Dark Birds over Water - Matrix or Spot Metering

[Brownbear]

I've been trying to figure out the best metering mode to use for dark coloured birds. Oftentimes matrix metering works just fine but I also often end up with an overexposed water or sky. For black birds like cormorants it seems to me that spot metering off of the bird is the best way to achieve proper exposure of the bird. Against a blue sky exposing for the bird blows the sky, against dark water it seems to work well even if it overexposes the water a little, it is not as much as the sky.

However, I am still confused as to the best metering choice... In the following example both shots were photographed with SS 1250 F8, exposure bias +.3, iso 1000 in the first shot and an iso of 1000 in the 2nd shot (auto iso)

Matrix Metering



Spot Metering off of the brown feathers



The photos are almost identical to me, including the histograms... The exposure in the matrix metered photo is a little lower but not much. I think I can see more detail in the goose in the spot metered shot but the matrix metered shot seems to produce a warmer bird and richer water.

I'm trying to learn to choose the best metering method for birds, and I'm not even sure what I am asking except to say that I would like to know more about matrix vs spot metering for dark coloured birds on water... I would like to understand the key differences and the pros and cons of each.


Thank you.

[Mike Buckley]

It doesn't matter which metering method you use in that you can achieve the same exposure using all metering methods, as we have discussed several times. The only thing that matters is which metering method most easily achieves for you the look that you desire.

Your answer to that might be the same or different from everyone's answer, so attend to the method that works best for you. You will probably come up with definitive thoughts about that only after lots of practice and experience. People can suggest what works best for them and you can repeatedly try whatever they suggest, but in the end you have to select a method that works most predictably and easiest for you.

You mentioned that the histograms are almost identical. The histograms displayed on my software are shown below. I suppose everything is relative, but they seem very different in my mind. That explains at least partially why your two photos look so different.

Photo #1 - Matrix Metering



Photo #2 - Spot Metering

[Stagecoach]

Hi Christina,

I suspect you are going to get a number of responses with differing opinions with some perhaps based upon different photographers preferences. So I am not going to make any suggestion as to which mode is the preferred.

What I would say is that lighting can change very quickly when photographing moving subjects such as these which can be caused by such things as clouds, reflections and direction. Perhaps it's also worth taking into account when determining which mode to use the amount of correction that you expect you can achieve safely in PP.

Grahame

[Brownbear]

Thank you Mike and Grahame for sharing your expertise and thoughts.

Mike, those histograms looked similar to me, and still do but then again I don't have much experience looking at histograms. I am pretty sure I kept the WB and edits in LR the same, but I will double check the WB...

I've been experimenting with metering for a few weeks now but maybe it will take me a year to learn properly. What I do know for sure is that if I use matrix metering on a black cormorant the bird ends up underexposed, but if I use spot metering (right on the black bird) (both on water) I can expose for the bird properly, so no noise.... Hence I am trying to understand this to improve my shots of black birds.

Thank you for sharing Grahame... Yes, the light changes quite a bit with the birds over the water depending on the angle and the direction. Great tip... I will try and start think about PP while photographing...

[Mike Buckley]

What I do know for sure is that if I use matrix metering on a black cormorant the bird ends up underexposed, but if I use spot metering (right on the black bird) (both on water) I can expose for the bird properly

That's great progress in the sense that you have eliminated the use of matrix metering because using spot metering renders more predictable results more easily for you. Now try center-weighted metering for awhile. You can't be sure which method works best for you in a given situation until you try using all of them. After awhile, you'll understand what the camera is doing and how you interact with it to know which method works in a particular situation the best for you.

[Brev00]

In my approach, I do not worry so much about the dark tones. It is very rare that I might overexpose the dark tones and get a grayish result. Even your goose has white patches. So, I try to watch the blinkie screen and keep my shutter speed high enough to avoid too much overexposure of the whites. The white feathers are too small to spot meter so checking on the lcd is maybe the only way. If I were in aperture priority, I would add -ev. Same result.
[IMG][/IMG]
I hope this is a good example of the kind of blacks you want to get. I would definitely try to keep my iso down as low as possible. You will always get more dynamic range at the lower iso numbers. Shooting this at iso 400 is a bit high for me so I might have been coming from shooting some soccer. Processing these shots in ACR really helps a lot as I can adjust the blacks and the fill and the brightness precisely to get just the right depth of color I am after. You really don't need a very high shutter speed for these sorts of birds unless you want to catch them in flight.

