Free Photography Class #7: All About Camera Exposure Explained

Learning Photography for Free #7: Beginners guide to Camera Exposure. Leave the sidelines of training, we are ready for pictures! Read More…

camera exposure
Camera Exposure definition, meaning, settings…- No longer on the sideline!

Your Camera Exposure Explained

Bet you are wondering why in the world do I have a picture of a sideline to start off camera exposure. Because this is the post you have been waiting for, you are off the sidelines and now ready to get out there and start taking pictures. After this lesson, you are officially a photographer, because you are going to learn how to start taking artistic images like the pros! We are going to learn camera exposure settings, meaning and definition. So, let’s discover how camera exposure works!

Let’s Jump in!

If you completed the previous six discussions, you now have an idea of what fields of photography you are interested in, along with the niches and specialties. And what lenses and equipment you need to get started taking the pictures of your dreams. Well after today, you will be off the sideline and into the game. We are covering the basics, but the most essential settings to take amazing pictures! So be aware, this is a long post, but this is the most important thing you can learn in photography.

First off, turn on your camera and either go into your main menu to change your image quality to RAW (check your manual, YouTube or send me an email). There will be several options: RAW+JPEG, JPEG, etc. You want to put your camera on RAW and only shoot in RAW, almost always. For real, always. This is a much bigger file but it holds lots of information JPEGs do not. Once you are happy with an image (after editing) you can always create a JPEG copy, but RAW files are the only way to go and the mark of a pro; I will give you an example toward the end of this post.


Next, you need to look at the dial on the top of your camera; it will have several letters and maybe a few numbers and letters in boxes… We will discuss some of these settings in later posts, but for now, turn the dial so that it is pointing at the “M” or manual mode and don’t move it from that mode. Every photographer learns this way and every one of them argued in the beginning that this part was not needed, but it is actually essential. Why?

Because you are not only going to learn how aperture, ISO, and shutter speed effect your pictures, but you are also going to learn now to adjust any and all of these to get the effect you want, when you want it like muscle memory. Put your faith in what I am telling you and you will go from a tourist with a camera to a competent and experienced photographer in no time.

Mirrorless or DSLR

Now if you have a mirrorless camera, you will be able to adjust your camera and look through the viewfinder or rear screen and see how the picture changes instantly.  If you have a DSLR, you will have to try new settings, making small adjustments and taking a picture; then compare those pictures to see the difference.  Either way, experiment. 

After reading this post, go outside and adjust your camera to get a picture just right.  Then go inside to a dark room, take pictures next to a window, turn on all the lights and see how that effects your pictures while you adjust your settings.  Experiment with different light, that’s the name of the game. So let’s dive right in!

exposure triangle, showing how aperture, ISO and shutter speed work together and directly effect the quality of your image.
Camera exposure explained- Camera Exposure definition, meaning, settings

Exposure Triangle

The chart above is called the camera exposure triangle and every decent photographer knows exactly what this is.  Each of the three settings (written in black) on your camera effects light and how it enters your camera or how it is interpreted by your sensor.  So, let’s break them down one by one. And don’t worry, we will have blogs on each of these settings later, so if you have trouble now, we will make sure it sinks in through repetition! The main thing is getting a grasp of it, enough that you can go out and experiment with a camera in your hands. Because that is inevitably how you will learn best.


explanation of aperture using the exposure triangle
Camera exposure explained- How Camera Exposure Works, definition, meaning, settings

As discussed in a previous blog on lenses, aperture is how wide a camera lens shutter can open. Really expensive cameras that you see the pros carrying, ever notice that they are really big around? That’s because, among other things, they want to make that shutter really big so it can really open up as wide as possible. The more open the shutter can open, the more light can pour in. Kind of like on a sink faucet.

If you were to turn the faucet handle just a little, then a little trickle of water comes out. But if you were to crank that bad boy wide open, then water comes rushing into the sink faster than the drain can handle it! Well in that case, the water is light. The sink is the camera body, and the hole in your faucet where the water comes spilling out of, that is your shutter. The size of the hole (determined by turning the faucet’s handle), the more water that comes through. That’s aperture.

