Wednesday, April 8, 2009

Life, Love and Part 3: The Aperture

Remember last time how I said the ISO was kind of like your pupil and the bigger it is the more sensitive it is too light? Well now you can forget that because this might just confuse you. The size of your pupil may better be suited toward the aperture size.


When talking about apertures it’s important to remember that bigger isn’t always better, a rule that applies to so many aspects of life I don’t even know where to begin. Let’s go back to the eye ball example. Your camera is like an eyeball, this being the case the aperture (often represented as by values like f/2.4, f4 and f8 called f-stops) is kind of like the pupil. The larger the pupil the more light gets in. In your camera the size of the hole that lets light in is known as the aperture. See the analogy? Cute yes? Truth be told how your aperture effects your camera is more of a combination of both the pupil and your eye lids. I’ll explain, remember that time you thought that chick at the midnight bowling alley was really hot? But you couldn’t quite tell so you squinted your eyes a little to sharpen the image and stared for a long time until your eyes adjusted to the lighting at which point the chick noticed you staring at her and he came over and the last thing you said before he beat you up was “Dude, I thought you were a chick!”Same thing, minus the beating.


A smaller aperture makes the images sharper, like squinting you’re eyes. A larger aperture increases the depth of field, meaning that one point at a certain distance will be in focus and all objects around it at varying lengths will be blurry and out of focus (hence the field looks deeper). Here’s a fun exercise: Go down to the local police department (note the activity has to be performed this way or it won’t work, no deviations) and stand in the parking lot facing the entrance. Now hold out your hand and extend your middle finger. Focus on your finger so everything in the back ground is out of focus. Now squint your eyes (shrink your aperture). Magically you can now see the background just as sharp as your middle finger; you’ll notice men approaching you. Run.


The image on the left was taken with a larger aperture (smaller f-stop), while the image on the right was taken with a smaller aperture (larger f-stop). You can see the difference in focus.


Understanding f-stops (remember f-stops are technical talk for the size of the aperture) is even worse. It’s like trying to understand a woman, it just makes no sense. Think about this: F/1.4 vs F/8. Which is bigger? F/8 of course. WRONG. F/1.4 is larger. The smaller the number the bigger aperture hole. Contradictory and confusing? Yes, you understand my woman analogy then.


Further more if you are trying to control the shutter, the ISO and the aperture things can get pretty difficult. Especially if you are managing them all through controls on the camera menu. Some lenses will allow you to manipulate the shutter speed by a ring much the same way you would control the focal length, but most the time you’ll have to do it through camera menu controls.


I’ve found the aperture to be the most difficult piece to master. It’s like having a thumb located on your coccyx, I’m sure it has some useful applications but for now let’s keep it simple.


What you need to know: Larger apertures let in more light. Smaller apertures bring more of the image into focus. Twilight was a horrible and ridiculously long movie based on faulty vampire logic. For the most part letting your camera decide the aperture is enough.


How to apply this: If you are taking a landscape photo you want more of the landscape to be in focus. You know that setting on your camera that has a picture of a mountain? That’s landscape mode, if you select that then your camera will shrink the aperture size to bring more of the image into focus.

This image had a larger aperture, the focal point was placed in the center so you'll notice that the top and bottom sand trails are a little hazy.


Sometimes you’ll want to take a picture of several objects a varying length but want them all in focus so you’ll shrink the aperture to like f/22. Now you click and … … … your shutter speed has been decreased to like 10 seconds. Remember, less light is getting through so the camera has to compensate opening the shutter longer. Otherwise the image will be black. I have not yet found a practical use for f/22. Instead I’ve found that about f/16 or a few f-stops slower are enough to bring every object into focus given decent light. Conversely if you wanted to make everything in your subject blurry except for the main subject, you’d simply take the aperture down to its smallest number and snap the shot.


