Photography basics: ISO

Have you ever been in a situation where you’ve taken one great shot after another only to get home and realize that the photos are all pixellated and grainy-looking when you pull them up on your computer? If so, there’s a pretty good chance that your ISO was high. I don’t know about you, but I’ve had several cameras and phones that would consistently give me grainy photos when I was shooting indoors on Auto. In today’s photography basics post, we’re going to take a look at ISO and what you can do to about it.

ISO is an acronym that stands for International Organization for Standardization. It’s a standardized scale for measuring your camera’s sensitivity to light; in the olden days, this actually had to do with the kind of film you were using. You can read more about that here since I’m focusing on digital photography. In the digital world, ISO determines how sensitive your camera’s sensor is to light. A higher ISO makes it more sensitive, so you can take photos with a high shutter speed or with a small aperture in low light. However, ISO also introduces noise to your images, which can be undesirable.

I zoomed in on this one so the noise would be more apparent. Click to see the full version.

The noise comes from the way your camera’s sensor works. A high ISO setting causes it to group pixels together, which is what creates those grainy off-color dots you see in a noisy photo. Cameras with larger sensors tend to have more pixels and smoother images in low light. Full frame cameras, which have sensors the same size as a 35mm film frame, are really good for shooting smooth images at higher ISO settings. Of course, a full frame camera is going to set you back more than a few pennies…It may not be worth the investment if you don’t have money burning a hole in your pocket and you’re not inclined to go pro. Newer cameras (say those made within the last 3 years or so) also get better low-light photos than older cameras; they’re designed to reduce the amount of noise and give the grain aesthetic appeal.

In my experience, I got a lot of noisy photos when I was only shooting in auto. Since I’ve switched to manual and taken control of my exposure, I rarely have issues with noise anymore because I try to keep my ISO setting as low as possible. Sometimes it’s unavoidable depending on what you’re trying to photograph, though.

Typical situations where you might want a higher ISO setting are indoor sporting events, concerts (make sure photography is permitted before you go), caves, nighttime or overcast outdoor shoots, or anywhere you need to take a quick picture but just don’t have enough light. Extremely long exposures can also create noise by causing your camera’s sensor to overheat–which is another reason you need to make time to really learn the strengths and weaknesses of your gear. A flash will help but it can also make your images look harsh or washed out, and some places don’t allow flash photography, so it’s not always the best way to go.

Here are a few examples. I took these pictures at the Lost Sea Adventure, a cave in Sweetwater, TN.

This formation was well lit already, but shooting with a low ISO was still too dark. Flash helped to brighten things up a bit more and it doesn’t look too washed out.

 

Anthodites on the cave ceiling. The noise example above is a zoom-in on this shot.
The sea itself is stocked with rainbow trout. Again, you can see the graininess in the water that’s due to the high ISO setting.

Later, I’d like to come back to this subject and talk in detail about things that can be done to reduce the amount of noise that’s present in photos taken with a high ISO setting. For now, I’m just going to give you a few bullet points.

  • Newer cameras have some built in noise reduction, and if your camera is less than about 3 years old, this post may be irrelevant to you. But if you’re a dinosaur like me, there are things you can do without shelling out the big bucks to replace your camera. I mean, unless you just want to buy another camera. (Don’t we all? I like my T3, but I’d looooove to upgrade to a full frame).
  • Keep your shutter speed as low as possible and your aperture as wide as possible.
  • Use a tripod and shutter remote.
  • Consider shooting in black and white instead of color.
  • Shoot in RAW whenever you can. JPEG files are already compressed and inherently contain noise called JPEG artifacts. I have my camera set up to record images as both a RAW (CR2) file and a JPEG. The downside to shooting in RAW is that you have to convert the files before you can upload them anywhere, and a lot of low end editing software and web apps don’t support the RAW format.
  • Edit. I can’t help you much with this one at this time, but you can find tutorials online if you look. The laptop I have right now doesn’t support Photoshop or Lightroom very well. When I upgrade to a better system, I’ll go over this in more detail. I know there are people who criticize photographers for editing photos, but I think some editing is just a part of the process. Authors don’t get criticized for editing their books. How is cleaning up some noise any different than ironing out spelling errors or bad dialogue?

