Photography Without a Light Meter

The Exposure Triangle

In a nutshell, I already understood the three elements of the “exposure triangle”: shutter speed, aperture, and film sensitivity.

Looking at my Nikon F camera and its 50mm f/1.4 lens, though, I saw what felt like a daunting pair of controls for setting shutter speed and aperture. In addition to “T” and “B,” my shutter speed dial included a range of selections from 1 sec. to 1/1000 sec. On my lens was a dial with more settings ranging from f/1.4 to f/16. As one would typically find in the film photography world, each progressed in full-stop increments.

I understood the reciprocity between shutter speed and aperture. Making the shutter speed slower by one stop, for instance, is the same as increasing aperture by one stop. The reverse is true, too. I also understood the effect of shutter speed on freezing moving subjects and the effect of aperture on depth of field.

What I didn’t fully understand, however, was what combination of shutter speed and aperture settings were appropriate for a given lighting scenario in terms of making the best exposure.

Further compounding matters was the third element in the exposure triangle: film sensitivity or speed. Here, too, I understood the basics. Those films with a smaller ASA number (100 and below) were the least sensitive and had the finest grain. I also knew that, as film speeds increased in full-stop increments to 200, 400, 800, 1600, and even 3200, they become more sensitive at the cost of the image appearing grainier. And I knew that going from an ASA rating of 100 to 200, for instance, is the equivalent of increasing light by one stop either by lengthening exposure time or widening aperture.

Film speed seemed like a further complication in what felt like an already complicated problem.

Existing Methods

Primed with my existing base of knowledge, I did a bit of research on the internet. I searched for answers on how to shoot without a light meter and came up with lots of hits.

Outdoor 8 Rule

In a February 2017 posting on his website, film camera enthusiast Mike Eckman suggested a more general guideline: set your shutter to the inverse of the ASA film speed number and your aperture to f/8. Calling it the “Outdoor 8 Rule,” Eckman wrote that one lesson beginning film photographers need to understand is that, to get a usable image, it’s not necessary to make a perfect exposure.

Indeed, as some of his readers pointed out, toy film cameras operate at roughly these settings when used with ASA 100 film. The Kodak Ektar H35 camera I had been contemplating and eventually came to own was one instance of this. The more I used my inexpensive half-frame camera, the more Eckman’s point was driven home: if I shot with a forgiving film like Agfa APX 100 at the camera’s set exposure settings of 1/100 sec. at f/9.5, or the rough equivalent of 1/125 sec. at f/8, I could expect at least passably decent exposures across a wide range of lighting scenarios. And that is exactly what I got.

If I could get at least a handful of adequate exposures using a toy camera with set exposure time and aperture settings, using a proper film camera like my unmetered Nikon F could only improve the situation further.

Sunny 16 Equivalent Values

As I pondered the question, I realized that my existing body of photography could serve as one source of insight. But I needed to consider its metadata in a more comparable way. What I essentially set out to do was to merge the EV system with the Sunny 16 Rule.

Turning to my past digital photography where I had complete ISO, shutter speed, and aperture metadata, I came up with logic for my own “Sunny 16 F-number equivalent” value, which I derived from those three exposure settings.

In essence, I determined what an existing image’s aperture would have reciprocally shifted to had I set my shutter speed to the fractional inverse of the image’s ISO speed (1/ISO) when I made the exposure.

For instance, consider a hypothetical exposure made at ISO 100, 1/250 sec., and f/8. If I had selected a shutter speed of 1/125 sec.—i.e., the full-stop shutter speed setting that’s closest to 1/100, or the fractional inverse of ISO 100—the aperture would have needed to shift to f/11 in order for it to have been exposed the same way as it was originally. Doing that same kind of conversion on all my past photos and deriving a “Sunny 16 equivalent” value for them made all my photos more comparable in a way that was easier for me to remember compared to what the EV system offers.

