Digital Photography Course #1

A buddy of mine recently purchased a Nikon D90, and is pretty new to digital photography.  I figured this would be an excellent time to get back to the roots of this blog by writing a quick primer on the most essential basics of Photography.   I can’t teach you how to take good photos, however I can teach you what it takes to take a photo.  Whether or not it’s good or not is quite subjective and beyond the scope of this tutorial.

So what is photography?  An artist would say, “it is painting with light”.
A philosopher would probably say, “capturing discrete moments in time, never to be experienced again”.
An engineer would probably say, “Given the distance to subject at x, and lighting coming from 4 different sources, to achieve a proper exposure at F2.8, one would need to be at 1/4000th of a second, at ISO 200”. Makes you really want to smack that engineer upside the head. Photography doesn’t have to be that complex, nor should it be. It just takes the spontaneity out of it.

That, in a nutshell, lies the beauty of photography.  It blends many different disciplines, and rolls it into one simple package.  As we all know, generally in it’s simplicity, lies an abundant amount of complexity  waiting to be explored.   It is my therapy from a stressful day. The sheer joy of Creating something, that something that can bring enjoyment to yourself and to your friends/families is very rewarding.

I find most people find digital photography very daunting.  There are soo many options, buttons, settings, features.  It’s quite mind boggling when you think about it.  However, my answer to that would be, eliminate everything, avoid all the complexity, and the key item that remains is:  “Exposure, Exposure, Exposure”  (Yes, it’s a derivative of the old real estate maxim, “Location! Location! Location!”).   Doesn’t matter if you have a fancy four thousand dollar digital SLR, or an old film camera, or just a simple point and shoot.  The principles are identical, and nothing has changed for a very long time.

What is exposure?  How does one measure it?  For the purpose of this document, I’m going to be basing my exposure on the use of the camera’s built in light meter. (aka the reflected light meter)
In the canon models, the light meter is that thing on the bottom of your camera. Looks sorta like this:
canonlm

And the Nikon looks like this:
nikonlm

Again, to avoid complexity, I’m not going to get into the metering modes, and all that jazz. All you need to know, and all you care to do. Is to make that line be close to the center as possible. The zen of photography, is balancing 4 variables, to get to the middle, or as close to the middle as possible.

For canon cameras, as you notice, it is in real terms. Negative being on the left side, zero (or zen), and positive on the right side.
If you notice in the Nikon photo above, you may ask yourself, why is it ass backwards? In Nikon land, Negative is on the right side, and positive is on the left side. Doesn’t really matter who’s right or wrong, what matters is the end game for both systems is the same. To reach the state of zero. An experienced photographer can reach the state of zero, and generally know what settings to put the camera in zero state, much quicker and adapt to changing lighting conditions much better than a novice photography.

Authors Note: To put things into perspective, the difference between a 500 dollar camera, and a 4000 dollar camera. The difference between a $200 r lens vs a $2000 lens is their ability reach zero in less than ideal conditions. Any camera can take a picture in sunlight under ideal conditions. However, not everyone can go into dark interiors, or dusty environments. To shoot in cold or wet conditions, etc.

So how does one reach zero? To achieve exposure, there are 4 variables: 

1. Aperture: aka f-stop is the iris of the lens. Think of them as fancy blades. The diameter of the blades are expressed in f-stops.
blades
As you can see in the picture, the blades open or close, therefore controlling the amount of light that enters into the film/sensor. (From now on I’m going to refer to it simply as “sensor”). Photographers generally complain: “My lens is too slow”. No, this doesn’t mean your lens can’t win in a horse race. It means when shooting wide open, (the maximum aperture your lens can go). It simply does not let enough light in, to reach zero state. The faster the lens, the closer to zero your number will be.
You will see that photos are described as shot using: F2.0, F5.6, 3.0, etc. (again, to avoid complexity, I’m going to stay away from the mathematics behind these numbers). You can achieve nifty effects with this variable. (Blurring, sharpening, etc, but I’ll get to that at a later date, today is just trying to get people to reach zero).

2. Shutter Speed: Aka “The curtain”.
Think of this as a curtain that slides up and down. The faster the curtain moves, the less light gets into the sensor. The slower, or longer the curtain remains open, more light is let in. As you can surmise, there is an inverse relationship between aperture, and shutter speed. Meaning, the wider the iris (lets in more light), the faster you have to set the shutter speed to limit the light going into your sensor…in order to reach zero. Conversely, the smaller the iris is set, less light is allowed in, therefore, you have to open your shutter speed much longer in order to let more light in, in order to (you guessed it… reach zero).
This number is expressed in seconds or fractions of a second. 1, 2, 3, 1/100, 1/1000, etc.

Authors Note: Generally cameras maximum shutter speed is 1/4000 of a second. Higher end cameras go to 1/8000 of a second (translation, very very fast).

