cpc

6 minutes ago, Phil A said:

The A7s is just up there with the worst offenders regarding rolling shutter. Which is somewhat surprising.

A7s is actually really nice RS-wise in APS-C mode (similar to 5dm3, which does binning). And it is still full readout of the 1.5x crop area, so it's also pretty good in terms of aliasing.

FF puts a lot of stress on the system cause there are infrastructure problems to resolve which depend on sensor area. FF will always have more RS than APS-C which will have more RS than smaller sizes (like 1") for the same number of pixels.

1 minute ago, Andrew Reid said:

Well EOSHD has always been about both photo and video in one camera body, so I think it helps. The vast majority here will use a mirrorless camera instead of an expensive dedicated video camera like the FS5 or C300.

And since the two are converging - stills and video - you're in the right place to talk about the future.

It is frustrating that the FS5 doesn't have the latest AF innovations, since it costs 5x what one A6300 does and was released just a few months earlier.

Yeah, but this is us and our wishful thinking. Sony people probably still see this as a photo camera with video added in. If they were positioning it as a hybrid (like A7s/A7s2) it would be a 12-16mp camera and wouldn't have these RS issues which the excessive pixel counts bring (and would likely cost a bit more). But it is still possible that they release such a hybrid.

Not sure how Sony operates but my understanding is that photo and video divisions are separate. Hopefully they aren't THAT separate though so that features move in both directions. I'd certainly love an FS5 II with great AF and IBIS. Or an A7s III with electronic ND and great AF.

30 minutes ago, JurijTurnsek said:

I believe you guys are dissecting this consumer camera way harder than an average user will. Once the price falls down to a more reasonable level (like A6000), these cams will be picked up by thousands of causal users like me - shooting photos and videos of your family and pets, usually clips shorter than 10 mins, documenting your travels, using high FPS sparingly etc. They (us) won't care about RS and overheating - IQ out of the box is key here.

Sony already caters to professionals with many models, so having this cheap option is just a bonus.

One of the problems is that this consumer camera has features that not some but all more expensive large sensor Sony cameras are lacking. Like decent AF. It will likely propagate up eventually, but it certainly can be a cause of frustration: putting it in a camera that fails spectacularly in other areas. And this does reinforce the image of Sony never being able to do everything right, there is always user frustration coupled with their technical inovations.

The fact that this is a photo camera in the first place doesn't really help much on video related forums.

11 minutes ago, Andy Welch said:

I'm a bit suspicious of those results. I have the feeling that either the tester, the FS7 or the Odyssey is doing something weird. Download and do a test grade on these FS700 RAW files and see if you think they are noisy or unusable. http://blog.domisljije.si/2013/07/18/raw-fs700/

Both FS7 and FS700 output processed raw, but the FS700 raw image is denser ( = more color info in there). Also, FS7 bakes WB in the raw image, FS700 doesn't.

My dream camera has the electronic ND of the FS5 and the AF of the C300 mark II. Now only if Sony would catch up with Canon on the AF front.

The (relative) tint you see comes from the difference of native white color temperature between the displays. This can usually be matched fairly well to the 6500K standard even with cheap displays, although you will limit the brightness if the native white is way off (low brightness is rarely an issue anyway). The more challenging problem is getting the various colors in the ballpark. First, the display needs to be able to cover (almost) all of the color space you target, otherwise doing calibration is pointless. It is best to have a display with hardware calibration LUTs, this limits banding. The cheapest displays don't have any hardware LUT support. Moving up, you get 1D LUTs (I think some Dells are the cheapest you can get with 1D LUT support). Better displays will have hardware 3D LUTs. 

It should be noted that calibration doesn't guarantee correct colors, especially with 1D LUTs. In my experience with various low-mid range LCD displays, blues are usually the biggest problem even after calibration. Some calibrated displays oversaturate low saturation blues and push them to cyan, some undersaturate high saturation blues and push them to magenta. It seems that there is an inherent issue with blues and LCDs; I recall reading an explanation about this issue somewhere by an HP guy talking about the Dreamcolor (but it is related to all LCDs).