[Colin Southern]

Hi Christina,

Do you understand how spot metering works? -- It's not how a lot of people think.

[Stagecoach]

Christina,

Colin asks a very valid question.

I have just done a comparison between the spot metering information in my camera manual and that on the Nikon site. The information on the Nikon site explains how it works far better than the manual.

[Colin Southern]

Christina,

Colin asks a very valid question.

I have just done a comparison between the spot metering information in my camera manual and that on the Nikon site. The information on the Nikon site explains how it works far better than the manual.

Just to give folks a quick run through ...

Common misconception is that spot metering gives a "correct" exposure for the subject matter under the spot, but in reality, all the metering does is adjust the exposure so that the area under the spot is middle gray. Spot meter a black cat and you'll have a gray cat. Spot meter a white cat and you'll have a gray cat.

So -- spot metering is fine (if other things are throwing the metering off) - BUT - after spot-metering, you then need to add positive or negative compensation to shift the tone to where it's supposed to be (assuming that it's not already middle gray). eg if it's something black then you'll need to dial in -2 EV; and if it's white, you'll need to dial in +2 EV.

In the case of a duck - personally - I wouldn't spot meter it unless it was a consistent tone all over; if, for example, it has a black head, white tail, and gray body, the exposures will be a lottery depending on which bit the "spot" is on.

Generally, I'd just stick to whatever mode covered the area that was consistently lit, and then bias the exposure a bit either way. Dark birds won't reflect as much light as, say, a white swan, but generally the camera captures way more info than is needed, so all one has to do is just just a bit of fill light in post production.

In reality "dark birds" are no different to "dark suits".

If I was shooting a lot of shots in the area I'd probably pick one exposure that looked good and then dial that into manual mode so all exposures were the same.

[jprzybyla]

Hello Christina, you seem to be searching for some magical setting that will work all the time... won't happen. Capture the data ( RAW ) and then work on the exposure in post processing. Using the global settings expose for the background ( water) and then using the Adjustment Brush work on just the bird. Sometimes the whole bird, sometimes an area, and sometimes just a feather. The digital camera in capturing RAW images is just a data collector. If the images are within a couple f stops of correct exposure and neither the bright or shadow highlights are clipped the image can be exposed correctly. That is why I use Matrix Metering with the blinkies to ensure that the bright highlights are not clipped and experience to expose for the shadows. Experience has shown that for white I need to underexpose and for black or dark birds to expose at what the camera's meter determines is correct. Normally there are not any shadows ( if the image is captured in good light ) that are too dark. I use an exposure that balances the exposure for the whole image frame and adjust from there using the +/- EV button. In post processing the control of an image is almost endless where trying to do it in the camera is always a compromise. In nature photography things happen to fast to sort out a compromise. Another point to remember is that dark birds require more light than white birds because they reflect less light.

[DanK]

Christina,

Colin beat me to it. I'll just build on what he wrote.

As Joe says, no one method will always give you the right exposure. I think it is both more accurate and in the long run more helpful to think of metering not as a way to get a correct exposure, but rather as a way to get information that you can use to get a correct exposure. All the automatic functions on current cameras obscure this fact, but it comes more naturally to those of us who grew up in an era in which the sum total of electronics in cameras was a built-in meter. In many cases, because of the sophistication of current cameras, the information from a well-chosen metering method will be enough for the camera to set exposure for you. Often it will not be. You have to learn when this is likely to be true. There is no rule for selecting metering modes that will do all this for you.

The big advantage of spot metering, which I use often, is that it gives you more control over where the information is collected. It comes from a small area, which you can park over any surface you choose, and unlike more complex metering methods, it is not being manipulated by a complex computer algorithm. Used with either exposure compensation or manual mode, this gives you a great deal of control. You can meter off a neutral tone and leave the exposure as the camera reads it, or you can meter off a bright or dark tone and adjust accordingly. When the tonality in a scene is hard for me to meter, I sometimes meter off the palm of my hand (in the same light, of course) and then open up one stop. Similarly, in a snowy scene, you can meter off the snow and open up one or two stops.

