-> Red color and JPG???
in [Digital Cameras]
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From: John McWilliams on 3 Apr 2010 18:56 Robert Coe wrote: > On Tue, 30 Mar 2010 20:36:19 -0700, Paul Furman <paul-@-edgehill.net> wrote: > : Laurence Payne wrote: > : > On 26 Mar 2010 09:58:24 GMT, Chris Malcolm <cam(a)holyrood.ed.ac.uk> > : > wrote: > : > > : >> Because bright red pigments are more easily come by than other > : >> colours, > : > > : > Historically, wasn't blue the original pigment generally available? > : > : I always heard barns were painted red because that's the cheapest paint. > > I jeard that it was because it's an extremely stable pigment that doesn't fade > in sunlight. OMG!! I've heard both, and I am not trying to be diplomatic...... -- john mcwilliams
From: NameHere on 3 Apr 2010 19:05 On Sat, 03 Apr 2010 18:22:50 -0400, Robert Coe <bob(a)1776.COM> wrote: >On Tue, 30 Mar 2010 20:36:19 -0700, Paul Furman <paul-@-edgehill.net> wrote: >: Laurence Payne wrote: >: > On 26 Mar 2010 09:58:24 GMT, Chris Malcolm <cam(a)holyrood.ed.ac.uk> >: > wrote: >: > >: >> Because bright red pigments are more easily come by than other >: >> colours, >: > >: > Historically, wasn't blue the original pigment generally available? >: >: I always heard barns were painted red because that's the cheapest paint. > >I jeard that it was because it's an extremely stable pigment that doesn't fade >in sunlight. > >Bob Every last one of you off-topic red-herring trolls is wrong. Red became popular because it was the cheapest paint pigment at one point. More barns were painted red in the beginning so it became successively cheaper to create more red paint, cost savings by quantity. Until red was the cheapest paint available anywhere. This is the same way that misinformation becomes popular on Google. More idiots and lazy minds that don't want to research something beyond their comprehension accept something as fact, so those become the pages with the most hits. Eventually everyone believes it. Not because it is the true answer, but because it is the most popular one decided on by popular vote coming from idiots and lazy minds.
From: Ray Fischer on 3 Apr 2010 20:36 Robert Coe <bob(a)1776.COM> wrote: >On 31 Mar 2010 05:48:42 GMT, rfischer(a)sonic.net (Ray Fischer) wrote: >: Paul Furman <paul-@-edgehill.net> wrote: >: >Laurence Payne wrote: >: >> On 26 Mar 2010 09:58:24 GMT, Chris Malcolm <cam(a)holyrood.ed.ac.uk> >: >> wrote: >: >> >: >>> Because bright red pigments are more easily come by than other >: >>> colours, >: >> >: >> Historically, wasn't blue the original pigment generally available? >: > >: >I always heard barns were painted red because that's the cheapest paint. >: >: Red lead (lead tetroxide) mixed with linseed oil made a water-insoluble >: paint. Problematic for obvious reasons, but ignorance was bliss. > >I'm not sure that red lead and barn red are the same pigment. The former, used >for painting bridges (e.g., the Golden Gate Bridge in California), looks a lot >more orange than barn red (deep maroon with a definite bluish cast). Maybe so, but the GG bridge isn't painted with red lead and apparently it was never the color of red lead. http://www.goldengatebridge.org/research/factsGGBIntOrngPaint.php -- Ray Fischer rfischer(a)sonic.net
From: Peter on 3 Apr 2010 21:06 "Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message news:dwng21qp3i5x$.dlg(a)mike.curvemeister.com... > On Sat, 3 Apr 2010 15:32:01 -0400, Peter wrote: > >> "Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message >> news:x18crd1j794q.dlg(a)mike.curvemeister.com... >>> Steve JORDI <stevejordiI_REALLY_HATE_SPAMMERS(a)hotmail.com> wrote: >>>>Hi, >>>>I tried to find an explanation on the web but without success. >>>> >>>>Does anybody know why the red color looks so ugly when a digital >>>>picture is saved as JPG? >>> >>> This is not always the case. Usually the blue channel is the weakest of >>> the three - more noise and less shadow detail. >>> >>>>It looks like it's the only dominant color that gets very pixelated >>>>and grainy. >>>>The