Dunno about Premiere but 2GB video RAM is not enough for 4K in Resolve. It should be fine for 1080p though.

Hey Andrew, when you say that film simulation doesn't work in video mode do you mean the film grain simulation only or also the film color modes?

BM Pocket with an optical AA filter?

Looking forward to seeing this in IMAX2D this week.Curious if the "approximately 13% Alexa 65" is actually distinguishable from all the other 87% Alexa footage.

It should be noted that the Alexa would probably be the easiest to match with Kodak since it takes a lot of cues from it. Also, most of the film look colorimetry related properties come from printing the negative on release stock, not from the negative itself. The reasons for this are quite deep, but essentially they boil down to negative film being technically more feasible to design without excessive color shifts because the orange mask allows for some clever tricks. Positive/projection films on the other hand don't have this luxury.

Since the two sources in the video are not printed, it is much easier to achieve a decent match by feeding them both into a P3/rec709 output space. Still a great video though, and I do agree with the sentiment behind it.

Photoshop (which uses Adobe Camera Raw) will only have the Embedded profile available since it doesn't recognize Blackmagic cameras. ACR debayers in ProPhotoRGB, and then does another transform (to sRGB) on display and export. This is approximately equivalent to rec709 in Resolve.

Resolve will not debayer in BMDFilm unless you set it to do so. Photoshop will not debayer in BMDFilm, because it doesn't know what BMDFilm is.

If you debayer in BMDFilm color space using BMDFilm gamma you should be able to match ProRes/Film colors. These settings are in the Camera Raw tab on the Color page.

Resolve's manual is actually pretty good and informative. It is a good idea to have a look at the relevant sections.

SGamut isn't friendly to manual adjustments because of the heavily offset green primary. This is the reason Sony introduced SGamut.Cine which aligns much better with P3 and sRGB/Rec709.

Cinema, Pro and Movie (same as Stills or at least very similar, I think) gamuts have primaries aligned with Rec709/sRGB and are for this reason easily moldable with simple luma curve adjustments without introducing hue disbalance. Skin hues are subtly rotated between these (Cinema is a bit towards yellow, Movie - towards magenta, Pro in the middle; but these are subtle), and there is a small difference in hue compression (Cinema > Pro > Movie; Movie is the most compressed) but all three are fine. I've been shooting s-log2/Cinema, but wouldn't hesitate to use any of these.

It is really a question of how you interpret the color values. Since SGamut is the largest it may appear less saturated (= more subtle) even after treating it. But it certainly does have the problem (without proper remapping) of pulling skin towards yellow.

Film/Video setting doesn't affect raw. It is always flat (film) internally, but what you actually see depends on the raw processing settings in your software. What app do you use for processing raw?

I really like what 5d3 raw does with faces. I find it has just about the perfect amount of sharpness. And I've yet to see a better HD/2k camera for narrative in terms of image quality. Interesting that the 5d2 can be made to match this. Is 5d2 raw usable at iso 1600 with proper exposure?

That's a strange thing to say. I think Canon color science takes a lot of cues from film. Now of course these promotional videos are all graded so they are more representative of the colorist's inclination than anything.

The autofocus features are beautiful. Dual pixel AF was great on the prev gen C cameras, and this is another step in the right direction. I like how they are pushing this with face tracking, manual focus guides and the movable AF area. A dream for documentaries.

I think this is the most interesting camera of the recently announced/released bunch. Curious which features will propagate down to the next c100.

Hello!

I haven't slept much last night but here it is, the α7R II low light test! (i also posted my initial thoughts at the beginning but feel free to skip to the test if you get bored!) 