Re Mike's histograms: If you want to master exposure, you will have to get to the point where you are confident in your ability to read them. With that knowledge, you can look at the histogram from one shot and see at a glance whether your initial decision about how to meter worked as you wanted. The two histograms are quite different in two critical respects. Look at the blue and cyan on the right. In this case, it is not so important which colors are there. What is important is that in the second histogram, the top of the distribution is farther to the right. That means that you have more pixels allocated to the brighter area at the right. Now look at the red on the left. There is more mass (more pixels) near the bottom end. That, in conjunction with the higher top end, means that the second photo has more tonal range. This is a very terse description, but I hope it helps.

Dan

[Brownbear]

Thank you to all... Tons of great information here for me to digest... Thank you for the edit.

I will reply later today when I have more time.

[RustBeltRaw]

In line with Colin's comments, I'd like to add that I stick with matrix metering at all times, simply because its exposure judgments seems most plausible compared to spot or center-weighted average. The histogram is always the key, regardless of the metering mode.

As a mainly manual shooter (a result of frequent flash use and personal preference), matrix metering seems to be the best match. Especially when shooting action, where metering off the central 3% of the screen can produce dramatically variable results. Point it at a player's black uniform, then they move and you've got a hot light in the center, and boom, your exposure swings 7 stops when the light on your subject hasn't changed. Matrix metering minimizes those swings, and in my mind, gives a more reasonable interpretation of the scene.

[Mike Buckley]

If you want to master exposure, you will have to get to the point where you are confident in your ability to read [histograms].

The histogram is always the key, regardless of the metering mode.

If the images are within a couple f stops of correct exposure and neither the bright or shadow highlights are clipped

Christina,

Notice that those quotes from three different people are of essentially the same theme: the histogram (though it's not perfect) is your guide.

Use whatever metering method most easily achieves a reasonable histogram and take your test shots. Review the histograms of your test shots and adjust your exposure accordingly if needed. Then continue shooting using whatever method ensures that your set of exposures will render approximately the same results, whether that's continuing with your preferred metering method or changing to manual exposure to lock in the results that were achieved using the camera's meter. Fine tune your results during post-processing.

[Brownbear]

Thank you to all. I'm really happy that I asked this question because I have learned a lot from everyone's replies.

Mike
Yes, I will continue to experiment with all types of metering including center weighted metering. Thank you for always summarizing the key points for me, it ensures that I don't miss the key points.

Larry
Yes, I can see from your edit what the true blacks should look like. The ocean water is blue but I will try an edit like yours to bring out the black and see if I can keep the water blue. Thank you for showing me this. Truly appreciated. I have to learn how to deal with the grey when using spot metering.

Colin

I have a fair understanding of the various metering modes and I'm experimenting with them so I can learn and see with my own eyes what happens...

I do understand that I have to dial in the appropriate exposure compensation but I did not know that there were set specific numbers of -2 and +2, I've just been going by my histogram but I will try those.

I am using manual mode on my camera but I often use auto iso for birds. Are you saying that I should lock in the iso, even if the bird is not going anywhere?

Joe
Yes I suppose I am looking for some magical way to achieve perfect exposure every time to limit post processing, especially lightening shadows on dark birds. Birds against the sky I can handle but I am not happy with the way my water looks on some shots and it is too, difficult to fix in post processing.

As always, thank you for sharing your expertise on photographing birds. I've learned a lot from you. All your points are duly noted but for some reason with black and white birds I have found more success using spot metering. (ie; totally black or white birds) It may well be that one day I will use matrix metering all the time.

Whenever I use matrix metering on a crow or cormorant the bird is underexposed in parts which means I have to lighten shadows which leads to noise. But I see that a lot of people are using matrix metering so I will just keep experimenting until I truly understand what I'm doing. Black birds are my biggest challenge right now.

Dan

Thank you for taking the time to point out the specifics of my histogram. I need to read more on histograms and revisit the tutorials on the subject here. I've read them before but of course as I learn more, the more I realize that I need to study more. I am also going to have to learn keep post processing in the back of my mind when I take photos. Thank you for sharing the palm metering tip.

Grahame, Thank you. I will check out the Nikon info.

Lex,
I did not know that matrix metering minimized those swings. Good to know.

