On this thread, my pictures taken in the SAMRA building have a red tint. I'm not sure why. The SAMRA building has fluorescent lighting. I have fluorescent lighting in my train room and the pictures are fine. Perhaps different fluorescent types in the SAMRA building? I have a Nikon 5000. The white balance is set to fluorescent. I thought this might be an obvious, common problem. The next time at SAMRA, I will try various settings and see how it changes. Thanks. OTOH, picture here. This plaster should be bone white; it appears to have a red tint on my monitor.
I suspect that the fluorescent has a different wave length than the ones in your train room. Since you said the pics in your train room come out fine I suspect you have "normal" fluorescent tubes. In the SAMRA bulding daylight fluorescents may be used or some other types. Does your Nikon 5000 have custome white balance? If so, put it in that mode and take a setting of the white plaster filling up the entire frame. Once set, your white balance should be set correctly for the SAMRA fluorescents.
It has an "auto" white balance. I will try that, too. Now...I suppose that if I knew what I was doing, I would have a white sheet of paper to do that all the time? Sounds like a good idea. Thanks for the help! :thumbs_up:
LOL, Flash if we all knew what we were doing, would not be near the need for this Forum. I for one have greatly benefitted from all of the knowledge here Keep up the good work all of you and thanks for the help
Flash: Your photo's of the boxcars posted in this week's photo fun also have that pinkish tinge as well. It must be the lighting in the room where the photo's were taken. Somehow you must adjust your camera to compensate for that if you plan to take more photo's under those conditions. Stay cool and run steam....
I had a chance to put a digital colorimeter on the image. Cameras take pictures on three channels: red, green and blue. Each channel has a range from 0 to 255. That is, there are 256 different "shades" or "intensities" for each channel. 0 is the darkest, 255 is the brightest. We get pure white when we combine channels with these values: Red=255 Green=255 Blue 255 You really don't want much pure white, except for calibration. So you might want something like R=230, G=230, B=230 What I got for these images (average) was R=200, G=150, B=160. That will certainly give you a pink result. If anyone cares for a technical explanation! [EDIT] It confirms that the club is using daylight bulbs, as the camera's color sensor is turning down the green and blue--the green and blue are brighter than expected.
Interesting info, Pete. Could you tell us a little more about what a digital colorimeter is? Also, it implies there are specific formulas / combinations of the R/G/B that have been devised to correct color balance. Any pointers to info on such formulas? Thx.
I should have known! No expense spared! So that means my camera should be set for a daylight picture? I will have a few more pictures next week with some variations now that we know about the daylight bulbs. Should be an interesting project. I have heard of the daylight bulbs, but I had no idea.
A digital colorimeter is included as a utility on Macs. You can set it to read one pixel (not very useful) or a small area of an image. It reads what it sees on the screen, and reports the red-green-blue intensities or values. It's very useful for me in dealing with commercial printers. They send me a series of color swatches, along with the values for their displays, which are calibrated carefully to their printers. I can then adjust my display to match their values. That means that what I see on my displays is what they'll see on their displays, which is what will be printed. There's no real formulas as such. There's a lot of physics, such as this hue has certain values of R-G-B. There are a lot of standards for both R-G-B, and the printing equivalent C-M-Y-K. Sometimes I'm lucky that the standards work between different displays; sometimes I'm not, so we calibrate. It's still more an art than a science, I think. If all monitors were exactly the same, it would be a science. But even the same monitors from the same manufacturers may have slight differences, which I can safety ignore. But there are huge differences between monitors of different manufacturers. I have two monitors on my dual display from two manufacturers--I can get somewhat close calibrating the the two, but rely on the main Apple cinema display for the final result. Apple is a favorite of anyone dealing with graphics because the monitors are usually spot-on, and are easily calibrated if not. Because all monitors are different, matching color swatches is a challenge. I adjust blue to find that red is off; I adjust red to find that green if off; I adjust blue to find that both red and green are off. Apple is simply better than most displays in making these adjustments. I'm using an older Samsung monitor as a second monitor; man, its response is a problem! There's just no consistency in the R-G-B response. The real problems with color come in the conversion from displays (R-G-B) to printing machines (C-Y-M-K). If a printer has to adjust his monitors to get true color off his presses, then I have to adjust mine. That's not a problem, as I can store a "color profile" and load it in seconds. So printer X has this profile, and printer Y has a different profile. All this probably is gibberish to a lot of users. Flash's R-G-B readings should probably read 220-220-210 for a bone white, although that may be a little gray.
I really love the MAC what a tool. I should have made the cange years ago. It has everything you need already included go figure.
I've always appreciated Macs, because Apple has understood the graphics industry since the first Lisa. I've been working on them since the Lisa in the late 80s. I neglected to mention printers and clients often supply me with Color Profiles, which are basically tables of the adjustments they've made. I then just load their profiles into Photoshop. As long as things are reasonably close in the raw adjustments, these work pretty well, and sometimes work perfectly. Sometimes it takes a few iterative test prints to see how close we are or, sometimes, what I can safely ignore! If you have absolutely no idea of what I'm talking about, don't worry. Many commercial printers (and many magazine editors) have no idea either!
Daylight fluorescents? Exactly! Only one of the several members present remembered that the bulbs had been purchased as daylight fluorescent. When I asked about their pictures, they all said they used "auto" and never had any problem, of course! (And these guys are my friends!) These bulbs are being replaced as they burn out. For the time being they will be replaced with more daylight bulbs. What if they are eventually replaced with normal fluorescents? How will that affect photography? The lettering on the GE fluorescent bulbs was, "F96T12SP35-WM." Here are the pictures taken yesterday on my Nikon 5000 on different settings. I believe that the auto setting is the proper one to use. The other results are interesting. These are taken indoors under daylight fluorescents without a camera flash, macro setting, HO scale. Fluorescent setting (same as originally posted; reddish): Auto setting. I think this looks correct. Cloudy setting: Fine setting: I sure would like to hear comments on these. I don't know what "fine" setting is. Seems strange that "cloudy" is so red or orange. Thanks to all, and especially Pete Nolan, for the help on this.
Flash the Auto white balance picture looks darn good. For most pictures I leave auto white balance only. I do like to experiment with different white balance settings, particularly with sunsets. Sometimes I do forget to switch it back. My better half has a set of Opus strobe flashes, before each session she is always setting the white balance depending on her mood. I believe she uses some sort of card that helps her set that up.
Cloudy setting adds warmth to the picture to try to take a little away from the drab. This causes the red/orange in the picture.
Unless I am facing unusual situations, I use the AutoWhite setting. I use rope lights on my layout in dark corners. Because they are very warm (perhaps 1700 C.?), I can have very blue results, as AutoWhite recognizes these values along with the prevailing fluorescents. At my real work, I can face unusual situations. Then I shoot raw, which allows for very fine calibration of color temperature. But I'm usually not the principal photographer in these cases, thank God!
