Evolution of Metering

I have been prompted by a few folks to write an updated post on my current metering techniques - or more precisely, how my metering has evolved over the years. As I am a hybrid shooter, I'll detail the various techniques I use per system (yes, I meter different for film and digital).

Over the years, my metering methods have changed quite a bit. From sunny 16 rules, in-camera techniques to handheld and spot meters of both analog and digital nature, I have had great success with a varied approach. As there is no true right way to meter, I want to put up front that these are techniques that have worked for me. Perhaps some will work for you, but I suggest playing around to see what gives you the results you like.

Metering for 35mm Film

Film Metering - 35mm Negative

For 35mm film, I always used cameras 25 to 100 years old, so I never trusted the built-in meters (if they had one). This put me into the realm of hand-held external meters (see my 2014 post on hand held meters of choice, which is still relevant). My favorite to date is still The Weston Master V - which I actually own 3 models for backup. 

35mm B&W negative film

Though I don't shoot much B&W, there are a couple stocks I like in 35mm: Ilford HP5 and Kodak Tri-X.

  • For Ilford 400 / Tri-X 400 I meter at full box
  • For expired B&W, one extra stop per decade
  • I only meter in extreme light changes
    • So, usually when I first get to a location
    • And only again in a drastic change like sunny to overcast
  • For metering with the Weston Master V, I set the "ASA" to 400 for the above mentioned film stocks (200 if 5-15 years expired, 100 if more)
  • Meter for the shadows and transfer the readings to the camera and lens.

35mm color negative film

I only use two stocks of color film these days, Kodak Portra 400 and Fuji Pro 400H.

  • For Portra 400 (above) / FujiPro 400H I meter at half box speed
  • For expired color (NC), one extra stop per decade
  • I only meter in extreme light changes
    • So, usually when I first get to a location
    • And only again in a drastic change like sunny to overcast
  • For metering with the Weston Master V, I set the "ASA" to 200 for the above mentioned film stocks (ASA 100 if 5-15 years expired, ASA 50 if more)
  • Meter for the shadows and transfer the readings to the camera and lens.
Light Metering Methods - Medium Format Film

Film Metering - Medium Format

Now, oddly enough, I do not use the same technique when shooting with medium format stocks. And I'll share a secret with you here - 99 out of 100 times, I do not meter medium format film at all. With the amount of latitude 120 film provides, I have turned to completely relying on my eye to meter a scene now, as I also know how my medium format stocks (Portra 400 & FujiPro 400H for color and the rare Ilford Delta 3200 - above) will behave. If you want an amazing post on where I adapted my numbers from, check out this one from Johnny Patience.

Medium Format B&W

With Delta 3200 (4 stops faster as I shoot this at box speed, rather than 1/2 box like color) I use:

  • Bright sun - f/11 for 1/500 second
  • High thin clouds - f/8 for 1/500 second
  • Overcast - f/8 for 1/500 second
  • Shaded subject - f/5.6 for 1/500 second
  • Indoor lighting - f/4 for 1/500 second

Medium Format Color Negative

These are my basic eye-ball "guesstimates" when shooting Portra 400 and Fuji Pro 400H color medium format film:

  • Bright sun - f/2.8 for 1/500 second
  • High thin clouds - f/2.4 for 1/500 second
  • Overcast - f/2.8 for 1/250 second
  • Shaded subject - f/2.8 for 1/125 second
  • Indoor lighting - f/2.8 for 1/60 second 

Zone Metering

I am just giving this a mention here, but I have an exhaustive post here on how I used to do it.  Since moving away from large format photography last year, I haven't touched it so I don't want to mention zone metering as a current method I use. I also don't want to open up Pandora's Box.