Here are some of my experiments using spot metering on black birds... I did not have to increase exposure or lighten shadows to bring out any detail, and in a few I likely decreased exposure a bit.

I think they show more detail. Yes or no?

Are they too grey versus too black? How do I deal with the grey in post processing?










A Cormorant

This is the black bird I am trying to capture in flight over water. When I use matrix metering the bird is underexposed and it is extra challenging to photograph this bird in flight because it is always soaking wet with water dripping off of its back.

[Mike Buckley]

I do understand that I have to dial in the appropriate exposure compensation but I did not know that there were set specific numbers of -2 and +2, I've just been going by my histogram but I will try those.

Colin was only using those as examples when shooting black or white subjects using spot metering. As an example, when photographing a black wall whether you use spot metering, center-weighted metering or matrix metering, a reasonable approach is to adjust your exposure compensation at -2 EV. Similarly, when photographing a white wall, you could adjust it at +2 EV. Naturally, depending on how black the black is or how white the white is, the amount of exposure compensation would vary. The use of +2 or -2 EV is nothing other than a typical starting point in those two particular situations, after which you should review the histogram and, more importantly, the image on your computer.

[Digital]

Christina, I saw on a video recently that in built cameras meters "see' everything as 18% gray, and are 100% stupid.


Bruce

[Brownbear]

Mike, Thank you for taking the time to clarify. I will use the numbers as a guideline... It would be nice indeed if there were set numbers.

Bruce.... Thank you for the best quote of the day.

[Colin Southern]

I've just been reading through all of the replies, and it's occurred to me that people might be missing the point. A technically correct exposure of pretty much ANYTHING is pretty easy to achieve; if the scene is purely reflective (eg a black swan walks up the boat ramp and across the grass and you photograph it with a long lens that doesn't capture any sky - and with the sun behind you) then evaluative/matrix metering will nail it each and every time.

In this scenario the correct exposure will mean that highlights (white things) will reflect the most light and be captured as highlights and dark things (including the black swan) will reflect the least amount of light and be captured as "shadows". The exposure will be correct, but the image won't be visually pleasing because the swan won't show a lot of detail.

One way around it is to add a stop or so of +EC - that'll raise the amount of detail visible in the swan (shifting it from a black to a medium-dark gray), but the problem is that it'll also bump up everything else to the point where they look colourless and washed out.

In reality, what you have here isn't an exposure problem so much as it is a tone mapping problem; the low tones need to be increased but without also increasing the midtones and highlights. In other words, it's a problem you're only going to be able to fix in post-processing.

For a purely reflective scene (ie with no back-lighting) I'd be wanting to use a metering mode that gave me a correct exposure where highlights were highlights, midtones were midtones, and shadows were shadows FOR THE WHOLE SCENE - and in that scene, the tones from the "black swan" would lay where-ever it is that they lay. Or from a different perspective, the narrower you make the metering scope evaluative -> partial -> spot, then (a) the more the rest of the scene will be a lottery and (b) the more aware you're going to have to be of dialing in correct compensation.

All of the above is for purely reflective scenes - if the scene has a degree of backlighting (eg shooting a bird into the light) then getting a good result is going to be tricky; thinking of the sunny 16 rule, people often forget that it refers to a front-lit object (ie the light behind you) - when you're shooting into the light then the back of the subject essentially shields the light and is thus by definition in shadow - and generally that drops the light by around 3 stops, but again, something has to give; if your metering takes the backlighting into account then the (in shadow) subject will be horribly under-exposed, but if you add +3EC to open up the shadows of the subject then the background will be unrecoverably blown. Again though, it's not an exposure problem -- it's a dynamic range / tone mapping problem in that you'll typically be capturing around 7 stops of info, but these have to be compressed in the right way so as they fit into the 4 stop range that we can print or the (slightly) larger range that we can display on our monitors.

By in large, I'd suggest using whatever mode captures the majority of the scene where it should be (probably evaluative/matrix for reflective scenes and evaluative/matrix + EC for backlit scenes), and then push/pull the tones in post-processing to get them where you want them (reveal dark detail with the fill light slider, and pull back the rest with Digital GND filters).

[jprzybyla]

Christina, remember Colin's explanation of spot metering wanting to expose for 18% gray. It appears that spot metering has overexposed the black birds to become gray birds.