Dette er et must for alle lysfolk å kjenne til: Mye lærerik lesning her :-) Christian CML-LIGHTING-AND-GRIP Digest for Monday, January 19, 2015. 1. Re: high-CRI lights 2. RE: high-CRI lights 3. Re: high-CRI lights 4. Re: high-CRI lights 5. Re: high-CRI lights 6. Re: high-CRI lights 7. Re: high-CRI lights 8. Re: high-CRI lights 9. Re: high-CRI lights 10. high-CRI lights 11. Re: high-CRI lights 12. Re: high-CRI lights 13. Re: high-CRI lights ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Adam Wilt Date: Sun, 18 Jan 2015 18:38:30 -0800 X-Message-Number: 1 > > Or is CRI really all that good of a rating for our purposes? Sadly, no. I mean, it’s better than nothing, but it’s not a whole lot better. Gross differences in CRI ratings are fairly predictive of gross quality differences in color rendering, but if you have two different lamps, both rated CRI 92, they may still render important scene colors very differently. CRI is an average of the qualities of color rendering of eight color patches illuminated by the light under test; the patches are colors of low saturation spaced somewhat evenly in hue around the color wheel (see en.wikipedia.org/wiki/Color_rendering_index for details). As the colors are low in saturation, they are fairly “broadband” in spectral content and thus are (relatively speaking) fairly easy to light up even with the spiky, discontinuous spectra from fluorescents and most “white” LEDs or clusters of colored LEDs. Where CRI falls down is in predicting how strongly saturated colors will render (such colors are “narrowband” reflectors, and much more easily “lost in the gaps” in a lamp’s discontinuous spectrum), and in giving a good account of how certain important hues are treated - like flesh tones. A lamp may score 100% on six of the eight averaged colors, but if its spectrum is unbalanced around R1 or TCS01, a.k.a. light greyish red, and R2 or TCS02, a.k.a. dark greyish yellow, then fleshtones are likely to render poorly. The various blues and greens may be perfect, so frogs and toads will look great, but people perhaps not so much. CRI doesn’t care about which colors we (as humans) care about more, it ranks them all equally. So one CRI 92 light, strong in the red but weak in the greens, may be great for people and bad for frogs, while another CRI 92 light with the opposite strengths may be disappointing for humans but could win an amphibian academy award. (And by “strong in the red, weak in the greens”, I’m not referring to overall color balance. I’m referring to the smoothness and continuity of the spectrum in those colors. A lamp with a smooth, full spectrum in the reddish wavelengths from, say, 600nm on up, will do a more consistent and predictable job of rendering reds and oranges that a lamp with the same total energy in the 600-750nm band, but all concentrated in one “red spike” at 633nm.) There’s an alternative metric on offer, the CQS: nist.gov/pml/div685/grp03/vision_color.cfm It appears to be a better predictor of color rendering quality overall, at least on a theoretical basis, though in my tests so far it isn’t always so (I’ve been running around measuring lights with a spectrometer that includes both CRI and CQS readouts). Really, what it comes down to is that you still have to do fabric and makeup tests under whatever light you choose, using *your* production camera: nothing else is a truly reliable predictor of how the lamp and the camera will interact. CRI and CQS can get you close (usually, most of the time) but they do not capture the nuances of critical color rendering. You still have to look at pictures and make your own judgement calls. Adam Wilt technical services: consulting / coding / camerawork Mountain View CA USA ---------------------------------------------------------------------- Subject: RE: high-CRI lights From: John Rossetti Date: Mon, 19 Jan 2015 03:17:56 -0000 X-Message-Number: 2 The European Broadcasting Union has done much work on a replacement to CRI (which for any discharge light is pretty useless.) In 2012 it introduced the Television Lighting Consistency Index 2012 (TLCI) Details are here https://tech.ebu.ch/tlci-2012 Many LED Lamps have been tested and are available on the EBU Site and here gtc.org.uk/tlci-results.aspx Cheers John Rossetti - London John.rossetti@btinternet +44 7836 298 881 ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Steven Bradford Date: Sun, 18 Jan 2015 19:23:39 -0800 X-Message-Number: 3 On Jan 18, 2015, at 6:38 PM, Adam Wilt wrote: > > CRI is an average of the qualities of color rendering of eight color patches illuminated by the light under test; the patches are colors of low saturation spaced somewhat evenly in hue around the color wheel (see en.wikipedia.org/wiki/Color_rendering_index for details). Thanks