• D7000 metering bias comparison

    After our previous look into how the D7000’s matrix meter favors the focus point, I decided to do a more rigorous comparison between the D7000’s matrix meter behavior against that of the D300 and D700. The idea here was to double-check whether indeed a camera like the D700 or D300 is more consistent than the D7000, as I originally suspected. It turns out all three cameras more or less behave similarly. An exposure from each camera with center-weighed metering using the “Average” setting is also included for your review.

    Focus point location D300 D700 D7000
    Center shadow area ISO200, f/11, 1/125 ISO200, f/11, 1/100 ISO100, f/11, 1/50 (equiv 1/100 @ ISO 200)
    Right chair back ISO200, f/11, 1/125 ISO200, f/11, 1/125 ISO100, f/11, 1/80 (equiv 1/160 @ ISO 200)
    Right chair stool ISO200, f/11, 1/160 ISO200, f/11, 1/160 ISO100, f/11, 1/100 (equiv 1/200 @ ISO 200)
    Left chair stool ISO200, f/11, 1/160 ISO200, f/11, 1/125 ISO100, f/11, 1/80 (equiv 1/160 @ ISO 200)
    Center, with center-weighed Avg/avg ISO200, f/11, 1/125 ISO200, f/11, 1/100 ISO100, f/11, 1/60 (equiv 1/125 @ ISO 200)

    Setup notes: The D300 and D7000 used the 16-85 VR lens, while the D700 used the 24-120 f4.

  • D7000: Matrix metering & AF area mode

    After reading about the D7000’s Matrix meter heavy focus point bias, some folks asked me to rerun the tests using an AF Area mode that employs more than 1 focus point, which is my default mode of operation. The idea (hope?) is that with additional focus points, the bias toward the focus point lessens, for more reasonable results. I performed several tests with 9 and 21 points, and here are a few samples for your review with 9 points (21 points didn’t behave differently).

    Single-point, focus point on white flower Single-point, focus point on shadows above flower
    9-point, focus point on white flower 9-point, focus point on shadows above flower
    Single-point, focus point on stamen Single-point, focus point on shadows at upper-left
    9-point, focus point on stamen 9-point, focus point on shadows at upper-left
    9-point, focus point on center flower 9-point, focus point on shadows just right of flower

  • D7000: biased Matrix metering

    It seems that with the advent of the D7000 many are pulling their hair out trying to figure out why the camera over-exposes. Without getting into the argument of who/what over-exposes, I thought I’d take a quick look at how my D7000’s matrix meter works. No surprises for me, since it appears it’s business as usual per my long ago earlier findings regarding Matrix Metering idiosyncrasies. Nikon is once again heavily biasing the focus point when making a Matrix meter determination — the good ol’ spot meter on steroids. To understand how this works (and why folks might be puzzled and frustrated), let’s walk through the next few samples. As a starting disclaimer please note that the following reflect -1/6EV that of exposure fine-tuning I have set for Matrix metering (not that it helped much).

    Suppose you arrived at this scene, set your D7000 to aperture priority, and snapped this shot. No problems here. The histogram shows a nice exposure. ISO 100, f/16, 1/80 sec
    Now you start moving around and zoom in for a different composition and… oh, boy. ISO 100, f/16, 1/25 sec
    So you remember the advice to spot-meter on a clear blue sky, you switch over to Manual mode, get the meter reading, and you get a more balanced exposure. ISO 100, f/16, 1/60 sec
    But it shouldn’t be this way, right? You scratch your head and think to yourself: what if it has to do with where I have the focus point? So you try the shot again, with the focus point the same as you had it before (you focused on one of the chairs, but you panned to recompose), in those shadows. Sure enough, you get the same over-exposure. At least we have consistency. ISO 100, f/16, 1/25 sec
    Now you move the focus point to the green chair on the right and re-take the shot. Hmm. Much better. Not only is it much better, but the exposure coincides with the manual exposure we achieved when spot-metering on the blue sky. Why? Well, the focus point is now falling on a middle tone (middle gray, if we were in B&W), and meters like to push things in that direction. Problem is, this explanation would make more sense if we were talking about spot-metering, but we’re not. Matrix metering should take the whole scene into account, and yet the focus point seems to be winning out in our results. ISO 100, f/16, 1/60 sec
    To make sure, you repeat this with the other set of chairs in the scene. First with the focus point in shadows… ISO 100, f/16, 1/30 sec
    …And then you move the focus point to the left chair. The exposure is about 1/3 under because now the focus point isn’t on a middle tone, but on a brighter shade, so the meter’s push toward middle gray darkens it a tad. ISO 100, f/16, 1/80 sec
    Finally, you go back to Manual mode and spot meter on the blue sky and aren’t surprised when you get a well balanced exposure. ISO 100, f/16, 1/60 sec

