What your need to run this photography test yourself, A Camera, A dimmer swich for lighing, a fan and some detailed objects in the background
Shutter speed, aperture, ISO and light
When doing photography you must remember the relationship between shutter speed, aperture, ISO and light. They are all connected to each other and adjusting any one of them can be compensated for by adjusting any other. In other words, if you make the room brighter by raising the lights, you’d have to make your shutter speed faster to compensate for it. It can be pretty complex and it can be really hard to explain, that’s why I’m going to walk you through a series of tests that you can do with your camera, to show you exactly how everything works.
Now, understanding these is important because not understanding can cause a lot of problems with your photography shaky pictures, and not getting everything in focus that you want to. Once you get an understanding of it you’ll be able to fix those problems, noisy pictures tool.
Let’s get started our photography started by taking our first picture on totally automatic mode. The mode I’m using now is programme mode, which is P on most cameras, and it lets the camera make all the decisions for you. If you’re ever unsure about the settings or you’re giving your camera to somebody who isn’t a competent photographer, set it on P mode and it’ll take care of everything for you. It’s a great way to go when you’re feeling a little bit nervous about your photography. However, for those of us who master shutter speed, aperture, ISO and light, it’s a mode that you won’t ever want to use because you’ll always want to be able to control those conditions. You can see the camera does just fine.
What you should to do now is to cut the lights in your room by about half and take another picture. Now, as you can see, the exposure didn’t really change between those two pictures. The brightness of the picture is exactly the same, and that’s because the camera auto exposed it. It looked at the light in the room and adjusted the ISO, aperture, and shutter speed in order to get a well exposed picture. However, those had a side effect. As you’ll notice, the fan is a little more blurred than it was in the previous picture, and that’s because they had to use a longer shutter speed to expose the picture properly with even less light. That’s one of the reasons you need to understand these, because you might or might not want that extra blur in there and you do have total control over it.
Now, you also notice that the brightness didn’t change and a lot of people think they can change any one of these settings and it will adjust the brightness of the picture in automatic mode. That’s not true. You can adjust the ISO or the shutter speed or the aperture or the light in the room and the camera’s always going to adapt to it, so changing any of one of those won’t change your brightness. If you want to change your brightness you use exposure compensation and on most cameras that’s controlled with a dial on the back, though sometimes you need to press an extra button or go into a menu system.
Just for an example,I want you to add 1 stop of exposure compensation so we can see the difference. As we can see there, the picture did get brighter. It got one stop brighter, to be precise, because you adjusted the exposure compensation by one stop. A stop in photography is a doubling or a halving of the light. If you double the amount of light in a room, you’ve added one stop of light. If you cut the shutter speed in half, if you go from 1/250th of a second to 1/500th of second you’ve increased the shutter speed by one stop.
Now, try moving the camera into manual mode. Whereas, the ISO, aperture, and shutter speed were all unlocked so that the camera could adjust any of them when I have it in program mode, in manual mode I can lock down everything and prevent the camera from making any automatic decisions. It gives me complete control. That’s what I’m going to do and I’m going to set it in manual mode and then configure it so that it will expose the picture properly and we’ll take a test shot.
Check what setting your camera using in auto and put the same setting in manual The correct setting for me when i did my test where, a shutter speed of 1/1000th of a second, f/2.8 and ISO 6400. Those settings together allowed the camera to expose the picture decently when taking my image the blade of the fan where just about frozen because 1/1000th of a second is pretty fast. You will also see that the objects in the background, they’re all pretty well blurred. You’ll see in some later pictures those will get sharper and sharper.
The first thing I’d like to do is experiment with changing the ISO. ISO, which by the way, is not an acronym. You can look it up. ISO is the sensitivity of the camera’s sensor. If you increase the ISO from say 100 to 200, you’re increasing the ISO one stop. That’s doubling the sensitivity of the sensor. The typical usable range goes from about 100 to 6400. In my test the ISO was set to 6400, which is a pretty bright ISO, because the room i did my test in was pretty dim. I am going to drop it down to 3200 and we’ll see the effects. As your see when doing your own test, the picture got darker. As your ISO gets lower, the camera gets less sensitive and if you don’t let the camera adjust the other elements, the aperture or the shutter speed automatically, then the picture is going to get darker.
Let’s move the ISO up two more stops to 12800 and see what the effect is. As you might have guessed, the picture got brighter because we increased the sensitivity of the camera without changing any of the other settings. We’ve been in manual mode where we locked all of the settings except for the one that we were controlling. Now you should switch back to program mode, which will make everything but ISO automatic and take a couple of shots at different ISOs so you can see the effects.
Here is an example of few different setting and what happens/changes. I did a test with a photo of a moving fan and the camera exposed the picture at 1/350th of a second and f/5.6 and it was well exposed. Now I will drop the ISO to 3200, that’s dropping it two stops, so the camera will need four times as much light. Your see, the picture will still be well exposed, the camera had to change the settings to 1/180th of a second and f/4, increasing the amount of light using the other factors, Now try taking a few photos of your own of the fan with a lower shutter speed and as your see, the result of the longer shutter speed are blades will be more blurred.
