Part Three: Photo composition. Creating depth and motion
Disclaimer: I am not a professional photographer though I am studying to be one. This is an introduction to cameras and photography for somebody starting right out and may be of less interest to experienced photographers, who may actually turn puce and run screaming for the hills at my words.
Hello again, and welcome to part 3 of this blog series introducing you to the world of photography. In today’s blog we are going to look at understanding the aspects needed to move away from automatic photography as well as composing a great photograph.
First of all I’d like to stop and talk about the word ‘stop’. If we change our stop in photography we are not getting off the bus in a different part of town, but making a change to our shutter speed or aperture size. To make things more confusing, whoever designed terminology for the lay photographer decided that, rather than search the dictionary for a different word to differentiate between aperture or shutter settings, simply to add a letter to the front. So we are going to discuss stops and f-stops. Don’t worry, it is less confusing than it sounds once you get used to it and we aren’t going to jump straight into it. Instead we are going to talk about how to create motion or depth in your photographs.
Have you ever seen those photographs of moving water where instead of frozen droplets of water it seems silky, almost milky? And yet in other photos you can see the water drops splashing? Ever wondered how the photographer creates the different effects? The answer may be “No”, “Yes” or “Yes Annalisa, but then I also wonder at 3am where the first potato came from”. If you are the 1st person this blog is probably not for you. If you are the second I am going to explain it all. If you are the third then don’t worry you aren’t alone, so do I. In short, if you want to change motion in your photograph you are going to need to change shutter speed. To change depth you need to change aperture.
In a DSLR the shutter acts like a curtain in front of the sensor.
- Shutter is down = curtains drawn, no light coming in.
- Shutter is up = you have opened the curtains and let the light in.
How long you leave them open will affect the exposure of your photo. The longer the shutter is up (curtains open) the brighter the photo will be. When you press the shutter button the shutter will lift. How long the shutter lifts for is your shutter speed. You or the camera set this. It is measured in seconds or fractions of seconds.
Do you recall in an earlier blog I mentioned that in the first recorded photo the shutter had to be open for several days? Luckily you don’t have to stand in a field quite that long any more. Many cameras now can open and close a shutter in thousandths of a second. The common speeds for a shutter are between 1/8000th of a second up to 30 seconds long. You can open a camera shutter longer than this but not automatically. This requires human control. So if you want to stand in a field for days you are more than welcome to. Light is measured in stops. As I mentioned, the common shutter speeds are now between 1/8000th of a second up to 30 seconds long.
Put your camera into shutter (S or T) priority mode.
You will have a dial that enables you to change the shutter speed. If you point your camera at something and turn the dial to adjust the shutter speed you are adjusting how much light can get to the sensor by either a full stop of light or a partial stop of light. You should also notice on the display or in the viewfinder that as you change the shutter speed the number with an F in front of it is changing. This is the camera adjusting the aperture to match your shutter speed in order to keep the photograph well exposed. There is a limit to how well it can do this depending on the lens you choose so eventually it will stop and begin to adjust your ISO instead. This is the sensitivity of your sensor. The higher the ISO the less or more light the sensor needs to develop the photo. Eventually the camera will also run out of options to do this and your photo will begin to be over or under exposed. But within a defined range, using shutter speed is a good first option for shooting your pictures semi-manual. A fast shutter freezes motion. A slow shutter blurs motion.
- Bigger fractions = fast shutter
- Smaller fractions/whole numbers=slow shutter
At night you also need a slow shutter to allow more light into the photograph to enable you to see the subject. During the day to use a slower shutter you will need filters if the speed is too slow to avoid ‘blowing out’ your photo by making it too bright. So start by having a go at shooting using Shutter priority. Pick yourself a subject and bear in mind if you want a fast or slow shutter. Remember the following:
- Fast=Freeze. (eg sports/wildlife)
- Slow=Soft/Blurred (eg arty photos using motion or to add light to night photos)
To give you a rough idea where to start this photo was taken with a shutter speed of 1/200 which was enough to freeze the wasp but not the wings. For the wings I’d have been looking between 1/1000 and 1/2000 at least. So select your speed and take some photos, allow your camera to select the Aperture and ISO for you and experiment to see how your photos change as the camera changes the aperture and then the ISO – bearing in mind, your photo will become grainier or more ‘noisy’ once the camera runs out of aperture options at a fast shutter speed, and begins to increase the ISO. It is probably not the time to start using semi manual right now if the photo is a one off and you don’t have time to experiment, stick to auto unless you do have the time to experiment or once you are more confident with the shutter numbers you will need. It is all entirely dependent on the photo you are taking so take lots of time to experiment and take lots and lots of photos. Photography, like anything else, will improve with lots and lots of repetitive practice. It doesn’t matter right now if you need 100 bad photos to get that elusive perfect one. You are just starting out. I go out and take photos for hours to try and improve my work.
Incidentally you will need a shutter of 1/30th or slower to blur water. For this you will also need a tripod. The slower the shutter is the more prone the photo will be to being affected by ‘camera shake’. If you imagine trying to hold your camera totally still without any movement for 30 seconds you can see how impossible it would be. It actually takes a remarkably small amount of time for the camera to move, and even movements that seem imperceptible to you can blur a whole photo. So unless you have an incredibly steady hand you will need a tripod once you get slower than about 1/80th of a second. I have occasionally gotten photos steady at 1/40th by using the crook of my elbow but at this or slower this I usually wouldn’t even try without at least a wall to rest my camera on.
This photo was hand held taken at a shutter speed of 1/30th and although the wings are nice and sharp you can see how there is a loss of definition to the body and eyes that might have been avoided with a tripod which unfortunately I didn’t have to hand at the time.
