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Michael Rodin

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Michael Rodin last won the day on July 11 2018

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About Michael Rodin

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  1. Interesting... Because, if I remember correctly, the parallel port at the back of non-R f900 output a 10-bit signal straight from the DSP, just upstream the downsampling/3:1:1 circuitry. I had the service manual vol.2 somewhere though, should look up.
  2. CA has nothing to do with the lens being "HD" (which's a meaningless marketing term since it isn't that only "HD lenses" resolve 110 lp/mm or, say, 40 line pairs at decent contrast) or not. High-end EFP, box lenses and especially D-cinema lenses like Fujinon E series or Canon FJ are better corrected for CA at wide apertures.
  3. Pushing doesn't increase the sensitivity (or granularity, at that) much - the film's sensitivity curve (H&D) is only slightly shifted to the left (towards lower exposure, by 1/3 stop or so) and quite noticeably upwards, which means denser fog and generally denser shadows. So yes, a one stop push pulls out more shadow detail, but it doesn't precisely compensate for 1-stop underexposure. What it does is, first of all, increase midtone contrast and let you see color there, while with normal processing strongly undexposed midtones are murky and desaturated. I would worry less about overprocessing the rest, since it was an overcast day and there were hardly any important details exposed more than 3 stops over key - if you weren't shooting in the shadow and shifting your exposure accordingly. A two stop push might look too contrasty to you on normally exposed shots, but it won't be much grainier than 1.5. Sky will get lighter and lose detail, clouds will stand out less, and it can look almost uniformly white. Highlight detail will be largely still there, just a little too dense for the telecine/scanner.
  4. The way sunlight looks has nothing to do with intensity, what's important is falloff (or rather lack of noticeable falloff) and quality - it's a practically perfect point source when not overcast. You can try to simulate it at any light level. The last thing to do though, is to set a light at half a meter from the face :) The farther away, the more it looks like sun. Mirrors are useful for this.
  5. It won't be a 16-stop sensor then :) Since 4-6 (or up to 11 if there's pre knee) stops of highlights will be all rendered as white (full). The same for shadows. You do need sufficient A/D bit depth to utilize the full range of photosites. Recording bit depth, on the other hand, has little to do with latitude.
  6. You can't get away without any color correction - even with impractically tight control of exposure and color temperature on set you'll see color/contrast variations on uncorrected scans with just a print emulation LUT applied. At least, you need an equivalent of optical printer lights - which are exposure/offsets in DI - to level them out. And you'll need to adjust contrast for your "print stock" - the output medium - at least on per-emulsion basis if you're shooting "for print" like in the optical days. Unless you're shooting expired film, you aren't correcting for inaccuracies of stock's color reproduction (maybe only if you were shooting under weird discharge lamps etc...) - Vision 3 color is neutral, slightly on the warm side, and very subjectively natural under any full-spectrum light. Much more color errors come from the scanner, from how it subtracts the mask in particular.
  7. No, it'd be like this if cameras all recorded in linear without any internal processing and their sensors were completely noiseless. Shortly, DR is mostly a sensor/encoding issue usually not connected with recording bit depth. Less shortly... The analog part's DR is limited not only by full well capacity but by thermal (Ikegami used Peltier elements to cool their CCDs which provided for a lowest-noise camera back in the day) and shot noise (which makes a difference at tiny currents inside there) as well. Then there's a preamp circuit. In CMOS - a huge lot of MOSFET transistors (or even differential amps) which are impossible to get precisely matched and off course add their own noise. I don't know of any CMOS camera that used anything nonlinear in the sensor to compress the range before digitization. Kodak designed a sensor with two amps per pixel with different gain. A technology used in Alexas and Varicams now. CCDs have an advantage (not only) here: they need a single preamp, which can be much more elaborate (we're not trading off real estate on silicon for more amp transistors) and include complicated nonlinear stuff like pre-knee. This means what gets sampled by A/D isn't necessarily a ful-range signal - it can be compressed, it can be two signals, and there's always noise which makes redundant bit depth, well, redundant. Then I guess you mixed up A/D converter bit depth with recording bit depth. I doubt there has ever been a pro camera with 8-bit A/D converters - 25 years ago they were already all 10 bit. Bit depth of A/Ds is generally such that lower bit(s) contain nothing usable. On cameras that output encoded video (either 709 or log) there's gamma correction taking place before bit depth gets lowered for recording. And if we're recording uncompressed raw, we're basically going straight from the A/D.
  8. How could a tungsten fresnel - and 300W at that - be dangerous at 2 meters from behind? It's not an HMI where you can get UV exposure if, say, a back lid is missing on an ancient 70s HMI fresnel. At 300 Watts neither does it heat up a small room too fast, even though something like 270W (compare that to a couple kilowatts that radiators and heat fans consume) goes into emitting infrared (some is focused into the beam, the rest heats the body). It's not that easy to start a fire with a beam of a 10K fresnel, a 300W can hardly melt foam if very close. It's VNSP pars and other pinpoint sources that burn gels and ignite things all the time. Make sure though there's some space and nothing flammable above the fixture. Remember school physics - convection? All the hot air from the fixture goes up.
  9. A Czech lab in Zlin, called Bonton, is reputable and not too far away. The nearest one is in Bucharest.
  10. Ikegami HL59 had a better camera head than 970, with very solid color science, surpassed only by D-Cinema cameras like F35 years later, but no progressive scan, of course.
  11. For adding a slight glow to highlights I like to use thin (1/8-1/4) White Frosts. They seem to be the most "trasparent" (as opposed to a dreamy and milky Double Fog look) kind of white blooming diffusion. The Black version will off course introduce less veiling, but for "black" mist diffusion, good old Tiffen BPM actually seems to be less obvious at the same densities.
  12. 2) ND filters. 3) Nothing to be afraid of. Nothing. Every 0.3 points of optical density equals a stop. Want to go from 22 to 5,6, throw in an 1.2. Or reset your meter from, say, EI 200 to EI 12. 4) No.
  13. These concepts are already simplified as much as possible, actually, oversimplified, as Sunny-16 is - to repeat what's already been said - only a rule of thumb to get a printable B&W negative. As a cinematographer, you need at least some minimal control over tonality and contrast. So you use "selective" metering (incident and spot) and knowledge of your stock reacts to various degrees of over/under exposure. I've written about it many times on the forum, can post a link if needed. Exposure isn't difficult to learn, calculating it from meter readings will get intuitive very soon. The underlying theory, which's sensitometery, isn't rocket surgery either. Always take readings of shadows or generally dark parts of the frame where you need to see texture or show detail. Make sure they read at an exposure which gets you enough density to reveal it. Say, on your batch of 7203 a middle-gray test object prints/scans as dark with little texture when underexposed 3 stops and are pitch black at 3 2/3 stops under. So you conclude, you need shadows read at least 2 2/3 - 3 stops under - or brighter - to have any kind of tonal scale. Actually, there's more to it when it comes to shooting color (saturation issues etc) but I'd rather not get into colorimetery as for now - this is the complicated stuff, not the exposure. On color neg, we're generally exposing much closer to the toe than to the shoulder of the curve, and it's easy to lose important shadow detail.
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