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Guillaume Cottin

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Guillaume Cottin last won the day on July 22 2013

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About Guillaume Cottin

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  1. Hi all, I was wondering if other companies offered products similar or competing with the Light Ranger 2. I can't find any online. Thanks
  2. Since I do not know what the film or the scene is about, my advice can only be a bit generic. I think your approach of having a low base exposure + highlights and modelling works. A super soft top light can read as ambient darkness. It is a pretty standard approach. Let me bounce some ideas at you. Maybe the characters have flashlights, cell phones or other sources of light? Then maybe you don't need a base exposure at all. Are there any luminescent algae or mushrooms on the walls of the cave? Maybe you can simply bounce your own lights onto the cave's surfaces so that your light takes some of the rock color? Maybe you actually can let things fall into complete blackness for extreme claustrophobia?
  3. CRI uses a limited number of color patches to give a rating. The newer TLCI measurement is more precise. Take a look at this article. In general, good LED lights are now "good enough" and the usability, features, efficiency more than make up for the few imperfections in color rendition. If a light has a CRI above, say, 95, that's fine by me unless it is some kind of critical application. However, anything under that and I would not use it as a key light but only as an accent or background light. Yes, absolutely! There will always be a need for big, powerful lights... regardless of the technology! One reason is lighting large areas, at night for example. Other times you need a high T-stop for depth, or high frame rates, or you need to compete against the sun. Another reason is that you need to work at a certain light level. Imagine that you are lighting a sound stage, so there is no light, and your brightest light is a 50w LED. You then use it to simulate sunlight... but now this 50w light has got to be the absolute brightest light in the scene. This means that everything else has to be much darker, because you need the contrast? In this theoretical scenario, can you imagine how dark the studio will be? A computer screen at normal brightness would light up the room! That is why you always need big powerful lights. LED does not alleviate that need, it just makes it more power-efficient to get a lot of firepower. All of them... Lower heat, higher efficiency... And with the fixtures that have the ability to dim down without color shift, you can dial any color temperature or white balance by the press of a button. It is just the beginning, as I think we will see some wild features in the coming years! Portable video walls? Moving lights? The cinema industry can take a lot of inspiration from stage lighting technology. As long as the CRI (or TLCI...) is good. Tungsten tech now has less uses and is becoming a low-budget short or specialty item even though some DPs still like to use Maxi Brutes or light arrays of tungsten lights. Personally I have rarely used tungsten lights over the past few years, except on sound stage where you need many units and it is still more cost-effective. On all other shoots, in my experience, tungsten lights have been almost completely phased out. They totally remain (and should remain forever) an available option. The one advantage of tungsten is that the color spectrum is excellent, and the same regardless what is the brand of the bulb or if it's a cheap bulb. The fixtures are much cheaper, too, and they do not become obsolete. I have heard of a new tungsten technology by the MIT that would be more power-efficient than LED, but that was a while ago.
  4. ⬆️ this And a bit of haze. The location makes the shot. If you look closely at the reflection on the floor, there is a reflection spot that is brighter than the sky. An 18K straight through the windows aimed slightly frame left would be the usual suspect.
  5. OK, I was really expecting someone to bring up that sort of thing when I added the Alexa chart. I was tempted to write " I am not trying to compare Alexa vs Blackmagic blablabla", but I thought it was so obvious that it would be an insult to the reader's intelligence, so I wrote instead " Adding some info" and "to have a reference point…" which, I thought, already conveyed the idea that I am not directly comparing the two. But it wasn't obvious enough so let me make it very clear. The subject is how to manage the limited highlight latitude of the BMPCC. The Alexa is the gold standard in highlight latitude. That's why taking that camera as a reference makes sense, but of course whatever tweaking or workflow we are able to invent with the Blackmagic won't match it anyway. Also, the Alexa handles the ISO changes quite similarly to the BMPCC yet with better allocation yet only 5 or 6 stops of overexposure latitude at some settings. That is why it is interesting to see both charts. As for iPhones: isn't there a Godwin law for cinematography that says "As an online discussion on cameras grows longer, the probability of a comparison involving iPhones approaches 1"?
  6. Adding some info. To have a reference, here is the same diagram for an Alexa. (source: Arri). The Alexa has 1.5 stops more DR than the BMPCC4K and its range is better balanced. I would be interested in seeing an over/under key light test at 1000 ISO and exposed for 2000 EI (either with a light meter or by using a custom viewing LUT). If the noise is OK and the image doesn't fall apart, then on paper it should give a nice balance to the BMPCC4K, at +6.3 stops over and -6.8 under.
  7. Hello everyone. Reading the manual of the Blackmagic Pocket Cinema Camera 4K (what a long name…) I stumbled upon this very interesting graphic: As we can see, the curve resets at 1250 ISO to adapt to the new sensor amplification. We can also see that the dynamic range is inferior at the 3200 ISO setting and beyond which is not surprising. What I want to talk about here is the significant unbalance between highlight and shadow latitude especially at lower sensitivities. Shooting at 100 ISO for example, feels like a terrible idea with only 2 stops of DR in the highlights, and a ridiculous 11.1 stops under middle grey. I haven't seen or read anyone talk about it online yet. Maybe people just always ETTR and may therefore never notice this as they never refer use middle grey as a reference. Rating the camera at 1000+ ISO (400 ISO native), gives the more balanced DR at the expense of noise. I have noticed some harsh video-like looking clipping in the otherwise great looking demo footage of the camera. Rebalancing the dynamic range by rating it at a higher ISO might help with those highlights. But then Blackmagic specifically advises not to shoot at 1000 ISO and instead switch to 1250 ISO "for cleaner results". So far this is all on paper because I don't have the camera and the footage Blackmagic provides is not sufficient to completely evaluate this topic. So I am wondering if any of the early birds and owners out there already tried "pushing" the sensor, and if the tradeoff of noise vs highlight DR is acceptable when doing so.
  8. I am surprised that no one mentioned yet the quite popular Astera AX-1 pixel tubes. They're essentially RGB LED tubes. They are rentable and it seems like they can be a great tool for this job.
  9. That's probably because many people, including me, will use the word "translite" as a generic term to describe a backdrop. I've never heard "digital vinyl", I'd call the type I was describing a "day to night translite".
  10. Hi Translite backdrops can be lit from both the front and the back. Light it from the front and you get your daylight scene. Light it from the back and the light passes through all the little windows in the buildings, which are actually semi-transparent, and so this reads as if the windows were lit in the night. Combine both for dusk/morning/etc... As for the choice of sources, it can be anything. Traditionally open face fixtures and molebeams. Kinoflos or space lights.
  11. Skypanel or good olde Kinoflos since you say you are on a budget. Also they are lighter than a Skypanel.
  12. Thanks Chris. Same for the XT Plus or just the SXT Plus? I am wondering in what cases you'd want to use the UMC-4.
  13. A little treat for the francophones in this forum ;-) http://www.youtube.com/watch?v=rrbXkUvOTVg
  14. Hi Connor, check out Secced as well
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