Other applications are to simply compensate for lighting the same way you would with the ISO or shutter. If it’s too bright, shrink the aperture (remember, smaller aperture = larger f-stop), if it’s too dark, well I’ll let you do some detective work on this one Lou.


That’s about all there is to know about apertures at this point. You should know that your aperture size is dependent upon your current lens. Pay attention to F-stops when purchasing, if you are getting a telephoto lens (longer zooms) then you will want smaller F-stop numbers because as the lens extends less light is able to get through. Smaller f-stops will also increase the price of these lenses (think about those ginormous monocular you see on cameras at basketball games, they’re so big because they need to allow for more light to enter).


For your next exercise head out to the beach, get four really hot girls (or guys), tell them you’re shooting a magazine called “four really hot girls (or guys)”. Stagger them at different lengths, focus on one and then take some pictures at different f-stops. Notice that even though through the lens the other sexy folk are out of focus, if the f-stop is large enough everything will be in focus on the image. Now that you have taken their pictures, tell them that you are not really from a magazine but are a wiccan and that you’ve stolen their soles with your magical soul stealing device.


There you have it, the holy trinity of the camera: The Shutter, The Iso and the Aperture full of grace.


Want some more lecture on the aperture?

Check the wiki

Or listen to some other guy's rantings

Thursday, April 2, 2009

Life, Love and Part 2: ISO speed

In a previous article I discussed how changing the shutter speed can greatly change the look and feel of an image. And once you tried a few of my suggested photos you immediately became entranced with my wisdom and I gained some street cred. But let me remind you, I’m a hobbyist at best and my amazing portfolio represents the few successes of literally thousands of failures, which sadly is a better track record than my dating life.

In this article we move on to a necessary counterpart to shutter speed: ISO speed. Remember how last time I asked you to compare the camera to an eyeball, with the shutters being the eyelids? Well this time you can still compare the camera to an eyeball but it will just get confusing when I talk about apertures. But what the heck, most things in life are confusing like feelings from gym class and swimsuits for fat people.

If the camera is an eye then the size of your pupil could be considered the ISO speed. Now let me explain why this is confusing, to be more exact the size of your pupil is more likely to be the aperture, or the size of the hole that lets the light through, but the sensitivity of your eye at different stages of pupil size makes more sense when analyzing ISO speed.

Think about the time you saw the matinee on a bright summer day. As soon as you left the theater you walked outside and everything was bright white and you screamed like a girl. This is ISO speed. At low speeds like 100 the film is not very sensitive to light. This is like being out at the pool at high noon with eyes wide open. When you were in the theater watching the movie your eyes were more like ISO at 800 or even 1600. When you were running from the cops through the moonlit forest at midnight because you failed to realize that no meant no your eyes were adjusted to the darkness and you could pretty much see the gist of your environment. This would be the equivalent of ISO speed at very high speeds like 1600 or even 3200.

Understand? Probably not, an easier way to understand it is just to know that ISO speed is how sensitive the film is to light. At lower speeds its less sensitive which means that it can capture an image just fine at noon day. At higher speeds it means it is very sensitive. This makes it possible to shoot better night shots.

ISO can do a few things for you. For one it can work to balance out your shutter speed. If you need to shoot something with a faster shutter around evening time you can set the ISO speed to be more sensitive (say 800 or 1600) making the shot brighter. Conversely you can set the ISO to 100 if you are going to leave the shutter open longer to mitigate light saturation.

For a while I used to shoot a lot of night shots at 1600. They were mostly of my neighbors and I didn’t want the flash to wake them or reflect of the bedroom window that separated us. The advantage was I could use a higher shutter speed in a dark environment and not have to worry about motion blur. Also flashes can drown out colors, reflect off surfaces and can make environments look very flat. The downside is that the end picture can be very grainy. Don’t get me wrong, you can still get some great pictures regardless of grain, but like garlic, use sparingly.