Adam, thats exactly what I was suspecting. And thanks to John Rosetti for posting that EBU link, Im checking it out now. My idea is maybe that we can post reviews (including about operation etc, not just color) of lights weve tried, with image links, and a description of the camera and settings used. Over time we can accumulate a body of examples. Steven Bradford Instructor/Cinematographer Seattle Washington seattlefilminstitute ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Paul Curtis Date: Mon, 19 Jan 2015 09:49:14 +0000 X-Message-Number: 4 > > On 19 Jan 2015, at 03:17, John Rossetti wrote: > > Many LED Lamps have been tested and are available on the EBU Site and here > > gtc.org.uk/tlci-results.aspx What a great resource, thank you. Ive spent some time battling with LEDs in particular. IMHO ive found the Area 48 Remote phosphor to be a wonderful light source in terms of colour and feeling. More recently ive gotten one of the those Aladdin A-Lights and have been stunned at how good i thought the light was and the above link seems to agree (glad to see my eyes are okay). I dont know who Aladdin are, aside from Korean, but whatever LEDs they are using or whatever mojo theyve added obviously works. I find it amazing at how different all those LED results are, such a myriad of options and a minefield to navigate. thanks for that link again cheers Paul Paul Curtis, VFX Post | Canterbury UK ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Thomas Vincent-Townend Date: Mon, 19 Jan 2015 10:01:20 +0000 X-Message-Number: 5 Lee Filters & Rosco arent going out of business just yet I suspect. Perhaps they should be releasing CTO/CTB & ±Green filters in 1/16th & 1/32th grades until people selling LED lamps aimed at professional film & television work get their standards sorted out. Tom Townend, Cinematographer/London ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Steven Bradford Date: Mon, 19 Jan 2015 11:59:59 -0800 X-Message-Number: 6 On Jan 18, 2015, at 7:17 PM, John Rossetti wrote: > > Many LED Lamps have been tested and are available on the EBU Site and here > > > > gtc.org.uk/tlci-results.aspx Check out the high ratings on the Ikea bulb! Anyone else tempted to buy ten of these $6 bulbs, some sockets and a board and make a softlight? ;-) Steven Bradford Seattle Washington seanet/~bradford/ ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Brian Heller Date: Mon, 19 Jan 2015 15:29:09 -0500 X-Message-Number: 7 Steven Bradford wrote: > > Check out the high ratings on the Ikea bulb! > > > > Anyone else tempted to buy ten of these $6 bulbs, some sockets and a board and make a softlight? ;-) A unit like that would get very heavy very quickly. Check out some of the high end LED tapes or ribbons. Brian Heller IA 600 DP ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Michael Sanders Date: Mon, 19 Jan 2015 20:44:50 +0000 X-Message-Number: 8 My kids have Ikea LED lights by their beds - I’ve taken a few pics of my daughter with them. And they are pretty darn good I have to say. Michael J Sanders: London Based DP/Cameraman online reel: mjsanders.co.uk M: 07976 269818 twitter: #hackneydp Flickr: flic.kr/s/aHsjGoHcoz > > On 19 Jan 2015, at 19:59, Steven Bradford wrote: > > > > Check out the high ratings on the Ikea bulb! ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Tim Sassoon Date: Mon, 19 Jan 2015 13:08:41 -0800 X-Message-Number: 9 I’ve put together a small lighting kit with IKEA LED fixtures, mostly for tabletop and macro. Works well, though I’ve mostly shot B&W with it. Tim Sassoon SFD Venice, CA > > On Jan 19, 2015, at 12:44 PM, Michael Sanders boundary=Apple-Mail=_DC616F03-8DE3-4884-A732-B19B1F72A929 wrote: > > > > My kids have Ikea LED lights by their beds ---------------------------------------------------------------------- Subject: high-CRI lights From: pbadger111@roadrunner Date: Mon, 19 Jan 2015 12:29:10 -0800 X-Message-Number: 10 > > Anyone else tempted to buy ten of these $6 bulbs, some sockets and a board and make a softlight? ;- They dont seem to have that exact one now instead they have this: m.ikea/us/en/catalog/products/art/20266225/ But at that price, Ill buy some for my house at the very least! If the color renditioning of these is really that good I could see a use for these especially if theyre dimmable. Although I have to say one thing I find so useful about the LEDs that I currently use, like the Kino Celeb, is the way you can dial in the desired color temp. Phil Badger Gaffer and electricity bill payer Los Angeles ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Jonathan Miller Date: Mon, 19 Jan 2015 13:59:20 -0800 X-Message-Number: 11 Or is CRI really all that good of a rating for our purposes Having spent the last few years judging a number of different LEDs, Plasma