jcs

Thanks Johnny!

We're very happy with the skin tones and 4K footage we get with the GH4 in studio lighting on a green screen:

I revealed the answer to which camera was used for this shoot (originally planned for the A7S): '?do=embed' frameborder='0' data-embedContent>> When I received the A7S shipping notice last week, we planned a shoot for Saturday. The camera was due Friday however apparently Sony(?) stopped B&H from shipping the cameras early; ours never made it out of the warehouse. B&H was kind enough to ship it out overnight at no charge on Monday. This review was from a few hours working with the camera. My co-director-producer Elena loves the GH4 skin tones, as did our model. Elena never liked the FS700 (Sony) skin tones (and loves the 5D3 skin tones the best). I agree with them and feel that the A7S, once the proper settings are found (not using Slog2!) and likely one of the cine settings with natural color in-camera, will be a useful tool in the toolbox, especially for low light and/or more shallow DOF shots (I'm still waiting for the EF to m43 active SpeedBooster to come out). It's really important to shoot people and skin tones to see how accurate a camera's color science is. Human beings are very well evolved to detect when skin tones are wrong or 'off', probably related to evaluating health (related to survival and reproduction).

This was shot on the GH4 at 60p (VFR mode), Natural profile, 12mm (Panasonic 12-35 F2.8, IIRC stopped down a bit to try to make sure model was in focus as we moved), a gen 1 77mm Fader ND with step down ring, and a Flycam Nano DSLR steadicam. This shoot was planned for the A7S after the shipping notice last Tuesday, however the shipment never made it out of the B&H warehouse (some folks got theirs early). I used the new masking features of Premiere Pro CC to bring the sky down to blue and to apply creative lighting and blur to the shot. As some pointed out, I'd need to do more time-consuming variable blur to better simulate camera blur (including roto-like masking of the model and the background). I also applied Neat Video, then added uniform noise everywhere but the actress: after uploading to youtube there was banding in the shadows (the added noise helped reduce it). Thanks for the compliments and feedback!

DXOMark reports GH4 at 12.8 and the A7S at 13.2, so a .4 stop advantage to the A7S. The flower video above could be real- the DR is very close between the cameras.

The GH4 does have more noise, and I don't use it above ISO 1600. Noise isn't always a bad thing, especially for 8-bit material. It helps reduce banding, acting like dither. The GH4's noise looks tuned to behave like dither: mostly fine and monochromatic. The A7S noise is typical colored noise, and IMO doesn't look very good. In studio shoots, we have control of lighting, so the GH4 does very well. We purchased the A7S for situations where we can't control the lighting. We're still testing the A7S, however so far I haven't seen any low-light A7S material that wouldn't be helped with Neat Video. YouTube/Vimeo tests folks are seeing online are effectively noise-reduced by low bitrate H.264 compression. Regarding XAVC-S and IPB: XAVC-S is an IPB codec on the A7S, the same as the GH4's H.264 variant (which also offers ALL-I for 1080p). XAVC-S is another flavor of H.264 (mostly a bitrate bump and spec support for 4K, 422, 444, and 10+ bits per pixel (not used by the A7S)).

We're shooting with the 5D3, FS700, GH4, and now A7S. My review is based on actual camera usage, not other's reviews. One of those cameras (not the 5D3) shot this: '?do=embed' frameborder='0' data-embedContent>> I'm sure 50Mbit/s XAVC on the A7S is better to grade than 24Mbit/s AVCHD on the FS700 (both are H.264- the primary difference is bit rate in this case (both 8-bit 420). The FS700 has much better slomo. Regarding Slog2 and DR- no gamma curve can help DR. All they can do is redistribute stops, so that in some cases we can count more visible stops. Actual DR won't change (noise floor to sensor clip). I'm looking for accurate color representation and I've already seen strange green/yellow in mid-tones with Slog2 on skin. To be fair, I don't use Cinelike-D on the GH4 due to the strange color handling (Natural is looking very good).

Quick Review A7S vs GH4 Where the GH4 is better: Build quality Viewfinder Flip out screen User interface (by a mile) Battery life (by a mile) Color science Skin tones Rolling shutter (by quite a bit) Detail (internal 4K and 4K to HD) Noise grain (mostly pleasing monochromatic) Built-in flash for stills When lens size is included, a much smaller package Can shoot best quality on < 64GB Class 10 UHS-1 cards (A7S requires >=64GB cards for XAVC-S) Price Where the A7S is better: Low light (it's very good however the noise grain is colored and multi-spectral; not as pleasing as GH4's mostly monochromatic fine-grain noise) Shallow DOF (add a SpeedBooster/focal-reducer to the GH4 and this isn't much of an advantage) Audio (no buzz; not tested thoroughly yet though) If a 5D3/full-frame owner: can use existing lenses with a non-focal-reducer adapter (with similar DOF) Super 35 mode allows use of many NEX lenses (some aliasing) Auto ISO After having worked with 5D3 14-bit RAW and RED RAW, where the unmodified RAW looks pretty good straight from the camera, Slog2, Cinegammas, Cine-D/V, etc., start looking like gimmicks. None of those gamma curves are providing a real increase in dynamic range. In certain cases they may provide more information for 8-bit compression, however they can be tricky to use and must be exposed carefully. I've had the best luck shooting Natural with the GH4 (and no crazy curves), though iDynamic is helpful sometimes (appears to be local pixel group based processing vs. a simple curve. The A7S has a similar feature (disabled if any picture profile or effect is active, though)). Rolling shutter is very challenging on the A7S in full frame mode (worse than the 5D3): not very usable for handheld without a lens with IS and/or a solid rig. The A7S menu and button system is a mess. The FS700 has a better design! (many folks find the FS700 non-intuitive to use). Both cameras have aliasing and moire in slow motion. Perhaps similar to the FS700 in 240fps mode (not as bad as FS700 480+fps modes). I haven't done a direct comparison, however the FS700 120fps and less slow motion is better than the GH4 and A7S (all slow motion modes). While the A7S isn't quite a one-trick-pony (low light), the GH4 is a much better all around camera. I haven't had the A7S as long as the GH4, so there may be other elements that make the A7S more compelling, yet to be discovered.