If you want a fun exercise go up on a hill that looks down on your home town at night. Set up your tripod and your camera and then set your shutter speed to about 3” or 5”. Now take a series of photos with varying ISO speeds. As the speeds increase you will begin to see a warm red glow engulf the city. This is another way you can affect the mood of your images.

When the ISO is lower your images fend off light giving it a colder paler look. At higher speeds the image tends to warm up, giving into oranges, yellows and reds. For instance if you take a picture of elderly people in swimsuits running through sprinklers in the summer months at mid day you’ll be tempted to shoot at a lower ISO to avoid saturation. Unfortunately someone will say “Good heck! Those poor old folk are running about in the winter!” This is due to what I mentioned before, most images at 100 ISO tend to have a cold stony feel to them. So now instead set the image to a high ISO, say 200 or even 400 and now set your shutter speed even higher. This will cause the image to have a warmer feel but the higher shutter speed control the amount of light coming through.

Let me give another example. If you’ve been a good study you’ve already gone out and played with your shutter speed but been horrified…HORRIFIED to find that often shadows are underexposed (too dark) and lit areas have been overexposed (too light). You’ve obviously been up late nights wondering how you can meet in the middle so that shadows aren’t too dark and lit areas aren’t all crazy white? The problem is this: When you focus your camera on your subject it adjusts to make sure the subject is lit enough (because even though you are playing with shutter speeds your camera will often still control things like ISO and aperture and adjust them accordingly. It’s like when you think you are using the big potty but you’re really using the little potty). So when the picture takes your subject is lit well but the shadows and sunlit areas are unintelligible because the camera didn’t care to take them into account. The answer my friend is ISO. If you’ve got shadows in the picture raise the ISO speed. If you’ve got pockets of light around lower your ISO.

You’ll run into countless opportunities to complain that your image is too dark or too light, if you’ve got a digital camera simply change the ISO and take the image again. If its still too extreme then give up, you’re clearly not a photographer. ISO is fairly intuitive and you’ll be able to quickly figure out how to make it complement shutter speeds. Apertures however are a different story.

Wednesday, April 1, 2009

Life, Love and Part 1: Shutter Speed

I’m a hobbyist at best. If you look at my portfolio you might be inclined to argue and I’ll flatter myself by agreeing with you but the fact remains, I’m a hobbyist at best. I have won a contest or two with my work and I’ve had several people ask me to take family photos or teach them how I do it but I promise you, to get to my skill level isn’t all that difficult. To begin with, it’s a numbers game. More like shooting a target with a shotgun, if you pack enough buckshot and point it in the right direction you’ll eventually get something into the bulls-eye. Likewise for every 100 shots you take at least one has got to turn out and the rest will quietly be removed from memory like the time you kissed your cousin. Something no one ever has to know about.

But it’s more than just safety in numbers. If you take a thousand shots letting your camera decide your settings you’ll simply get average photos. We don’t want average photos, what we want to do is improve our odds, mitigating the suck factor. This is where a little understanding comes in. Working with your camera should be a romance, clumsy and full of abuse at first but eventually you become familiar with all the buttons that get them going just the way you want them to at the right time.

Obviously it’s important to understand the fundamentals. Sure you can read about the basics of photography, the rule of thirds, looking at the background, framing the subject, blah blah blah. Don’t get me wrong, those are all important in positioning the camera right, but you also need to understand how to capture the light and movement best (shutter), change the depth of field (aperture), and use warm and cold colors (ISO). For the purpose of this article I will only talk about the Shutter.

For any beginner I believe the Shutter is the best starting point. To begin think of the camera as an eyeball, in this analogy your shutter is your eye lids. Every time you blink you are opening and closing the shutter. Now understand that instead of this eyeball processing several images it only processes one image per opening of the shutter. This means that the longer your eyelids are open the more light is landing on your film. The more light that that lands on your film, the brighter the image becomes. If too much light gets on the film then you will only see white, if too little gets on the film images become too dark to see or even black. So is the shutter on your camera.