cause of this artefact? >>> >>> It's hard to answer this without seeing an image that demonstrates what >>> you >>> are saying. There could be several reasons for a poor quality red >>> channel: >>> >>> 1) lighting - skylight is strong in blue, weakest in red, and could >>> cause >>> noise and jpeg artifacting, which matches some of what you are >>> describing >>> 2) exposure - saturated red objects, roses being an example, often blow >>> out >>> the red channel, resulting in orange or yellow areas with little detail >> >> >> Mike, thanks for the explanation of my issues shooting red flowers. >> Do you have any suggestions for a cure? > > One technique that deals well with this is channel mixing. The idea is to > take information from the green and/or blue channels and mix it in with > the > red channel. If it's done right, you'll see detail in the blown out > areas. > > Dupe the image to a new layer and set it's mode to luminance. Use curves > on the blue and/or green layers to bump the contrast, and voila - detail > in > the blown out red areas. > > Apply image can be used in a similar way. > > The roses are starting to bloom in my neck of the woods, and I'll consider > doing a video tutorial on how to do this. I am looking forward to it. Meanwhile, I am playing with your suggestion using levels, since I am not very comfortable using curves. Yes, I understand you can get a lot more control with curves and I will try it. BTW, I should have mentioned I do all my shooting in raw -- Peter
From: Mike Russell on 3 Apr 2010 21:29
On Sat, 3 Apr 2010 21:06:19 -0400, Peter wrote: > "Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message > news:dwng21qp3i5x$.dlg(a)mike.curvemeister.com... >> On Sat, 3 Apr 2010 15:32:01 -0400, Peter wrote: >> >>> "Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message >>> news:x18crd1j794q.dlg(a)mike.curvemeister.com... >>>> Steve JORDI <stevejordiI_REALLY_HATE_SPAMMERS(a)hotmail.com> wrote: >>>>>Hi, >>>>>I tried to find an explanation on the web but without success. >>>>> >>>>>Does anybody know why the red color looks so ugly when a digital >>>>>picture is saved as JPG? >>>> >>>> This is not always the case. Usually the blue channel is the weakest of >>>> the three - more noise and less shadow detail. >>>> >>>>>It looks like it's the only dominant color that gets very pixelated >>>>>and grainy. >>>>>The cause of this artefact? >>>> >>>> It's hard to answer this without seeing an image that demonstrates what >>>> you >>>> are saying. There could be several reasons for a poor quality red >>>> channel: >>>> >>>> 1) lighting - skylight is strong in blue, weakest in red, and could >>>> cause >>>> noise and jpeg artifacting, which matches some of what you are >>>> describing >>>> 2) exposure - saturated red objects, roses being an example, often blow >>>> out >>>> the red channel, resulting in orange or yellow areas with little detail >>> >>> >>> Mike, thanks for the explanation of my issues shooting red flowers. >>> Do you have any suggestions for a cure? >> >> One technique that deals well with this is channel mixing. The idea is to >> take information from the green and/or blue channels and mix it in with >> the >> red channel. If it's done right, you'll see detail in the blown out >> areas. >> >> Dupe the image to a new layer and set it's mode to luminance. Use curves >> on the blue and/or green layers to bump the contrast, and voila - detail >> in >> the blown out red areas. >> >> Apply image can be used in a similar way. >> >> The roses are starting to bloom in my neck of the woods, and I'll consider >> doing a video tutorial on how to do this. > > > I am looking forward to it. Meanwhile, I am playing with your suggestion > using levels, since I am not very comfortable using curves. Yes, I > understand you can get a lot more control with curves and I will try it. > BTW, I should have mentioned I do all my shooting in raw Levels is an inadequate tool. If you are in raw, try using highlight recovery to get detail into the red flowers. -- Mike Russell - http://www.curvemeister.com |