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#1
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White balance, factor or offset?
Hi!
How does the white balancing work? Does the camera derive a fixed offset for each channel or a factor to multiply each channel with? (I imagine it ought to be a factor otherwise black and white would become difficult to do for the cam.) The reason is I sometimes take picture in difficult lighting conditions (buildings at night) and I'd like to try separating the white balance out of the shooting. So, what I plan to do is to shoot one exposure series with normal daylight white balance and take lots of pictures of a warmcard set using all the different lamps lighting the building (also normal daylight balance). Later at home I'd like to recolor the images of the building with the white balances of the warmcards. (Btw, does anyone have an idea on how to do this in photoshop elements?) Lots of Greetings and Thanks! Volker |
#2
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Sounds like fun...if you like standing around outside at night and not
knowing what you are going to get. While you are at it spend a few more seconds and take a RAW file (which does not white balance). Then you can do all those adjustments you enjoy at your computer in a comfortable chair...but that doesn't sound like as much fun. "Volker Hetzer" wrote in message ... Hi! How does the white balancing work? Does the camera derive a fixed offset for each channel or a factor to multiply each channel with? (I imagine it ought to be a factor otherwise black and white would become difficult to do for the cam.) The reason is I sometimes take picture in difficult lighting conditions (buildings at night) and I'd like to try separating the white balance out of the shooting. So, what I plan to do is to shoot one exposure series with normal daylight white balance and take lots of pictures of a warmcard set using all the different lamps lighting the building (also normal daylight balance). Later at home I'd like to recolor the images of the building with the white balances of the warmcards. (Btw, does anyone have an idea on how to do this in photoshop elements?) Lots of Greetings and Thanks! Volker |
#3
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Volker Hetzer wrote:
Hi! How does the white balancing work? Does the camera derive a fixed offset for each channel or a factor to multiply each channel with? (I imagine it ought to be a factor otherwise black and white would become difficult to do for the cam.) The reason is I sometimes take picture in difficult lighting conditions (buildings at night) and I'd like to try separating the white balance out of the shooting. So, what I plan to do is to shoot one exposure series with normal daylight white balance and take lots of pictures of a warmcard set using all the different lamps lighting the building (also normal daylight balance). Later at home I'd like to recolor the images of the building with the white balances of the warmcards. (Btw, does anyone have an idea on how to do this in photoshop elements?) I'm not understanding your questions. I never heard of a warm card, just gray card. Normally, just one gray card shot is needed (for each setting) so why take many card shots? Anyways I'll try to explain what I understand about the isssue. The ideal answer to your question is to shoot RAW instead of jpeg mode but I guess that's not an option for your camera. Still, take a look at the manual under white balance. There might be a way to set custom white balance by shooting a card & have that apply to all pics afterwards. I have full PS and with that, you can Save out a levels setting, then in another photo, add a levels adjustment layer & Load the saved settings. I'm not sure if you can do that in Elements. This assumes you want to use the eyedropper on the gray card to establish RGB adjustments. I believe certain RAW conversion programs can do their magic on jpeg files also. That would help you if it's true. Image Adjust Color balance seems the best PS tool for adjusting WB in jpegs. That has three sliders: cyan red magenta green yellow blue PS RAW plugin has two sliders: temperatu blue orange tint: green magenta Temperature seems the most important, tint is secondary. I'm not sure if those are exactly the colors adjusted, just my guess by looking at it. I heard mentioned here recently that the orange street lights are almost impossible to correct WB for. I think it's the blue channel that is almost completely missing. Now I have another question. How do people handle this with film? |
#4
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I'm not understanding your questions. I never heard of a warm card, just gray card. Normally, just one gray card shot is needed (for each setting) so why take many card shots? Anyways I'll try to explain what I understand about the isssue. Warm cards come in a set of several slightly different shads of a sort of blue green. By white balancing on them you force the camera to take warmer photos...sort of like the golden hours near dawn and dusk. There is also a card for counteracting florescent lights. The concept was designed for videographers but recently a set was designed for digital still cameras that also comes with a grey card. www.warmcards.com (I think...maybe no "s") |
#5
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Gene Palmiter wrote:
Sounds like fun...if you like standing around outside at night and not knowing what you are going to get. While you are at it spend a few more seconds and take a RAW file (which does not white balance). Then you can do all those adjustments you enjoy at your computer in a comfortable chair...but that doesn't sound like as much fun. Of course I'm taking raw shots. Nevertheless, if you watch them, the recorded white balance gets added to it. Besides, I do want some more hints from the original scene, and these are the white samples of differently coloured sheets. Greetings! Volker |
#6
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paul wrote:
The ideal answer to your question is to shoot RAW instead of jpeg mode but I guess that's not an option for your camera. Still, take a look at the manual under white balance. There might be a way to set custom white balance by shooting a card & have that apply to all pics afterwards. Yes, I will use raw (coolpix 5000) but I don't think I'll be able to come up with good pictures by just trying out different settings. warmcards are slightly bluish cards which, when used for white balancing give a red cast. As a beginner I'm simply trusting that they did a better job than I can do. Normally I would have to white balance with such a card then shoot then white balance with another or the same in different light (my motives are lighted with at least two different lights) and so on. I am hoping to cut from NoOfWhites times NoOfExposures to NoOfWhites plus NoOfExposures. I have full PS and with that, you can Save out a levels setting, then in another photo, add a levels adjustment layer & Load the saved settings. I'm not sure if you can do that in Elements. This assumes you want to use the eyedropper on the gray card to establish RGB adjustments. Yes, that's what I'm trying. I'll see whether I can do that in elements. Image Adjust Color balance seems the best PS tool for adjusting WB in jpegs. That has three sliders: cyan red magenta green yellow blue PS RAW plugin has two sliders: temperatu blue orange tint: green magenta Thanks for the hints! I heard mentioned here recently that the orange street lights are almost impossible to correct WB for. I think it's the blue channel that is almost completely missing. Now I have another question. How do people handle this with film? They don't. I have seen this when trying to get a decent picture of Eilenan Donan Castle in Scotland. I spent two evenenings on it (yellow, incandescend and halogene lights at the same time) and in the end I got one picture which as a novice I could barely live with. The colours of the postcards in the shop were totally irrational compared to that. This easter I'm having another go at tower bridge which is much more complex and would be impossible to shoot like I did the castle. (Last time I took about 150 pictures with none really satisfying me.) That is why I think about taking the colour balance separately from the motive and combine them at home. Lots of Greetings! Volker |
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