3. ISO: Is the International Organization for Standardization. In the land of photography, it is expressed in a number that represents the sensitivity to light. Expressed in 50, 100, 200, 300, 400, 800, 1200, etc.
What on earth is sensitivity to light? Well the lower the number, the less sensitive to light it is. In very simple terms, the sensor in your camera doesn’t such in ‘that much light information’. The higher number you go, the more sensitive to light it is. So you ask yourself, well why not put it at the highest number possible?! Then you can shoot in darker conditions right? Well the answer is, because there is a trade-off. The more sensitive it is, the more ‘grain’ or ‘noise’ that will be in the image. Think of your sensor working in over-drive. Trying to suck in as much as possible, and that includes grain, fuzziness, and noise. Yes, that means if you shot at ISO1600 or so for awhile, it does tend to drain your batteries a little more (not my much), and it takes longer for your camera to ‘process’ a shot because most cameras have algorithms to pre-filter out the noise that will also come into the image due to the extra ‘sensitivity’.

Authors Note: Point and shoot cameras are generally are utterly useless at ISO 400 or above. The small sensors can’t handle that much. Entry level DSLRS, generally go up to 1600, ISO 3200, but in terms of ‘usability’. I try to stay within the realm of ISO 800 or 1000. Higher end cameras and new cameras can have ISO’s that go up to 6400 and 12800. With even better algorithms and fancy magic voodoo sauce to mitigate noise. For me, if I’m shooting indoors, I know my cameras peak out at ISO 2000 or so, so I try not to ‘push’ it beyond that, otherwise I’ll sacrifice image quality. Your camera may vary, and I suggest you play around with the setting to see what your camera’s ‘limits’ are so you know how much you can push it.

4. Focal Length: Now you may think I’m crazy, but bear with me here. What is focal length? Focal length, is your lens. Expressed in mm or millimeters. (Yes, the world uses the metric system, and our backwards ass country still uses inches and feet. *sigh*. What is mm? You see it all the time. A 28mm lens, a 14mm lens. A 200-400mm lens. What on earth is it? Well, it’s actually the distance between the lens, and your sensor/film. Take your hand and place it right in front of your eyes palms flat. If your eyes are the ‘sensor’, and your palm is the lens…if you notice, the closer you move to to your eyes, you see ‘more of your hand. A much more wider perspective. Conversely, if you move your hand further away from your eyes, you start to get a more myopic view. Translation? The smaller the number, the wider the view. The larger the number, the closer you are, but you don’t get much of a ‘wide’ point of view. So a prime (or fixed focus lens is expressed by a single number).
28mm, 14mm, 200mm lens. A ‘zoom lens’ has 2 numbers. 24-70mm. 70-200mm, etc.

Back to the topic at hand. How on earth does focal length affect my ability to reach zero? Simple! The more zoom you have in your lens, the more you will notice the effect of ‘camera shake’. That’s why lenses that are 200mm or so have image stabilizers. Because any ‘slight’ movement, means you will shake shake shake yer booty.
Wider lenses, shake much less, due to the field of view, any camera shake is much less noticeable. My rule of thumb…always multiply your focal distance by 2. And that’s the minimum shutter speed you need to be at before you shaking effects you. For example, if you are shooting with a 50mm lens. In order to not get blurry images, you have to shoot at 1/100 of a second at a minimum. You can go below this if you have maaad steady hands, but this is just a ‘general’ rule.

Take another example, if you have a 14mm lens, well you just have to be shooting at 1/28 of a second to mitigate shake. What a difference it makes huh? 1/100 of a second lets is much faster (lets less light in, than 1/28 of a second). Conversely, if you’re shooting a 200mm lens. At a minimum, you should be at 1/400 of a second.
That’s a huge difference, because if you’re shooting at night, you need to let all the light in you can possibly muster. And 1/100 or a sec, or 1/400 of a second won’t let enough light in to get a proper exposure.

Tying it all together!

Practical Applications: (AKA use cases).
indoors:
So you’re cruising around with your 50mm lens shooting pictures indoors at your child’s piano recital. There’s not a whole lot of light and your indoors. So first thing you should so is set your ISO to 800. (Or whatever you think your camera can do before it makes too much noise). Well you have focal length, and you have ISO. That leaves 2 variables left! Knowing what you know, about the focal length multiplier, you now have to be sure that your shutter speed is at 1/100 of a second. With this set, you now will have to look into your light meter, and see where that needle is at. Is it under exposed? (too little light) Or is it over exposed (too much light). You now bring aperture into the equation. Most parent’s digital kit lens has a maximum aperture of F3.5 (kinda slow for my tastes). So you set your aperture as high as it would go (f3.5) and look at that meter. If it’s still below, well, now you are at a cross roads. Do you bump the ISO sensitivity to allow for more light in but sacrificing noise? Do you lower the shutter speed, to let more light in, potentially causing image blur? It’s up to you.

It’s more of like a ‘choose your own adventure book’. If you choose poorly, your wife will be upset because you didn’t capture the moment of your kid’s recital. Then you will be forced to sleep on the couch. (One good reason to hire a professional! =) I generally calculate all these conditions and set things on the fly, and you have to do this in split seconds as events and lighting conditions change and unfold (these things come with experience and time). For now, feel free to shoot like a granny. Take 4 or 5 minutes to adjust your settings, to reach zen. It’s ok, after a few more recitals and better photos later, your significant other may let you back into the bed!

