HOW TO: Sunny 16 & Zone Focus on a Leica M3
The recent acquisition of a Leica M3 has taken my film photography journey to a new destination! I honestly never thought that shooting a 60 years old camera, offering only the bare essentials to take pictures, would bring something new to how I approach photography.
From this experience, I’ve learned two easy but effective photography techniques, that when combined will transform any Leica M or rangefinder into a Point & Shoot camera.
Table of Contents
Introduction
I’m not reinventing the wheel here but if you’re new to film photography, or discovering the joy of shooting with a 100% mechanical camera, then you may have never heard or used these old but proven techniques. Techniques that every photographer should use at some point to understand the ground rules of how exposure and manual focusing work.
The first technique we’ll talk about is known as the “Sunny 16 Rule”. Sunny 16 basically gives you a baseline to read light without light meter. Light meter not always existed and this method to measure light has been used since the early days of photography and there must be something we can learn from that.
The second is called “Zone Focusing” which is used to pre-focus before raising the camera to your eye. Combining these two methods will save you precious seconds when you are out shooting, and get off your shoulders the technical aspects of photography, so you can concentrate on what matters most: Composition.
Today I’m using a Leica M3 to illustrate my points but these two methods are perfectly applicable to any cameras without built-in light meter (or dead batteries) and lens with distance scale.
What Is & How To Use Sunny 16?
The trade-off with the M3 is that it doesn’t have a built-in meter. If you are used to the comfort of modern Leica rangefinders, a camera without meter can be as intimidating as riding a bicycle without training wheels for the first time. From here you have four options:
- Get a handheld light meter
- Mount a Leica Meter on the camera hot-shoe
- Use a metering app on your phone
- Use the Sunny 16 Rule to estimate the exposure
With any of three first options, you need to rely on another piece of gear to get your light measure and it can get in the way by slowing you down. On the other hand, the Sunny 16 rule, even if a little hazardeous and less precise compared to proper light meter, depends only on your ability to look at the sky and see if it’s sunny or cloudy. Doesn’t sound too difficult, right?
“So how does it work?”
Well, there’s nothing more simple than Sunny 16! Imagine a beautiful day when you are out shooting with a shining sun and blue sky above your head. Still me with? Ok, so from here set your aperture on f16, and match the shutter speed with the ISO of your film:
- 100 ISO => Aperture f16 + Shutter speed at 1/100th second
- 400 ISO => Aperture f16 + Shutter speed at 1/400th second
- 800 ISO => Aperture f16 + Shutter speed at 1/800th second
- etc…
And voilà, your camera is ready to shoot and will give you a decently exposed negative. From here, you’re free to adapt the aperture or shutter speed to your needs as long as you maintain the same exposure couple: when shooting at wider apertures decrease the shutter speed or increase it if you stop down to f22 for example.
Samples of Sunny 16 on Colour and Black & White Film
The photos below where all shot a Leica M3 & Street Candy ATM400 OR Kodak Pro Image 100 using the Sunny 16 rule.
“Shutter Speeds on my Camera Don’t Match my Film’s ISO?”
The good thing with film (Color Negative and Black & White) is that’s very forgiving to exposure mistakes so don’t worry if you’re off by one or two stops, especially overexposed.
The first rolls I shot were some Street Candy ATM400, which is, you guessed it, a 400 ISO film so I would need a shutter speed of 1/400sec. As my M3 only has 1/250 or 1/500sec, I chose 1/250th as the film can easily handle a little overexposure (when shooting slide film, accurate exposure is highly recommended!).
From here you are free to adapt the shutter speed if you shoot at a different aperture. (Edit: I’ve learned later than the M3 has a variable shutter speed dial, meaning that if you set the shutter speed between 1/250 and 1/500 you should get close to the required 1/400th sec)
“It’s always cloudy where I live, which rule should I use?”
I’m fortunate enough to live in a region where we have +300 days of sun per year but not everyone as this privilege. When the sky is partly covered, I’d suggest to shoot one stop below what you would with the Sunny 16 and two stops for overcast days. Same thing if you’re shooting in the shadows on a sunny day.
- Partially covered sky: 400 ISO => Aperture f11 + Shutter speed at 1/400th
- Overcast day: 400 ISO => Aperture f8 + Shutter speed at 1/400th
- Thick clouds: 400 ISO => Aperture f5.6 + Shutter speed at 1/400th
These are approximations that should give a decently well-exposed image but with practice, you’ll get better and better at reading light. In the beginning, I suggest to try guessing the exposure first, and only after confirming it with an app on your smartphone. Until today I’ve used Pocket Light Meter on my iPhone and it has always been spot on but there are a lot of free and paid apps that will do a great job too.
Alternatively, you can also use another camera (film or digital) to get a reading if you happen to carry one with you. To avoid confusion, just make sure that you’ve set the same ISO on the other camera.
Now that we know how to live without light meter, let’s take care of getting your shots in focus!
What Is & How To Use Zone Focusing?
Would you believe someone who tells you that manual lenses can be faster to focus than autofocus ones? Doesn’t make sense, right? But what if I tell you that there’s a simple technique that will make your rangefinder or SLR the fastest camera you’ve ever shot with.