sources as well as more traditional sources such as HMIs, tungsten, and fluorescent the CRI, CQS even the good work done by the EBU all fall a little flat when it comes to giving a pure number score. Yes anything below an 80 on either of the 3 scales is worth avoiding, but differentiating between lights with a score of 90 - 100 based on the score alone can be pretty misleading as to which light you actually want to use. The truth is the only real way to know what you are getting is to look at the actual spectrum. Both looking at spectrum graphs showing us what is coming out of our lights between 400 - 700 nanometers and also looking at chip charts, shot with the camera/cameras you intend to use. Many lighting companies are coming around to publishing their spectrums and making a point to release the information along with chip charts. But beyond that if you dont trust the information provided by the manufacturers thankfully spectrometers are becoming less expensive and more practical. The new Sekonic meter, which I have been lucky enough to play with a couple times has struck me as very useful sekonic/downloads/pr--c700&c700r.pdf and I am an owner of an Allied Scientific Meter: alliedscientificpro/shop/worlds-first-smartphone-spectrometer-lighting-passport/ which I am a huge fan of and use for day to day testing, both are under $2,000. As always in the spirit of full disclosure I am one of the owners of Hive Lighting a plasma source manufacturer and we proudly display our spectrum here: hivelighting/plasma-technology/full-spectrum-color/ and tout our 94+ CRI (although I really dont think it tells the whole story). But I really encourage all CML members to ask to see spectrum graphs and to search out trust worthy spectrometers when judging any light source before purchase. And of course when in doubt CAMERA TEST, CAMERA TEST, CAMERA TEST! Jon Edward Miller Co-Founder/CPO Hive Lighting Inc. DP in semi retirement Los Angeles (working under some lovely daylight and some pretty good LEDs) hivelighting ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: [email protected] Date: Mon, 19 Jan 2015 17:23:24 -0500 X-Message-Number: 12 IKEA LEDs are surprisingly good, although for Edison socket replacements I prefer the high color index Cree lights available at Home Depot. Much more expensive though. IKEA also has the terrific little Jansjo series of accent lights. Theyre quite inexpensive ($5-$15) are mounted to metal goosenecks, can run off AC or USB, and are perfect little stash lights to get a bit of illumination in a corner. Color isnt perfect tungsten (perhaps a touch magenta) so I wouldnt use one for a close-up, but fine to make something pop in the background. m.ikea/us/en/catalog/series/18294/ Mitch Gross Director of Communications Convergent Design ---------------------------------------------------------------------- Subject: Re: high-CRI lights From: Tim Sassoon Date: Mon, 19 Jan 2015 14:49:41 -0800 X-Message-Number: 13 Yup, those are the ones I bought. Cute, easy and cheap. Built a full mini-kit for under $100 :-) Tim Sassoon SFD Venice, CA > > On Jan 19, 2015, at 2:23 PM, Mitch Gross charset=us-ascii wrote: > > > > IKEA also has the terrific little Jansjo series of accent lights. Theyre quite inexpensive ($5-$15) are mounted to metal goosenecks, can run off AC or USB, and are perfect little stash lights to get a bit of illumination in a corner. Color isnt perfect tungsten (perhaps a touch magenta) so I wouldnt use one for a close-up, but fine to make something pop in the background. > > > > m.ikea/us/en/catalog/series/18294/ --- END OF DIGEST 1822 members of CML-Lighting on the 7th November 2003 Copyright 2003 CML ----------------------------------------------------------- Wed like to thank the following sponsors of CML: Gold sponsors * Lemac-Oz * Kodak * Codex Digital * 24-7 Drama * Cooke * Tiffen * Band Pro * TCS/Technological Cinevideo * Varicam * AbelCine * Solid Grip Systems * JVC-Pro * FJS International * Cam-A-Lot * Zylight * LVR Rental * SIM Digital * Convergent-Design * Blackmagic-Design * K5600 * Litepanels * Arri * Canon EOS-C * Light Illusion * Sony * F&V Lighting * Dolby Laboratories Inc * Flanders Scientific Silver Sponsors * DSC Laboratories * ZGC * Schneider * Sound Devices * South Coast Film and Video * Double Data * Hive Lighting * VMI * Barger-Lite * V3 * Mole Richardson * CW-Sonderoptic* West Coast Cine Video ----------------------------------------------------------- If you find CML useful and would like to help with the costs then please subscribe:- cinematography.net/subs.html If you want to share files the use the CML-FTP site..... 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Posted on: Tue, 20 Jan 2015 10:32:06 +0000
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