Welcome back to my blog! Before getting into the famous zone system, if you haven’t yet, please check the Dynamic Range post because it will give you some useful information you’ll need before getting into the zone system.
So for once, I’ll get into it without going around in circles …
What is the zone system?
The zone system is a photographic technique of previsualization, light metering, and exposure developed by the amazing Ansel Adams and Fred Archer. This system which was invented during the black and white photography era, translates your dynamic range into a ten-zone scale from black (zone 0) to white (zone IX). When color film came out, the zone system was not as useful as it used to be but once digital photography came into play, the zone system started gaining popularity again as photographers started seeking to get the most out of their camera sensor.
However, with technology, more tools have come up that made the zone system less favorable like the histogram which you can now find in most (if not every) digital cameras. Nevertheless, I do think that this is what made a difference in my photography and that’s why I’m so eager to share it. Understanding each zone is still very useful, even with the technology and cameras we have nowadays.
Now, let's remember that the camera meter measures the reflected light from the subject. The way the digital sensor measures light is by using the light meter that is already installed in your camera. All the information you need about the camera's exposure settings, metering modes (spot meter, matrix metering and center-weighted metering), and other things to understand exposure are in my other posts. So go have a look and come back when you are ready.
In my post 'Camera Metering Modes Explained (How & When to Use Them)' I explained how the camera meter worked by setting my camera to black and white and defocusing the scene. Now keep this in mind for a little bit while we go through the explanation of the zone system because it might help you understand things a little bit easier.
In the following table, we can see all the zones: from pure black to pure white. The number might change from author to author (most authors talk about from ten zones to twelve zones) but the idea is still the same.
ZONE 0 | Pure black with no detail |
ZONE I | Nearly pure black with no detail. It looks more like charcoal or deep deep gray rather than black |
ZONE II | Slight detail (more like texture) in the shadows |
ZONE III | Details and textures are visible in shadows |
ZONE IV | Very rich color and texture for the gray tones |
ZONE V | This is your 18% gray card color, a middle gray value |
ZONE VI | Caucasian skin tones |
ZONE VII | Pale and light skin tones and colors |
ZONE VIII | Pale gray (almost white). This is the last zone with details |
ZONE IX | Almost white tones with no texture or details but not quite as white as the next zone |
ZONE X | Pure white with no detail at all |
Now, let me explain what the table above is for. Each camera has its own zone system that looks something like this table. The amount of zones will depend on its dynamic range. So the idea is that if you are taking a picture of a person that has fair skin (picture it like the image of Leo above where you only see tones and not details), in order for everything to be properly exposed then her face should be placed in Zone VII (according to the table above - the zone number will depend on your own table). If the person has darker skin, then maybe it should be placed in Zone V. But how do you do that you ask?
Well, we know that if the scene has the proper exposure, then the light meter will look like the picture below.
So that "proper exposure" point is your Zone V or 18% gray card. That is your middle ground and your point of reference. Each stop you go up or down will mean you are moving between zones. Going back to the portrait example we were talking about above, you can take a meter reading of the person's face and properly expose the scene. Then, step up until you reach Zone VII. Ideally, we should be able to place all the tones and colors from the scene into a zone which will guarantee that everything will have the correct exposure and enough details.
Don’t freak out just yet! Once we complete the gray scale test, you will be able to construct your zone system ruler and start to understand and visualize the zone placement customized for your individual system which is the ultimate exposure control! So take a deep breath and complete the test.
Stepped Grayscale test
For this test, all you need is your camera (duh!), access to Photoshop and an 18% grey card. You can find these in photography stores as well as Amazon. I have left a link below.
I don’t get any commissions on this so feel free to choose any 18% gray card you want. The one below is for you to see more or less what it looks like. For practical reasons, it’s better to have a small gray card so you can carry it around but for this exercise it’s better to have one of the big ones. It’s up to you really, it won’t make a difference to the results.
I have also used a gray paper from a normal paper store like Office Max. In that case, when I checked the RGB values (you'll understand what I'm talking about later when you reach the Building your Zone System Ruler section) they did vary quite a bit. Not enough to repeat the test but it wasn't as exact as it was with the proper gray card. Up to you what you want to use, I'm just giving you options in case you don't want to buy another accessory. Also I want to clarify that I haven't done this test as many times as it sounds... just a few with different cameras to check out their dynamic range.
I used my Nikon D7500 for this test as this is not a professional camera and it is probably more relatable but let me know in the comments if you want me to do the test with my Nikon z7ii to compare the dynamic range.
Lastly, you can use a tripod if you like but it’s not really necessary. It can make the test a little bit easier but I have done this test with and without the tripod and it works just fine either way.
