a1 Photo Tips

This post ties in with previous ones I have written about how to get creative control; either using the aperture, or using the shutter speed settings. Now I address a special type of situation: You want to capture something, maybe an event, that takes place indoors, and you either are not allowed to use flash or you don’t WANT to use flash.

The event could be a public performance or maybe a wedding ceremony. In either case, using flash may be a no-no. Assuming you have a camera with built-in flash unit and nothing more, the result of a picture snapped with the flash unit as major light source is nothing much to brag about. Sure, you can clearly see what is going on but that’s about it. The light is harsh and ugly, everything close to the camera is very brightly lit and whatever is further away gets gradually darker, disappearing into blackness.

Then there is the fact that firing off a flash may be very distracting and irritating. Like during a wedding ceremony - how romantic is it to have a flash zapped in your face at the exact moment you say “YES”?

If you want to tackle situations like these successfully, getting both beautiful pictures that convey the mood of the event AND remaining friends with people around you - then learn to work in ambient light without any flash!

And again, I bring out the good old Exposure Triangle:

1. Exposure Time = Shutter Speed

2. Aperture = Size of Light Opening

3. ISO Setting = Sensor-sensitivity

These are the main in-camera factors you have to master, to be successful. — Now, would you believe me if I told you the picture above was made with a hand-held camera, without any tripod or such support? Yet I’m told it was. And the only light comes from that candle!

How was that possible? Well, the photographer must have a firm understanding of The Exposure Triangle. To get a picture like this, you have to get as much light into the camera as ever possible, at a short enough time to avoid motion blur. Now look at those three factors. Which one do you use to get as much light as you can into the camera, in short order? Right, number 2; the aperture setting!

So, you set the aperture at the largest opening (ie. the lowest number on the scale) possible. If you are lucky enough to have a digital SLR, you may be able to choose between different lenses, and pick the one with the largest maximum aperture (= the “fastest” lens).

Now, what else can you do to get a clear image with as little light as possible? Correct! - You crank up item number 3, the ISO-setting, as far as it goes! This makes the camera sensor react to smaller amounts of light, at the expense of a somewhat impaired image quality. You get more “noise”. And you may be willing to live with that noise, which won’t be so noticeable if you don’t make the image very large.

Or you can actually get rid of at least most of it using post-processing. I’ve heard there is for instance software called “Noise Ninja”, designed to reduce such image noise.

By using a large aperture and a high ISO-setting we have, hopefully, been able to acieve our goal: To use a shutter speed (ie. exposure time) short enough to get a sharp image without motion blur. And if there still isn’t enough, here is another little photo tip: Deliberately under-expose the image slightly! You can correct that later, using any image-editing software like Photoshop.

Of course, how much light is “enough” varies depending on your ability to hold the camera still using a long exposure like 1/15 of a second or so. I gave you some how-to tips on that in an earlier post: How to Hold Your Digital Camera. And if the subject moves slightly during the exposure, the effect may actually be very interesting - with some luck!

Photo credits: child picture: Ctd 2005; performer picture: reportergimmi

Get your aperture right, and you may get mucho better pictures! Now what is Aperture really? OK, I think I recall there is (or was) even a famous fine-art photo magazine called “Aperture“. So, it seems to be an important concept in the field of Serious Photography.

Wikipedia says: “In optics, an aperture is a hole or an opening through which light is admitted… Obviously, the aperture also determines how many of the incoming rays that are actually admitted and thus how much light that reaches the image plane.”

Well, Wikipedia has got it spot-on, as usual. You use a large aperture, ie. a large hole, and lots of light streams in. You use a small aperture… what do you think happens? Right, less light gets through during a set amount of time! One detail to remember: in your camera, large apertures have small numbers and vice versa, like f=2 is a large aperture and f=8 is a small one. Expensive, “fast” lenses are capable of large apertures. OK, I guess we could stop here and let you figure out the rest yourselves…

Still there? OK, the thing about aperture is to get control over how you use it in your photos. You see, if you use a large aperture, the depth of field is small - and conversely: small aperture equals large depth of field.

This is the important thing to know about aperture. Maybe I should add a few words about what depth of field is. Think of it this way: You focus the camera on something, say a flower in a field. Usually, not only that particular flower will be rendered sharp in the picture, but also some of the flowers closer to the camera as well as some of those further away.

This is the phenomenon called “depth of field”. Just how much of it you will get in each case depends on several factors, but the main ones are your distance to the subject and your aperture setting. Assuming you have already chosen a distance that you like, you can now adjust the depth of field by playing with the aperture setting.

Do you have a somewhat distracting background which you’d rather get rid of? OK, try using a large aperture to put that pesky background out of focus! Since the depth of field is now smaller, everything that is significantly further away from the camera than the subject you’re focusing on will be rendered blurry - and hopefully less distracting.