The whole idea behind this was to boil the number of variables in play down to one I could remember. When making a decision about exposure settings, I realized it would be far easier for me to think in terms of just one variable, which of course is what the Sunny 16 Rule does in a very general sense. If I knew I had ASA 100 film loaded into my camera and that my baseline exposure time was 1/125 sec., for instance, the only variable that was left to consider was aperture. If I wanted more or less depth of field, I could set my aperture as appropriate and change the shutter speed reciprocally.

(I should digress here for a bit and make a note about ASA and ISO. Since film is rated using ASA while digital photography tends to use ISO, and since both are more or less interchangeable, I tend to refer to film speed in ASA terms and digital camera sensitivity in ISO terms.)

I had long since created a custom database application for managing my photography—again, this is the database developer in me coming out. Using this data, I wrote some programming to calculate a “Sunny 16 equivalent” value.

I started with EV. I eventually discovered that one can very simply calculate EV by plugging ISO, shutter speed, and aperture into the following formula:

EV = log₂(N² * 100 / (T * S))

where N represents the F-number, T represents shutter speed in seconds, and S represents ASA/ISO speed.

I love simple yet elegant solutions like this, and I couldn’t resist adding this logic into my database application.

After loading a lookup table containing tens of thousands of combinations of exposure time, F-number, and ASA/ISO values in full- and third-stop increments, I created another lookup table that correlates EV with what I called a “Sunny 16 equivalent” value.

Since my film camera only has settings in full-stop increments, my general approach was to round EV to the nearest whole number. That way, if my digital camera went for third-stop increments of shutter speed, F-number, and/or ASA/ISO, the exposure would compare to whatever the closest full-stop exposure setting equivalents would be on my film camera.

If that derived “Sunny 16 equivalent” value falls outside of the practical range of apertures found on my film camera lenses (f/1.4 to f/16), I created an additional value indicating whatever further adjustments to shutter speed would be necessary. If f/1.4 is at one extreme of my derived “Sunny 16 equivalent” metric, I would indicate f/1.4 plus however many full stops I would need to slow my shutter speed down to in order to get to the equivalent exposure settings for a particular image in a low-light setting. If f/16 is at the other extreme, I’d indicate f/16 plus however many full stops I would need to speed up my shutter speed to in order to get to the equivalent settings in a harshly bright setting.

My ultimate goal was not to get lost in computer programming puzzles but rather to learn how to shoot my manual film camera without the help of a light meter. The usefulness of my derived “Sunny 16 equivalent” value lies in the fact that it gives me an analytical framework that speaks to me in terms of real camera settings. It tells me how I would need to manipulate them when I actually have a non-metered film camera in my hands. And it does so more concisely and intuitively than what EV tables and their necessary conversions offer.

Getting Out and Practicing

Analyzing data and programming a computer to do conversions is one thing. Training one’s eye to judge real-world situations is quite another.

Practicing with a Digital Camera

In addition to my programming work, I actually got out with my Canon EOS M50 digital mirrorless camera and practiced assessing a scene not for artistic composition but instead for making judgments about light pure and simple. That in itself was an education. It was the first time I had ever done anything like that.

As I got out there and practiced, I shot with my camera set to aperture priority and kept my ISO set to a single value throughout my session. If I had my camera set at ISO 100, for instance, I looked at a scene and tried to determine what aperture setting would get my camera’s light meter to choose a shutter speed of around 1/125 sec.

For a particular subject, I might have a mental conversation with myself that would go something like this: “Is this an f/11 situation? No, it’s too dim. How about f/8? Hmm... maybe it’s even an f/5.6 situation.” I made my best guess for an appropriate aperture setting, brought my camera up to my eye, set my aperture, and metered the scene. If I was right and my camera picked a shutter speed of around 1/125 sec., I patted myself on the back and took the shot. If I was wrong, I adjusted my aperture up or down to bring my shutter speed to 1/125 sec. All the while, I’d be making mental notes about what scenario called for what aperture setting for a given shutter speed.

