Canon EOS 5D Mark III Product Advisory
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BDD said:Alker said:
Maybe beause they test the camera with the lenscap off.......
This only happens with the lens cap ON? I assumed with it off. If it only happens with the lens cap ON this really isn't an issue.
Well, to be fair, it'll also happen if you're photographing black cats at the bottom of an unlit coal mine. Granted, in those kinds of conditions, using the backlight (or a flashlight) on the top LCD is an entirely reasonable thing to do. But using the built-in meter in those conditions is not a reasonable thing to do, which is why those of us who take pictures of things other than the insides of our lens caps are so puzzled....
I think if people understood the nature of a logarithmic scale, this wouldn't be an issue. Let's say that the backlight lights up the meter sensor the same as a gray card in -6 EV light (which seems to be about what the math suggests). If you're actually in the middle of nowhere at midnight on a clear moonless night, using the backlight will change your exposure from 4 seconds @ f/2.8 @ ISO 12,800 to 2 seconds @ f/2.8 @ ISO 12,8000 and you'll underexpose by one stop.
Now, let's say you come back a week later and you've got a half moon out lighting up the landscape. Proper exposure is up to 1 second @ f/2.8 @ ISO 12,800, but you decide to keep a slow shutter and drop the ISO for 2 seconds @ f/2.8 @ ISO 6,400. You turn on the backlight. This time, it's not adding a stop to the proper exposure, but only a quarter stop -- maybe not even enough to register on the meter, maybe enough for it to be off by a third of a stop if it's right on the cusp.
Another week later, the moon is full, and you're at 1 second @ f/2.8 @ ISO 6,400, and the backlight is only adding an eighth of a stop to the exposure reading. Nothing short of putting the lens cap back on will make the "problem" detectable now.
The next night, you go to the county fair at night. You're at 1/60 second at f/2.8 @ ISO 800. The LCD's pollution is 1/4000 of a stop.
Remind me why we're having this discussion...?
Cheers,
b&
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E
esi32
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Viggo said:
In Evaluative, the metering is tied to the AF system to determine the importance of a given zone (in focus or not). It may also be tied to Servo v. no servo because they present different "focuses" on operation (tracking a moving object v. a non moving one).
Moreover, in general the focus affects the metering by changing the light that's incident on it. So does changing the focal length if the aperture doesn't precisely change to compensate. Inner and rear focusing lenses change focal length (which is why the generally breath) when focus is changed. If the aperture isn't precisely compensating for the focus, the result can be a sufficent error in light transmission, hence the meter changes.
sparda79 said:
I've both gaffer taped over the LCD and compared the exposures to those on my 1D3 and I get the same reading within a 1/3rd stop. So in my experience, black gaffer taped LCD, uncovered LCD, and 1D3 with similar framing and identical lens, perform nearly identically in practical shooting situations.
As I said a page back I'm going to be going though a much more riggerous testing routine, and publishing my findings, simply because it interests me. But in my un-scientific, but generally way better controlled than I've seen anybody else do, tests I find that in practice the meter is completely unaffected over the design ed 1-20EV range, and maybe a few stops more than that. THough one of the things i'm looking for is the relative difference in power between T-LCD incident light and though the lens light to start skewing an exposure.
TrumpetPower! said:
So far as I can tell, the meter has a noise floor around -4EV, due to thermal/dark current noise and the fact that there are those LEDs in the viewfinder contributing light. And by the specified design, anything darker that 1EV isn't guaranteed to meter correctly in the first place.
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CarpetFeet said:
+1.
All I have seen is some slight odd behaviour with the lens cap on and the eyepiece blocked and completely expected behaviour with the lens cap off.
Move along, nothing to see? A bit like the back of a lens cap....
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ramon123 said:
As far as I can tell all they have done is acknowledge the 'phenomena'. The only mentions of recalls has been in the near hysteria all over the forums.
ramon123 said:
Hopefully when they have assessed it and decided what, if any, action is necessary.
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TrumpetPower! said:
You make too much sense. I find your logic and reason in wake of such hysteria to be quite disconcerting ;D
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TrumpetPower! said:
And what about a white bear in the snow storm? Will it be correctly exposed?