Aperture’s effect

The amount the shutter opens also effects how your picture will appear. The more open (confusingly called a higher f-stop but is symbolized by a lower f-stop number such as f1.8, f2.8, etc.) the subject you are focusing on will be sharp and the background and world around them will be artistically blurred, called bokeh. The less open (confusingly called a lower f-stop but symbolized by a higher f number such as f16, f24, etc.) the more the subject and the world around them will be in focus. Below are examples we used in another post using a macro lens.

f 2.8

picture of baseball taken with 100mm macro lens displaying bokeh when using a high aperture like f/2.8
Taken with an aperture of f/2.8. Since the shutter is really wide open, notice how the top of the ball (where I focused) is really sharp, but everywhere else is blurred or “soft”.. that’s bokeh. Camera exposure explained- How Camera Exposure Works Camera Exposure definition, meaning, settings


Picture of baseball taken with a 100mm macro lens to display a low aperture and lack of bokeh at f/24
Now see when we adjust the aperture to be more narrow (f/24), no matter where I focus, the whole ball is really sharp! Bonus- changing the aperture here reduced the amount of light, so I had to use a slow shutter speed to get the same amount of light. We will cover this more later! Camera exposure explained- How Camera Exposure Works, Camera Exposure definition, meaning, settings

Shutter Speed

explanation of shutter speed using the exposure triangle
Camera exposure explained- How Camera Exposure Works, definition, meaning, settings

We have also touched on shutter speed when discussing lenses, but now we will get into the down and dirty of it. Your shutter speed is how quickly the shutter opens and closes. So again, aperture is how wide it opens, shutter speed is how quickly it opens at your set aperture and then closes again. When the shutter opens, it lets in light. So the faster it opens and closes, the less light it allows. Aperture and shutter speed work together to control the light coming into the lens and reach the sensor.

Like the faucet analogy, shutter speed would be how quickly you turn the faucet on and off. If you turn the faucet on full blast or wide open (aperture) but only allow the faucet to stay open for one second, that 1 sec is an example of shutter speed. Leaving the faucet open for one second, even wide open, will not produce as much water as if you put it on a trickle but left it on all night, right? So this would be called, “shutter drag.” Leaving the shutter open longer, or dragging the shutter, will allow more light to come into the camera but if you move the camera or if the object you are photographing moves, even a small amount, it will make your picture or subject blurred.

more on dragging

When shutter dragging, you typically want to use a tripod and even a wired or wireless shutter release since your hand is never going to be steady enough to keep the camera from moving. And sometimes you can even cause movement just from hitting the shutter button, even when on a tripod!

So what is so special about shutter speed? Well, if you are taking pictures of your kids playing soccer, you want to use a really fast shutter speed so you can catch their movements instantly. Since those kids of yours are moving so quickly, the slower the shutter speed the more likely you are going to blur their little legs as they are moving quickly down the field. So a quick shutter speed will instantly capture their image even if they are moving. But have you ever seen a picture of a beautiful waterfall and it looks like the water is flowing down with smooth streams of wispy aqua? That is an example where you want to use shutter drag for motion.

Long shutter drag

Leaving the shutter open for a little longer, say 3 seconds, will make water look smooth and silky. But remember that leaving that shutter open is allowing more light in, so on a bright and sunny day, we need to use a more narrow aperture to keep from overexposing (making the picture too bright). It’s okay if that is confusing, we are going to go into detail of how these settings work together to make perfect pictures! Below are examples of action shots using faster and slower shutter speeds, just for you!

This is a picture of shutter drag, where we allow the shutter to stay open for 3 seconds. In this picture, you are seeing 3 full seconds of water moving over the dam, but on one exposure, it's all together giving it a flowing look.
Here, we slowed the shutter down to 3 seconds. So the shutter literally stays open for 3 seconds to draw a lot of light and to make the water look smooth and silky. So in essence, you are seeing all the water that flowed over the dam for 3 seconds. Kinda cool right!? Camera exposure explained- How Camera Exposure Works, camera exposure definition, meaning, settings

ISO– Camera Exposure

ISO explained using the exposure triangle
Camera exposure explained- How Camera Exposure Works camera exposure definition, meaning, settings

The third and final component to the camera exposure triangle is ISO.  This setting is often overlooked since it doesn’t give the unique effects that aperture and shutter speed can provide, and it is definitely the easiest of the three to set and forget.  But don’t overlook the power of ISO, it is a very useful tool and can make the difference of perfection or deletion. 

History lesson to help understand ISO

So for the history lesson for all those kids who never used a 35mm film camera… back in old times before there was Facebook or Google… We used to have to purchase rolls of film to put into our cameras, then develop that film, go to the counter to pick it up and look at the hit or miss pictures we took of our memorable vacations.  When you were purchasing your film, typically Kodak, there were ISO numbers like… 100, 200, or 400, which was the industry standard for how sensitive the film was to light. 

