spot metering with my nikon d3100 help

[woodystyle]

Im trying to get spot metering down with my nikon d3100, but am having some trouble completing the task (I think). I understand the concept of it, finding a midtone in the picture, metering on that point and then recomposing in a nutshell. But I'm having a little trouble with the technical side of it. This is what my instruction manual says:

1. SET METERING TO SPOT METERING (I've got this)

2. LOCK EXPOSURE.
Position the subject in the selected focus point and press the shutter-release
button halfway. With the shutter-release button pressed halfway and the
subject positioned in the focus point, press the AE-L/AF-L button to lock focus
and exposure.

3. RECOMPOSE THE PHOTOGRAPH
Keeping the AE-L/AF-L button pressed, recompose the photograph and shoot.

So I guess what I'm confused about is when and where to start pressing buttons. The second step is where i'm lost.

Do I find the spot I want to use and press the shutter-button down on this and the AE-L together and then recompose? If so how will I refocus on the actual subject I want? This is really confusing. Here's a picture of my camera if it helps.

Any help would be appreciated

 

[Graystar]

The default setup for Nikons is to support the Focus & Recompose method, which I don't really think much of. Anyways...F&R and Spot metering are a mismatch...you shouldn't be doing it. You should be using Matrix metering with the method described in the manual.

Spot metering is the most demanding form of metering. If you get the exposure wrong, you can't blame anyone (or anything) but yourself. It lets you get exactly what you want, but only if you know what you're doing.

For any form of metering, there are always at least two separate methods...one for constant-light conditions and one for changing-light conditions. In constant-light conditions you want to set your AE-L button to "AE lock (hold)" (see page 146 of your manual.) You also want to extend the time that the meter stays on. The default is 8 seconds. You want to set the "Auto meter-off" to at least 10 minutes (I keep mine set to 30 minutes.) See page 143. You want to select Auto off Timers in the setup menu and then set it to Custom. Now you'll be able to set a longer Auto meter-off time. With these two options set you're ready to use Spot metering in constant-light conditions.

Under constant-light conditions your lighting is stable for some period of time. Examples are clear sunny day, stadium and convention center lighting...any time that the lighting is fairly even and unchanging. Under these conditions you can set your exposure once and use that exposure for most of your shooting. Some people will suggest that you use manual exposure, but you get more flexiblility by using A mode (and even more with Auto ISO.) The first step is to identify your reference for metering. If you're standing in the same light that your subject is, you can use yourself as a reference. For example, I know that my palm is +1 EC. So I hold my palm in the light, point my camera at my palm, and press the AE-L button (note: it may be suggested to first half-press the shutter button to turn on the meter. however, I've found that my D90 will get the same reading from pressing the AE-L button, even if the meter was off. So...no sense adding steps that aren't needed.) After pressing the AE-L button I will now press the EC button (the +/- button behind the shutter) and set EC to +1. Now my exposure is correct for the light. (That said, I usually use the white balance card in my pocket instead of my palm, because I use it to set exposure and white balance at the same time.)

With your exposure locked you can start taking pictures. Here's where using auto modes factors in. If you're in A mode and you want to change your aperture, you simply do it and the camera will maintain your locked exposure. This allows you to have the consistency of exposure that manual mode gives with the flexibility of auto modes. If you don't shoot within 10 minutes (or 30 minutes, depending on your Auto meter-off option) then the meter will turn off and you have to set exposure again, which usually isn't a big deal if you're working from a gray card or white balance card like I do. Of course, what you really want is to be able to recognize what tones can be used for setting exposure. That's something that only comes with practice and experience. It's a good exercise to set manual mode, then set your exposure, and then point to different colors to see how the meter reacts. Those changes to the meter are the exposure compensations needed to get correct exposure with those colors. That's the skill of spot metering...you meter and then offset your meter by an amount determined by knowledge and experience to get the correct exposure.

This skill is really important when shooting in changing light conditions. Examples of changing light are clouds moving overhead, blocking and unblocking the sun, and indoor illumination by floor and table lamps (very uneven light...distance from the light is important here.) In changing light you take advantage of your multiple focus points. Spot metering follows the focus point in Nikon DSLRs. When shooting your subject, decide on a spot to act as the focus target and exposure reference. Look at the tones of your chosen spot and make an Exposure Compensation decision. Even take a shot or two to fine tune your EC. Once your EC is set for your selected spot you can start taking pictures. As you reframe your subject, move the focus point to keep it over your selected spot on the subject. If you do this then exposure will always be consistent even as light changes before your eyes.

