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Evan Richards

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About Evan Richards

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  1. But if the UHD version has an extra layer of blacks for more contrast, then I guess it wouldn't be as simple as a LUT. You'd have to do some tone mapping I guess (for going from Rec 2020 to Rec 709)?
  2. Thank you, this is very useful as this is exactly what I am trying to do. To my eye though, the color of the "simulated" images seems far enough away from the original Bluray that it make me wonder which image more closely represents the DP's vision. I mean, people have been watching blurays on standard HD TVs for years, but does the fact that the UHD blurays look so different mean that standard blurays never truly represented what the DP wanted you to see?
  3. Yes. I suppose that's true. I had forgotten that as we always have the show LUTs built into Nuke and RV that automatically convert our images to the proper viewing space without us having to do anything.
  4. Hmmm. That's interesting. I haven't found that on the blurays I've examined, but I guess I haven't looked at bery many. The ones I examined were "The Post", "Atomic Blonde", and "Moonlight". If what you say is true, that most are SDR made from 2k sources, it seems like you'd be able to apply a rec 2020 to rec 709 LUT to make the 4k bluray footage match the HD footage? But I haven't found that to be the case. Check out these 4 images from Atomic Blonde (slight nudity warning). https://imgur.com/a/1jZD3jm The First image is taken from the bluray, the second image is taken from the UHD bluray and had the color tweaked as it was being extracted. They don't look too similar. The UHD images look much more colorful, contrasty, and overall brighter. It seems like the way the UHD looks would have the original intention for how it should look, but both of these images are backed down to JPGs which means they COULD have gotten this look in the HD bluray, but chose not to. So...maybe the was the HD bluray looks IS more or less how the film was expected to look?
  5. I'm not sure I understand what's going on with 4k blurays. So, these films are somehow scanned at 4k resolution in High Dynamic Range using Rec 2020 colorspace? How is this accomplished? I've mainly worked in VFX, and I know that the films I've done VFX for did not have effects shots that were high dynamic range. A lot of matte paintings, sky replacements, etc were decidedly low dynamic range. I can understand if all the the negatives were re-scanned then you could capture something that might be higher dynamic range than you had baked into the digital version found on a standard bluray, but how can SDR footage be converted to HDR? I'm asking out of curiosity because I've been trying to get 4k stills out of movies as reference images, but they all end up looking very different from the regular HD/bluray. I don't know much about the conversion process, but it SEEMS like you should be able to take 10bit HDR footage and make it look like the 8bit SDR HD footage. Any thoughts?
  6. I think I've noticed that about Tony Scott's movies. I think Ridley uses long lenses a lot too. I'll have to take a look at "Revenge". Thanks!!
  7. Do you know what the idea is behind this? Was it to increase the background movement in a long-lens camera move? Or was it to say...compress the distance between the buffalo stampeed to make them appear closer to the actor and more dangerous? What effect is he achieving by using this technique?
  8. I'll check these out. Thanks David! Yes! That's the one! Will take a look. Thanks!
  9. I'm looking for some examples of scenes shot on extremely long lenses (200+ mm). I know there was a shot in "Tinker, Tailor..." that was shot on a 2000mm lens, I think "The Alamo" had some 400+ mm shots (I'm trying to find the exact scene). Can anyone recommend any other scenes in a movie that were shot with extremely long lenses? Thanks!!
  10. Sorry this is going to be a little vague, but if I suspect someone on this forum will be able to point me in the right direction. I read an article (or watched a video) where Dean Semler talked about shooting some shots in "The Alamo" with really long lenses. If I recall the lenses were 400+ mm. Maybe even as long as 800mm? Can anyone point me towards a reference that talks about this? And which scene(s) were shot with these lenses? Thanks!!
  11. Yes. I suppose that makes sense. When you put it that way, it seems so logical. But then I think about it more...and it starts to confuse me. Maybe my definition of what a "stop" is is off. I had always thought of it as doubling or halving the light. If you increase your aperture by one stop, you double your light. If you drop in a .3 ND (1 stop) you cut the light in half. So it seems like if you had two cameras with different dynamic range as long as you start with the same exposure on both cameras doubling the light (increasing by one stop) on each camera would be the same increment regardless of sensor. Double is double. Different dynamic ranges allow one camera to shoot MORE stops than another, but the stops themselves would be the same. How am I thinking about this wrong?
  12. In my mind I guess I was thinking exposure would be an objective measurement and and one stop increase would be the same irrespective of which camera is being used. So, it seems like what you're implying is that maybe the best way to measure where the exposure lies would be to shoot a test and view it on a waveform monitor. Expose a gray card to 50% (just for ease of measurement) then expose up one stop at a time until it gets to white and expose down a stop at a time until it gets to black. Thanks David!
  13. There has to be a correlation right? Lets say I shoot a 18% gray card and it is sitting at 50 IRE on a waveform monitor. What would an increase of 1 stop read? A decrease of 1 stop? I'm trying to create some customized false color LUTs just for my own purposes to analyze images in resolve. But I'd like to be able to say ok, gray = middle gray, one stop over that should be yellow, two stops over that should be orange, three stops over that should be red, etc. but I'm struggling with knowing how to measure the exposure gains. Thanks!
  14. I understand. I think. So if you were grading a 10 bit image, anything over 940 or under 64 will be blown out or crushed after it is saved as a rec709 image. Would be nice if they gave you the option to change the scale to IREs. Most other monitors I've seen use that scale. Perhaps it's not useful for grading 10 bit images though. But it does go up to 120 and down to -40. Seems like that would give you some more latitude. Thanks!
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