-> Red color and JPG???
in [Digital Cameras]
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From: Savageduck on 3 Apr 2010 22:29 On 2010-04-03 18:06:19 -0700, "Peter" <peternew(a)nospamoptonline.net> said: > "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, If you are doing all your shooting in RAW, you should be able to make the adjustments in ACR or whatever RAW converter you are using. I am making the assumption you are dong more than White Balance adjustments with ACR or your RAW converter. Just to check, here is ACR "White Balance" adjust panel; http://homepage.mac.com/lco/filechute/ACR-WB-01.jpg Then "Camera Profile" panel; http://homepage.mac.com/lco/filechute/ACR-Camera%20Profile-01.jpg and "Hue, Saturation & Luminosity" (HSL) panel; http://homepage.mac.com/lco/filechute/ACR-HSL-01.jpg Those alone should give you what you need to make the adjustments to those reds. There are all the other adjustment available in ACR, so give them a try. -- Regards, Savageduck
From: Peter on 3 Apr 2010 23:39 "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message news:2010040319293137709-savageduck1(a)REMOVESPAMmecom... > On 2010-04-03 18:06:19 -0700, "Peter" <peternew(a)nospamoptonline.net> said: > >> "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, > If you are doing all your shooting in RAW, you should be able to make the > adjustments in ACR or whatever RAW converter you are using. > I am making the assumption you are dong more than White Balance > adjustments with ACR or your RAW converter. > > Just to check, here is ACR "White Balance" adjust panel; > http://homepage.mac.com/lco/filechute/ACR-WB-01.jpg > > Then "Camera Profile" panel; > http://homepage.mac.com/lco/filechute/ACR-Camera%20Profile-01.jpg > > and "Hue, Saturation & Luminosity" (HSL) panel; > http://homepage.mac.com/lco/filechute/ACR-HSL-01.jpg > > Those alone should give you what you need to make the adjustments to those > reds. > > There are all the other adjustment available in ACR, so give them a try. > I try to do as much as I can in ACR, except sharpening. My red problem is only with flowers. The problem with ACR is that it shifts all colors. Also, when I view the flower in the camera LCD it looks washed out even though the histogram shows proper exposure. Also, -- Peter
From: Peter on 3 Apr 2010 23:59 "Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message news:1m9qpcc1kmksh.dlg(a)mike.curvemeister.com... > 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. Thanks for that suggestion. I agree that levels is inadequate for many tasks. I primarily use it for haze elimination and to give the shot a little more punch. I have a thing about not using presets, as each image is different. I can to some effective things with curves, but there is much more to learn. At this point I am waiting for CS5 for its context aware selections that I hope will help me with what I am trying to accomplish. -- Peter
From: Savageduck on 4 Apr 2010 00:13 On 2010-04-03 20:39:36 -0700, "Peter" <peternew(a)nospamoptonline.net> said: > "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message > news:2010040319293137709-savageduck1(a)REMOVESPAMmecom... >> On 2010-04-03 18:06:19 -0700, "Peter" <peternew(a)nospamoptonline.net> said: >> >>> "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, >> If you are doing all your shooting in RAW, you should be able to make >> the adjustments in ACR or whatever RAW converter you are using. >> I am making the assumption you are dong more than White Balance >> adjustments with ACR or your RAW converter. >> >> Just to check, here is ACR "White Balance" adjust panel; >> http://homepage.mac.com/lco/filechute/ACR-WB-01.jpg >> >> Then "Camera Profile" panel; >> http://homepage.mac.com/lco/filechute/ACR-Camera%20Profile-01.jpg >> >> and "Hue, Saturation & Luminosity" (HSL) panel; >> http://homepage.mac.com/lco/filechute/ACR-HSL-01.jpg >> >> Those alone should give you what you need to make the adjustments to >> those reds. >> >> There are all the other adjustment available in ACR, so give them a try. >> > > > I try to do as much as I can in ACR, except sharpening. My red problem > is only with flowers. The problem with ACR is that it shifts all > colors. Also, when I view the flower in the camera LCD it looks washed > out even though the histogram shows proper exposure. > > Also, In ACR have you tried the "targeted Adjustment Tool" from the toolbar in conjunction with the HSL panel. Select that tool, open HSL, pick H, S, or L click in the ajustment value window. place the tool on the flower needing adjustment, and click & drag to left or right to adjust the target. -- Regards, Savageduck
From: John McWilliams on 4 Apr 2010 00:41
Savageduck wrote: > On 2010-04-03 20:39:36 -0700, "Peter" <peternew(a)nospamoptonline.net> said: > >> "Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message >> news:2010040319293137709-savageduck1(a)REMOVESPAMmecom... >>> On 2010-04-03 18:06:19 -0700, "Peter" <peternew(a)nospamoptonline.net> >>> said: >>> >>>> "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, >>> If you are doing all your shooting in RAW, you should be able to make >>> the adjustments in ACR or whatever RAW converter you are using. >>> I am making the assumption you are dong more than White Balance >>> adjustments with ACR or your RAW converter. >>> >>> Just to check, here is ACR "White Balance" adjust panel; >>> http://homepage.mac.com/lco/filechute/ACR-WB-01.jpg >>> >>> Then "Camera Profile" panel; >>> http://homepage.mac.com/lco/filechute/ACR-Camera%20Profile-01.jpg >>> >>> and "Hue, Saturation & Luminosity" (HSL) panel; >>> http://homepage.mac.com/lco/filechute/ACR-HSL-01.jpg >>> >>> Those alone should give you what you need to make the adjustments to >>> those reds. >>> >>> There are all the other adjustment available in ACR, so give them a try. >>> >> >> >> I try to do as much as I can in ACR, except sharpening. My red problem >> is only with flowers. The problem with ACR is that it shifts all >> colors. Also, when I view the flower in the camera LCD it looks washed >> out even though the histogram shows proper exposure. >> >> Also, > > In ACR have you tried the "targeted Adjustment Tool" from the toolbar in > conjunction with the HSL panel. > Select that tool, open HSL, pick H, S, or L click in the ajustment value > window. place the tool on the flower needing adjustment, and click & > drag to left or right to adjust the target. Depending on the version of ACR, you should be able to very fine tune reds, hues of reds, and saturation thereof. I happen to use Lightroom to do the same. -- John McWilliams |