beauh44 Posted December 6, 2004 Share Posted December 6, 2004 Hello All, What can I say? I had too much time on my hands tonight and thought I'd check something out that I'd heard about here on Photo Net. I took four (bad!) jpeg shots of my cat using my 20D, a 70- 200mm f/2.8L IS lens and a 550EX, in four different modes: Program, Manual, Aperture Priority and Shutter Priority, to check out what difference, if any, I'd get from the camera in terms of White Balance. Well, lo and behold, I got four different White Balances, and I'm not sure why Canon would do that. My camera was set to ISO 1600 and the Adobe RGB color space. It wasn't a huge surprise that selecting Program Mode automatically changed my ISO to 400, but I was somewhat surprised that the camera also used the sRGB color space in Program Mode. Interestingly, to my eyes, the Program Mode (the one with the green square on the dial) seemed to take the most accurate shot in terms of color space. By the way, apart from the flash, my (way too over- active) cat was illuminated mostly be a 40 watt tungsten bulb. I hope the color temperature differences show up once I post them - I can certainly see them easily enough even on my laptop display. All I did to these images was resize them and put the text in there. I didn't convert any profiles, sharpen or even run levels. Would anyone care to venture a guess as to what Canon's rationale might be in doing this? Perhaps there's some flaw in my admittedly unscientific methodology. Thanks!<div></div> Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 ^@ - that didn't display too well did it?<div></div> Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 D'oh! I even gave it a caption! Oh well...<div></div> Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 Just livin' right I guess . . .<div></div> Link to comment Share on other sites More sharing options...
aardvarko Posted December 6, 2004 Share Posted December 6, 2004 what did you have the white balance set to? it really looks more like four different EXPOSURES and two different balances - and the latter only because that miserable little onboard flash fired Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 White balance set to flash. I changed nothing between shots except the mode dial. Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 I used a 550EX - no miserable on-board flash. ;-) Link to comment Share on other sites More sharing options...
beauh44 Posted December 6, 2004 Author Share Posted December 6, 2004 Come to think of it, the exposure probably did change a bit as I went from mode to mode, but I'm not concerned about the exposure - I'm just curious why the white balance changes between modes is all. Link to comment Share on other sites More sharing options...
charlie_vigue Posted December 6, 2004 Share Posted December 6, 2004 I fyou shoot RAW you can see what WB was from the RAW data. Heck, it might even be in the JPEG EXIF data .... Link to comment Share on other sites More sharing options...
ilia Posted December 6, 2004 Share Posted December 6, 2004 Just a sidenote: Program mode is designated by "P" on the main dial. Green rectangle is so-called "idiot mode" where you surrender all controls to camera. Link to comment Share on other sites More sharing options...
kipling Posted December 7, 2004 Share Posted December 7, 2004 "Just a sidenote: Program mode is designated by "P" on the main dial. Green rectangle is so-called "idiot mode" where you surrender all controls to camera." <p> Is Canon trying to tell 20D owners something? A $1500 semi-pro camera with an idiot mode, pathetic. Link to comment Share on other sites More sharing options...
ture_p_lsson Posted December 7, 2004 Share Posted December 7, 2004 One obvious method flaw is that you have very little control over the balancing between ambient light (which I assume to be incandescent or fluorescent) and the flash, or at least you have not described what measures you took to control it. In "green" mode, Canons tend to go for flash-only exposures, while in Av and Tv they will use ambient light as much as possible. In a mixed tungsten/flash situation, this would easily account for a noticable shift in image colour. Link to comment Share on other sites More sharing options...
beauh44 Posted December 7, 2004 Author Share Posted December 7, 2004 Hi Ilia, The EXIF data calls it "Normal Program" mode. I think this is the first time I've ever used it! Charlie, I went back to look at the EXIF data and while it doesn't have the WB setting, I found something I never noticed before. On all of the shots except the "Normal Program" mode, there is a field called "White Point" and all three have a value of .3. On the shot taken in "Normal Program" mode however, that field is not present; instead there is a field called "yCbCr" and the value is "cosited". I haven't a clue! Anyone know what's up with that? Kipling, I don't think Canon is the only DSLR manufacturer with an "idiot mode"; doesn't Nikon have that mode as well? If a Canon user can't abide by the "idiot mode" of the 20D, they can always cough up for a 1D or 1Ds MKII. As I said, I believe this is the first shot I've ever taken using this mode. I am curious as to why the WB seems more "correct" in this mode. Ture, the ambient light as mentioned above, was indeed incandescent. But again, my question isn't in regards to exposure - in fact all of the images were exposed at least OK - but rather, the obvious shift in *white balance* as one changes the mode dial. Is this a "feature" and if so, why? It's no big deal; I think the 20D certainly does *much* better with flash than its predecessor, the 10D did. Thanks to all! Link to comment Share on other sites More sharing options...
