FS7: Adobe CC2015 looking interesting

Great post, James. Let's hope that those who will benefit from it the most it take the time to read it carefully and let it sink in.
 
Viddovation said:
Firstly, know the relationship in terms of the image sensor: the FS7 UHD just crops the left and right edges off, simply not recording them. There's no scaling involved. It's still using the same algorithm to make pixels from the sensor as it does for DCI 4k.

Secondly, UHD (3840x2160) is exactly 4x the pixels as 1080p (1920x1080). Divide 3840/2, and you have 1920. Divide 2160/2, and you have 1080.

Third, the UHD from the FS7 is not the same as upscaled 1080p. Many single chip implementations of 1080p clock in at only a little over 2MP. The Sony PMW-F3 came in on the high side for 1080p, using 3.36MP to resolve 1920x1080. The FS7 uses about 8.3MP for it's UHD (3840x2160) mode.


You have two choices: either scale your 4k content, resulting in letterboxing (black bars, top and bottom), or crop the edges. There's a tendency to think downscaling is good, and that therefore letterboxing is fine, but you're only scaling the 4k to ~93.75% going to 3840x2160. It doesn't divide well - the adjacent pixels have to be averaged and the result is far softer and lower resolution than cropping the edges.

You might respond that you wanted to letterbox. Fine. If the display source is UHD, you'd get a sharper image by cropping to the letterbox (from DCI or UHD) instead of scaling ~93.75%.



Mind you - if your work is actually going to a 4k DCI output and being watched in the manner, than by all means - record 4k DCI. But UHD is being demonized terribly by people who aren't thinking through where their content is actually going to be watched.
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These are the points I was making in the Atomos forum. It was being argued that UHD could be scaled up to 4k and tbat I would not be able to tell the difference.
I countered the point about quantizing error and smoothing.

Your points are clearly articulated and should be communicated to the individuals on the other forum, who do not grasp the quality issues with non integer scaling. They prattle on about how ARRI Alexa is 2.7k, but scales to 4k and is claimed to look like native 4k. Hogwash. Glad someone here has an understanding of the issue. Thanks for posting this.
 
basspig said:
These are the points I was making in the Atomos forum. It was being argued that UHD could be scaled up to 4k and tbat I would not be able to tell the difference.
I countered the point about quantizing error and smoothing.

Your points are clearly articulated and should be communicated to the individuals on the other forum, who do not grasp the quality issues with non integer scaling. They prattle on about how ARRI Alexa is 2.7k, but scales to 4k and is claimed to look like native 4k. Hogwash. Glad someone here has an understanding of the issue. Thanks for posting this.
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Sure, but... again, who are your clients... and where is the content being shown? There are a lot of people out there determined shoot DCI 4k because they're convinced more is better and that DCI is cinematic, but if their going to only have their movie show once at a festival and then be streamed on Netflix or Bluray for the rest of it's life... well, better to project UHD file at the festival, and have a very crisp Netflix and Bluray product without letterboxing or cropping.

Now, let's say, either by design or accident you need to project UHD content on a DCI projector. You could upscale it, but that would cut-off the top and bottom. A smarter solution might be to use the the 1:85 Flat mode, where the DCI frame is reduced to 3996x2160... and re-encode your file to this size, with 156 columns of black pixels on either side of the centered image. If an entire movie were projected this way, most audiences either won't notice. And you're not doing fuzzy resizing math.

But many times you won't even get a 4k DCI projection at a festival. Many still project 2k DCI. And some may not even use DCI at all, either wanting DVD or Bluray sources or digital files, to be projected over 1080p or other non DCI projectors.

If you're not making movies to be seen in theaters, DCI isn't king. Not unless they start replacing UHD televisions in living rooms with DCI televisions.
 
Very interesting info, coming from two F3 cam shoots for 1080p streaming end use I've been considering how best to utilise my new FS7 and I had already pretty much decided on UHD downscaled for the 1080p delivery (still using one F3 as B Cam). If I have understood the math right then my decision is made UHD to 1080p not DCI to 1080p. A better 1080p end result plus still retaining the ability to reframe / push in on odd shots here and there.
 
I always shoot DCI 4K because it gives me the maximum amount of flexibilty for stock footage and for reframing a downscaled HD image in post. Sometimes it is nice to be able to slide the image a little to the left or right. As far as I'm concerned, there is absolutely no reason not to shoot DCI. And if I ever want to turn a DCI clip into UHD, I can just crop off 128 pixels from either side and I will have the exact same framing and quality that I would have had with a clip that was originally shot as UHD. . But you can't go the other way. If you don't record those extra 256 pixels in camera, you can never get them back later. That's .5MB of image size thrown away.
 
If people want 16:9 I shoot UHD. If they want 4k DCI I shoot 4k DCI. If I shoot for myself on something non-commercial I shoot 4k DCI. Not sure why that's even a bone of contention in a world where people are happily using their cameras to shoot for clients in Mpeg 50mbs etc. .
 