Obviously, if you use a larger aperture you need to change one or both of the two other points in the Exposure Triangle - shutter speed and ISO-setting. You will need to use a faster shutter speed and/or a lower ISO-setting to avoid having the picture over-exposed to light. Complicated? Not at all - I’m pretty sure there is some setting on your digicam which takes care of this automatically. Like, you set the aperture you prefer and the camera takes care of the rest. If in doubt, consult the manual…

Now, suppose you are snapping a picture of something and you want all of it in focus - what do you do? Right again! - you use a SMALL aperture setting. Like the photo of the spiral staircase here, note how all of it is rendered sharp, even the knob in the lower-right corner which seems quite close to the camera.

This is how you play with aperture to control the depth of field in an image.

Before closing, I like to give you another short photo tip: You need to remember that the camera’s autofocus always thinks whatever is in the center of the picture is also the thing to focus on. This is by NO means always the case, as in the staircase case here. The photographer wouldn’t have managed to get everything sharp if he had put the focus on the most distant part of the picture - which is in the center. Instead, he must have focused on some point about half-way up the stairs, to get this splendid result.

Photo credits: eye by DownTownPictures, staircase by procsilas.

In case you are new to photography, you may feel it is convenient to just put your digital camera on automatic and hope for the best.

If you do, I bet you will soon get a bit frustrated with how your pictures often don’t come out the way you intended, and you sit there wondering what’s going on.

OK, then it is time to take the first steps toward having control over the camera - as opposed to having the camera control YOU!

Take the clown picture here for example. Imagine how dull it would have been if you had taken the picture using automatic settings. The camera would then have fired the built-in flash unit and ruined the mood of the event (and you may also have gotten thrown out for disturbing the act!).

On the contrary, the photographer here had total creative control. He took the picture using the ambient light, and used a very long exposure time. And, yes, the result was motion blur.

However, what do you feel when you see that “blurry” photograph? Personally, I feel it is a great shot! And you could never make a picture like this unless you had creative control over your camera.

The Exposure Triangle

To begin with, there are basically THREE WAYS you can control how the image is exposed in the camera when you press the shutter. You can think of these as the three tips of a triangle; the Exposure Triangle.

1. Exposure Time = Shutter Speed

2. Aperture = Size of Light Opening

3. ISO Setting = Sensor-sensitivity

The exposure time, also known as “shutter speed”, determines how long time the camera sensor is exposed to the light from the subject of interest. Long exposure is another word for slow shutter speed.

The aperture setting determines how big the opening is allowed to be, for the light coming in. And remember that the larger the aperture opening, the lower the number on the aperture scale. Expensive camera lenses usually allow the use of larger apertures, making it easier to work with them in low light.

Finally, the ISO setting determines how high you crank up the light sensitivity of the sensor unit in the camera - the part that transfers incoming light to an electronically stored image. Higher sensitivity means more “noise” in the image. To get the best quality you usually set this to 50 or 100 ISO units.

So, a few words on shutter speed. Generally, if nothing you’re trying to capture is moving much you can use shutter speeds down to maybe 1/60 of a second. With practise, you can use even slower shutter speeds, ie. longer exposures, for non-moving subjects. In case you want to freeze movement, you need a faster shutter speed. For instance, a car driving past you and going fast may require a shutter speed of 1/500 of a second to “freeze” its movement.

The picture of the surfer here was shot at a very fast shutter speed, to “freeze” the movement. Fast movement = fast shutter speed.

To get creative control over the shutter speed point of the Exposure Triangle, you need to consider how you want to use that setting to control the mood of the image. Like, do you PREFER to “freeze” the movement by using a fast shutter speed, or would you rather experiment with a very slow shutter speed to get intentional motion blur, as in the clown picture?

In the case of the clown picture, the low ambient light wouldn’t allow a very fast shutter speed - and neither would it be needed or even desirable in that situation. Conversely, in the surfer photo the light was quite strong which allowed the photographer to snap the picture at a fast shutter speed - likely 1/500 of a second or even faster.

You could have made a very different surfer picture by using a slower shutter speed, to create some motion blur. Then you would have needed to adjust the two other points of the Exposure Triangle accordingly - smaller aperture and/or lower ISO setting, to avoid over-exposing the image.

In conclusion: You use the shutter speed point of the Exposure Triangle to control how you render movement in an image. If the rendering of movement - either by “freezing” it or by using motion blur - is a top priority in a particular situation, then your first priority is to adjust the shutter speed to a setting that fits your intention. The other two settings (aperture and ISO) will take the back seat, so to speak. You simply set them to whatever is needed to get a correct exposure.

Photo credits: clown: Ctd 2005, surfer: abnelphoto.com