I think that’s all I’ve got for today. Next week, I’m planning to spend a little time going over the math behind the elements of exposure and the relationships they have with each other and with your camera’s sensor. It’s going to be a little more advanced, but I’m hoping it won’t be confusing if you read my other posts first (links in case you missed them: exposure, shutter speed, aperture). In the meantime, please make sure you share this with your friends! Do you have any questions for me? Is there a topic you’d like to see me cover as part of my basics series? Please let me know by leaving a comment below. Thank you!

Photography Basics: Aperture

Welcome to another photography basics post! This week we’re continuing the exposure theme and talking about aperture. Your shutter speed, ISO, and aperture settings work together to form the foundation of an image by controlling how much light reaches the sensor of your camera, as well as how it happens.

Aperture is probably my favorite element of the exposure triangle because it allows you to add depth to your photos. Here’s how it works. If you imagine that your camera’s lens is its eye, the aperture is the pupil. It dilates or contracts to allow light to reach the retina or, in the camera’s case, the sensor. A wider aperture, like a wider pupil, allows more light to pass through to the sensor while a narrow aperture keeps some light out.

I might come back and replace this one later…

Different lenses will have different aperture ranges available to them, so keep that in mind when you’re shooting; you might end up needing to move around a bit or even switch lenses to get the best possible photo.

I think the most confusing part to aperture is how it is measured. Aperture is expressed in f-stops; the higher the f-number, the smaller the opening. So an aperture of f/16 is a fairly small opening, while f/1.4 is very large. There is a reason behind this, but it’s…a lot of math. I plan to go over all of the math behind exposure stops in a later post, after we’ve finished going over all three of the basic elements, but I thought I’d leave it out today for simplicity’s sake. I’m not sure how many of you are interested in the mathematical and technical side of photography, and how many of you are more interested in the creative side, but I’ll hazard a guess that it’s mostly the latter. So let’s keep going.

The biggest creative aspect to controlling your aperture is having control over your depth of field. This will allow you to take sweeping landscape shots with every part of the image is in razor sharp focus or, if you’d rather, you can take portraits with soft blurs or bokeh behind your subject. You have to be mindful of your depth of field when you’re composing a shot and selecting your aperture setting, otherwise your subject may end up a little out of focus.

Notice how the sunflower in front is in focus and the other is not? Oops. My aperture should have been a little smaller to get both flowers looking sharp.

When I’m shooting a subject that is not in motion, I try to determine my aperture first so I know what part of the image needs to be in focus, and then use shutter speed and ISO to compensate for the amount of light that comes through the lens opening. Most DSLRs have an aperture priority mode, which helps you to keep your exposure balanced while giving you control over your depth of field, but I prefer shooting in manual and having full control over my camera.

When taking landscape photos, you generally want to have a small aperture so the entire scene is in focus. I haven’t done a lot of landscape photography at this point, but I do have a few examples to share with you.

Mead’s Quarry

Here’s a shot from my walk around Mead’s Quarry the other day. A small aperture (f/10) allowed me to take full advantage of the morning sun and beautiful landscape. I probably could have gone a little smaller and gotten an even better shot, but I think this is pretty good. I love the reflection of the rocks in the water.

Knoxville taken from Sharp’s Ridge. It’s a shame about the power lines because this is a magnificent view.

This shot is from Sharp’s Ridge. Once again, I used a small aperture (f/16) to really take in the scenery. If it had been a clear day, we would have gotten a really great view of the mountains in the distance, but I think this is still pretty good.

Now let’s look at some of the benefits of using a large aperture.

In my experience, a large aperture is better for portraits or for shots where you want to have a dramatic blurred background or foreground. Have a look at some of these to see what I mean.

