Jason Rodriguez Posted October 3, 2004 Share Posted October 3, 2004 Just curious, there's a "facts about film and electronic capture" on the Kodak website that I was flipping through, and saw at the bottom of point #3 where they were talking about the creative flexibility that film gives you, that motion-picture stock has 20-stops of dynamic range. Hmm . . . okay, so where's this "20-stops", and how to I take advantage of it? Seems like when I overexpose 18% grey by more than 4-5 stops things start looking pretty white. On the 20-stop scale that means I should have another 15-stops under 18% grey?? 20 stops means it can get a 1,000,000:1 lighting ratio-I don't think so. Just curious, I mean I love it when Sony comes out and claims some outlandish stuff, but that doesn't mean there's some mis-information or fantastic statistics being thrown around on the other side too. BTW, if somebody knows where this 20-stops went, and how to extract it, I'd love to know. Link to comment Share on other sites More sharing options...
Premium Member Kevin Zanit Posted October 3, 2004 Premium Member Share Posted October 3, 2004 I believe they are saying 10 stops in either direction. Either way, they are not saying film has 10 USEABLE stops, just that it has the ability to hold some sort of detail before hitting the D-max of the film. Kevin Zanit Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 3, 2004 Share Posted October 3, 2004 I believe they are saying 10 stops in either direction. Either way, they are not saying film has 10 USEABLE stops, just that it has the ability to hold some sort of detail before hitting the D-max of the film. Kevin Zanit <{POST_SNAPBACK}> Could someone point us to the actual publication, or at least quote it.... Mike Brennan Link to comment Share on other sites More sharing options...
Premium Member Laurent Andrieux Posted October 3, 2004 Premium Member Share Posted October 3, 2004 It might take account of the processing/ printing ability as well... Please post us a link, Jason! Link to comment Share on other sites More sharing options...
Jason Rodriguez Posted October 4, 2004 Author Share Posted October 4, 2004 Sorry, here's the link. It's under fact #3 Link to comment Share on other sites More sharing options...
DavidSloan Posted October 4, 2004 Share Posted October 4, 2004 Well they do say that, and it's misleading if you don't know what they mean...you should contact Kodak about that if it really bugs you. Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 4, 2004 Share Posted October 4, 2004 No it is not Kodak stating facts. It is a presentation of opinions from users, presented as facts. Expensive well considered advertising, drawn from interviews? by a PR? company of selected users. Respected (edited) opinion yes. But facts?....... Mike Brennan Link to comment Share on other sites More sharing options...
Premium Member Laurent Andrieux Posted October 4, 2004 Premium Member Share Posted October 4, 2004 May be one should post in the "stock" section, may John Pytlak could give us advice Link to comment Share on other sites More sharing options...
Premium Member John Pytlak RIP Posted October 4, 2004 Premium Member Share Posted October 4, 2004 May be one should post in the "stock" section, may John Pytlak could give us advice <{POST_SNAPBACK}> The data is based on actual tests, not just opinion. Kodak image scientist Dr. Roger Morton and his team published a technical paper "Assessing the Quality of Motion Picture Systems from Scene-to-Digital Data" in the February/March 2002 issue of the SMPTE Journal (Volume 111, No. 2, pp. 85-96). The analysis of dynamic range was done by a special test scene using various shiny metallic spheres reflecting specular highlights to evaluate the dynamic highlight range above an 18% gray. The film tested was Kodak VISION 500T Color Negative Film 5279. The data showed the "Dynamic Highlight Range of 18% Gray" was 15.9 stops. In other words, the film was able to record detail in highlights as much as 15.9 stops above a normal 18% gray card exposure, plus darker scene elements 3.3 stops below an 18% gray (Figure 16 in the paper). The paper concludes "Thus, real world scenes can produce 20 stops of dynamic range, or an intensity range of about 1,000,000:1". The published paper details how the test was conducted, and has