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03/04/2005 05:50:47 AM · #1 |
Too much bright white can be blinding.
White can make other colors look brighter.
Light is the key to the change in white or the colors.
I am curious how many out there that practice this.... Measuring light?
Do you use a white piece of paper in different situations to change your setiings?
Do you know what to change your settings to?
Here is a an excellent link to this topic of [url=
//www.apogeephoto.com/july2004/jaltengarten7_2004.shtml]white[/url]...White temperatures I still have yet to master it with my fugi but I am trying and practicing everyday:)
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03/04/2005 06:02:56 AM · #2 |
Just to clarify what Tracy's saying:
How many of us pay attention, close attention, to setting the white balance on our cameras? We photograph under many colors of light, and we need to change white balance often to get truly "neutral" color rendition. Beyond that, changing white balance off-neutral can have a strong emotional impact on the image. We can add subtle (or not-so-subtle) color shifts to the entire image through creative use of white balance.
This is particularly useful for those who have a camera that allows inputting a specific value (in degrees kelvin) for the light color. The linked tutorial gives a chart of different light sources and their color in degrees kelvin, and explains this in greater detail.
One thing they DON'T mention, that I will mention, is that you can use a COLORED piece of paper to set custom white balance and get some truly off-the-wall results.
Those who shoot in RAW, of course, can set their white balance in post-processing.
That pretty well summarizes it I think.
Robt.
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03/04/2005 09:09:08 AM · #3 |
Shoot only in RAW so it has never concerned me. Light color was a major concern for me with film.
Message edited by author 2005-03-04 09:10:32.
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03/04/2005 09:19:35 AM · #4 |
| That was an in depth tutorial,Thank you for sharing!! |
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03/04/2005 09:40:45 AM · #5 |
I always manually set my white balance when shooting indoors using a gray card. When shooting outdoors I just use AWB and have never had any problems that I could detect.
Tom
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03/04/2005 10:20:46 AM · #6 |
One of the misconceptions that a lot of people have is that all like can be described by its color temperature, in fact only a view light sources can, sunlight can as well as incandescent lights. Other lights can̢۪t be described by a simple colors temperature, like Fluorescent lights, or a shaded area that is mainly lit by the blue sky.
In general it takes two numbers to specify a color. When dealing with color we can plot it on a two dimensional chart know as a CIE chart. On this chart you can plot what is know as the black body curve, the colors that a black body will glow at for different temperatures (a black body could be the filament in a light bulb). When we try to give a color temperature to light who̢۪s color does not fall on this black body curve we have to pick the closest point on the curve to the color of the light.
What this means is that dialing in a color temp for the light you are shooting in will not always work. Setting the color preset with either a gray or white card will work.
I find one of the hardest places to shoot with good color balance is out the windshield of a car, you don̢۪t notice how green it is until you start looking at your photos. I try to do a color preset on a passing white car or truck, this normally works great.
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03/04/2005 10:40:06 AM · #7 |
| Most all reflective light meters read every color at 18%, which is what a gray card is. An incedent meter will read the light that falls on the scene, not the light that is reflected. If you use a reflective meter (the kind in all cameras) it will give you a reading to make all colors appear netural gray. Different colors reflect light at different wave lengths. Reflective meters work well if the scene has a wide range of colors. That is why you have to adjust your settings when you are shooting snow or a beach, or a very light scene or a very dark scene. Where as an incedent meter will give you the correct reading of the light falling on the scene. That way the reflectiveness of the colors do not effect your readings. |
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03/04/2005 10:46:35 AM · #8 |
Almost all car windows are tinted these days. Green is a common tint color for whatever reason (this can often be seen by opening a window and looking down on the edge of the glass.
I use either preset or auto WB. Mostly auto. It does fail me though - where i have the most issues is with mixed light. I shot at a friends studio. Big flashes, and the windows were coverd with shades, but it was not completely dark. I shot in RAW, AWB and Flash. You can see a slight difference in skin tones with different WB settings.
The one that trips me up most often is indoor shots -snapshot like shots- with flash, particularly the pop up flash. You have (usually) incandescent light and the flash are way different in color...and then the shutter speed can affect the mix...
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03/04/2005 01:07:40 PM · #9 |
Originally posted by gwphoto:
Most all reflective light meters read every color at 18%, which is what a gray card is. An incedent meter will read the light that falls on the scene, not the light that is reflected. If you use a reflective meter (the kind in all cameras) it will give you a reading to make all colors appear netural gray. Different colors reflect light at different wave lengths. Reflective meters work well if the scene has a wide range of colors. That is why you have to adjust your settings when you are shooting snow or a beach, or a very light scene or a very dark scene. Where as an incedent meter will give you the correct reading of the light falling on the scene. That way the reflectiveness of the colors do not effect your readings. |
That part in bold is not strictly true, although the overall point of the post is. Since this thread is about accurate color rendition, it's sort of misleading.