Light Metering - Digital

Digital Metering

This is where I get super-lazy these days. For digital metering, I rely on in-camera metering and the occasional glance at the histogram. Modern sensors and meters have gotten so good, that I can rely on their results nearly every time. To get my preferred exposure for Lightroom editing with Rebecca's Pro Set IV, I actually set the exposure comp on my Sony's to - 2/3 EV. I like them about 2/3 stop under-exposed and feel her presets shine most with that setting. When composing my image, I rely on the camera's metering and monitoring of the histogram to avoid clipping of highlights and shadows. If I see a wall on the far left or far right of the histogram, I'll adjust the exposure.

For those a little... in the dark... about histograms, read on.

The Histogram 

A histogram depicts the range of tones in an image from the darkest on the left of the graph to the lightest on the right side; with the mid-tones in the middle. Anything beyond the left or right side is beyond the ability of your sensor to record. When viewing on a modern digital camera, there are a few histograms you can look at. The one I tend to view is the luminosity histogram that evaluates the overall brightness of the scene. There are also 3 separate color histograms which display the red, blue, and green pixels of your sensor.  For this discussion, I am talking about the brightness or luminosity of your scene - which is usually represented with a white histogram on your camera's EVF and/or rear screen.

On my Sony, I have the histogram enabled in the EVF as a small overlay in the bottom right corner. I give it a quick glance to evaluate where my highlights and shadows are sitting for the scene. I am looking for something like the middle graph to the right (just pay attention to the grays). The goal here is to not have the data slam into either "wall" of the histogram.  If data is slamming into either side, you're clipping.

To give a quick explanation of the visual on the right (though they are out of Lightroom for ease of capture), here are what each means:

  • Data touches shadows wall (left) - shadows underexposed 
  • Data not touching the walls - no clipping in scene
  • Data touches highlights wall (right) - highlights overexposed 

When the shadows are underexposed, you're not able to rescue them. The data is beyond the graph, and therefore, not recorded (clipped). You get the opposite effect when you overexpose the highlights. The data wasn't recorded and the highlights were clipped.  In the middle graph example, the tones are very even across the scene and not touching the walls.

When viewing these in Lightroom, the little triangles at the top show white, signaling you've screwed up. You may have heard people talk about the in-camera "blinkies" that can also show through live view and display via flashing colors what you're about to clip. It's an alternative and quick way to see if you're capturing all the data you can in a scene.

Evaluate your Scene

Don't confuse data-heavy graphs to the right or left with proper exposure and clipping. Again, the histogram is overall brightness of the scene. So data heavy left means a dark scene (like the below-left image), but if it's not running into the wall, you're not clipping. Just a dim scene. Same logic with a right-side data heavy graph (below-right image) is just a bright scene.

Granted, a good balanced histogram doesn't mean a good picture, it just means you're capturing all the data that you can with your sensor.

When Clipping is OK

Now, it would seem there is never an OK time for clipping as you want all the possible data you can gather. But in a scene like this to the right, there is absolutely no data to be had from that midnight sky. The histogram for this guy is not only left-heavy (dark scene) but also hits the left wall with a vengeance.

The point is, know your scene and evaluate everything given what your objective is. Am I OK with clipping a pitch-black sky? Is my main subject going to have proper exposure and no clipping? (To be honest, the highlights do have a slight clip in the spotlight, but let's pretend that's not there.)

I've really simplified what's happening with the histogram, but thought it might shed a little light (pun intended) for those wishing to understand it at a basic level.

RGB Clipping

Though I am not getting into this here, when viewing the color histograms I mentioned above, you can check to see if colors are clipping. Similar to luminosity clipping, but dealing with specific colors instead.

Summary

So, I used a lot of words here to say this is the lazy way to meter. And it is really straight forward and simple once you know what a histogram is trying to show you. When metering, it's quite literally a half second glance to see if there's clipping, and then moving onto the framing and taking of the image. I'm honestly relying on the camera meter to tell me all is well.

But no matter what medium / film stock you're using, use the method that is most reliable to you. This is what works for me - in a convoluted way. Many photographers use many variations on this - some using an external meter, no matter what, some using in-camera only, some using nothing at all, ever. It's up to you. The results are what should matter to you.