For The Newbies: Aperture
Creative use of DOF
When finished, hopefully you’ll know what is an aperture and why it’s important. So, let’s start:
An aperture is, quite frankly, a hole. By varying the size of this hole, we can increase or reduce the amount of light that reaches the sensor. Say what? Let me put it another way. Let’s talk very briefly, first, about exposure. Exposure is the amount of light + the amount of time that the light is left on the sensor, or film.
A jug of water
In order to have a property exposed picture, you need the right combination of light + time. If you have a container that holds liquid, for example, a 1 gallon container, when you go to the sink, or perhaps to the garden hose, you can control the filling of that container by varying the quantity of water that is coming out of the hose. If you open the spigot to its maximum opening (aperture), then the container will fill very quickly. However, if you let but a trickle of water come out at a time, it might take several hours to fill the container. This is exposure. Time + quantity (intensity) of light. The intensity being controlled by how wide you open the spigot. The time that is needed to fill the container, shutter speed.
Away from water. Back to cameras.
If you were to take one of your lenses, hold it to the light and look through it, you’d see a hole created by diaphragm blades. If your lens has an aperture ring, turning the ring would make the opening larger or smaller, depending on the direction that you turn. The purpose of this hole is to increase or reduce the amount of light coming into the camera. This is your aperture.
What do all of those numbers mean?
Looking at my 50mm lens, I see the following numbers: 1.8, 2.8, 4, 5.6, 8, 11, 16. Looks like some weird math sequence that you’d have to figure out for a college entrance exam, doesn’t it? Well, these numbers are aperture numbers, or f-stops, and each one of them, starting left to right, represents a smaller aperture, that is, it lets in less light (1/2 the amount of the previous number). The bigger the number, the less light it lets in. Think of it as a divisor.
A little math! Piece of Pi !
Uh, oh! No one said that there would be math involved! You can skip this part if you don’t want to know why these numbers are as they are. Let’s just say that it has to do with circles and Pi.
So, if you decided to keep reading, here’s what those numbers mean:
Given the above formula, let’s plug in some values for a 50mm lens:
f = focal length
N = the aperture Number.
Area = 3.14(pi) * ( 50/2 * 4 )^2
Area = 3.14 * ( 50 / 8 ) ^2
Area = 3.14 * (6.25)^2
Area = 3.14 * 39.06
Area = 122.7 square millimeters (area of the circle).
Using the same calculations for the same lens, but different aperture (5.6), gives and area of 62.6 square millimeters, or approximately 1/2 of the surface area, so one half of the light! Isn’t math wonderful?. Try it for the others and you’ll see that the math works. Now you know why each step to a higher number results in half of the light being let through, and each full step to a lower number, twice the light. You are changing the surface area of the hole.
For your math savvy folks, the above formula is the calculation for the area of a circle. pi * r^2. The division in the ( ) is the calculation for the radius, but enough of this math stuff!
So, that’s all very interesting. How can I use this?!
OK, now that we know how to control the the quantity of light coming through, what advantage does it offer us? This allows us to control our depth of field. Depth of field is how much, front to rear, of our picture is in focus. We might not always want everything in focus from the tip of John’s nose to the end of the street. We might want to isolate John and provide a nice, blurred background.
DOF and Bananas (click for larger image)
Depth of field can be altered by many factors: focal length of lens, distance of lens to subject, aperture, distance of subject to background, etc. For the purposes of this article, we’ll stick with depth of field as it pertains to aperture. We’ll also only demonstrate DOF for one lens, a 90mm f/2.8.
Because the birds won’t hold still long enough for me to take 8 shots in a row, I had to use some bananas that I had sitting around. Bananas are very cooperative, as a bunch, generally! 
As you can see, each step down (move to a higher number, smaller aperture) in aperture causes a corresponding increase in depth of field. When I was at f/2.8, the banana was very well isolated from the background and only that point that I focused on, at the stem, was in sharp focus. As I decreased the size of my aperture, more things start to come into focus, which may or may not be what I really wanted.
In this way, DOF can be used not only to control the amount of light coming in, but to also control what appears in acceptably sharp focus. So, now you know!
Aperture Priority / Aperture Value (AV)
This is the mode on a camera where you choose one half of the exposure equation, the aperture, and leave the camera to choose the other, shutter speed. That’s it!
Other things: Fast lenses
OK, so you’ve heard the term, perhaps, “fast lens”. It has nothing to do with how fast you can put it onto your camera! 
It may have to do with how fast it can drain your bank account, though! Fast lenses can be a lot more expensive than their slower counterparts. They are also heavier because they use larger pieces of glass to let in more light.
A tale of two lenses
For example, a Nikkor 300mm f/4 costs $1,124, while the same type of lens, one stop faster, the Nikkor 300mm f/2.8 VR costs a whopping $4,449! You pay a lot for that extra stop of light. A lot of engineering goes into that lens. Also, the former weighs in at 3.5 pounds (1.6 kg), the latter, 6.3 pounds (2.9 kg). Certainly something to consider when making a purchase.