scanned images showing the results of the test. Kodak normally evaluates color negative film sensitometry over a 4.0 log exposure range (about 13 stops). Dr. Morton's test was part of an evaluation that took film to the limit in a practical scene, with super-highlight specular reflections in metal spheres that went well beyond the normal 13 stop range routinely evaluated. By routine sensitometric measurements (4.0 log exposure), the new VISION2 films generally have better latitude and linearity than the older generation of films. But you would be extrapolating to say what was happening with another 7 stops of exposure. I'm sure the new Kodak VISION2 films will be included in any future work by the team that wrote the 2002 SMPTE paper. The SMPTE holds the copyright to any papers published in the Journal. The SMPTE does have an on-line library of recent Journal articles, but it requires membership in SMPTE to access: http://www.smpte.org/members_only/library/ http://www.electronicipc.com/JournalEZ/mo/...fm?code=4539001 The earlier version of Dr. Morton's paper that was presented at the SMPTE Conference in Pasadena in 2000 is available there, but it dealt mostly with sharpness evaluation: http://www.smpte.org/members_only/library/...file=morton.pdf Here are two more recent papers by Dr. Morton's team, comparing film and digital sensors for aliasing artifacts: http://www.electronicipc.com/journalez/det...=45390011120508 http://www.electronicipc.com/journalez/det...=45390011120705 Link to comment Share on other sites More sharing options...
Dominic Case Posted October 6, 2004 Share Posted October 6, 2004 John says, cautiously . . , But you would be extrapolating to say what was happening with another 7 stops of exposure. Say I have scene of 7 stops brightness range. Based on the normally understood uesful exposure range of colour negative ofabout 11 stops (for Vision2), I can vary my exposure by 2 stops either way (more typically one under or three over) and still get back to an identical image by correcting the neg on telecine or in the printer. If I shoot another 7 to 10 stops over that, I don't think I would expect to be able to correct the image back to normal. BUT I WOULD be able to recover some sort of tonal information even at the extreme highlight end of the range. I think that is what the technical paper published in SMPTE journal reported - presumably quite accurately. It's perhaps misleading to see this precise, objective, almost forensic type of information presented in a pop way on a flash website. Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 8, 2004 Share Posted October 8, 2004 John says, cautiously . . , It's perhaps misleading to see this precise, objective, almost forensic type of information presented in a pop way on a flash website. <{POST_SNAPBACK}> There are subjective statements in the ad being touted as fact. Like "Film is the only world wide distribution format" ! Most of the "facts" are (meant to be) supported by the opinions of DPs. Some folks will be mislead. Mike Brennan Link to comment Share on other sites More sharing options...
Premium Member Max Jacoby Posted October 8, 2004 Premium Member Share Posted October 8, 2004 There are subjective statements in the ad being touted as fact.Like "Film is the only world wide distribution format" ! And what would the other formats be? For theatrical release film is the only one I know. Certainly the 100 odd digital screens don't count as 'worldwide'. Link to comment Share on other sites More sharing options...
Filip Plesha Posted October 8, 2004 Share Posted October 8, 2004 "World" means Kenia, and Kongo and Mongolia, and Turkmenistan too... Now I can't be sure but I doubt you will be able to play HD tapes in all of these countries, but you will be able to play 35mm film anywhere. Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 9, 2004 Share Posted October 9, 2004 "World" means Kenia, and Kongo and Mongolia, and Turkmenistan too...Now I can't be sure but I doubt you will be able to play HD tapes in all of these countries, but you will be able to play 35mm film anywhere. <{POST_SNAPBACK}> Who said anything about HD? And you are clarifying the statement to read "film is the only worldwide distribution format to cinemas" (?) Mike Brennan Link to comment Share on other sites More sharing options...