One last thing! Try to do this test on a clear day. If you have clouds passing by, your light will change and this will affect your test. It can be a cloudy day as well, as long as it has evenly overcast conditions, it doesn’t matter.
Alright, let’s get into it…
Step 1
If you haven’t already, setup your camera in Manual Mode (M). Set you ISO to 100 and aperture to f/8. If it’s too bright and sunny, you can use f/16 instead.
If your camera has the option, set your image quality to RAW.
Step 2
Place your gray card on a vertical surface. This can be anything really: a wall, a fence, etc. Just make sure that it’s evenly lit. Try to avoid places that might create a colour cast so just take your time and find the right spot.
Now I have placed my camera and tripod in the picture below to give you an idea of what the setup should look like. I put my card in the shadows to avoid any changes in the light so if there are a few clouds in the sky, this is an easy fix. Another thing you might notice is that my fence will definitely create a color cast. You can either cover part of the fence with a neutral color paper/fabric or find somewhere else to put your card. This was only to show you what the setup might look like. The only way to learn is by making mistakes so don't be afraid to be wrong... It's part of the process.
Step 3
Position yourself in front of the gray card so that the card fills the viewfinder completely. Make sure you are not casting any shadows.
Step 4
Take a picture of your gray card. In your ‘White Balance’ settings, select ‘Custom’ and use the picture you just took of your gray card.
If you don’t have this option, you can use the ‘Auto White Balance’ function instead.
Step 5
Set your camera lens to Manual Focus. This is to help your camera focus since your subject is a boring gray piece of cardboard. If you keep it in Auto, your camera might not let you take the picture (some do but some others will keep trying to focus and not actually take the shot).
Step 6
Half depress the shutter speed so your light meter takes a reading. This will let you know whether your exposure is correct or not. If it’s not correct, adjust your shutter speed until it is.
Make sure you take note of what the settings are. This will come in handy in Step 9.
Step 7
Take a photo of the gray card (finally!). This should come out as gray (or at least close to it). If this is not showing a gray color, you will need to go back to Step 4 and adjust our White Balance.
This is your starting point of your Zone Ruler, also known as Zone V.
Step 8
Increase your shutter speed by one stop (remember that one step will double the number - some cameras might be able to increase in halves or thirds so just make sure you you increase it by a full stop) and take the picture.
You are going to repeat this step until you complete all 6 exposures (apart from the one you already got in step 7).
Step 9
Return to the original settings (see! I told you it wold be handy). Your exposure should be correct once again. Now, we are going to decrease the shutter speed by one stop at a time and take a picture at each stop.
Step 10
Upload all these images onto your computer.
Building your Zone System Ruler
Now let’s jump into Photoshop and we are going to open each image. Go to File > Open
We need to see the RGB readings so if you don’t have the Info Panel open, please do so now (Window > Info).
The window will like the image below.
The first image you took should be the one you took in step 6 and this should be your Zone V. Go ahead and save each file under the zone name so it’s easier to identify it.
Now for this test, you will need to check that all the RGB colors are the same. If they are off slightly (say a few units), it’s ok. But if the numbers are off by 5 units or more, then it might be a good idea to redo the test and pay extra attention to the white balance step (Step 4).
So you should create a table that looks something like this:
Again, different authors start at different zones and have different amounts of zones. This will depend on your camera so don't worry too much about the zone number until you've completed the exercise.
Starting with Zone V, let’s have a look at the RGB values:
As you can see, my Zone V had RGB values of 98, 98, and 98. Do not freak out if your numbers are different! It really depends on the camera.
Now we are going to repeat this step with all the other zones. Try to take the reading roughly from the same area as there will be a slight difference along the image. There are many reasons for this like uneven light, lens, etc.
Once you have all the readings, your table will look like this.
From this table, there are few things we can say:
The dynamic range of my camera is 11 stops.
My grey card exposure (Zone V) favors the highlights.
Numbers were not exactly the same in every place of each picture (variations of 1 or 2 between R, G, or B) but since it wasn’t significant, it can be said that there was no color bias.
I have to admit that I found it a little hard to understand what was happening when I was taking the pictures the first time I did this test. But once I downloaded the pictures on my computer, it made a lot more sense. So don’t get frustrated and trust the process.
Now, if you want to put all your images together, it should look something like this.
Hopefully, this gave you a little more insight on how your camera works. This might sound like a lot of information but take it one step at a time. It took a while for my head to get around it but once you do, it's like a switch that turns on. I still miss some shots every now and again but my understanding of exposure is a lot better because of the zone system.
If you have any questions, do not hesitate to contact me via the Contact Us page or by emailing me at info@belenradaphotography.com
Happy shooting!
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