In other words, if you photograph a white wall based on the reflected light reading in the camera, it will be rendered as an 18% reflectance "gray tone", yes. And if you photograph a black wall, ditto. However, if you have light balance set for tungsten and shoot the same white wall in daylight, it will render as a blue-gray, not a neutral gray. And if you have light balance set for daylight and photograph that white wall under tunggsten light, it will render as a yellow-gray, not a neutral gray.
The meter knows nothing about color, it's just calibrated on the assumption that the average reflectivity of the object being metered is 18% gray, or "Zone V" gray.
Robt.
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03/04/2005 03:08:17 PM · #10 |
Originally posted by gwphoto:
Reflective meters work well if the scene has a wide range of colors. That is why you have to adjust your settings when you are shooting snow or a beach, |
That may be one reason, but the most important factor in ajusting exposure under these lighting conditions is that large amount of UV light reflected from the snow, sand and water throws off the readings and you need ajust to compensate.
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03/04/2005 03:49:13 PM · #11 |
Originally posted by nsbca7:
Originally posted by gwphoto:
Reflective meters work well if the scene has a wide range of colors. That is why you have to adjust your settings when you are shooting snow or a beach, |
That may be one reason, but the most important factor in ajusting exposure under these lighting conditions is that large amount of UV light reflected from the snow, sand and water throws off the readings and you need ajust to compensate. |
UV can be corrected with filters. not exposure. |
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03/04/2005 04:10:21 PM · #12 |
Originally posted by nsbca7:
Originally posted by gwphoto:
Reflective meters work well if the scene has a wide range of colors. That is why you have to adjust your settings when you are shooting snow or a beach, |
That may be one reason, but the most important factor in ajusting exposure under these lighting conditions is that large amount of UV light reflected from the snow, sand and water throws off the readings and you need ajust to compensate. |
Umm, color or exposure? The exposure is off because the meter assumes a balanced photo, not one that is 90% white snow. Same issue if try and take a pic of a banana on black velvet - the meter will see lots of dark black and it will throw off the exposure reading.
As to the color - th ecolor of the snow will vary - bluing on dauys with clear skys and graying on overcast days - it is just reflecting the sky's current color. By definition, UV rays cannot be seen by human eyes, so a UV filter may well block them, I doubt you can see the difference assuming the film/sensor can record it and then it cam be reproduced in the output medium.
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03/04/2005 04:17:53 PM · #13 |
Nsbca and Prof are right: Snow reflects a huge amount of UV radiation in addition to the visible light. It can throw things off dramatically even compared to "white" in the same light. Want to prove it? Lay a bright white piece of paper, the really bright, 92% reflectance kind, on the snow and take a in direct sunlight. The snow will be noticeably brighter than the paper, assuming it's pure, fresh snow and the light is bouning off the snow'paper towards the lens. With the light behind you, the effect is less noticeable because the uV is geing reflected away.
Robt.
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03/04/2005 04:33:17 PM · #14 |
Originally posted by gwphoto:
UV can be corrected with filters. not exposure. |
Both.
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03/04/2005 04:34:37 PM · #15 |
I was under the impression that the sensors in most if not all digital cameras have a UV filter "built-in" just above the sensor. I did a lot of reading about this back when I started trying to play around with UV photography when I got basically zero exposure when illuminating subjects with nothing other than a UV lamp (the kind you read TLC plates with in laboratories).
I believe that the reason that the snow is so much brighter than the paper is that the snow is actually a clear crystalline material while paper is a more or less opaque fibrous material. The snow is merely more efficient at reflecting the sunlight than the paper is. I do not believe that the UV radiation has much or anything to do with the difference in brightness but I am no expert on this matter.
Tom
Originally posted by bear_music:
Nsbca and Prof are right: Snow reflects a huge amount of UV radiation in addition to the visible light. It can throw things off dramatically even compared to "white" in the same light. Want to prove it? Lay a bright white piece of paper, the really bright, 92% reflectance kind, on the snow and take a in direct sunlight. The snow will be noticeably brighter than the paper, assuming it's pure, fresh snow and the light is bouning off the snow'paper towards the lens. With the light behind you, the effect is less noticeable because the uV is geing reflected away.
