View Full Version : Metering for white birds vs black birds
I was reading some info about metering light for white birds and the various pitfalls and good strategies. So, when faced with a bird that is predominantly black (e.g.., black swan), does the inverse apply?
Whilst perusing the options on metering re white birds, it did seem that there were various options available and many varied opinions about said options - almost a "dark art"? I feel it might be educational to have some input on this.
If it has already occurred (and I did have a quick search), then please feel free to point me in the right direction, however, I'd love to hear some views from the great users of light on this forum, cheers Deb :)
arthurking83
23-04-2015, 6:23am
The problem with metering is that there is no right way or wrong way to do it.
The reason why is simple ... it's rare to have the exact same shooting conditions replicated.
The subject matter doesn't really matter, other than for the colour and tone.
That is, the point that the white matter under consideration is a bird is irrelevant! What's important is that you notice the whiteness of the subject matter, how large it is in the frame and what metering mode you are using.
The fact that the white subject is a bird is unimportant, so the subject should be treated in a non specific manner. A white bird will meter the same as a white building, or white sheet of paper or cloud .. etc.
Again same with the blacks .. black is black. The only important consideration is how black do you want it to look.
My preference is to use spot metering and meter for the tone I'm trying to capture.
So(if I can) I'll spot meter on my white subject, and set metering with +1 to +1.5Ev exposure compensation to get that subject white.
As I said earlier tho, because not all situations are the same, sometimes you can't actually spot meter on your subject. This could be for various reasons such as your spot meter doesn't extend to that point in the frame .. or more simply that the subject is too fast to accurately track. Other situational changes are that the subject isn't large enough in the frame to actually spot meter from.
As an example of this: lets say the spot meter area for your camera works on a 6mm area in the viewfinder in your camera. If a white bird(say against an all blue background) is small and far away, it may only encompass a 1mm area of the frame. Doesn't matter how fully featured your camera is in that it may allow spot metering from edge to edge of the frame of your camera, the spot metering feature in this situation is rendered useless for metering for the bird as white. So you need to adapt.
Because the background is predominantly blue, and the white bird only takes up 1/6th of the spot metering area, the other 5/6ths of the spot meter area are therefore going to see blue.
So what I would do is (before the situation arises) I test to see how my camera and lenses react, or render, to conditions where different colours and tones are needed to reference another colour/tone.
From memory(noting that some of my lenses render differently) but to render a white subject +1Ev using blue as the reference point, I just set zero exposure compensation for the blue.
Again, this also depends on other factors such as am I using a CPL(not always, but occasionally I do) .. and which lens.
If I'm using a CPL, and it's working efficiently(that is, has darkened a blue sky well), then I may set -1Ev instead.
Back to the white bird. Remember I like my camera to render white at about +1Ev(maybe more).
The reason I do this is simple. The camera's meter is set to render any 0Ev exposure at a middle tone level.
So if your scene is basically greyscale, and if you meter at 0Ev on a middle grey subject, the camera will render that subject at middle grey.
If you meter on a white subject at 0Ev, the camera doesn't know that it's white. It thinks it's white because of some elaborate programming technique done at the manufacturers premises, but it doesn't see the way we do.
So the resultant 0Ev exposure on a white subject is that while it looks pretty white, it's a dark white. A little bit (what is generally called) muddy in tonal value.
if you want a more true white, you need to give it more exposure. ie. +ve exposure compensation on the white.
But again, this depends on how white your white subject actually is.
From my experience(s)... a domesticated duck(muscovy I think??) is not really bright white, they tend to be more dull, almost grey(but not grey). They're always dirty so I meter them at 0Ev. Seagulls(if I can get them large within the frame) tend to be brighter on some parts, but obviously they do have variable tones, tending into grey and black in some parts of their feathers.
The amount of light on the seagull makes a difference on how much exposure I give them.
I tend to see them more so in direct sunlight, so they not only appear brighter, but are obviously reflecting more light back .. hence the bright exposure. But under shadow, or simply in darker lit conditions, you would obviously vary your exposure to reflect this different condition.
As you said, black is the inverse. when I spot meter on black subjects, it's always -ve compensation.
I can't specifically remember black swans(haven't seen one for years), but my folks have a black dog, and in many conditions I tend to expose him at -2Ev up to -2.7Ev(spot metered). He's a very dark black tone.
hope this helps.