You had to purchase your film based on the type of shooting you were going to do!  So you would normally buy 100 (not very sensitive to light) if you were only going to be shooting outside in bright light, 200 if you wanted some versatility, and 400 (very sensitive to light-takes less light to make a good picture) if you were shooting inside like a museum. 

So then you got 24 or 36 pictures to take at that ISO number.  You couldn’t very well change it out until the roll was used up because you couldn’t expose the film to the light.  Once you were done, you would crank a little dial or maybe even had an automatic button to “rewind” the film back into the cartridge and take it to the store for development. 

ISO Today

ISO still represents that same process, the only difference is instead of film, there is a sensor. If you have a full-frame camera, typically the sensor is the same size as that 35mm film, crop sensors are a little smaller. So, since you don’t have designated film with a fixed ISO, digital cameras allow you to change the ISO at any time! Actually kind of amazing when you think about it. Not only can you adjust going inside and outside while not even having to turn off your camera, but now you can adjust while looking through the viewfinder on mirrorless cameras and see the image in real time before you take the shot!

ISO Demystified

We will go more in depth on ISO in our next discussion, but in a nutshell, ISO 100 take a lot of light to get a clear picture. So if you are set to 100 in a dark room, you may only be able to see the windows which have heavy light and the rest of the room will be dark. If you were to bump it up to 400, then you may have a nice clear picture almost how your eye sees the room or brighter (also depends on shutter speed and aperture of course). This is because the sensor is more sensitive to light, so less light will show up brighter from the sensor.

Digital cameras are now so advanced that, at one time, I couldn’t find ISO 800 film without going to a specialty photography store, now even $300 cameras may offer ISO 25,000 or even 40,000! But there is a catch to all this. The lower the ISO number, the sharper your image is going to appear. You won’t notice a huge difference between ISO 100 and 200, but try taking a picture at ISO 3,200 and you will see exactly what I mean. We will see grain, almost like when your TV doesn’t have a clear signal. You see fuzziness, which can be removed with programs like Lightroom or Photoshop, but the result will be more smooth than crisp and sharp.

Setting ISO

This is where the other settings come in from the triangle. In almost all situations except for a couple we will discuss in the ISO discussion coming up, you want to set your ISO first in manual mode and you want to make it as low as possible for the conditions you are in. So if you are outside in bright light, just go ahead and put it on 100 and worry about your other settings to get everything else perfect. Now indoors, it can vary, so let’s see an example of the grain so you learn to recognize it!

ISO 40,000

Displaying a pineapple with heavy grain due to using a really high ISO of 40,000
Here is an example at ISO 40,000. Notice how grainy this image is. It’s in focus and you can definitely tell what we are taking a picture of, but it’s just fuzzy! Fun fact: I have never needed to use an ISO over 3200 in a real photoshoot. Camera exposure explained- How Camera Exposure Works Camera exposure definition, meaning, settings

Let’s Test Your Camera Exposure Knowledge (with a cheat sheet below with all the answers)

So now let’s see how these three things work together with some examples.  I took some horrible pictures and provided the settings that need to be adjusted to make the picture come out perfectly.  All the answers are below, but don’t cheat.  Try to figure out what settings you should change then look to see what my recommendation is.  Learning this process is the mark of a professional photographer, and remember, there isn’t always one answer.  So let’s get started and take our first steps to taking professional pictures! Remember, this is for learning so you may not guess right or you may not even know how to start guessing. That’s okay! Read through and see the answers, you’ll get the hang of it!

Scenario one:

I’m inside a dark kitchen with only window light taking a still shot of a pineapple. I have a pumpkin in the background that I want to be out of focus (bokeh). So, I set my ISO to 100, my aperture to f2.8 to let in lots of light and give me more bokeh, then I lowered my shutter speed in 1/30 sec on a tripod to keep it from moving but the picture still came out too dark! I need your advice, what should I do!? Should I change ISO, aperture, or shutter speed? And should it go up, or down? Help!!! See this troubled picture below and help me find an answer!

Scenario One: what should I do? ISO 100, f/2.8, shutter at 1/30 sec Camera exposure explained- How Camera Exposure Works definition, meaning, settings

Camera Exposure Scenario #1 Answer Below: Spoiler Alert!!

Scenario one answer: Okay, you have two options here. You don’t want to adjust your aperture because the end goal is to make the pumpkin and bananas in the background blurred in the background, so since f2.8 is as wide as you can go, you want to leave it right there. F2.8 is already allowing as much light in as aperture can provide anyway, so we need to either adjust the shutter speed or ISO.