French macarons from Honey Bee Bakery in Knoxville

See how the macaron in front is clear and the others are blurred? I shot this with f/2.5 to give it that soft look. I wish I had better lighting in my kitchen, but renters can’t be choosers I guess. (And we’re planning on moving soon anyway, so keep your fingers crossed that I find a place with good lighting). This kind of shooting is good for food bloggers who want to show off their delicious creations. It would also be an attractive way for someone to display items they’re trying to sell online.

A hibiscus on a wire bench.

This is a pretty cool one. Both the foreground and background are blurred, leaving the flower and the back of the bench in focus. The aperture for this shot was f/7.1, which is sort of a middle ground.

I hope those were good examples for you. If you have any questions, please be sure to ask in the comments below or send me a message on Facebook. I want these articles to be easy to understand and helpful for beginners who are branching out into manual mode. If it’s overwhelming for you to shoot strictly in manual like I do, try experimenting with aperture priority if that’s a feature your camera offers.

Remember, you can also use your ISO and shutter speed to control how much light is in an image. These three elements play off of each other, and figuring out the best way to balance them takes some practice. Don’t be discouraged if your first foray into manual mode doesn’t give you perfect results; just keep trying until you get it right. Next week, we’ll cover the last element of exposure, ISO. In the meantime, please be sure to comment and share!

 

Photography Basics: Shutter Speed

Like I mentioned last week, exposure is the foundation of photography; it can be difficult to master, but having a basic understanding of how it works will help you improve your photo game by leaps and bounds. Learning how to operate your camera in manual mode will help you to take advantage of everything it has to offer, but you’re going to have to figure some of that out on your own since every camera is different. It’s unlikely that you’re using the same model that I am, so I probably can’t advise you on the technical aspects of your digital camera.

My camera, a Canon EOS Digital Rebel T3. It’s definitely not the new hotness, but it still gets the job done.

What I can do is show you how controlling the elements that make up exposure will affect your photography. We’re starting with shutter speed.

First, the technical details. The sensor in a digital camera acts a bit like film in an analog camera. It captures the light that comes through your camera’s lens and creates the image that you see. I’m not going to get that technical, so here is a helpful article if you want to know exactly how a sensor works. The shutter is like a little curtain inside your camera that opens and closes to expose the sensor to light. Your shutter speed determines how long the curtain stays open. It’s usually measured in fractions of a second.

Shutter speed is circled; it’s currently 1/200 of a second.

All three elements of exposure have two features. Shutter speed determines how long your sensor is exposed to light, which will make your photo brighter or darker depending on your surroundings. The longer the shutter is open (i.e., the slower your shutter speed), the brighter your picture will be. It also determines how motion is captured in an image. For example, a high shutter speed will freeze birds in flight while a low shutter speed can give an artistic blur to flowing water.

When I’m getting ready to set my shutter speed, the first thing I try to consider is whether something is moving in my shot and how I want to capture that motion. My next concern is the amount of light that is available to me.

If nothing is moving, I use shutter speed and ISO to control the amount of light in the image, and aperture to determine what parts of the picture will be in focus. We’ll discuss using aperture this way in more detail next week, so for now let’s concentrate on motion. You’re going to want to practice this ahead of time if you have any big shoots planned. Don’t expect perfection on your first try; it can be a fiddly process to get everything just right.

To freeze motion, you want a high shutter speed. This means that your aperture will need to be a lower f-stop than you might normally use, and your ISO might need to be higher as well. The three elements play off of each other at all times; how you adjust one will affect the other two. There is some math behind this, but I’m saving that for the end of our exposure series; I think it will be easier to explain and understand once we’ve gone over all three elements in detail. For now, here’s a practice scenario for you.

(Note: This is just the way I do things. I’m a kinetic learner–I can read or hear about something until the cows come home, but the lesson isn’t going to stick until I actually start trying to do it. I end up experimenting a lot.)

Let’s say I want to take photos of bees. I don’t, really, I’m terrified of bees, but they’re easy to find and they make a pretty good example for this subject. What I would do is set up my camera with my shutter speed fairly high, then use my aperture to focus on a flower, and take a test shot. It’s usually pretty bright outside when bees are around so I can keep my ISO at its lowest setting, which is 100. If my test shot is too bright, I’ll raise my shutter speed even higher and take another test shot. I’ll continue this until I’m satisfied. Then I’ll try to compose an interesting shot with flowers and bees. If necessary, I’ll make other adjustments and shoot again until I get what I want. Like I said, it’s a fiddly process and I’m still learning.

