Probably you have access to more recent Alexa but with my footages (2 different, quite recent cameras), with standard ISO 800 and V3LogC linearisation highlight area (like big fire, chimeras, butterflies etc.) are clipped on value around 37. There are higher values- around 50- but that are not real "scene pixel" values but just artifacts of debayer algorithm altogether with sharpening. When I change algorithm and set sharpen to 0, those exces pixel values just disappears. It's definitely not fair to say, that Epic is so bad. For me it's just compromise between noise and dynamic range. With standard settings Epic has less noise but with cost of dynamic range in highlights. In my opinion most DPs accept higher noise level from Alexa because it looks more like film grain than ordinary "electronic" noise from Red. But for me noise level with the standard Alexa ISO 800 is not acceptable for VFX, even if dynamic range is better than in Epic. When you takes it into account in your comparison, difference between them goes down to around 1 stop instead of 3 I think. Best Adrian W dniu 2014-04-30 01:52:24 użytkownik Schneider, Abraham <[email protected]> napisał: Hm, don't really get your point. Of course I linearized both footages. If I'd compare linear with log, the values are different. But if I linearize both with the correct curve and have one footage clipping at values below 5 and the other at 54, that's a huge quality difference to me. Of course it would be better to test the cameras side by side at the same location, but I don't have a RED cam available. That's why I'm asking here if anyone knows if it is normal with RED to have clipping at such 'low' values (compared to what I'm used from Alexa). Abraham Am 30.04.2014 um 01:12 schrieb Adrian Baltowski: Just remember that with all digital cameras these are arbitrary logarithmic-like curves applied on top of the linear data captured by the sensor. Currently I'm working on the Alexa footage: night shot with house on fire. With AlexaV3logC curve maximum linearized values of fire are around 36 and are clipped. Just change curve to standard Cineon and THE SAME clipped highlights goes down to 9, with just little change of values below 1. And redlogfilm curve is intended to mimic cineon. So to be fair You need to make tests side by side, with the same scene captured by both cameras and then compare the results. Best W dniu 2014-04-29 20:38:40 użytkownik Randy Little <[email protected]> napisał: Isnt there a pdlog 685 setting still in red? But it would have change with redlog and color space if it was going to change at all I suspect. (Maybe) On Apr 29, 2014 1:07 PM, "Schneider, Abraham" <[email protected]> wrote: You're suggesting 'RedlogFilm' in the RED settings, right? Doing this and using a separate colorspace to do the Log2Lin gives similar values than using the Read colorspace. My maximum value in the image is lower than 5 compared to the > 54 with an Alexa image. Am 29.04.2014 um 18:17 schrieb Randy Little: > What happens if you do pdlog in red settings and then use a colorspace node > to do loglin. Read node loglin does weird things. Colorspace node seems to > work better. > > On Apr 29, 2014 11:43 AM, "Neil Rögnvaldr Scholes" <[email protected]> wrote: > Ha - this is interesting i don't know the answer but i do know a good DP who > hates RED for exactly it inability to retain highlights. > > > Neil Rögnvaldr Scholes > > www.neilscholes.com > > On 29/04/14 16:33, Schneider, Abraham wrote: > Thanks! > > I assumed all this. Just wanted to make sure there is no mistake in doing one > specific way. > > My main question is: is it true that RED cameras can only deliver/capture > highlights that are way darker then what the Alexa does? So in my example, a > maximum value of around 4 from the RED would be more than 3 stops less than > the Alexa with it's value of 54 (linear floating values measured in Nuke). > > So the provocative question would be: is RED really that much worse than the > Alexa? > > Abraham > > > Am 29.04.2014 um 17:10 schrieb Simon Björk: > > Some info on Red footage an it's curves: > > - Half Float Linear is the correct linear curve. The one that says Linear is > scaled/offset to be between 0-1. > - RedLogFilm is a Cineon curve. By applying a standard log2lin operation, the > result is identical to Half Float Linear. > - Both Half Float Linear and a linearized RedLogFilm will produce values > below zero. You can avoid this by converting to PLogLin instead, or just > bring up the values with a standard Add node. > - Rendering RedlogFilm or linear EXRs from RedCineX will produce identical > result as importing the R3D directly in Nuke. > - By rendering out an ACES file from RedCineX you will get a larger color > gammut, but you will not get any more information in the black/white point. > > To sum up: > > If the values are clipped when using Half Float Linear in Nuke, you will not > get any more information by applying different settings or going to a > different application. > > Best regards, > Simon > > > 2014-04-29 16:20 GMT+02:00 Schneider, Abraham <[email protected]>: > Hi there! > > As we're more used to Alexa footage here, I just wanted to ask about RED, as > I have some footage here that let's me wonder about the capabilities of the > RED camera: > > I have some shots with fire, sun, lamps, etc. in my images. Shot with EPIC-X. > When importing them into Nuke and linearizing them, I always see that these > bright highlights are clipping at around a value of 3 to 4 (depending on the > channel). > > This happens, no matter how I treat the footage: > - importing the original R3D file in Nuke and use "half float linear" as > gamma space and 'linear' as the Read colorspace > - importing the original R3D file in Nuke and use "RedlogFilm" as gamma space > and 'cineon' (or PlogLin) as the Read colorspace > - converting the R3D in RedCine X Pro to DPX with RedlogFilm and importing > with 'cineon' or 'PlogLin' > - converting the R3D in RedCine X Pro to EXR with ACES and importing with > 'linear' > > Having similar takes shot with the Alexa as AlexaLogC, bright highlights will > clip at a value of 54! > > I don't want to start a 'war' Alexa vs. RED, but just wanted to know if this > really is 'normal', so the RED will not deliver higher values, or if there is > something wrong/strange is going on here. > > Thanks for your help, > > Abraham > > > Abraham Schneider > Head of VFX pipeline / VFX Supervisor > > > Türkenstr. 89, 80799 München / > Phone +49 89 3809-1096 > > EMail [email protected] > > Visit us on Facebook!________________________________ > > > ARRI Film & TV Services GmbH > Sitz: München Registergericht: Amtsgericht München > Handelsregisternummer: HRB 69396 > Geschäftsführer: Helge Jürgens, Josef Reidinger > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
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