Flicker Begone!
Save My Shot! Everything is just fine with the shot at the right, right? Wrong! It's okay now, but it started life as a disgusting mess that could threaten your sense of self-worth, happiness and/or mortgage. Think I'm kidding? Think I'm exaggerating? Read on... If you shoot time-lapse images with any of the current crop of digital SLRs, the chances are great that you will end up with a number of scenes that poke your eye out with an aberration that only technology could create: Flicker. Frames in a row that aren't microscopically perfectly identical exposures. You did everything right. You manually set aperture and shutter speed. You locked off the focus, you shot every image X-number of seconds apart, you may even have used an internal or external intervalometer to assure yourself of perfectly smooth motion. When you finished the shot, you took all your frames back into your computer and you loaded them into a program (such as QuickTime Pro [windows] [mac]) that strung them together into a movie scene at some appropriate frame rate such as 24 fps, 25 fps, 29.94 fps or 30 fps (depending on what chunk of the world you're in) and the motion came out just fine. But that dang flicker showed up, ruining the shot. The clouds were bashing you in the face with ever-so-slight differences in exposure from frame to frame. What causes intervalometer flicker? It's not what you might think. Nothing is wrong with your camera or your post-production workflow. It's that darned lens. I cleaned up that last sentence. Modern lenses are designed to be mechanisms that live and/or die by the computer. Computers focus them, computers control their every thought. The computer in your camera tells the lens to stop the aperture down to f/11, and actuators in the lens comply. In fact, they get it about 94% correct every time. They get it sooo close, that you never have a complaintfor still photos, that is. Who gives a rat's if the next still photo is 5~11% brighter or darker than the last? Nobody, that's who. Photoshop can fix minor exposure tweaks in a stroke. It's when these modern lenses with their high-tech aperture estimation systems attempt to shoot a stream of frames into a moving image that the 11% whoopsie shows its face and punches your lights out. So you end up with a time-lapse movie that your boss says is a complete waste of time, and what the hell is he paying you to do, anyhow? Here's one of those shots complete in all its indignity. Just as it popped out of the camera. Double click on the image to run it, and single click on the image to stop it from looping:
There I was on a lonely craggy peak in New Zealand. Wind whipping all around me as I set up the shot, tested the exposure, examined the histogram and set my Phottix Nikos Intervalometer for 4 seconds per interval. Then I stepped back and let the camera do its thing while I braced myself against the chill. Later in the hotel, after I had loaded the frames into my computer and processed them with QuickTime Pro, I was heard to mimic the Maori Death Cry at top volume. "Aieewaweeeeee!" D'ble ewe ti eph! (Maori for "What the fudge?") No doubt about it. It's a mistake. Completely unusable. And I can't go back and reshoot it. Aw, #∑££. It wasn't until late in the process of writing the D90 eBook that I revisited my broken cloudscape as an example of what not to do when shooting time-lapse, and I asked myself the fundamental question, "Can I fix it?" More than that, can I engineer a repair process in Photoshop that could automate a fix? I love self-challenges. There's no executive committee to fire my derriere if I miss the mark, which has the effect of letting me think outside the frame. After a number of theoretical avenues turned up completely unacceptable results, I broadened my horizon and eventually found a core technology that was never designed to fix movie scenesbut could. Once the Fundamental Method was found, I created a series of Photoshop Extended CS4 iNovaFX Actions so I could repeat my fix on other flickering time-lapse scenes from the past. (If you don't have Photoshop CS4 Extended, you can't use the set of Actions.) Major Point: Only PS CS4 Extended has Photoshop Video modes that are compatible with these new iNovaFX Actions.) And it costs $300US more than regular Big Photoshop CS4 at $1K US. Ouch. Here's what the repaired scene ended up looking like: No doubt about it. Every frame is dead onidentical to its neighbors, and the shot looks as solid as a rock. When you view the big low-compression original, it looks much better than this web-compressed version. If you didn't know the shot's history, you never would have guessed that it had been "repaired" at all. Most of all, when you show it to the boss, it won't get you fired. Or killed in a knife fight in the Bowery. It fixes HDSLR scenes that didn't have the exposure locked, too. And that's a lot of them. Locking exposure takes an extra step with an HDSLR so it often gets overlooked until you:
If your shot has these random exposure jumps, the iNovaFX anti-flicker Actions will even out the exposure quite a bit. Here's a live shot that suffered from massive exposure bounce. Rather a worst-case scenario: And here it is having been processed with the new iNovaFX Photoshop Extended CS4 flicker repair Actions: Okay, it isn't perfect, but it did cover more than a full stop of exposure discrepancy, producing a take that has a chance of looking fine within the context of an edit. You might not get to use the whole 8 seconds, but you certainly could pull a four-second clip from it without shoving a major mistake in your audience's face. But that was an extreeeeeeme example. Most exposure bounces tend to be far less obvious. This shot is more representative of exposure bounces that typically find their way into scenes when exposure wasn't locked. Six exposure pops pollute this take: Aww. Too bad. The shot's unusable, right? Maybe not. Instead of quacking about the unwanted jumps in exposure, here's what you might make of it by processing it in the new iFlickerFix Actions: That's about as close to a perfect fix as you could ever hope for. Now the whole take has been repaired well enough to be useful from any in-point to any out-point. A friend who shoots loads of time-lapse looked at my results and said, "You should sell that." Hence this page. But cool as this kind of repair isand I've never seen anything else like itI have no idea what it should be worth. You can get these Actions as one of the new sets of iNovaFX Photoshop Actions that come with the D90 eBook, but what would it be worth as a stand-alone product for dedicated time-lapse image creators or HDSLR cinematographers? Drop me a line and we will chat.
Get the eBooks. |
||