I was trying my hardest to get a shot of the bee in the air to illustrate this point even better, but it just wasn’t happening that day.

You can probably get away without using a tripod in this situation because your shutter speed is high and camera shake won’t be as big of a deal. It’s when you get into low shutter speeds, let’s say slower than about 1/60 of a second, that you will probably want to use a tripod to get the best possible shot.

Now let’s look at low shutter speeds. Although you’re usually shooting in fractions of a second, a slow shutter speed can be full seconds depending on what you want to capture. Some cameras even have what’s called B or bulb mode, which keeps the shutter open for as long as you hold the button down. When your shutter speed is low, your sensor is exposed to light for a longer period of time. This means your aperture needs to be a higher f-stop and your ISO might need to be higher as well. It can be hard to get a long exposure shot on a sunny day without overexposure; for best results, try shooting on overcast days or even at night when you want to use a low shutter speed. Here’s something fun to try at night.

Set up near a fairly busy road. Obviously you don’t want to be so close that cars will hit you. A rooftop or an overpass that has a sidewalk will be ideal. You want a low shutter speed, start out around 2 or 3 seconds. Use your aperture to focus on any stationary things or objects of interest in the area. Your ISO should be low, around 100, because this is all about the light and you want it to be as free from noise as possible. Wait until a car is coming by, then take the photo. Pretty cool, right?

The white lines to the left are the headlights of a passing car. This would have been a lot more impressive if there had been more traffic.

You’ll definitely need a tripod for this sort of shooting. A shutter remote helps as well because then you don’t even have to touch the camera and risk shaking it. You can get some interesting effects if you set a low shutter speed and move the camera deliberately, though, so feel free to play around and see what happens.

A deliberate camera shake can add some interesting effects to a long exposure shot.

There is some math involved in the relationship between your shutter speed and the amount of light that reaches your sensor, but I decided to keep things simple since this is supposed to be a basics post. I wanted to cover this somewhat briefly, and I think this is probably enough for one day, don’t you? Leave a comment here or on Facebook if you’d like me to break the numbers down for you, and I’ll be happy to explain! Next Friday we’re talking about aperture, one of my favorite elements of exposure. I’m going to do my best to have some fun pictures to share. In the meantime, I hope you’ll like and share this post with your friends! Thanks for reading; see you next week!

Photography Basics: Exposure at a Glance

Welcome to my basics series! Although a lot of my posts involve DSLR shooting, since that’s what I primarily use, I wanted to create some articles that would be universal to photography with almost any digital camera. For those of you who don’t know, DSLR stands for Digital Single-Lens Reflex, and it refers to the way the camera uses a single lens and a mirror to process light into images. At this time, I’m more interested in the art of taking photos than in the more technical details of how a camera works; I’m planning on writing some posts in the future about different types of gear when I start getting ready to upgrade my equipment, but today is not that day. Today we’re talking about exposure, which is the foundation of photography no matter what kind of camera you’re using.

But I won’t leave you tech fans high and dry. If you want to know more about the differences between types of cameras on the market, here is a Wikipedia article that talks about DSLRs, traditional digital cameras, and the newer mirrorless system cameras. Enjoy!

Exposure is basically how bright or dark your image appears. It’s something I’ve touched on before here and here, but so far have not discussed in detail. It’s one of those things that seems simple in theory but can be tricky to master.

I’m going out on a limb here and guessing that most beginner photographers shoot in Auto, or whatever their camera’s approximation of Auto is. It’s easy and safe, and most cameras will probably produce decent pictures in Auto. There’s nothing wrong with that.

But what if you want to do better than decent? Well, then it’s time to get out of the safe zone that Auto mode provides and start taking control of your photography. This is a process, by the way–don’t be discouraged if your pictures are bad at first. Set aside time to practice and you’ll eventually see your hard work pay off.