Matt Wells Posted October 15, 2004 Share Posted October 15, 2004 Who said anything about HD? And you are clarifying the statement to read "film is the only worldwide distribution format to cinemas" (?) Mike Brennan <{POST_SNAPBACK}> I think that, in the context, it means distribution to cinemas. However I would still suggest that 35mm is still the only truly worldwide distribution format - it is the same everywhere. Matt Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 16, 2004 Share Posted October 16, 2004 I think that, in the context, it means distribution to cinemas. However I would still suggest that 35mm is still the only truly worldwide distribution format - it is the same everywhere. Matt <{POST_SNAPBACK}> Now you are getting closer. If they said film has a common frame rate in cinemas around the world then this would be true. In Europe many features are shot 25 and played off speed. Mike Brennan Link to comment Share on other sites More sharing options...
Matt Wells Posted October 18, 2004 Share Posted October 18, 2004 Now you are getting closer. If they said film has a common frame rate in cinemas around the world then this would be true. In Europe many features are shot 25 and played off speed. Mike Brennan <{POST_SNAPBACK}> As a low budget production in Europe, I have heard people suggest that you should never shoot at 24fps because 1) it is easier to shoot at 25; and 2) if you are struggling to break the 90 minute barrier with your film, knowing it will be presented at 24fps gives a little extra running time! Matt Link to comment Share on other sites More sharing options...
Premium Member Laurent Andrieux Posted October 20, 2004 Premium Member Share Posted October 20, 2004 It's true that most theaters in France project 25 fps nowadays, unfortunatly... It allows more adverts to be showed before the feature... Most production who shoot 25 fps do so when they have a TV plan as well, or just want the film to be sold to TV even afterwards... The problem is screening a film at 24 if shot at 25 - the sound gets really damaged - but the other way works ok... Another point is that shoting at 25 costs 4% more than 24 for the same length... Link to comment Share on other sites More sharing options...
Matt Wells Posted October 20, 2004 Share Posted October 20, 2004 The problem is screening a film at 24 if shot at 25 - the sound gets really damaged - but the other way works ok... Why is this, and not the other way round? I have to say I've never heard this before. Why should projecting at 25 allow more adverts to be screened? I know that they are probably all shot at 25, but, again, why is slowing the frame rate by 1 fps going to be any more damaging than speeding it up by 1 fps? I know that the feature films shot by Jones and Jolieffe (writers of "The gurellia Filmakers handbook") were all shot at 25 and they recomend never shooting at 24 because of the additional hassles. Matt Link to comment Share on other sites More sharing options...
Mike Brennan Posted October 25, 2004 Share Posted October 25, 2004 Why is this, and not the other way round? I have to say I've never heard this before. Why should projecting at 25 allow more adverts to be screened? I know that they are probably all shot at 25, but, again, why is slowing the frame rate by 1 fps going to be any more damaging than speeding it up by 1 fps? I know that the feature films shot by Jones and Jolieffe (writers of "The gurellia Filmakers handbook") were all shot at 25 and they recomend never shooting at 24 because of the additional hassles. Matt <{POST_SNAPBACK}> The pitch can be corrected but the keen of hearing notice that music tracks play slow. The same happens in reverse. Not an issue unless you have lots of music. Bearing in mind more people see movies on TV and DVD than at the cinema some will say shooting 25p is overall an excellent choice. Mike Brennan Link to comment Share on other sites More sharing options...
Premium Member Laurent Andrieux Posted October 25, 2004 Premium Member Share Posted October 25, 2004 Why is this, and not the other way round? I have to say I've never heard this before. Why should projecting at 25 allow more adverts to be screened? I know that they are probably all shot at 25, but, again, why is slowing the frame rate by 1 fps going to be any more damaging than speeding it up by 1 fps? I know that the feature films shot by Jones and Jolieffe (writers of "The gurellia Filmakers handbook") were all shot at 25 and they recomend never shooting at 24 because of the additional hassles. Matt <{POST_SNAPBACK}> Sounds gets more damaged if played slower than faster. Screening at 25 gives you 4% more free time. that gives you 3 minutes and a half on a 90 min feature... enough for maybe 5 more ads before the show... Link to comment Share on other sites More sharing options...
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