2. outdoors
It’s a bright and beautiful day, the sun is shining, the flowers are singing. And…oh crap, your kid has a soccer game, and you’re responsible for taking photos. Nghia, Your favorite photographer is no where in sight, so you have to man up and do it yourself. Well first of all, it’s sunny as heck outside, so you want to set your ISO to it’s lowest possible setting. ISO 100 for canons, and I believe Nikon’s minimum is 200. The last thing you need is something more sensitive to light because you don’t want to overexpose your image. Next, you pick your focal length. For soccer games, you want to get into the action, so cameras with 55mm or less just won’t cut it. Usually for sports I go with 200mm, or so, and even then that’s not enough reach. Rich ass parents have shiny 300 or 400mm lenses (that they don’t know how to use).
For the most part, a kit lens may go up to 55, maybe 105, it really depends. So, you have your aperture, you really want to take nice blurry background shots, so you set that aperture as wide as you can. (F2.8, F3.5, F4.5, whatever your lens goes to). Check the light meter, and then move your shutter speed accordingly until it reaches zero, then snap! Done!

3. Every spouse’s nightmare
So you have a brand spanking new baby. You are a zombie, you can’t sleep, so you get into reading about photography and stumble upon this blog. You want to take cool photos of your baby, but can’t afford to hire ‘yours truly’ because you spent all your money on diapers. What do you do? Well flash photography hurts your baby’s sensitive eyes. You tell your wife, you don’t want to use flash. You set your aperture at F3.5 and you go down as low as you can go on shutter speed, while maxing out your ISO at 800. Yet it’s still too dark, and you are missing precious moments, feeling very inadequate because you are unable to capture the shot. You show the dismal, dark photos to your wife, and she throws you back into the couch, then rips up the photos in disgust.

What do you do??! Well, you have a brilliant idea! You now have an excuse to get a faster lens! Yaay! I recommend the 35mm prime, F2.0, or if you can afford it, a 35 F1.4. Now you know that F2.0 or even better, 1.4, can let much more light in! the iris opens nice and wide, so you are now able to snap awesome pictures of your precious little baby…But wait! There’s more! You then convince your wife you clearly need a better camera body. You want one that has higher ISO support for cleaner images so you can shoot even better more fantastic photos of your baby in their dark dungeon of a room! Yaay another new toy! OOhh…and then you realize, man they’re growing up, and the baby is starting to crawl, and walk and run outside. Auugg, now you need yet another lens to keep up with the baby’s wild antics! Bruhahhaha… now you’ve spent thousands of dollars, but the good news is. Now you have an excuse! =)

Authors note: What I generally do is judge the scene, first thing I do is evaluate my surroundings and set my ISO first. Indoors, I go to IS0 600, 800, etc. Outdoors, I put it at 100 or 200. Then I set my aperture. Why? Because aperture, controls the mood of the image. Blurry smooth photos? The lower the f-stop setting. Sharp, group photos, the higher the f-stop. Once I have those two variables in play, the last part of the equation is adjusting my shutter speed to get the proper exposure and then snap.

And that, ladies n gentleman, is photography in a nutshell.
Disclaimer: This is assuming you set your camera to Manual Mode. The only mode I shoot in. If you set to Auto, well, the computer makes all the decisions for you depending on the conditions, but as we all know. Nothing beats the expressive nature of our minds, and there are just some things the computer, no matter how powerful, can replace or simulate.

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About greenbeanfx

Photography is what I do =) If you wish to contact for a photoshoot, send me an email or comment on a blog with your info and I'll get back

Posted on April 25, 2010, in Aperature and tagged , , , , , , . Bookmark the permalink. 3 Comments.

  1. Nice write up… you should also mention that for beginners instead of shooting in manual, they can use AE or TV setting and let the camera control the shutter speed or aperture. That way they can master the other variables before going full manual. After all whats the point of having a camera if you need to set everything by hand? Understanding ISO should be the first thing. Once you know the proper ISO for the light condition you can tweak one of the other variables fstop or shutter speed and let the camera adjust/set the other variable for you. For instance if you set the ISO and you only want to control the fstop let the camera adjust the shutter speed for you (you can always override this adjustment) or vice versa if you want to stop the motion of something with shutter speed let the camera adjust control your fstop. Once you master that you can go full manual to play around with the adjustments to get it more artsy. I like that you mention the cameras light meter. You should show the histogram and how to read it so you know you have the right balance, too far left or right is also an indicator of over or under exposure.

  2. hmm, yeah I’m gonna get to that as soon as I delve into each of the 4 items. Didn’t want to overwhelm people with extra long narrative. The actual ‘how’s on each camera body will be up next =)

  1. Pingback: Crash course #2 What Lens to Use? « GreenBean’s Corner

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