Robt. |
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03/04/2005 04:43:46 PM · #16 |
Originally posted by ovenbird:
I was under the impression that the sensors in most if not all digital cameras have a UV filter "built-in" just above the sensor. I did a lot of reading about this back when I started trying to play around with UV photography when I got basically zero exposure when illuminating subjects with nothing other than a UV lamp (the kind you read TLC plates with in laboratories).
I believe that the reason that the snow is so much brighter than the paper is that the snow is actually a clear crystalline material while paper is a more or less opaque fibrous material. The snow is merely more efficient at reflecting the sunlight than the paper is. I do not believe that the UV radiation has much or anything to do with the difference in brightness but I am no expert on this matter.
Tom
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Most do have a filter. That is why it is so much easier to get good blue skies with a digital camera then it was with film. But the in camera filters only go so far. An external filter, exposure compensation or both should take care of the rest.
I'm gearing up for another season of shooting a rookery. This is located on the water and the majority of birds I am photographing are white. It is real easy to fool the camera's meter in this situation. Strong UV filters help, but often I compensate by underexposing by half a stop to keep from blowing out the highlights.
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03/04/2005 05:04:18 PM · #17 |
That is interesting. I actually have a lot of experience shooting white birds and have found that if you actually meter off the bird you will get a correctly exposed bird without any additional filter. This has been the case for egrets in rookeries as well as various white birds wading in the water on bright sunny days.
I have actually tried using external UV filters from a number of manufacturers (Heliopan, B+W, Tiffen & Hoya) and seen no effect with my digital rebel or 20D. This testing was done after I noticed no effect that was advertised on the package of some of the filters that I had purchased (bluer skiesâ€Â¦). I mentioned this to a pro photographer friend of mine and he suggested the built-in UV filter over the sensor and that I try my experiment using a film camera. Guess what, I did see the effect with the film camera.
Based on those experiments and those with my use of a UV lamp from both a UV/VIS spectrometer and a hand-held UV lamp I have come to the conclusion that the UV filter on at least the Digital Rebel and EOS 20D cameras is extremely effective at blocking UV radiation.
Have you tried using a spot meter with your white birds and setting the exposure manually?
For a very good tutorial on metering I would suggest checking out this site:
//www.luminous-landscape.com/tutorials/understanding-series/understandexposure.shtml
Tom
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03/04/2005 05:44:48 PM · #18 |
Originally posted by ovenbird:
.
I have actually tried using external UV filters from a number of manufacturers (Heliopan, B+W, Tiffen & Hoya) and seen no effect with my digital rebel or 20D. This testing was done after I noticed no effect that was advertised on the package of some of the filters that I had purchased (bluer skiesâ€Â¦). I mentioned this to a pro photographer friend of mine and he suggested the built-in UV filter over the sensor and that I try my experiment using a film camera. Guess what, I did see the effect with the film camera.
Based on those experiments and those with my use of a UV lamp from both a UV/VIS spectrometer and a hand-held UV lamp I have come to the conclusion that the UV filter on at least the Digital Rebel and EOS 20D cameras is extremely effective at blocking UV radiation.
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You seem to be right. I just did a little (un-scientific) test of my own. I shot a picture of just the sky with and without an external UV(0) filter and the histogram didn't move. The color also looked the same. I guess old film habits are sometimes hard to kick.
As far as metering the birds, it isn't always as easy as just spot metering, although that is what I usually do. Often you have several birds in the frame, some of which may be in full or partial shade. It then becomes a matter of educated guess work. When in doubt, bracket.
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03/07/2005 06:31:17 AM · #19 |
Thank you for sharing that extra tuturial it was one more confirmation that I needed to convince myself that I need to keep experimenting with filters. I am using a UV polarizer mostly in the outdoor sun. Sometimes in shade I can get a neat contrast and the light highlights are kind of cool too if I use the uv poarizer on and set my camera in shade mode.
And thank you everyone else for replying. This is a guessing game still even after almost two months of studying this subject, and experimenting I think its showing just a little in my pictures:)
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03/07/2005 07:53:38 AM · #20 |
you are so right- much of what peopele would consider "digital looking" about an image probably comes for a digital sensors misinterpretation or presentation of a low SLIGHTLY under-lit or "underexposed" shot.
But in reality, digital photography is like real estate. All the realtors want to make their "license" matter- when in reality, eventually everyone becomes a realtor and finds with a little knowledge or talent anyone can do it. Same with traditional photographers and digital. It opens up th efield, monetarily at least, and everyone can test their own mettle.
or at least try not to underexpose, sorry for the rant. |
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