Similar to how my “Sunny 16 equivalent” programming logic rounds whatever third-stop settings were recorded with an image, I evaluated my camera’s light meter recommendation by rounding it to the nearest full-stop value. Again, my ultimate aim was to be able to shoot my manual film camera without a light meter. Since my film camera has settings only in full-stop increments, I began training myself to think in terms of full-stop shutter speed and aperture increments. The same goes for ISO: I always choose an ISO setting that matches the ASA rating found on most film stocks.

Keeping a record of all three exposure settings—ISO, shutter speed, and aperture—became critical if I really wanted to learn from these exercises and begin to see a pattern. My modern kit zoom lens didn’t present a problem because my camera body communicates directly with the lens via its electrical contacts. Upon generating an image file, it has always recorded aperture along with ISO and shutter speed metadata.

When I got out in the past and shot with my old adapted lenses or my modern manual lenses, my camera still recorded shutter speed and ISO with my image files since both settings are made by the camera body. But it was incapable of recording aperture metadata since there are no means of communication between those old lenses and the camera.

Before I set out to teach myself how to shoot without a light meter, I never really bothered to note them. But now that I was much more interested in developing a keener sense of proper exposure settings for a given scene without the aid of a light meter, I began keeping better records. When using my older manual lenses, I often go old school and use paper and pen. (I must look odd to passersby who see me jot down notes every time I shoot an image.) When I’m back home, I transcribe that metadata into my photography database.

Since I’m interested in gauging light and not color in a scene, I also found shooting in black and white to be the most helpful. In black and white, I’m better able to assess light without the distraction of color. My Canon EOS M50 mirrorless camera’s exposure preview features was helpful in this respect. When my camera is set to monochrome mode, my viewfinder renders a scene in black and white, making it easier for me to do the kind of light assessment by eye that I’m seeking to get better at.

When I got out and actually started to think about my shutter speed and aperture settings more critically, I was often surprised to see what my camera’s light meter recommended to me for certain subjects. Seeing some landscapes under bright and direct sunlight on clear days, for instance, I would remember the Sunny 16 Rule and would often think to myself, “Oh, that’s definitely an f/16 situation.” But when I actually metered the scene with my camera with my ISO set to 100, I often saw that f/11 was the appropriate aperture setting if I wanted my camera’s light meter to pick a shutter speed of around 1/125 sec. That surprised me. “Wait a minute,” I thought to myself, “it’s clear and sunny afternoon, and I’m shooting a wide-open landscape at ISO with a target shutter speed of 1/125 sec. Why did my light meter go for f/11 and not f/16 like the Sunny 16 Rule calls for?”

It didn’t take me long to realize how much the Sunny 16 Rule is really only a very general starting point. I discovered how widely shutter and aperture settings can vary even when shooting various subjects in wide-open landscapes on clear and sunny days. In those settings, the Sunny 16 Rule says keep your aperture at f/16 and your shutter speed at the inverse of ISO (1/ISO). But in the real world, there was far more variation.

My experience reinforced what I read in Ben Long’s book Complete Digital Photography about how a modern digital camera’s light meter works. In his words, it does only one thing: “it measures the luminance [or brightness] of the light reflected by your subject.” As I soon learned from my own experience, various subjects reflect vastly different amounts of light. Accordingly, a general “Sunny 16” rule, albeit useful as a starting point, is incomplete. It doesn’t take into account the tones of a subject and the extent to which those lighter or darker tones affect the amount of light that is reflected off them.

Going back to my example shooting landscapes under clear and sunny midday skies, I found my digital camera’s light meter telling me that, if I wanted to keep my ISO at 100 and my shutter speed around 1/125 sec., I needed to shoot at anywhere from f/8 to f/16 depending on what tones were in my scene and how much sunlight they were reflecting. Had I blindly stuck with the Sunny 16 Rule and shot several scenes containing a lot of darker tones at ISO 100, 1/125 sec., and f/16, I would have underexposed many of my images by a stop or two.