    (*) Note: though for older Nikon DSLRs, this sort of behavior has been tied to how Matrix metering works in AF-S mode, for these shots, I used AF-C.

    If Matrix metering is driving you a little crazy on your new D7000, you might want to keep these results in mind. My recommendation would be to rely more heavily on spot metering in Manual mode. In the end, you’ll be glad you took control over your exposures this way.

    To be balanced, however, I think it is perfectly reasonable for folks to be upset about the seemingly erratic choices Nikon keeps making for Matrix meter behavior. To illustrate what I mean, a few minutes after taking the D7000 sample shots, I headed out with my D700 to see how it behaved. As you can see, it gets the exposure within 1/3 EV and in neither case does it over-expose.

    Here’s the D700 in aperture priority mode, with matrix metering, focus point on the shadow areas. ISO200, f/16, 1/100 sec
    Still in aperture priority mode, with matrix metering, focus point on the right green chair’s back. ISO200, f/16, 1/125 sec
    Again, the D700 in aperture priority mode, with matrix metering, focus point on the shadow areas. ISO200, f/16, 1/100 sec
    While still in aperture priority mode, with matrix metering, focus point on right chair’s back. ISO200, f/16, 1/125 sec

    In parting, I’ll note that even with the D700’s (and D300’s) more reliable metering, I always rely on spot metering in manual mode far more than I rely on Nikon’s metering choices. I recommend you do the same.

  • D7000: when Sunny 16 isn’t

    With respect to the D7000’s Matrix meter and its reported tendency to over-expose, many recommend the simple sunny 16 for those scenes under bright sunlight and lots of dynamic range from bright highlights to deep shadows. As I reported previously, for previous cameras I tested (D80 and D90) when I use Sunny 16 for brightly lit scenes here in sunny Southern California I obtain under-exposed results. Would the D7000 behave similarly? The next few samples tell the tale.

    Suppose that you trusted Matrix metering to tell you the exposure for this scene. Here’s what you would get: about 2/3 stops of over-exposure (see below). Nikon D7000 & 24-120 f4 @ f16, 1/30s, ISO 100
    Suppose that muttering under your breath you said, “fine, since the sun is blasting this scene, coming from behind me, I guess I’ll just go with Sunny 16.” You would get this shot, arguably and under-exposure. Nikon D7000 & 24-120 f4 @ f16, 1/100s, ISO 100
    “Well,” you say to yourself, “I think I heard that this is the tone curve response. If I change the Picture control to a brighter one, like the Portrait or the custom D2XM1SIM picture control, I won’t get under-exposure. You take the shot after switching Picture controls and you get… Nikon D7000 & 24-120 f4 @ f16, 1/30s, ISO 100
    You finally realize this is not going to work, and you decide to spot meter on the sky. The exposure you get is much more reasonable and seems to handle this challenging scene with the best balance of shadows to highlights.