Mark L
23-04-2015, 10:56pm
I respect your knowledge AK, though for birds that are reasonably close this is the inverse of what I would do? If I have a white spoonbill filling half of the frame that I've spot metered on and then +ev I'm blowing any detail in the feathers?
arthurking83
24-04-2015, 7:09am
...... If I have a white spoonbill filling half of the frame that I've spot metered on and then +ev I'm blowing any detail in the feathers?
I guess it depends on the camera model, lens, actual conditions, etc .. and more importantly how much +ve compensation you're dialling in.
my metering info thread (http://www.ausphotography.net.au/forum/showthread.php?132254-Camera-metering-what-it-s-doing-and-why-it-s-dumb)
In that metering thread, the two images shot with spot metering and appropriate compensation: where the spot was on the white box, with +2ev the image lost no details in the highlight area.
of course the dynamic range isn't overly massive, but the idea is the same.
The most crucial point to remember with metering(mainly spot metering) is that the idea behind it is that the exposure is going to come out neutral toned. If the metered area is mid grey ... perfect!
Just as you would do with a grey card in a studio to determine an accurate exposure point. Shoot the grey card with no exposure bias and that's your exposure level.
But white needs to be rendered brighter(than grey) .. so more exposure is required .. ie. +ve exposure bias .. and as Deb says .. the inverse for any black subject(-ve exposure bias).
The amount of whiteness or blackness you want to render determines your exposure compensation amount.
The term blowing out detail is a relative one. The loss of detail is going to depend on what image type mode you shoot with(jpg/tiff/raw) .. and how well your software can recover any 'pseudo' lost highlight detail.
eg. with my D70s, I can probably recover up to +1Ev lost highlight detail. That is, I don't dare shoot more than 1Ev of over exposure with that camera. But with both the D300 and D800E, I can shoot just a touch more .. maybe +1.5Ev over and still recover back all the lost detail and colour.
Note that this doesn't mean that I limit(or used too limit) the D70s to +1Ev compensation. I'd still set it to +2Ev (or even more) if the conditions required it, if white was my reference metering point.
Same with the other end .. I'd shoot well into the -2Ev compensation range if the subject I'm spotting on is really black.
Of course you don't need to push the amount of exposure, or dynamic range capture in every image, and where i don't need too, I don't. In fact in most of my captures I prefer to shoot a bit below what most would call a normal exposure(more and better colour :th3:)
You push the exposure point only if you need to maximise the amount of dynamic range for the scene. This is a separate idea to exposing for a particular tone.
as an example:
my folks have this little black dog. He's quite black in some parts, and a little grey around his face. If I'm photographing him against say a very bright background, and I don't want it(the background) over exposed .. normally I'd shoot the pooch with about -2Ev dialled in(that's something I know is my default .. with a few tweaks). But if the background looks nice and I want it captured, then I'd dial in even more -Ev to capture the background too, knowing that I may lost some shadow detail in pooch .. so, lets say at about -3Ev I'm losing shadow detail. I know that I can recover up to about 3-4Ev of shadow detail in the D800(maybe 2Ev with the D300 and D70s).
So, if my base exposure for a black subject is about -2Ev normally .. and I want about -1Ev of dynamic range extension .. then I shoot at -3Ev. The lost shadows are recovered in PP, and if the highlights are still blown then an attempt will be made to recover those too.
The alternative is that I may shoot for the highlights, set exposure compensation to about +1 to +2.5Ev so that I can recover them later in PP. The amount of over exposure depends purely on the apparent colour of the highlights.
Real interesting thread!
Ansel Adams Zone System is worth looking at to understand exposure and metering. It was originally developed by Ansel Adams and Fred Archer in the 1930s to help them achieve constant perfect exposure.
Here's a really good tutorial on the Zone System: http://photography.tutsplus.com/tutorials/understanding-using-ansel-adams-zone-system--photo-5607
I hope it's OK for me to post the link in this forum?
I'm by no means a zone system expert but having an idea of how the zone system works gives you some tools to use when you're desperatly staring at your matrix metered photo on your camera and think "Damn it! Exposure is not how I want it to be but I don't know what to do about it!"
Anyone else using Ansel Adams Zone System?
J.davis
15-07-2015, 8:24pm
Read this for a "this is what I do' explanation of bird pics.
http://www.melissazappelli.com/blog-collection/2015/7/12/alfred-cove-photography-tip-exposure-for-white-birds
Bennymiata
30-07-2015, 6:12pm
I've found in my experience that most camera meters tend to expect a neutral gray, and so when taking photos of predominately white objects, I usually use +1 or +2 exposure compensation.
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