This was taken on auto at sunset. It’s not a bad photo overall, but I prefer the manual version below.
This one was taken in manual, just a few seconds after the auto picture. It is a bit darker, but I feel like the sunset looks much deeper. Honestly, I probably should have gotten in place a few minutes earlier.

The first step in the process is to dig out your camera manual and figure out how to change the settings. You’re looking for three things–shutter speed, aperture (or f-stops), and ISO. If you don’t have the manual, look for your camera model in a search engine and see if one is available to view online or download. If you’re shooting with your smartphone, consider an app that will give you that level of control over your phone’s camera. Open Camera (Android) or Halide (iOS) came up after a quick Google search for me; I don’t use either of them, though, so I can’t tell you how well they perform. You’ll have to try them out on your own and then come back and tell me about them. (I’m 100% guilty of leaving my phone in Auto all the time; I don’t take pictures with it all that often.)

Step two is learning how these three elements interact with one another to create an image. This one’s going to take some practice. For now, we’ll just go over what the elements are.

Shutter speed–In a digital camera, shutter speed refers to the amount of time the camera’s sensor is exposed to light. In a nutshell, high shutter speeds are good for bright places, while slower ones will allow more light to reach your sensor when it’s dark. But wait, there’s more! Your shutter speed will also determine how much motion is in an image. A high speed will allow you to capture subjects in motion while lower speeds introduce blur. Shutter speed is usually measured in seconds or fractions of a second. We’ll talk more about this next week.

This was shot at a fairly high (I want to say 1/250 but of course I didn’t write it down) shutter speed. As you can see, the water in the fountain is “frozen” midair.
Same fountain, same time, the big change was a much slower shutter speed. I also had to adjust aperture to keep from overexposing the shot. You can see the motion of the water here, and the background is brighter as well.

Aperture–We’ve talked about aperture before, and we will again. You can’t have a complete understanding of exposure without learning about all three elements, and I feel like this one allows you a great degree of creative control over your photos. Aperture is the opening in the lens of your camera (and different lenses will allow you to achieve different apertures, which is another bonus of a DSLR or a camera that allows you to switch out lenses); it’s measured in F-stops. Small numbers are wider openings, which allow more light to pass through the lens. Large numbers are smaller openings and let in less light. But that’s not all! Your aperture also determines your depth-of-field, or which parts of the photo are in focus. Large numbers are good for landscape photos or pictures where you want everything to be the same level of focus. Small numbers are good for softness or artistic blur.

This field of sunflowers was shot at a high f-stop (I want to say 16 or 20), so all of the flowers have about the same amount of focus.
This sunflower was shot at an aperture of F 1.8, the widest I can produce at the moment. The image in the foreground is fairly sharp and the soft background makes it stand out even more.

ISO–The ISO determines how sensitive your camera is to light. Lower numbers are less sensitive, while high numbers are more sensitive. Like shutter speed and aperture, ISO is also a twofold element. A high ISO will allow you to take photos in darker environments, but it also introduces noise to your photos. I don’t care for noisy photos, and I had a serious problem with cameras taking very noisy pictures in low light. So taking control of this was a big deal for me. I tend to shoot with a low ISO and only change it if I can’t get the shot I want by altering my shutter speed and aperture.

Here’s an example of a photo with noise. I shot this on Auto a long time ago. See all the speckles in the background? That’s noise caused by a high ISO.

When you’re getting ready to take a photo, exposure is one of the first things you need to consider. It’s not just how bright or dark you want your image to be, but also how you want to capture motion, depth-of-field, and the amount of noise you’re willing to put up with to achieve your desired shot. It’s a balancing act. Over the next few weeks, I’m going to try to show you how to manipulate all three of these elements so that you can find the balance in your own photography.

Thanks for reading, everyone! Please come back next Friday for a more in-depth look at shutter speed. I’m working on putting some really cool stuff together for you. In the meantime, you can follow me on Facebook for more pictures, articles, and other goodies.