    Nikon D7000 & 24-120 f4 @ f16, 1/50s, ISO 100
    This is still bothering you, and you start wondering whether the lens is causing the problem. To rule this out, you swap lenses and you take another Sunny 16 exposure. Hmm, different lens, same result. Nikon D7000 & 16-85VR @ f16, 1/100s, ISO 100
    You spot meter on the sky again, and all is well with the world. Nikon D7000 & 16-85VR @ f16, 1/60s, ISO 100
    Incidentally, if you shoot RAW, not all is lost with that first matrix metered exposure. Take into ViewNX2, apply -0.7EV (1/30-1/50 = 2/3 stops) of compensation, and you get a fairly good result. Nikon D7000 & 24-120 f4 @ f16, 1/30s, ISO 100

    If you’re still protesting that Sunny 16 is universal, worldwide, etc., do this test for yourself. Find a midday bright scene, use Sunny 16 for subjects under direct, strong sunlight, and see what you get.

  • Exposing skin tones in shade

    In a previous installment we saw how proper exposure of skin tones is as close as the palm of your hand. Today we will apply this approach, comparing what a D700 does in Matrix metering vs. our take-control metering approach. Take note this is a D700, not a D80, D90 or D7000. The last 3 cameras are reputed to over-expose when used in Matrix metering mode. You might be surprised to see that the D700 doesn’t really fair any better.

    These two shots are taken in Aperture priority mode, letting the camera’s Matrix meter pick the exposure. Under-exposed subjects and blown backgrounds are the result. Yes, a D700 did this.
    These next two shots used Manual mode, using spot-metering on the nearest cheek to bring up the exposure. The result is still under-exposed, especially around the eyes, where the deepest shadows reside.
    The solution would be to spot-meter on those darker areas, with a goal to bring them into the midtones. Of course, that’s not what I did. I took one look at the histogram and knew immediately that opening up by about one stop would do the trick. Yes, the background is severely blown, but I chose what’s important in this exposure: the skin tones.
    As it turns out, center-weighed metering gives the same exposures.
    For this next set of shots, we use the post-processing method we discussed in prior articles: apply negative compensation (here with ViewNX), then add shadow protection to keep the skin tones where we want them. The result compresses overall dynamic range (and contrast), taming down those bright highlights.
    For the final set of shots, we used the 2nd set and applied only shadow protection in ViewNX. In terms of exposure look and feel, the results are nearly identical to the previous edited images, except that pixel-peeping will reveal additional noise creeps in the shadow areas around the eyes.

    If none of these results seem ideal to you, you’re probably right. Shadow pushing has really taken a toll on those two last pairs of photos. If you need to grab a quick snapshot where your subject is properly exposed, this approach will do in a pinch, but nothing can make up for bad light. This brings up a key point: this is not a metering or exposure problem, as much as it is a bad light problem. Moving your subject into a better lit area, or augmenting the foreground lighting with flash or reflectors will not only produce better exposures, but better photographs overall.

  • Metering in the palm of your hand

    When we looked at how to meter using the usual suspects, we saw that out in open sunlight, spot metering on clear blue sky gives us well exposed mid-tones. For me, this works out really well when I shoot outdoors, especially when capturing landscapes in those non-golden hour times of the day.

    Now that I’m doing more portrait work, however, with a key goal of keeping skin tones well exposed, things get a little tricky. As it turns out, for skin tones that lay somewhere along the midtones (middle gray in black and white), the solution is right in the palm of your hand. The next few sample shots demonstrate this approach.

    The first sample used matrix metering in Aperture priority mode, to let the camera choose its own exposure.

    At first glance, it looks like Matrix metering did a fairly good job. Upon closer examination, however, we can see that the reds are clipping (check out the histogram for yourself), seen here in the bright skin areas.

    What if we use the spot-on-clear-blue-sky trick? The results aren’t great, now heavily clipping the reds.

    Spot-metering on the palm of your hand, however, solves the problem. Though if you examine the histogram it will look like the highlights and the shadows are missing, the midtones are where they should be: in the middle.

    Will this work if we step back into the shade?

    The background may be blown now, but the skin tones are where we said we wanted them to be: in the middle. If you were to take a portrait under the same light of someone whose skin tones are approximately the same as the palm of your hand, their facial features would be well-exposed – not necessarily well-lit, but at least not blown or in deep shadows. Try this next time Matrix metering lets you down.