Doug Jensen said:
I always shoot DCI 4K because it gives me the maximum amount of flexibilty for stock footage and for reframing a downscaled HD image in post. Sometimes it is nice to be able to slide the image a little to the left or right. As far as I'm concerned, there is absolutely no reason not to shoot DCI. And if I ever want to turn a DCI clip into UHD, I can just crop off 128 pixels from either side and I will have the exact same framing and quality that I would have had with a clip that was originally shot as UHD. . But you can't go the other way. If you don't record those extra 256 pixels in camera, you can never get them back later. That's .5MB of image size thrown away.
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Doug,

I get your philosophy, and if you control all editing for what you shoot, and have the workflow down, then that's great.

But, in my opinion, if you turn over footage for others to edit, shooting UHD is "idiot-proof" if delivery is 16:9. If you shoot DCI for clients who deliver in 16:9 to UHD or 1080p, you leave room for them to make poor decisions.

Also - for what it's worth - some people have fast turn around edits - either that they do - or that the client does - when this is the case, making the footage "idiot-proof" is even more valuable.

And the counterpoint to "throwing the data away" is you're not eating storage space with data you don't plan to use.

And personally, my philosophy is to shoot the exact framing I want, and not encourage post to alter my choices on set. But, to each their own.
 
James, I can see the sense in your philosophy to make it is simple as possible for the client. I was just attempting to point out that, inexperienced clients aside, there is no technical reason not to shoot DCI. Some of the comments on this thread kind of left the impression that perhaps it wouldn't conform as well to HD. Fortunately, most of my work is either for myself or for clients who understand S-LOG, grading, DCI, RAW, etc. and they can handle whatever I throw at them.
 
Doug you are lucky that way, for the most part in broadcast (news, news mags and doc) you deal with people with very limited understanding and there is always at-least one mouth breather with no opposable thumbs in the pipeline who will screw things up and blame you for his ineptitude - the clueless producer will believe him because they know even less. So overall you have to make things idiot proof because in TV idiots are your demo.
 
You're preaching to the choir. Although I have moved away from that sort of work in the past few years, I spent many a year working the grind as a typical 2-person, network level, crew with my wife (audio tech). 60 Minutes at the high end, down to crap like Extra at the bottom and everything in between. Fortunately I have reached a point where I can be more picky about the clients I choose to work for, and it is rarely a day-hire type of deal anymore. But I get what your saying, believe me, you've got to fool proof your work cause there's a lot of fools out there.

All I was saying is that, when people know what they are doing --- there is really no downside to shooting DCI. That's all.
 
Doug Jensen said:
You're preaching to the choir. Although I have moved away from that sort of work in the past few years, I spent many a year working the grind as a typical 2-person, network level, crew with my wife (audio tech). 60 Minutes at the high end, down to crap like Extra at the bottom and everything in between. Fortunately I have reached a point where I can be more picky about the clients I choose to work for, and it is rarely a day-hire type of deal anymore. But I get what your saying, believe me, you've got to fool proof your work cause there's a lot of fools out there.

All I was saying is that, when people know what they are doing --- there is really no downside to shooting DCI. That's all.
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Im right behind you but with one foot still in the grime.
 
I'm in 100% agreement with Doug on this point. However, my beef is with Atomos for calling their product "4K" when it is presently (due to unfinished firmware) recording in UHD only. That said, my wife took me to the movies at our local IMAX AMC Loewes complex to see Jurassic World. I have not been in a theater but once in the past 20 years, and I was struck by the lack of a 2.35 screen. What they had there was close, if not identical to 1.78.

The FS7 has a certain horizontal angle of capture in DCI, which is reduced in UHD. Not sure the exact number, but it appears close to 10° angle of view lost in UHD. At least with DCI, you have the option to crop off the ends to achieve UHD output. If you record UHD, you can never get 4K out of it (in any proper sense--yeah, you can upscale, then you've lost the clarity).

My friend who sells high end projectors is selling commercial grade stuff to millionaire clients. These behemoths weigh 300lbs, use 3 phase power (he had an impressive electrical panels setup in his garage that looks more like the electric service to a manufacturing plant than a theater enthusiast) and use a pair of 5kW Xenon lamps. Most are DCI compliant. He had one for sale, used demo that needs new lamps, for $10K and I was seriously tempted, but when I saw how large it was in person, (size of a washing machine) I gave up that plan and opted to get the FS7 instead. I'm still looking to go 4K projection in my screening room eventually, but waiting for the tech to become more mainstream, thus lower in cost.

Personally, I like the DCI aspect ratio. Where 1.78 requires a taller ceiling to get a decent screen size, 1.9 gives you more width, but not quite as vertically skimpy as 2.35. I think it may be the perfect aspect ratio.

WRT customers, it's better to have things baked in if others will do the edit. For that, I simply shoot MPEG and hand it over. Recently, I did an investor relations shoot for Burger King and chose to shoot it on Atomos Samurai Blade from my EX3 as I had confirmed with the client that Prores422 was an acceptable format. The video looked a lot better than would have been the case with MPEG, plus another 1/2 stop of dynamic range than gets recording to SxS internally. In such cases, a lot of other issues come under consideration, such as color rendering and whether to go pure REC709 look with no stylistic color rendering.
 
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