When you discover the rangefinder system, it may seem a little odd and slow to align the rangefinder patch to have your subject in focus. I’ve personally missed many shots because I was too slow trying to have it perfectly focused. This has caused frustration on many occasions and made me wonder quite a few times if rangefinders were good cameras for me. On the other hand, focusing with a SLR seems much faster and easier, but there’s a simple method that will get your shots focused in a heartbeat and will suit most situations.
Zone Focusing is used to pre-focus a lens and determine a specific distance range to be in focus. Then you only have to place your subject within this range to have it focused. This is ideal to capture the decisive moment since you only have to concentrate on pressing the shutter button at the right time and nothing else. That’s why street photographers love it because they can react in a fraction of second to get the shot. This technique puts to rest any auto-focus camera!
Zone Focusing Requirements Checklist:
✅ Wide angle
Wider lenses have greater depth of field compared to longer focal. It’s often used on lenses with a focal like 35mm or 28mm. I’ve used it on a 50mm without trouble but wouldn’t recommend using zone focusing on longer focal unless you’re really confident in guessing distance!
✅ Focusing Scale
Old lenses, especially rangefinder ones all have a focusing distance scale. This is essential as we need this scale to determine the range we want to be in focus. Depending on the aperture selected (f/ stop), the focusing scale tells you where begins and ends the in-focus area.
✅ Small Aperture
To work best and have a greater depth of field, a small aperture is recommended, especially on lenses longer than 35mm. Using a high f/ stop will increase the in-focus area. It’s usually used with apertures going from f8, f11 and onwards, to get a greater depth of field and have a maximum of your image in focus. This works great when there’s plenty of light like when you can use the Sunny 16, or when you have a fast film that will compensate for the small aperture required.
✅ Enough light
Using a small aperture means that there’s less light hitting your film so you’ll need to compensate with a slower shutter speed and/or a faster film. That’s why you need a decent amount of ambient light otherwise you’ll have to use a slower shutter speed and risk motion blur. Another solution is to push your film, which I describe a little more in this post.
✅ A Subject
Using zone focusing usually means that you already got an idea of what you want to shoot. As I said, it’s often used in street photography but can work with landscape or architecture for example. Shooting close up and portraits may not be ideal with this technique as your focus needs to be spot on and often work with a narrow DOP because of the small f/ stop.
Understanding How Depth of Field Works
To understand the relation between aperture and depth of field, here is a neat little video made by my friend Jordan Lockhart from Cameraville. It shows you how the DOP increases depending on the focusing distance and aperture selected.
For this example he used a 50mm which has by nature a shorter DOP than wider lenses have. On 35mm lens, it’s easier to achieve a longer DOP at the same aperture.
To summarise his video, the closer you are focusing, the shorter will be the DOP. Stopping down (high f./ number) increases the area in focus. Move the focus point forward, and the DOP will increase substantially, this combined with the smallest aperture on your lens should get you almost everything in focus from the closest focus distance all the way to infinity.
Mastering Your Focusing Skills
Those of you who’re always up for a challenge can also try covering up the rangefinder window on your camera. This will make the rangefinder patch disappear and leave you only with the frame lines.
Taping the rangefinder window will mask the patch inside the viewfinder
Normal viewfinder on the left and light version on the right without focusing patch.
This can be useful once you’ve built enough trust into your Zone Focusing skills to avoid distraction when raising the camera to your eye. I’ve found myself guilty of refocusing because of the misaligned rangefinder patch. My shots would have been in focus anyway but I couldn’t help it and had to align perfectly. So to get this out of the once for all I’ve put a piece of black tape on the window which has make this problem disappear!
If you’ve made this far into the article, thanks for staying with me!! It was a bit of a lengthy article this time but I sincerely hope you could learn a few things from my experiences and if you have any techniques that made you a better photographer, I’d love to hear about it!

Hi, I’m Vincent Moschetti! I love shooting film and talking about it 📸
One Reply to “HOW TO: Sunny 16 & Zone Focus on a Leica M3”
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I’ve used the Hyperfocal Distance method of focusing for many years, with Leica and Contax. The latter has a viewfinder I call “squinty” as it’s quite small. I use the accessory Albada folding finder plugged into the accessory shoe. For focus, I simply move infinity OO off the central stop and align it with the DoF marker corresponding to the aperture set, after metering by hand (the inbuilt meter is wildly inaccurate). I’ve started to recognise the positions for various apertures. However, I only use f5.6-8-11, adjusting shutter speeds to keep above f5.6. I use the same technique with my pair of M3 bodies and my MD. the latter has no viewfinder or rangefinder so the tecnique is a must.
This body exclusively uses the VCR 25mm f4 Snapshot Skopar lens at top-mounted finder. Brilliant in cities. Just moving the focus off infinity by 1/2″ give DoF from a couple of feet from the front of the lens to infinity. And once set, does not move. Even lifting the gear out of the pocket of a disgraceful old Barbour jacket does not disturb this setting. Far faster than the autofocus on Digital Johnny’s plastic camera that he has to plug into the mains overnight. Not for me. Even my light meter is non-battery ( Weston Master V).