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Jaron Berman

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Everything posted by Jaron Berman

  1. Well, thus far one of the major user complaints has been about the monitoring output. As it stands, the output does not accurately reflect whats being recorded in terms of exposure or color. I would imagine that fixes are on the way, but I too was horrified by some of what I saw on the SDI output, only to find that the files themselves turned out nicely. Back to the subject at hand, physically there are some obstacles to be overcome, and after a visit to Element Technica today, I'm confident that very smart people are working on clever solutions. Currently, RED's accessories are pretty quirky,,, the equivalent of "outsider art." Interesting ideas on how to shake things up, but they require a leap of faith from established methods of camera rigging and building...i.e. some reinvent the wheels that work. Element Technica comes from a film background, and they seem to understand that the best and quickest way for RED to become established in the industry is to offer methods to integrate it into what we find comfortable and efficient. Right now there are a few nits to pick usability-wise, but having now seen many of the immediately upcoming 3rd party accessories, I can say honestly that I'm finally relieved and looking forward to shooting a project with the RED. Obviously "help is on the way" is not terribly comforting to those who need these items yesterday, but in the bigger picture companies like Element are helping all of us so that when we show up on set and find RED instead of whatever camera we expected, there won't be any panic, it'll handle just like it should.
  2. Absolutely. Good grips are worth their weight in gold. For some, that's a lotta gold! Seriously, though, I've seen grips work like magicians and save my (and production's) arse. Not every production has the luxury of skilled producers, and the extravagance at the beginning can end up as shoestrings in the end. When it comes down to getting the shot or not, having the experience of improvising can really be helpful. Knowing how much you can get away with is certainly as important as knowing how the cadillac equipment functions.
  3. Ballasts make a huge difference in terms of output. however, different tubes use different phosphors, and thus have differing output. Kino tubes tend to be dimmer than off-brand tubes, due to their particular phosphors. BUT, note that most lower CRI tubes use a huge spike in green output (an easy color to make using this technology) to pump their output. Your eyes "white balance" it out, so it looks white, but that's why you see a green tint on film. Video can generally do a good job of balancing this out, or you could gel it out or on-camera filter it out depending on how much light you can lose and time you can take to do the corrections. The advantage to the gel/filter/white-balance method is that you could buy $1 tubes instead of $20 tubes. If you're re-lamping a whole room full of fixtures, it may save you time to just color-correct the green tint out. If you're looking to build a couple of cheap flo's, then getting electronic fixtures from a home center will work with just about any tubes that fall in the wattage range, including inexpensive daylight or tungsten-balanced high CRI tubes.
  4. Homemade stuff works in a pinch. Not sure if you've seen it but this is a great resource for all sorts of things grip related: http://www.rondexter.com As for the skater - just using it as an example of a small motorized camera dolly. No reason you couldn't improvise something similar should you need to.
  5. Modern "High Frequency" ballasts are electronic ballasts, similar to those within the Kino fixture itself. Older style ballasts, known as "instant start" or "quick start" ballasts are magnetic, meaning they pulse at the line frequency of the power they're wired to. In the U.S. they"flicker" 60 times/second, in the U.K. is 50/sec (50 hz). High-frequency ballasts also flicker, but 40,000-60,000 times / second, so it's very unlikely you'll be shooting fast enough to catch a ballast-related flicker on electronic ballasts. If you remove the covers of the lights you're re-lamping, you can read the ballast to figure out what you have. Don't assume every fixture has the same ballast! Especially in large offices, as lights have problems and ballasts burn out, they get replaced (usually with the cheapest pieces possible). Also note that electronic ballasts are significantly more efficient than magnetic ballasts, and you will almost always see a large gain in output from the same tube if hooked to an electronic ballast. As for flicker, if you're shooting at an off speed (see Davi'd link to the safe framerate tables), you'll probably see some. However, with older tubes you may ALSO see flicker, due to the ballast being unable to sustain the plasma within the tube. This can happen even with electronic ballasts, so be aware of the age of the tubes you're putting in. Fluorescents have mercury in them, which brightens the output of the lamp, and helps create the correct frequency of radiation to excite the coatings inside the tube. As the tube ages, the mercury migrates into the coatings and glass, away from the electrodes and causes unstable "burn" of the tube, which can appear as a color shift or flicker. Freya also makes a good point - Kino is not the only game in town when it comes to color-correct tubes. Find a lighting wholesaler that deals in fluorescent, and ask what they have in the way of high (>89 or >91) CRI tubes of the fitting and color temp you're looking for. Chances are, they'll have about 5-6 different tubes that fit your needs, and prices significantly cheaper than Kino.
  6. How about a dolly grip? Not sure exactly what effect you're going for, but usually the simplest solution is the best one. No small motor will be able to start and stop a dolly w/ AC and Op as fast or gently as a grip will. If it's for motion control, the pulley and cable probably won't be accurate enough to make repeatable moves, you'll probably need to put the camera on a remote head to drop the lbs, and come up with a direct drive to the track that is repeatable - some kind of close loop servo system that knows where it is at all times. If its an experiment, you could always try it out on a smaller scale...perhaps something large enough for a camera but not a rider. Some lightweight track spread between tripods or even leveled saw horses could hold a camera on a small, motorized dolly. The less mass you have to move, the less force you need to move it. With less moving mass, you can either down-size your motors, or work out your gearing so they can start and slow the dolly more quickly and accurately. Check out the P&S technic Skater Dolly: http://www.pstechnik.de/en/skater.php with a DIY version, you wouldn't have to use Heden or Preston servomotors - you could definitely substitute cheap gear-head motors or steppers (if you know how to control them). Or, again, you could just have someone push the dolly.
  7. The short answer is no - if they're the same wattage, they draw the same current and thus can be interchanged if they physically fit. I assume you're looking to use standard Kino tubes in a home-depot style T8 electronic fixture? If so, this will work, and it will give you a pretty significant output increase over using a Kino tube in a magnetic T12 fixture, but probably less light than in a Kino fixture. While I've never actually measured it, it's rumored that Kino overdrives their T12 tubes (I would guess at 2x based on the size of their ballasts). The cool thing about those cheap home depot T8 fixtures is that you can buy 2 of them, put both ballasts into a single fixture, and drive Kino tubes as brightly as they would be driven in a Kino fixture. With just about any electronic ballast, you can overdrive a tube. Oh, and note that overdriving a tube does NOT change the output color. The law of diminishing returns limits how far you can actually go efficiently, but with a 2-tube electronic ballast driving a single tube (2x overdrive), expect 70% more light. 2x 2-tube electronic ballasts driving a single tube (4x overdrive), you get about 2.5x the light of the standard driven tube. People with aquariums and grow rooms do this all the time because they're limited on space - they drive their tubes harder to get way more light in the same amount of space on top of the tank or plant. In the end, it's probably worth it to get catalogs from all the major tube manufacturers, and order from a supplier. Most will show all the specs you need. If you're keying talent, it's still possible to find >91 CRI tubes in either 5700 or 3500K for under $10. For general use, you can find >80 CRI for about $2/tube.
  8. I work mostly in video/HD, and on the rare occasion I shoot film, I haven't ever really asked before. So what's the difference between a video tap, video top, and video door? Thanks!
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