's it. But with all the variables, like brand and type of film, brand an type of camera and lens, how much light, the temperature of the light - it all works together in an "analogue" (which is endlessly variable) way so that predicting the result is almost impossible. On the other hand, digital results are very predictable. There is only one sensor - not a slew of different film possibilities. Colour temperature is controlled by the camera automatically (and therefore changed to best suit conditions), or manually by whatever temperature you purposely pre-select. Digital imaging itself is not endlessly variable like analogue, but confined by the numeric bit-depth of the sensor and processing computer within the camera. Film is designed to handle the variables to vast limits, but not in a predictable way. With digital, the sensor is not nearly as forgiving to the variables, but so much is pre-determined before, during and after taking the picture, there are no surprises. So, to tell a digital camera to "make this picture look like Film-X", all it can do is emulate some of the more predictable known qualities of Film-X, but probably not some of the unpredictable ways in which Film-X behaves when pushed beyond the limits.
The predictable things about "Film-X" have to do with it's characteristic colour curves - and these are easily manipulated in Photoshop, or in my case GIMP. Here, I'll show you the original JPEG again, followed by the same file with curve manipulation applied to make it into "Dave's Film-X":
I decided that Dave's Film-X should have a warmer tone to it, and so using GIMP, I tweaked the three colour curves (Red, Green and Blue) to do just that. It wasn't too hard.
Now, everybody talks about "film grain", as if it's a sure fire way to make your picture look like film. Here's the same picture, with lots of film grain added digitally-
Film Grain Complements of Photivo
Personally, I think this is a lot of shite. Although film grain certainly looks better than digital noise (as in "speckle"), it doesn't necessarily suggest that film was used. I've shot Fuji Pro 400 ISO in my Rolleiflex, and you don't see a hint of grain in it at all. on the other hand, a roll of Kodak Ultramax-400 in my Pentax Zoom-90 showed a bit of grain, but the same film taking the same picture at the same time in my Olympus Trip-35 was less grainy. See what I mean by variables? Now, with the above picture, with lots of very bright snow on the ground, if you were using film, the preferred ISO would be 100, so grain wouldn't make any sense. Therefore, if you want to make your picture look like it was taken with Dave's Film-X100, you wouldn't add film grain - it would just look stupid.
Finally, GIMP has a filter available called "National Geographic". Whether they use film or digital, it matters not- National Geographic is certainly the crown-royal of excellent photography. Think about it, those of you who suppose you can make a digital file look something like film by somehow deteriorating it (like adding grain) - how did this fine publication survive all those years before digital photography? For most of it's lifetime, National Geographic gave us demonstrations of the finest photography available, not with digital imaging, but with true film photography and offset printing.
The GIMP filter claims to be "Simulating high quality photos" presumably from your less than high quality digital files. Let's look and see what it does:
JPEG with GIMP "NatGeo" Applied
Original EOS 7D JPEG
To me, the National Geographic treatment is subtle, but makes the photo a bit brighter, warmer, and more in focus by applying more local contrast. This would be the "film emulator" I would be looking for, I think, because contrary to popular belief, film emulation is not about degrading your digital picture, but quite the opposite - adding a "National Geographic" quality touch to them.
But if you're really interested in emulating film, nothing would do it better than film itself.