Practicing with a Film Camera

Using my digital camera to develop my ability to shoot without a light meter is great, but there’s nothing like the real thing.

As opposed to using a digital camera as a surrogate, I prioritized getting out more with my Nikon F. As I got more practice, one thing that really struck me was how much more exposure latitude I have especially with negative black and white film photography.

To be sure, there is no substitute for getting an exposure right to begin with. After all, this is not a license to be sloppy. But even if my exposure was one or two stops off, I found I still had a usable negative to work with. Sometimes an exposure was still usable even if was three stops off. Film photography proved to be far more forgiving than I understood when I was completely new to it.

Exposure Setting Brackets

The more practice I got, the more it dawned on me how forgiving film can be. Ultimately I realized that I could simplify matters even more by thinking in terms of every other stop on an aperture ring or shutter speed dial.

If it’s true (within reason, of course) that I can still get a very usable negative even if my exposure settings are a stop or two off, I realized that I can operate within a limited set of apertures—f/1.4, f/2.8, f/5.6, f/11, and, if available, f/22—and shutter speeds—1/500 sec., 1/125 sec., and 1/30 sec., the latter being the slowest shutter speed that most people can shoot while holding a camera by hand and still get a reasonably sharp image.

Even with this limitation, I still have 15 combinations of aperture and shutter speed settings to work with. And if whatever lens I’m using doesn’t stop down to f/22, I still have 12 combinations. Either set covers quite a broad range of lighting scenarios.

With this simplified system, it’s even easier to remember which lighting scenario goes with what exposure setting.

Lighting Scenarios

The following lighting scenarios apply mostly to reasonably bright days. For those times when dark-cloud overcast prevails, I’ll add an extra stop or two of exposure.

1/ASA at f/22 (EV 16)

Use this setting or its reciprocal equivalent for harshly lit outdoor subjects—snowy scenes or when the camera pointed right up at clouds, for instance. If your lens doesn’t have an f/22 setting, you can shoot at f/16 and increase your shutter speed by one stop, which is what I do when using my Nikon F.

I shot these images with the exposure equivalent of the aperture set to f/22 and the shutter speed set to to the inverse of ASA (i.e., 1/ASA):

1/ASA at f/11 (EV 14)

Use this setting or its reciprocal equivalent for the typical landscape or well-lit ourdoor scene on bright days.

I shot these images with the exposure equivalent of the aperture set to f/11 and the shutter speed set to to the inverse of ASA (i.e., 1/ASA):

1/ASA at f/5.6 (EV 12)

Use this setting or its reciprocal equivalent for outdoor subjects with a blend of highlights and shadows on bright days.

I shot these images with the exposure equivalent of the aperture set to f/5.6 and the shutter speed set to to the inverse of ASA (i.e., 1/ASA):

1/ASA at f/2.8 (EV 10)

Use this setting or its reciprocal equivalent for shady outdoor areas on bright days or areas with small dapples of sunlight.

I shot these images with the exposure equivalent of the aperture set to f/2.8 and the shutter speed set to to the inverse of ASA (i.e., 1/ASA):

1/ASA at f/1.4 (EV 8)

Use this setting or its reciprocal equivalent for well-lit interior scenes like stores or commercial spaces.

I shot these images with the exposure equivalent of the aperture set to f/1.4 and the shutter speed set to to the inverse of ASA (i.e., 1/ASA):.

Other Lighting Scenarios

I handle more extreme scenarios on either end of the above range as follows:

On the brighter end:

1/ASA at f/22 with 2 stops faster shutter speed (EV 18): shooting directly toward the sun during a sunset when I want to deliberately underexpose the image and emphasize colors (e.g., 1/500 sec. at f/22 with ASA 100 film).