These are also some water shots as discussed. The first shot was taken at approx 1/100th going by memory. The 2nd was shot at approx 1/30th with the camera resting on a wall. You can see from the left to the right how the water changes but also the light. The water goes from being frozen in place to very smoothed out. However, the extra light the slower shutter allows in means the highlights are starting to blow out. An ND filter would solve this problem.
So we have discussed using shutter speed to add motion to your photos. Now for aperture – my favourite way to control my photographs. Aperture is not changed in the camera but in the lens and is a measure of how wide or narrow the lens opening is. In the human eye the equivalent is the pupil which constricts or dilates to compensate for the light coming in to keep eyesight steady which is why you adjust to sudden bright light or darkness. Aperture needs to be
- Wider in low light
- Narrower in bright light
If you remove the lens from the camera and (carefully) peer down it somewhere bright you should be able to see the lens blades, arranged in a circular pattern creating a hole in the centre. The measurement of the diameter of this hole is your aperture. The aperture is measured as an F-stop (not a ‘stop’ which is the light measurement for shutter speed. Just to be difficult) with numbers available from between F/1 to F/32 though more commonly F/1.4 to F/32. And because you don’t have enough to remember, the numbering is counter intuitive. The WIDER the aperture the SMALLER the number. There are mathematical equations for working out the F-stop of a lens which are to do with the ratio of the focal length of the lens. I find them quite mind boggling so if you wish to learn them I highly recommend Google. I find it easiest to remember the backwards numbering being because of 1 being a whole and any smaller ones being a percentage of the whole and not particularly worrying about the maths a huge amount. It’s not exactly accurate but it helps me. Or you simply mutter wider-smaller/narrower-bigger to yourself a lot while you are taking photos (not that I have spent countless hours doing this). Obviously the wider the opening is the more light it will let in while the shutter is open, and vice versa. So in low light you need a lower number and in bright light a higher number to make the aperture wider or narrower for more or less light. I will discuss the numbering of stops and F-stops in the fully manual blog but for now this is pretty much enough as moving away from automatic shooting can be daunting enough. And most modern cameras are pretty obliging about doing the number work for you.
Aperture is also responsible for depth of field of your photograph. Have you ever seen the photographs where the front of the picture is pin sharp but the background is totally out of focus, often with lovely shapes in it? That effect is called ‘bokeh’ and is caused by a shallow depth of field, so it is caused by a wide aperture/low F number. However, some photos will be sharp from the front to the back. This is a deep depth of field and is caused by a narrower aperture/higher F number.
- Wide D.O.F = narrow aperture/high F number (1st pic)
- Shallow D.O.F = wide aperture/low F number (2nd pic)
So turn your camera to the Aperture priority (A) setting.
Imagine you have a line of 3 people in front of you. If you wanted to focus on all 3 you would need to use a high F number to bring those blades in tight, create a small aperture opening and deepen your depth of field. If you do this on your camera you should see the shutter number change accordingly. As less light comes in the shutter speed will slow to compensate by allowing more light back in. If, however, you only wanted the first person in focus and the rest of the photo out of focus, or maybe a bokeh effect like the flower above, you would use a low F number to open the blades out to create a large aperture opening. Again, if you do this, you should see the shutter number change to a faster shutter to balance out the light requirements. This is, of course, assuming the first person is your focal point. If you wanted only the second person in focus of the 3 you would still use a shallow depth of field ie. F/2.8 but set your camera to focus on the 2nd person. This would cause the foreground AND background to blur but the mid ground to focus. As you can see with this wasp the depth of field is very shallow as the head is not sharp, nor is the background but the abdomen hairs and the food are very distinct. This is a shallow depth of field but with a mid point focus.
So again, have a go at experimenting with your Aperture priority setting giving yourself a deep field and a shallow field depth and see the difference it makes to your photo AND how the shutter speed will vary. Generally the more expensive the lens the wider the range of aperture settings you will have. The widest aperture will be marked on the side of the lens amongst the numbers we discussed last blog. On a prime lens it will be marked as something like 1:2.8 so will be an aperture of F/2.8. On a zoom lens, an 18-55mm for example, it will be marked as something like 1:3.5-5.6 which means at 18mm (wide angle) it will be 3.5 but zoomed in at a narrower angle of 55mm it will go up to 5.6. Interestingly the human eye has a pupil aperture of about F/8.2 during the day and F/2 at night.
You can also use Aperture priority to find the ‘sweet spot’ of your lens. If you set the camera to A mode and put it on a tripod, start with the widest aperture and take a series of photos of the same object at each different aperture setting. This will give you a chance to see how the look of the photo changes but once you upload the photos to your computer and zoom in on them you will also find the aperture at which your camera takes the sharpest photos. Whilst the highest apertures might keep everything from front to back in focus you will probably find that, for overall sharpness, you are looking at a midrange aperture. This is the ‘sweet spot’ of your lens which is usually in the mid range. Knowing this information is useful to keep in mind when you want to take a photo that will give you the maximum possible sharpness when shooting in natural light. The rule of thumb is that it is 2 F/stops up from the widest lens aperture. As lenses can have apertures that are 1/3rd or ½ of an F-stop I have included a chart of full F-stop values below.
Being able to have more mastery of your aperture and shutter speed is important as they form 2 sides of the ‘exposure triangle’ with the third side being the ISO. Once you can put these 3 elements together you can take great manual photos. The exposure triangle will be covered in the manual shooting blog so for now take some time to practice moving away from the Auto setting of your camera and having some fun playing with depth and motion in your photos.