.

 

[apaflo]

Im trying to get spot metering down with my nikon d3100, but am having some trouble completing the task (I think). I understand the concept of it, finding a midtone in the picture, metering on that point and then recomposing in a nutshell. But I'm having a little trouble with the technical side of it. This is what my instruction manual says:

1. SET METERING TO SPOT METERING (I've got this)

2. LOCK EXPOSURE.
Position the subject in the selected focus point and press the shutter-release
button halfway. With the shutter-release button pressed halfway and the
subject positioned in the focus point, press the AE-L/AF-L button to lock focus
and exposure.

The camera can be configured to have the AE-L/AF-L button lock both exposure and focus, or just focus or just exposure.

See page 146 of the user manual. In the Setup menu set the AE Lock option to "Off" (the default) and then a half press of the shutter release button will not lock exposure but will lock focus. The AE-L/AF-L option can then be set to either "AE lock only" or the "AE lock (hold)". The lock only option locks exposure as long as the button is held down, the hold option locks exposure until either the button is pushed a second time or the timer expires.

With that configuration exposure can be locked on one target and focus locked on a second target (by holding the shutter release at half press), and then of it can all be recomposed again before capturing an image.

3. RECOMPOSE THE PHOTOGRAPH
Keeping the AE-L/AF-L button pressed, recompose the photograph and shoot.

Alternately if it is configured to hold the lock there is no need to continue pressing the button. Of course the lock has to be released with a second push of the button or wait for the time out.

The Setup Menu option for "Auto off Timers" determines how long the lock can remain. There are limited options with the D3100, and apparently 1 minute is the longest? The manual doesn't say if the custom setting can be set longer or not, so you'll have to look to find out.

So I guess what I'm confused about is when and where to start pressing buttons. The second step is where i'm lost.

Do I find the spot I want to use and press the shutter-button down on this and the AE-L together and then recompose? If so how will I refocus on the actual subject I want? This is really confusing. Here's a picture of my camera if it helps.

Any help would be appreciated

I would highly suggest that spot metering is probably not as productive as other methods. Your camera can display either a 4 channel (RGB combined plus each RGB channel) histogram or a blinking highlight display (see page 130 in the manual to enable them), and these are extremely useful once you learn how to use them. You might consider shooting with the histogram display as your default way to review images, and when setting exposure controls you can switch back and forth between that and the blinking highlight display.

You can use any of the automatic exposure modes, and then use Exposure Compensation to calibrate the light meter up or down to get what you want.

Another very useful method is to enable Auto ISO. It will work with the automatic exposure modes, but it is just fabulous when used with Manual Exposure! You manually set both aperture and shutter speed for desired artistic effects, and the camera uses the light meter to adjust ISO to set the brightness of the image. Exposure Compensation is then used to offset unusual light conditions.

For all of the above either Center-weighted or Matrix metering is probably best. Center weighted gives 75% weight to a circle in the center of the viewing screen that is about half the height of the screen. Matrix metering is a mode that compares the scene to an internal database, trying to provide the correct Exposure Compensation automatically. (Some times it works!)

Note that using an histogram display as a light meter is by far the best and most useful technology that digital photography has brought to the camera. Oddly a lot of people resist the idea of taking an exposure vs taking a separate meter reading! It doesn't make any difference that an entire image is captured just to get a very fancy meter reading though, because "film is cheap" is really true. Ansel Adams, before Polaroid film, would take many readings with an exposure meter. You can take many too with one exposure. Adams of course adopted Polaroid when that became available. First a few meter readings, then a few Polaroid exposures, then a film exposure. Today we can do all of that with a couple test exposures to get a look at the histogram. In the process we capture a record of light metering if you wish to have it, and if the first one just happens to be right then it's a done deal. But there is no need to be concerned if it takes 4 or 5 (or even dozens) of captures to find precisely the right exposure.

 

[nelsonal]

I usually use spot either when I have a grey card and the subject can hold it (less chance of the meter being fooled by clothing or something else), or if it's tricky/wide dynamic range so I can spot meter the highlights and shadows to set an exposure that keeps as much detail as possible. I usually still need to chimp a few to get it exactly right, too.