The Sony F3 Put to the Test: 12+ Stops of Dynamic Range and a Bit of Aliasing
Video gurus Art Adams and Adam Wilt have put the Sony F3 through a suite of proper resolution, aliasing, IR sensitivity, and tonal-scale tests, and compared it with the Panasonic AF100 (now in stock at B&H), RED, and ARRI ALEXA cameras. We'll have to wait for Zacuto to publish their forthcoming single-chip shootout to get a look at proper real-world comparisons (their DSLR vs film shootout was nominated for an Emmy), but here are the result for the time being. The F3 gets 12 + stops of dynamic range -- before upgrading to S-Log, which Sony is claiming offers significantly more dynamic range -- which, in this price range, is unprecedented. More from their results:
Both cameras maintain fairly constant dynamic ranges through all their gamma curves; the different gammas do good jobs of affecting the overall “look” of the images while grabbing as broad a range of brightness as possible. The AF100 captured 10+ stops as far as I could tell; the F3 managed 12+ stops (the combi chart steps in 1-stop increments, so it’s hard to get a much more precise reading. In some gammas there was a hint of another stop just creeping up out of the black, but it’s hard to quantify).
However, I'm not tremendously excited about the AF100, and here's one reason: in reaction to the resolution test, where they note the AF100 resolves 680 lines, Adam states, "it’s got 12 megapixels—that’s about the same as a RED ONE—and this is the best it can do?" Ouch. To be fair, the AF100 is roughly a third the price of the F3, but at the same time, it's three to five times the price of a good HDSLR (and Panasonic's own EVIL cam, the hard-to-find GH2, offers a pretty similar image at one fifth the price). The AF100 is a good camera and it's certainly adequate to most tasks, but to me it's not a game-changer. So let's move onto the F3, which I think along with the RED EPIC-S is going to be the camera of choice for indie features for the next few years.
Definitely click through to read the full article, wherein they get extremely technical, but not all is roses in F3 land: the camera exhibits moire and aliasing, not nearly on the level of a Canon DSLR, but it's there. Which is disappointing for a $13,000 camera, but not a deal-breaker given it's not going to rear its head in many real-world shots -- but in some situations, it could. Apparently the F3 uses a 3.36 megapixel sensor, which gives it enough resolution to survive the roughly 25% resolution loss involved in demosaicing to yield a true 1080p signal, but there is some funky chroma aliasing going on -- not something I'd worry too much about in the real world, but it is something to be aware of. They also publish charts from the ALEXA and RED, and neither of those cameras have any aliasing problems whatsoever.
Back to the bright side: Adam pinpoints an issue I've already complained about -- the F3's lack of a smooth roll-off in saturated highlights (the video I linked to is a perfect example of this, as it's a blown-out skintone). He says the F3 behaves the same way as the EX1 and EX3, which he previously explained:
The standard-gamma knees work properly for uncolored highlights, but when a highlight has a strong chroma component, the knee shuts off prematurely, allowing colored highlights to suddenly blow out. The degree of this blowout depends on the saturation of the highlight, and it only happens in standard gammas... Cine gammas are not affected by the problem.
So not only does the F3 offer 12+ stops of dynamic range -- before any upgrade to S-Log -- but the highlight problem I was worried about apparently only affects non-Cine gammas (which I never touch anyway). Unless your feature film is about the life and times of a resolution chart, the F3 is a proper competitor to RED, as I've said all along. You can talk all you want about 4K, but look at it another way: the small form factor of both cameras will be as big a deal for filmmaking as any specification. Check out this guerilla short shot on the F3 by The Big Mamoo, with no permits, at LAX airport of all places:
Sony F3? Possible. RED EPIC? Possible. ARRI ALEXA? No way. A full-size camera would attract too much attention. There's more to choosing the best camera for the job than the decision to shoot in 2K, 4K, 5K, or 23098402394K.