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February 11th, 2008, 12:50 PM | #1 |
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Xh A1 - Purple is Blue
All, I am a newbie. I looked around this forum as well as the Net and didn't find much on this. Every camera that I have owned including both digital camera and digital video camera has trouble with the color purple. With just about every camera, purple looks blue. I have set the white balance and in some cases, it helps but purple still isn't purple.
I recently purchased a Canon XH A1 and totally realize the camera is capable of a lot and the only thing holding it back is my abilities and knowledge. It is slightly better but when I set the white balance, it still makes the purple objects appear blue. All the rest of the colors look great. I tried the presets that came with the camera plus loaded around 19 more and nothing really made it look a whole lot better. After using Sony, Canon, and Panasonic in a variety of models and seeing the same thing, I am pretty sure it is me and not the camera. Any tips on how to get purple to look purple when shooting indoors with artifical light? I have seen dozens of smaller camcorders and whenever I look at their screens, their purples are blues as well so this seems to be a problem with most novices and virtually anybody shooting on auto modes, which I actually don't. Any and all help is appreciated. |
February 11th, 2008, 01:01 PM | #2 |
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Every time I've shot anything purple with any camera it's been purple. I either white balance to the light I'm using or use the 3200 or 5600K preset, depending on the situation.
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February 11th, 2008, 01:46 PM | #3 |
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I was worried as can be when I shot a wedding and the bridesmaids' dresses were purple and looked blue in the LCD and VF. When I captured it and brought it into the computer, they were purple. Go figure. Perhaps its the LCDs they use?
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February 11th, 2008, 02:35 PM | #4 | |
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Quote:
Are you judging the color on a known on a good (calibrated) monitor, the LCD/viewfinder, a general purpose computer monitor, flat screen TV, etc?
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February 11th, 2008, 03:05 PM | #5 |
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Answer
The asnwer to the question posed back is I am typically referring to what is on the LCD/Viewfinder most of the time.
However, I haven't seen it change when I bring it back and view it on my flat screen computer screen or on the TV once I have created a DVD. It appears blue to me on all of them. As I change the White Balance, the blue does seem to change shade a bit. This seems to be most prevelant in school gymasiums when I am shooting competitions or sporting events. The best I can do is bring along something white or hope for a good white object somewhere in the gymnasium to adjust white balance but nothing really gets me super close to purple although as mentioned all the other colors look good. I will keep playing with white balance and also check to see if it would change going straight to a different source than LCD such as to a High Def TV without going through my computer first in case, it is just what my LCD is showing me. Any additional ideas are great? I have asked my wife and she says the items look blue as well, but could it be my eyes? There is a UV filter on the front of the camera lens, unless for some reason that is messing it up but this happens to me on cameras with no UV filter as well. |
February 11th, 2008, 03:43 PM | #6 |
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This issue was posted on Wolfgangs blog http://www.fxsupport.de/ a while back, but since then his site has been revamped & doesn't seem to have that archive anymore.
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February 12th, 2008, 11:45 AM | #7 |
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Maybe a solution
Well, I ran a test at home. I put a "purple" minnesota vikings sweatshirt out in a room of my house with absolutely no natural light. I kept setting my white balance including setting it with a white piece of paper on the sweatshirt to make sure the lighting was exactly the same and nothing really got me purple. Maybe a dark shade of blue or slightly purple but not really purple. Auto-white balance was even worse.
I next tried to use the White Balance presets and the outdoor was worthless as would be expected and indoor setting did make it look purple but everything else was terrible. I used the + - adjustments and could get it to look OK but nothing great. Next test was to use the Pre setting and Kelvin option. I will say this was the best option at about 3000K, I got a view that made the sweatshirt appear Purple and still maintained other colors pretty well. I still like the color of the overall scene better by manually setting white balance, but this gave me my best colors and still maintained purple. At least, I know enough about setting white balance with auto, manual, pre settings and Kelvin that I should be able to adjust to just about any situation. My only concern now is my LCD and VF going to be exactly what shows up on tape. More tests to come, but thanks for all the help and suggestions. |
February 12th, 2008, 10:12 PM | #8 |
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Just an observation. Gym lights may have a weird white/color balance, especially if they are a discharge type of lamp. That is because the lamps do not have a uniform output spectrum, and it can fool auto white balance systems big time. Our eye-brain system is able to process the information and achieve a better sensed balance than any mechanical system. And I suspect that purple is a difficult color. For good color and white balance you need a light source with a reasonably uniform output spectrum.
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February 13th, 2008, 12:31 AM | #9 |
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Purple is blue
Just an observation ....