phil vaughan - yorkshire u Posted December 7, 2004 Share Posted December 7, 2004 Beau, as Ture said the balance between the 2 different types of light is very telling. In the idiot mode there is so much of the exposure reliant on the flash, that there's no ambient light visible. In AV mode the exposure leans more to the ambient light using flash as fill in (and different modes have different balance ratios). Now if the flash was only balancing against daylight you wouldn't see the colour difference, however because you're balancing flash against an incandescent light, the WB will go all over the place. Hope that helps. Link to comment Share on other sites More sharing options...
beauh44 Posted December 7, 2004 Author Share Posted December 7, 2004 Hi Phil, That sounds logical. I'll try it again, outdoors, in daylight. Of course, this morning it's foggy as hell here! Thanks! Link to comment Share on other sites More sharing options...
phyrpowr Posted December 7, 2004 Share Posted December 7, 2004 FWIW, several years ago I went to one of the Nikon schools, and the presenters told us flash impaired folks to use the idiot mode, that the computer knew more about flash than 90% of photographers. It's worked pretty well for me. One caveat: focus first in a different mode (P, Av, whatever), as idiot mode will pick out a bad focus point almost every time Link to comment Share on other sites More sharing options...
phule Posted December 7, 2004 Share Posted December 7, 2004 << Is Canon trying to tell 20D owners something? A $1500 semi-pro camera with an idiot mode, pathetic. >> Where is it written that photographers of any skill level can not purchase the 20D? Why is having a full auto mode on a 20D somehow "wrong" just because /you/ think it's "semi-pro" ? Link to comment Share on other sites More sharing options...
scott_ferris Posted December 7, 2004 Share Posted December 7, 2004 Hi all, hope this helps!<div></div> Link to comment Share on other sites More sharing options...
scott_ferris Posted December 7, 2004 Share Posted December 7, 2004 Hope this helps too,<div></div> Link to comment Share on other sites More sharing options...
scott_ferris Posted December 7, 2004 Share Posted December 7, 2004 Hope this helps, three<div></div> Link to comment Share on other sites More sharing options...
scott_ferris Posted December 7, 2004 Share Posted December 7, 2004 Hope this helps, four, Beau you need to keep the longer side smaller than 511 pixels to upload within the thread. Take care, Scott.<div></div> Link to comment Share on other sites More sharing options...
scott_ferris Posted December 7, 2004 Share Posted December 7, 2004 P.S. I agree with Ture and Phil, the WB is showing true colours, in the idiot mode it is all flash, in the other modes different amounts of flash and ambient are being represented accurately depending on the bias of flash to ambient. Take care, Scott. Link to comment Share on other sites More sharing options...
mark u Posted December 7, 2004 Share Posted December 7, 2004 You need to read the flash bible at www.photonotes.org which explains the different ambient and flash exposure choices made using the different exposure modes. If you had read the manual you wouldn't have been surprised by the switch to sRGB in green square mode. Mean time, check your EXIF data and I'm sure you'll see different shutter and aperture selections. Those who said that the lighting is different, producing a different colour cast are correct. Link to comment Share on other sites More sharing options...
test11664875106 Posted December 8, 2004 Share Posted December 8, 2004 I've got 20D less than 2 weeks ago, but the first thing I did was to learn how to "teach camera what is gray". I always carry pocket-size gray card with me (even when I was shooting film only) and first shot I do is of this card. Now with 20D it's not only EV reference, but also serves as "calibrating target" for WB - in Menu/Custom WB tell camera "hey, this one is your white balance reference". Not only it sets WB more accurate, but also you have wider range of color temperature (lowest limit 2000K versus 2800K in other modes) and can account for bizzare magenta/green shift of flourescent lamps. All this in assumption that you want to get as close to actual colors as possible. For 'warming up' the image I'm still planning to play with WB-shift. Link to comment Share on other sites More sharing options...
chris_schultz2 Posted December 9, 2004 Share Posted December 9, 2004 <em>"Is Canon trying to tell 20D owners something? A $1500 semi-pro camera with an idiot mode, pathetic."</em> <BR> If a consummate semi-pro were in the middle of nowhere with a 20D and wanted his/her picture taken with a slowly moving target (giant sloth?) so self-timer not an option, and a photo-idiot wandered by, the semi-pro might be happy to have the idiot mode. Is the owner of a camera the only person who is allowed to press the shutter release? Link to comment Share on other sites More sharing options...
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