Now drop the ISO way down to ISO 100. As you can see, because it’s in automatic mode you can change the ISO to anything and the picture is still properly exposed. Load your photos onto your PC and review them. Your see some really important differences. As we get really close to those pictures we’ll see that the pictures at the high ISOs are really, what they call, noisy. Noise is the digital equivalent of film grain and it’s not pleasant, it’s something to always be avoided. Now, if you look at your photos taken with ISO 100, you can see that it’s nice and clean and beautiful. ISO 100 is almost always better than the higher ISOs, but one of the challenges of photography is that when you choose a low ISO you’re going to have to change some of your other settings, such as the shutter speed and aperture as well.
Now lets take a look at the shutter speed. You can control the shutter speed by putting your camera into shutter priority mode. On almost all cameras that’s marked by an S. On Canon cameras though, it’s marked by a TV. To put your camera into shutter priority mode it gives you control over the shutter so you can specify how slow or how fast you want it. The camera will change the other settings for you, most notably the aperture and perhaps the ISO if you have it set to auto ISO, to allow the picture to be exposed properly. You want to use shutter priority mode anytime the speed of the picture is important to you. If there’s a moving subject in your picture, you want to switch it to shutter priority mode. Yes, at your kid’s basketball game, if you’re taking pictures of your dog running or a bird flying, those are all times you want to be in shutter priority mode. Now take a picture with the default settings in shutter priority mode.
At 1/250th of a second the fans on that blade are pretty well blurred. Now, let’s imagine that I wanted to be able to show those fan blades nice and crisp. Going to crank that shutter speed even faster, so let’s jump up to 1/1000th of a second. That’s better, they look nice and sharp. What if that isn’t the effect you want? What if you want to show motion blur? This is really common if you’re shooting a moving car, for example, you’ve got to get some spin showing in those wheels, and if your shutter is too fast you’re going to freeze too much motion. Intentionally showing blur is one of the tricks and one of the benefits of using shutter speed.
Let’s drop that down to 1/60th of a second and see the effect. Your start to see a nice blur that we wanted. At that speed the fan blades are a complete blur. Shutter priority gives you a control over just how much motion your pictures show. There’s also motion in your own hands and if you’re hand holding a picture and it’s ending out blurry, it’s probably what they call camera shake, and you can control that by using shutter priority and specifying a shutter speed that’s fast enough for you to hand hold.
Now I will show you what happens when you change the lights. Shutter speed gives you control over the shutter and the camera will not change it. The camera will change the aperture and if you’ve chosen auto ISO it will change the ISO as well, but it will never ever change the shutter, you have control over that.Now try lowering the lights to about half the brightness as before and taking a few photos and we’ll see what the camera does differently. As you can see, when you lowered the lights in the room, the camera compensated for that, not by changing the shutter but by lowering the f-stop number. Choosing a lower f-stop number opens up the aperture, the iris of the camera, letting more light in. It had to do that in order to get the picture properly exposed, but in shutter priority you control the shutter, the camera controls the aperture.
Let’s take a deeper look at aperture now. Now switch the camera into aperture priority mode and a picture.Try setting it to f/8 which is a pretty moderate f-stop number. One of the things that aperture controls besides the amount of light that gets in through the iris is the depth of field. Now, there are other factors that influence depth of field as well, but for the sake of this, we’re only controlling the aperture. At f/8 I your get the objects in the background kind of in focus. Let’s say you want them nice and sharp, what should do is to choose a higher f-stop number. Let’s crank that f-stop number up and your see the background becomes sharper too .
Now try at f/32 Your have enough depth of field that you could read the title of a book in the background. I control the aperture in aperture priority mode, the camera doesn’t do it. Let’s imagine that I don’t want to see the background in focus. Let’s imagine I want a nicely blurred background. This is really popular in portraits where having a nice blurred background helps to eliminate any distractions. To do that I’m your need to choose a low f-stop number because a low f-stop number means low background sharpness. Let’s crank that down to f/2.8 and take another picture. At f/2.8 that detail is completely blurred and your also notice those fan blades got a little more distinct. That’s because the camera chose a faster shutter speed because it was using a larger iris, a larger aperture, which let in more light. That’s how aperture works.
There’s one other thing that I’d like to go into and that’s how a flash can control the amount of light in the room totally automatically. If you attach a flash to the camera. The flash will have an interesting effect on the fan blades, it will frezze the motion of the blades but at the same time you can still see some blur. When the flash fires the imprint of the blades at that current position were burned into the sensor, but because they are moving the rest of the time the shutter is open your see this interesting effect where they’re blurred and then frozen, almost like a ghost moving into position. It’s one of the cool tricks that you can do with flash.
Why might you want to use a flash and add light? Well, first you might want front lighting. If the subject is backlit, a front light would help fill in any shadows. You might also want it because you’re not happy with the compromise of ISO, aperture and f-stop given the amount of light. If you’re forced to use ISO 6400 and you just hate how noise it is, put a flash on, add a little light to the room and that’ll let you use a lower ISO.