Lowering the shutter speed means it will take longer to expose, so any movement will make the whole picture blurry, but we have a tripod, and that pineapple isn’t going anywhere, so that is definitely an option since the camera is nice and steady as long as we don’t move it when we hit the shutter button. We could also raise the ISO up a bit but that could take away from the sharpness and add a little grain. But let’s see how it does on ISO 400 since that won’t add that much grain, but will brighten the picture since the sensor will be more sensitive to light…. Check out the result below!

Applying corrections to scenario 1

Scenario one answer: Raising the ISO up to 400 gave me just enough light! Camera exposure explained- How Camera Exposure Works definition, meaning, settings

Oh man, I really like how the light from the window is only lighting up one side, great job! I think this is a keeper! I don’t see much of a quality difference from changing the ISO to 400, and I am happy with the result, but since we do have a tripod, let’s try lowering the shutter speed a little just to see what happens.. Check out the result below!

Another option for scenario 1

2nd Scenario one answer: Dragging the shutter (1/13 sec) worked too, could lower it even more to get even more light. Camera exposure explained- How Camera Exposure Works definition, meaning, settings

Really the same result right, and you could drop the shutter speed more to make the two look almost exact! Thank God for tripods! So this shows that you could adjust either shutter speed or the ISO, even both to get the same result. It’s the same light you are using, you are just controlling how much comes in and how the sensor receives that light. Without a tripod, you definitely would lean toward ISO since lowering the shutter speed would probably cause blurriness since our hands will be a little shaky.

Scenario two:

Ooops… I did something wrong because this picture is way too bright! I love the bokeh with my camera still set at f2.8 and I kind of dig the little bit of grain since it adds a little texture to the background thanks to my ISO being at 3200. Since a 1/30 sec shutter speed worked last time, I figured it would work now… but obviously something is off, what should I do? Look at the mistake picture below and help me figure this out!

Scenario Two: Too bright, help!! Camera exposure explained- How Camera Exposure Works definition, meaning, settings

Camera Exposure Scenario #2 Answer Below: Spoiler Alert!!

Scenario two answer: Easy one, right? It’s okay if you didn’t get it the first time, that’s what these scenarios are for! So if I want to keep the grain in the picture, lowering the ISO would remove that but would make the image darker, raising the ISO would add more grain but would only brighten the picture.. So that’s not an option.

I could also narrow the aperture by reducing the aperture to f8 or so, that would darken the picture, but it would take away from that beautiful bokeh in the background… so that’s not an option either… all I have left is shutter speed. So do I lower it or raise it to make the image darker? Well lowering means the shutter stays open longer and lets in more light, that’s a no go… so let’s raise our shutter speed to make it close sooner, letting in less light and BAM! ISO 3200, f/2.8 and 1/125 sec shutter speed just nailed it! See the result below, beautiful!

Scenario Two corrections!

Scenario three: Well I like how this turned out, but there is just too much bokeh, I would really rather the image be super sharp! On this one I used an ISO 200, f/2.8 and 1/50 sec. If I make the aperture more narrow, that’s also going to let in less light since the shutter won’t open as wide, but I definitely have to adjust the aperture, so I guess I will have to adjust something else? I am using a tripod at least, what should I do? See the picture below that needs correction and let me know what you think.

Scenario three: let’s remove this bokeh and get this thing sharp! But remember to keep it bright enough to see… probably have to adjust two settings! Camera exposure explained- How Camera Exposure Works definition, meaning, settings

Camera Exposure Scenario #3 Answer Below: Spoiler Alert!!

Scenario three answer: So first, I’ll adjust my aperture since I know that has to be higher… let’s set that to f/16 to eliminate almost all the bokeh except for a little bit of softness in the corners, that way we still get a little more light then setting it to f/24 or f/32. So since we are losing light by narrowing the aperture, let’s first set the ISO to 400 since we know that won’t hurt the sharpness that much, but will make the sensor a little more sensitive to light and brighten the image.

Then, if that’s still not bright enough, we can drag the shutter a little more, since we have the tripod. Let’s set that to about 1/2 sec. Perfect! It’s the same brightness as before but much less bokeh, great job! Check out the sharp results we produced by changing the ISO and the shutter speed to offset the reduction in light from a more narrow aperture!

Scenario three with corrections

Scenario three answer: Perfect! Nice and sharp and still well lit! Camera exposure explained- How Camera Exposure Works

Note: to figure out what shutter speed on a mirrorless camera, we would just slowly lower the speed until the screen or viewfinder was the perfect brightness, in this case it was 1/2 sec.  Bonus advice: You also could have just kept lowering the shutter speed until we got to the right brightness without even touching the ISO, and that is totally fine since we are using a tripod. 