A fast lens means, generally, those with maximum apertures of 2.8 or more. Remember, the smaller the number, the wider the opening. Think divisor. Fast relates to shutter speed. The wider the lens opening, the faster shutter speed you can use for the same lighting conditions. For example, a 100mm f/2.8 is a faster lens than a 100mm f/3.5, by almost a complete stop (1 stop equals twice or 1/2 as much light, depending on the direction that your heading.). So, it is a stop faster.
Now, hopefully, you know about apertures, how they affect exposure, and why having control of it can be important.
Your favorite photography podcasts or books?
Almost any time that you see me I can be found with my camera in my hand. If I don’t have my camera, I have a book. If not a book, then I’m walking my dog, or perhaps playing with him. Where you’ll most likely not find me is in the company of the television.
With regards to books, I love a good fiction book. Unfortunately, so many of them are crime dramas, or perhaps horror, etc. I need a break from that sometimes. One of my favorite, daily breaks, is the Tao Te Ching.
I, like a lot of people, own an iPod; however, I rarely use it. It sits idle for very long periods of time, on the order of months. I think that I’d like to have it with me when I take Hobbs on one of our longish, 4 or 5 mile, walks, but I want to have something interesting/inspiring to listen to.
I would like to know which podcasts or books that you’ve found particularly interesting or perhaps inspiring. I would prefer that they be photography related. Not necessarily a how-to , but it can be a work of fiction where, perhaps, a photographer is on a journey of discovery, etc. I like books about journeys. It can be a book or podcast about a famous photographer. The sky is the limit.
Thomas shared a couple of Ansel Adams videos that he found on You Tube. I found them inspiring. I’m open for videos, too, but would prefer podcasts or books on CD when I’m walking the dog. It’s kind of hard to watch a video at that time without stepping in a hole or out in front of a car. Safety first!
Well, off to take that pooch for his morning walk.
Thanks for your input!
Sustained growth
Yesterday, the US stock market index, also known as the Dow Jones Index closed at 11,453. Mind you, this number is an arbitrary number and I understand that when it continues to rise, things are going well, so to speak. When it begins to tumble, the worries set in. Some years ago there was a big celebration among traders and all of those who cared when the number hit 10,000. Since then, it’s dropped below 10,000, eclipsed 11,000, and does what it does … meanders about causing all types of euphoria and despair. So many people hinge their happiness, success, prosperity, etc. on this little number.
However, I don’t want to talk about the stock market. I only use the index as a jumping off point to talk about growth. Investors seem to want their stock prices to increase without bounds, never having periods of quiescence. Some businesses seek endless growth, trying to conquer everyone in their path, looking for total domination. Microsoft, for example.
At times I feel like that about art, especially my own. I feel that I am in a period of quiescence and sometimes it’s uncomfortable. I know, both logically and intuitively, that this plateau is necessary and good, but periodically I try to fight it. I seek that ever upward spiral of growth. But, I realize that it is necessary to stay in this place and cultivate, experiment, familiarize, and understand where we are, as an artist. As a person.
Even with lots of time on my hands, I am finding it difficult to create something new, something better. Therein lies the struggle. I know that I cannot make anything happen. Things just happen when I let them, not when I try to force them. Sometimes a change in scenery is a huge boon to creative production, like my recent trip to Utah. Other times a different approach to the same subject is warranted. Yet, other times, nothing seems to be able to move that creative index in the ‘positive’ direction. Nothing.
Perhaps that is it. I have too much time on my hands to think about art or creativity, rather than letting it happen. At other times, it’s like a lightning strike. Like with this picture. Richard and I were sitting in a small restaurant in St. George, UT, and an older couple walked in. I saw the lady’s hat, her boots, and most strikingly, her long braided hair and my trigger finger started itching. My mind screamed: “That’s Utah!!!”. Unfortunately, I hadn’t brought my camera in with me, so Richard was kind enough to loan me his. I didn’t repeat that mistake of not having my camera again. We must always be prepared for the muse to awaken and give us the creative direction that we need. If only for a moment.
I know that pause, or slight interruption, of growth is certainly not a negative thing. How do you handle your plateaus?
It’s a cultural thing!
A very small Brazilian Christmas gathering. Very small! Christmas 2007
Thoughts are interesting things. They seem to have a life of their own. I find it interesting how one thought leads to another and another. Each thought taking a particular fork in the road, meandering around until, in the end, you end up some place that you never would have expected.
I was watching a movie the other day, Fools Rush In. It’s a cute story about a couple, a white man from New York, and a Mexican lady from somewhere in Central Mexico and their relationship trials.
One scene reminded me of an experience that I had on our trip to Brazil to visit my wife’s family: Isabel, played by Selma Hayek, has asked Alex, her boyfriend, join her family for their weekly family dinner. He agrees to go, thinking that dinner will be like it is in his parent’s house. Basically, he thinks they’ll just sit around quietly and eat dinner. That’s it. When they arrive at her house and walk around the back, there’s lots of music, laughter, and a great party atmosphere. The back porch is teaming with people. He’s stunned. He turns to her and says something like: “This is a family dinner?!”, clearly overwhelmed at the number of people present. She responds, a bit disappointed: “Yeah. I guess a lot of people couldn’t make it!”. After dinner, he said that he was overwhelmed, but amazed. He didn’t know that people actually spoke to each other at dinner!!!