TrumpetPower! said:
I dunno but I know now why I haven't bought it. I had a feeling I could not make good photos of black cats at the bottom of an unlit coal mine and white bear in the snow storm...
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marekjoz said:
Actually, yes. Snowstorms are generally pretty dim conditions. The spec for the 5DIII goes all the way up to EV 20, which is a few stops beyond the white bear on an ice plain at high noon in the middle of summer. Actually, EV 20 is 1/2000 @ f/22 @ ISO 100, so much of anything beyond that and you'll need an ND filter just to be able to get the camera to record the scene at all. Not to mention welding glasses for yourself....
Rest assured, the 5DIII is excellently suited to polar bear photography. Can't help you with the spelunking felines, though, I'm afraid. I hope that's not a deal breaker...?
b&
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TrumpetPower! said:
Happily my cat is red-haired and very jealous of me making pictures of other cats, no matter how deep they would try to go
Truely speaking I'm not decided yet whether to sell 5d2+7d, add some cash and go for 5d3 or get some another glass...
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marekjoz said:Happily my cat is red-haired and very jealous of me making pictures of other cats, no matter how deep they would try to go
Hmmm...to be honest, I haven't even thought of taking pictures of other cats. I don't think mine is the jealous type, but I'm not sure it'll ever occur to me to find out....
That actually should be a pretty simple decision to make.
If you exclusively or mainly do slow-paced low-ISO work, especially in studio settings or landscapes or that sort of thing, get the glass. No question.
If you do anything performance-related, especially events / weddings / sports / journalism / kids, or if you want to do that sort of thing or are planning on doing it, get the 5DIII. Again, no question.
Cheers,
b&
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TrumpetPower! said:marekjoz said:
I almost came to same conclusion but still try to fight against new toy
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B
BDD
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I did a little more reading on this LCD light changing the exposure issue. Turns out it's related to the LCD on the top of the camera. If it's dark and you illuminate...that's when it happens. I didn't think any one actually used that feature (illuminating the LCD display on tops of cameras). I never do. So this is a non-issue. All the same this should still be addressed by Canon. For those that like to shoot in the dark and illuminate the top display.
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sparda79 said:
Oddly enough, this is the one test that I didn't see anybody carry out even though it is the only test that would even matter. Take a shot with camera under direct noon sun shooting into deep shadows, if it doesn't affect that then the whole thing would seem to be much ado about nothing. Where it does affect things in the deep, dark district 12 mine I don't see why you would be expecting to use the meter or not using liveview anyway. Perhaps there are some legit circumstances since Canon have made a big deal about it but it seems hard to think of. Honestly I'd look into getting a sharp 1.6x crop video mode and some zebra stripes and focusing peaking in there for video and removing the /250th max min shutter speed in AutoISO and fixing up EyeFi card usage before wasting time and money on this exposure thing which might possibly not be an actual practical issue. Although I guess they do get props for listening to forums.
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C
cschmeer
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Canon Europe has posted the same message
http://www.canon.co.uk/Support/Consumer_Products/products/cameras/Digital_SLR/EOS_5D_Mark_III.aspx?faqtcmuri=tcm:14-924822&page=1&type=important
Waiting for a fix! Love the camera, but what I don't like so much about the Mark III is that the buttons feel kind of cheap when you press them in comparison to the Mark II and the large thumbwheel makes variating rattling noises when you turn it (the Mark II had a rock solid clicking thumbwheel). Maybe it's just my 5D Mark III that has this rattling thumbwheel?
http://www.canon.co.uk/Support/Consumer_Products/products/cameras/Digital_SLR/EOS_5D_Mark_III.aspx?faqtcmuri=tcm:14-924822&page=1&type=important
Waiting for a fix!
Love the camera, but what I don't like so much about the Mark III is that the buttons feel kind of cheap when you press them in comparison to the Mark II and the large thumbwheel makes variating rattling noises when you turn it (the Mark II had a rock solid clicking thumbwheel). Maybe it's just my 5D Mark III that has this rattling thumbwheel?
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