Lower Shutter Speed?

So if you guessed to lower the shutter speed, you were right! And your image will be a hair sharper than this one, so great job!  But you shutter speed would have probably been like…. 3 seconds, there are chances of camera shake that would blur the picture in that amount of time.  So I chose to raise the ISO a little so I didn’t have to drag the shutter that long.. If you were handheld, raising the ISO would have been the only choice to make, even if it ended up a little grainy. 

So, that was a bit of a trick question since it has two answers! Great job!  (If you have a DSLR, you would just take pictures and look at your screen as you are lowering your shutter speed until you get the image you want… just delete the pictures you don’t like).  But you see how nice a mirrorless is!?

Final Scenario, real world example:

I can’t believe I just messed this moment up with bad settings! Since it was a dusk game, the light was really low so I put my ISO on 400 to keep good detail but still keep the sensor pretty sensitive, so don’t want to mess with that! My other settings are f/5.6 and my shutter speed is 1/80 sec, but I blurred the hands since they were moving so quickly… What should I do, I gotta update my camera quick and take another picture before this moment is gone forever!!!!! see the blurring of some of the hands below as the kids are cheering for a game well played!

Final scenario: blurred hands are ruining this moment! Help!!!! Camera exposure explained- How Camera Exposure Works

Final Scenario Answer Below: Spoiler Alert!!

Final Scenario Answer: This is a real scenario I ran into and I really did get the shutter speed too slow. I can’t tell the kids to hold the pose, I am trying to take a candid shot so I have to raise the shutter speed. I could adjust the f-stop to make the shutter open wider to offset the faster shutter speed… but these kids are all standing at different depths and at f/5.6 everyone is perfectly in focus… So I can’t adjust that. So now I have two choices.

I can either take a darker picture by increasing my shutter speed to 1/150 sec and just try to brighten it in post processing using Lightroom, or I can sacrifice some of the sharpness by adjusting the ISO to around 800. But that extra grain will just take away from what I wanted. So when in doubt, always take a picture a little darker and brighten it in a photo editing software. If you remember, we are shooting in RAW, so that’s where we have a huge benefit.

Always RAW?

All the information is saved in RAW, a much larger file than a jpeg. If the image is dark, much of the detail is still there and can be brightened to bring it out. If you make a picture too bright, that is called “clipping” and those details are gone. Over exposing an image takes all the details out since it’s too bright for the camera to see textures, contrasts, etc.

So since I have to take this picture quickly, I am going to just raise my shutter speed quickly and get the picture before the moment is gone. I’ll have to edit the picture to get it perfect, but it’s better than taking a risk and clipping my highlights and losing details I will never be able to get back. So after editing, this is what we got!

Final scenario answer: much better! That made a huge difference! Camera exposure explained- How Camera Exposure Works


Still some slight blurring but much better. I probably could have used a shutter speed of 1/250 or more but I don’t want to go too dark or the camera won’t have ENOUGH light to make out details. That was a hard one, kind of like a bonus question on a quiz.  We are going to go into depth on each of these so don’t worry if you are still a little lost.  This is why you get outside (and inside) and just start shooting. 

Look at your pictures the same way we did each of these and try to figure out what you could have done differently.  And celebrate when you nail those settings perfectly!  It’s a real accomplishment and you are officially doing something that 90% of folks who own a professional camera have no idea how to do.  Now you can confuse them by critiquing their exposure with the knowledge to back it up! And if you are having trouble, send me your picture and settings and I am always happy to help you out!

Wrap up!

Next we are going to dive deeper into ISO.  It won’t be as long of a post as exposure but it will really help firm your grasp of this setting and help when we move into aperture and shutter speed.  Now get out there and practice and keep a count of your pictures.  Your goal is to take 10,000 thought through pictures to really master this art.  It’s not as hard as it sounds… last weekend I took nearly 2,000 pictures between a pumpkin patch with my kids and soccer games. 

But your first 10,000 pictures in manual mode will be your worst pictures you will take in your career.  This could take weeks or months, but don’t go out and “spray and pray,” think through your photos and adjust those settings to see the effect it has. From there, you will be amazed how quickly you adjust your settings and think through each image.  You CAN DO THIS, and you will!

Need new equipment? Give KEH a try! But certified used equipment that is graded by experts. You can even sell or trade your old gear for new gear!

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