At first it doesn’t sound that exciting; you may be thinking “Whoopee, I can make my pictures brighter and darker with this.” True, but you’d be surprised how much an image changes by restricting how much light can get through. Don’t believe me? Try this exercise. Take your camera out to photograph a sub-average sunset. Now take your camera and set the shutter to about 1/1000 to 1/2500 and start taking photos. If you’ve got a digital camera you’ll instantly be surprised. You’ll see that your camera is capturing brighter colors because the light doesn’t have as long a window to get in there and dilute the image.


Two pics taken at the same time with different shutter speeds (the one on the left was taken with a faster shutter speed).


Want something even better? Go to the beach a couple hours before sunset, have someone walk between you and the ocean and snap the picture with a shutter of 1/4000 of a second with the sun directly in the photo. What will happen is your friends and family will suddenly think you are Mozart or are wasting your life in accounting when you could be shooting for National Geographic. But you and I both know better.

So tricking the light is really cool. But there is another side effect of playing with the shutter: movement. This can either be really annoying or really cool. For instance if you are taking a night picture you will want your shutter to be open longer to let more light in, however when you take the picture you’ll notice that everything is blurry. The problem is when you hit the button on the camera you jerk it slightly so the entire image continues to record itself slightly off center. This is where tripods and timers (letting the camera count down before taking a photo, this reduces camera movement that happens when your finger pushes the picture button) come in handy. But it isn’t all bad. You know those photos of rivers and waterfalls and fountains where it looks like white cotton candy is flowing or the images of the stars rotating in perfect circles? These can be achieved by lowering the shutter speed to settings such as 1/25, 1/10, 1” (1” is one second for those of you wondering) and so on.

Slower shutter speeds can also be great if you want to show action in a photograph. Like a racecar careening off the track at 160 mph or an eagle attacking an orphan. When there is an element of blur in the image it tends to convey a better story than the crisp images that are achieved with higher shutter speeds. But again, you’re the artist and I’m sure if you get a picture of an eagle attacking an orphan people will be impressed regardless of whether there’s an element of blur involved or if it’s completely still or if that one guy that manages to get his head in all your pictures is standing off in the distance.

Now if you are really smart you’ve already caught the catch 22. You’re thinking if I slow the shutter down then won’t more light get in? And if I slow it down to 1” won’t my image be completely white? Depends.

First you’ll need to adjust for the time of day. Slower shutter speeds are better for darker spaces. However if you really want to get that cotton candy effect of the rapids (which is way cool) then slower is better. It is possible to shoot 1” and even slower shutter speeds at mid-day. You just have to make sure you’re adjusting the aperture size and the ISO sensitivity to compensate for the amount of light. The bad news is that is just a little beyond the scope of this article. The good news is that most cameras now days are pretty smart. They’ll realize that by leaving your shutter open for one second they’ll also need to shrink the aperture size and lower the ISO speed.

Practice with the shutter speed to begin with and soon you’ll find you have a pretty good feel for it and some pretty cool photos. I recommend getting a digital camera because you get immediate results and can quickly remedy an improper setting and even experiment to learn some new tricks.

The faster the shutter the higher the bottom number, the higher the bottom number, the less light will get imprinted onto your image. At extremes this can lead to some incredibly artistic representations of otherwise mundane scenarios.

The slower the shutter the lower the number, the lower the number the more light gets onto your image. This is advantageous if you are shooting in an area with limited light. But remember that it will record more movement as well. Not entirely a bad thing, as it too can be used to reinvent a landscape or show a story. Just remember that when you are shooting at lower speeds you will probably need a tripod and should probably use the timer on the camera.

One last bit of advice; if you’re using a telescopic lens you should know that they are incredibly sensitive to movement. Faster shutter speeds are recommended, if light is low however, you should use either a monopod or a tripod. Otherwise all your pictures will be very blurry and your heart will be very sad.