FS700, GH4, or A7S?

In simple terms, it's possible to get decent reconstruction using statistical analysis (vs. simpler methods such as bilinear interpolation (which is easy to code and is very fast)). If one starts with super high resolution, such as with RED (say 5K) and are targeting 2K, the quality of the debayer step is less important than say 5D3 RAW 2K debayered to 2K (ACR and Resolve do a much better job than the on-camera hardware+firmware: much sharper and more detailed images when debayered in post). Interestingly , RED Epic at 5K debayered (and without any sharpening) looks softer and less detailed than GH4 4K H.264 compressed (100Mbps):

Per Nyquist sampling theory, we need to sample at 2x the frequency (or resolution for images) to get alias-free results. A 4K Bayer sensor can't actually capture 4K- it's some percentage less, perhaps 3.2K-3.8K. Adobe Camera Raw does an excellent job with Canon 5D3 1920x1080 debayered to 1920x1080. The price for this super-reconstruction algorithm is it's very slow. 4K from the GH4 is greater than 1080p- perhaps see test charts shot for the GH4 to see how much resolution it can resolve before aliasing and extinction of details. Watching GH4 4K material on my 2560x1600 monitor is clearly more resolution than downscaled 4K to 1080p. The only mathematically true (almost!) 4K video camera is the Sony F65 with an 8K sensor. The RED Dragon at 6K can produce very good 4K, especially with high-quality post-debayering. The GH4's internal debayer is pretty good- looks great compared to post-debayered RED Epic.

Lol- there won't be any cats, ducks, buildings, matches, cigars, cigarettes, fireflies, smoked fish, day-for-night, skewed trains or test charts.

A lot of folks are still on the fence. After more real-world reviews, making the decision will be easier. For our testing, if the A7S can replace 5D3 RAW for most video uses, it'll be a keeper. The 5D3 will be way better for stills unless we invest in some native lenses. We will compare it to the 5D3 (RAW), GH4, FS700, and even the iPhone 5S (has really good color science and looks great in bright light). Not sure if we'll have time for a video review, but will report what we find.

The FS700 comes with an AC adapter. Class10 works fine: slomo is written out from the memory buffer to SDHC at 24fps (24Mbps).

Got a notice from B&H that the A7S we ordered has shipped.

Last night I was shooting RED with Zeiss Super Speeds (@T1.3) in a very dark environment which we could not light (and had to wrap when it got too dark): the A7S would have been very helpful. The GH4 works great in good light and for low light Neat Video cleans it up very well. The GH4 noise is mostly fine monochromatic and effectively works like dither to reduce banding. 5D3 14-bit RAW looks great and can cut between Alexa/Amira and RED Dragon (some of the most popular higher end cameras). A popular cellphone camera shot this Bentley commercial:

The GH4 appears to have an AGC, even with the Limiter set to off. This example show's what the buzz sounds like with a very quiet input (I found the same results + analyzed in Audition. The buzz is over 2x the amplitude of the noise floor and is a triangle wave):

If you have no budget for lighting and only need basic slomo, consider the Sony A7S. Fullframe and the top low-light camera available. Even the GH4 with an iPhone LED and a little Neat Video works well in low-light. A sub-$100 LED panel would provide plenty of light at close range. For $68 (you'll need Sony NP format batteries- very affordable) this is a great deal and has many uses: http://www.amazon.com/Yongnuo-Professional-300pcs-sheets-Camera/dp/B00AZFE5DS/

Here's a Sound Devices preamp using MIC level output into the GH4 with mic level -12dB. An expander ("Dynamics") filter was used in PPro CC to clean up the audio (including room tone):

np. Looks pretty solid if using manual lenses.

http://www.amazon.com/Signstek-Version-Electronic-EF-EMOUNT-Adapter/dp/B00F3ZFQK6/ (same Commlite adapter)

Looks pretty nice: http://cheesycam.com/fotodiox-vizelex-nd-throttle-variable-nd-lens-mount-adapter/ A smart version with aperture, IS, and AF would be a very trick piece of gear. For the GH4, a version with a focal reducer (if physically possible) would be stellar.

Yeah, just ordered V4 from B&H.

Andrew- why not the Metabones Smart EF Adapter version 4?

If you need slomo (up to 240fps), the FS700 is good for what it costs. You might look into renting an Odyssey 7Q to get you ProRes or RAW with the FS700 (the 7Q will also help with critical focus). Also consider a RED Scarlet. Many rental houses are upgrading to the Dragon sensor and non-upgraded Scarlet's might be a lot cheaper now (up to 120fps slomo). I have found it's best to set up the FS700's color profile(s) to do close to what you want for the final output. It's reasonably gradable, however when shooting people/skintones, it's best to get the color profiles as accurate as possible and to expose and set WB precisely so that skintones look their best.