The results are very surprising, whereas during the day i couldn't really spot a difference in quality between the FF and S35 modes things are completely different when the lights go down: the S35 mode is vastly superior to the Full Frame, they are not even in the same league! I don't know if that is only the result of the better readout from the sensor in S35 or there is some noise reduction wizardry happening in real time but the output from the S35 mode is way cleaner.

It is not surprising and the reason is exactly the same as the reason FF mode has less rolling shutter than s35: the camera simply uses more photosites in s35 mode, hence less noise. 

This only applies to humans. We simply don't see color well at low light levels because of the way human vision works.

Cameras don't have this problem. What you perceive as lack of color in low light captured images is for a couple of reasons:

1) In naturally occuring low light situations the spectrum of the light is often overly monochromatic. For example, dusk light has lots of blue and tungsten has a strong red component. This offsets the image toward monochromatic.

2) Overly noisy image.

Anyhow, the A7s s-log2 lacks tonal precision even when shot at its minimal ISO (which is 3200) and overexposed for healthier signal.

Not enough of a difference for you to care then, I presume?

That's what I've observed in this synthetic case but I'm not gonna claim that it is universal law.  

Thanks.

Actually, my whole point with this paragraph was that even uncompressed 8-bit 4:4:4 log has its limits and they aren't particularly high.  : )

re: Cineon

I don't know what do you mean by R', G,' B' (gamma corrected values?), but Cineon encodes film densities which do represent scene light intensities logarithmically, the same way digital log curves do. It is indeed meant to be printed on print film. But the comparison is fair I think. If anything, one actually needs more precision for digital because print film grain, as fine as it is, still acts as dither.

Incidentally, a few months ago I was involved with tone mapping and grading this real-time rendered short:

It uses high resolution 8-bit textures, so the source image is effectively 8-bit RGB (4:4:4) and the engine works in high bitdepth precision and/or floating point (so negligible quality loss with lighting and processing). There is a (perfectly flat) log conversion operation from the engine linear space at the end of the pipeline for film out simulation purposes (simulated Kodak print). It is parameterized for around 12 stops. The grade is done over this perfectly flat curve. I found that somewhere around 12 stops is where you start to see issues if you are picky (and I am), even considering the pulled down whites in this grade and the overlayed grain.

As an a7s owner, with all due respect, I can say that you are wrong. There is huge difference between s-log2 and raw. Both color and image density are significantly worse with s-log2 compared to the raw stills. Also, a7s externally recorded 4k downscaled to 1080p is easily more gradable than the in-camera 1080p.

good examples here: http://blog.inventome.com/Blog/2015/2/a7s4Ktests/Sony-a7s-Exposure-and-Noise-Workflow-with-UHD-and-Odyssey-7Q-Plus

Sensor, noise, processing, etc surely matter a lot but downplaying the importance of the available tonal precision is pointless. Yes, you can have badly quantized and processed data encoded in 10 bits, and it will still be crap. And you can have well sampled, quantized and processed data encoded in 8 bits. And it will STILL be bad if the curve is too flat for the available space. Ideally, one needs well processed data in at least 9-10 bits for log encodings with extensive DR.

It is no coincidence that the father of all log curves Cineon log is 10-bit. Back then nothing was taken for granted, nor there was any prejudice about 8 bits, so this was extensively researched by Kodak. They concluded that 9 bits are likely enough but went for 10, since 10 fits better with computers; plus, a little bit of redundancy doesn't hurt.

And lets not forget chroma subsampling. After all 4:2:2 is twice the chroma info contained in 4:2:0, and 4:4:4 is four times the chroma info contained in 4:2:0. So not all 8-bit is created equal.

In general, wider color gamuts do help grading by having better color separation, but there is no point having a wide camera gamut if there isn't the color precision to encode it properly as is the case with S-Gamut and s-log2 in the a7s. Note that many digital cameras have native color gamuts wider than film leading to color precision smaller than scanned film when encoded with the same bitdepth.