On the dimmer end:

1/ASA at f/1.4 with 2 stops longer shutter speed (EV 6): home interiors with good illumination at night (e.g., 1/125 sec. at f/1.4 with ASA 400 film).

1/ASA at f/1.4 with 4 stops longer shutter speed (EV 4): home interiors with dimmer lighting at night (e.g., 1/30 sec. at f/1.4 with ASA 400 film).

Before long, my efforts—my programming, my real-world practice, and my data entry—all started coming together into something I could really use in a very practical sense.

Is All of This Really Worth It?

So why does this all matter? Is learning how to shoot without a light meter an idle exercise in going old school just for the sake of going old school? Haven’t we progressed beyond primitive camera gear? Read any review of modern digital cameras and you’ll see that the writer spends a great deal of time on a camera’s automatic features (auto-focus, light metering, etc.). Are any of these old-school skills really relevant anymore?

Thanks to this whole exercise, I’ve gained a much better understanding of exposure theory than I would have achieved had I simply gone on my merry way trusting the light meter, blindly following what it told me to do, and simply letting the camera operate in automatic modes (program, shutter priority, aperture priority). And I’ve gained an appreciation for why understanding exposure theory is fundamentally important.

The benefits go far beyond developing my skills with using old fully-manual film cameras without a light meter. Even with a modern digital camera, I feel like I’m in a much better position to take the exposure recommendation from my camera’s light meter as just that: a recommendation. I feel like I can make a much better judgment about how to shoot my scene and achieve my desired artistic effect.

A camera’s light meter may take in a scene and recommend X or Y settings. With no knowledge or intervention on the part of the photographer, one is left to trust the camera purely on faith and do nothing except press the shutter button.

That’s boring! I don’t want to be that kind of photographer. Armed with better knowledge of what my light meter is doing and more experience with using my eye to make my own judgments about a scene’s light, I feel far less reliant on my light meter. I feel better equipped to use whatever camera I have in hand more effectively as a tool to achieve the end I have in mind when I see something interesting to photograph. Hoping that a light meter will get me to what I intended to accomplish doesn’t always work.

I’m reminded not only of what Henri Cartier-Bresson said about using light meters but also of what I thought to myself when I first read what he had to say. In a 1971 interview with Sheila Turner-Seed, he offered his thoughts on using light meters, which had become increasingly commonplace since they first began appearing built into cameras around the late 1950s and early 1960s:

I don’t see why it is done. It is a laziness. During the day, I don’t need a light meter. It is only when light changes very quickly at dusk or when I’m in another country, in the desert or in the snow. But I guess first, and then I check. It is good training.

“It is a laziness”? Humph! What a snob, I remember thinking to myself. But now I understand what he was getting at much, much better.

I’ll admit it: sometimes when I’m out and about with a modern digital camera, I’m more easygoing and simply want to shoot. If I want a bit more control, I may set my camera to aperture priority, make a judgment about what kind of depth of field I want to capture, and make aperture adjustments accordingly. Mostly, though, I find myself relying upon my light meter to do its thing and shoot away.

But my laziness in those kinds of situations—and, yes, Henri Cartier-Bresson was right: it is a laziness—doesn’t always get me to the best outcome. Even when I shoot in fully manual mode, I may still consider the recommendations of my light meter, and I may even be quite reliant on it in certain tricky situations. But in the end, I’m the one making the final decision when I press the shutter button. In automated modes, the photographer cedes that control to a computerized machine. In manual mode, there is far more consideration involved. That more deliberate act often results in a better exposure and perhaps even a better expression of artistry.

Sometimes it’s just fine to use automated modes. After all, modern light metering technology has become incredibly sophisticated and impressively accurate. But other times call for a more nuanced approach. Making a judgment about what approach is most appropriate for a given scenario is one key mark of a good photographer.

In the end, learning how to shoot without a light meter isn’t just a neat parlor trick to use with old gear. It’s given me a much better understanding of my craft, and it’s made me into a better photographer.