In this part of the world (Brisbane, Australia), we have a lot of Jacaranda trees. In early summer each year they bloom, with masses of flowers of the most subtle purple. So spectacular are they that for many years photographers have tried to capture their display. I have not tried with my A1 camera, but in the days of film, no matter what brand was used, Kodak, Agfa, Fuji, and no matter what exposure or lighting, the flowers always reproduced blue. No one ever explained why. Odd ... |
February 13th, 2008, 01:27 AM | #10 |
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Found this info when Googling...
"As it turns out, almost all colors are in fact just as real as any other color--with the exception of purple. Purple is mostly an artifact of the way our eyes and brains perceive colors and try to make sense out of a world which doesn't always make sense. The explanation of what makes purple radically different than say orange is rather easy." "We now know that purple can not be a single pure frequency of light as it does not appear in the visible spectrum. But we also know that we can see something which we call purple, and it is definitely not blue or green or even orange. Purple must be something, but what is it exactly? It turns out that what we observe as purple is always a mixture of other colors, usually some form of red and some form of blue. So purple is not pure in that it is not a single color. We can see pure orange light, but there is no such thing as pure puple light. Of course this should not shock us too much as most people know that the color "white" has the same property; it is not a single pure color either but is a blended mixture of many other colors." More on this here: http://deron.meranda.us/topics/purple/ |
February 13th, 2008, 04:07 PM | #11 |
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I have seen this "purple as blue" myself when shooting with my PD170. Football uniforms were definitely purple on the field and held their color pretty well in sunlight, but then the sun went down, the field lights came on and the purple became blue. I figured it was because I was auto-white balancing and it just didn't correct properly.
Then a couple of weeks later I was watching some NFL network show of game highlights, in particular the Minnesota Vikings, and their uniforms looked blue. I was about to ask my (football fan) wife if the Vikings had changed their colors when the show switched from some video highlights to film highlights - as you can probably guess the film highlights properly displayed purple. Back and forth, with video shots intermixed with film shots, you could clearly see the color difference. So now I'm not feeling so bad about my lack of color accuracy. It must be the case, as mentioned above, that the stadium lighting is such that you can't get purple when shooting video. Maybe its the same with film or perhaps the film was color corrected. Mike.
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February 13th, 2008, 06:34 PM | #12 |
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Perhaps this is where custom presets and tweaking the color matrices come in to play?
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February 14th, 2008, 11:33 PM | #13 | |
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Quote:
I'm not sure if this is of any help to you, but it certainly is one possibility. You might want to bring in another set of eyes to look at the images on your screen that are coming out blue and see if they can confirm it. If they see the same blue then you would know that it isn't your eyes. |
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February 15th, 2008, 07:23 AM | #14 |
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Hi
I read this post a couple of days ago but, honestly, did't make any notice of it by then. But then something happened inside my head and I woke up one morning with a thought that I can't get rid of. But to explain my theory I must first tell you that I live in Sweden, and then go back in time to the early black and white film period. The reason I mention that I live in sweden is that our flag is blue with a yellow cross as you can see as figure 1 in the attatched picture. If this flag is filmed with a black and white film, it will be gray in two different shades, the dark gray will represent the blue colour and the light gray will represent the yellow color, as figure 2 shows. But! In the early days of film, black and white of course, the swedish flag showed up as in figure 3, where LIGHT gray represents the blue colour and DARK grey represents the yellow colour. It's verystrange to watch old movies where the flag more looks like the finnish flag, white with a blue cross, than the swedish. Of course there is a reason to why the colours show up like this. In the early days of film they used acoating (or if it was the film itself i'm not shure) on the unexposed film which had the effect that light with high frequency/high effect/short wawelength exposed the film more than light with lower frequency/low effect/long wavelength. The film was sensitive for the EFFECT of the light, NOT the INTENSITY of the light. That's the reason why the blue colour (high effect) is lighter gray than yellow (lower effect) on these films. The film was exposed more by the blue, high effect colour, than by the yellow colour, even if our eyes experience the blue colour as darker. What has this to do with purple? Well, this is my theory, I'm aware of that! If you look at the spectrum of visible light you will see that red and blue are on the opposit sides of the scale. As purple is a color that is a mixture of blue (high effect/short wavelength) and red (low effect/long wavelengt), the blue colour seems to be stronger exposed than the red light. In some way the lue colour will be stronger and "win" over the red colour. The camcorder can't se colours, it only sees light. Inside it there is a prism separating the incoming light into red, green and blue sensors, the CCD:s. The energy of the red colour is lower than the energy of the blue color and somewhere during the process the image processor makes a descision that blue is the color that should have the highest priority. It's also a fact that camcorders have a hard time with the red colour. I know, this theory might not be the truth and honestly I haven't filmed anything purple to see for myself, but I think that it somehow makes sense as the camcorder must handle a mix of colours from the opposit sides of the visible spectrum. Regards, /Bo |
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