My own story
This was the type of feeling that I had when I met my wife’s family. I was extremely overwhelmed for the first week, quite honestly. We stayed in Brazil for 3 weeks. My wife has 4 brothers and 1 sister, for a total of 6 kids. Add to this about a gazillion cousins, all of who seemed to be there at that time. For the entire week, people spent the night, stayed up until daybreak, and partied. They didn’t party to get drunk. There ‘drunkenness’ came from the high that they got enjoying the togetherness of family. I had never experienced this. The remaining two weeks, only about 50% of them stayed.
After about a week, I got used to it … somewhat, but it was a change. Over the past 16 years, I’ve changed and sometimes enjoy that level of interaction. I, for the most part, am a somewhat solitary guy, but I do enjoy family and friends, just not in huge doses.
Brazilian society, in contrast to American society, is night and day. It has been a difficult road for my wife, at times, as our society seems to value isolation … every man/woman for himself. Brazilians value leisure and family time.
You can just look at your neighborhood and think about how many people you know. I know a couple of my neighbors, and one of them, Harry, I talk to most every day. When I say talk, I mean I go to his house, we sit in the garage with the door open, our dogs play together, and we solve the problems of the world for 60 to 90 minutes at a time. The great majority of people that I know say that they have no clue about any of their neighbors. I’m 46. Harry is 60+.
I read a couple of psychology papers that talked about the increased use of therapists because Americans are so busy living the American Dream that they don’t have time to cultivate friendships. The number of personal confidants per person have fallen from 2, in the 1950s, to nearly zero in 2000. A confidant being someone that you trust and with whom you can discuss personal things.
So, if you are an American, do you still cultivate friendships? Have confidants? If you’re not American, how social would you say is your culture? If you are living in another culture, other than the one you grew up in, how does it feel? Do you feel isolated at times?
I just love learning about other cultures! Maybe I should have been an anthropologist!
BTW, my wife is the one in the screaming red sweater!
The value of workshops?
My neighborhood
I was thumbing through my most recent edition of Outdoor Photographer. I should also say that it is my last one, as I have let the subscription expire. It seems that every month, the content is getting less and the advertisements, more. The ads seem to be taking up more than half of the magazine.
There are numerous advertisements, page after page of workshops. Each one claiming that they are the best and that they will take you to all manner of wonderlands on the planet. Africa, India, Antarctica, Australia, you name it!
I’ve been a part of two workshops. Both different. Both beneficial; however, past two, at least for me, I see it as less of a learning experience, and more of a social outing, or perhaps a very expensive vacation. Of course, there is something different to learn from each teacher, but once you’ve gotten your own style, or way of doing things, you tend to shoot that way and utilize the workshop as a means of socializing, which certainly has value, in and of itself.
This, admittedly, may be a very biased opinion because I’ve taken two workshops from the same teacher. If I were to add a third one from a different teacher, perhaps I would differ in my opinion. Were I to take another workshop, it would be a specialty workshop, such as lighting. It would have to be something in which I am a complete novice, or to go to a place that I’ve never gone before, nor could I get there on my own, like Antarctica. I doubt that I would, for example, take another landscape workshop.
Has anyone been to more than 2 workshops? If so, was it worth it? I know that there are a couple of my Jekyll Island friends who have attended several workshops, but who sit silently lurking about. So, let’s hear it! Kate? George? Usha? Yes! I called you out by name, so now you have to answer me!
Heck, if you’ve ever taken even one workshop. Was it worth it to you?
Something for the newbies
I wouldn’t spend more than $100 on a tripod. They’re all the same.
-Wolf Camera Employee
When I was a Newbie photographer, things were complicated enough. We had to make choices between aperture priority, shutter priority, manual, or a bit later, program cameras. There were all sorts of film choices and heaven help you if you decided to develop your own film. Now, add choices of film developer, paper, paper developer, enlargers, fixers, etc. Unfortunately, camera store employees, especially in the big chains, were of little help. They had a passing interest in photography, at best. The very small stores where were you wanted to go. And, if you can believe it, there was no such thing as The Internet! Now, with digital, the choices seem endless. The situation has not improved. What’s a person to do???
Stephen’s story
Yesterday, I had a conversation with my friend Stephen, of Two Black Guys in a ditch fame, and he was relating to me his experience of going into Wolf Camera and trying to purchase a camera. He said that when he went in he kind of new what he wanted, but not really. A friend or coworker had suggested that he get a Nikon D80, but hadn’t really given him more information as to why he should make that purchase. Could he have gotten a D40, D40x, D70, or perhaps he should have gotten a D200, D300, or perhaps a D3? What about Canon? Pentax? The choices seem endless. He even said that after he got home and started looking at all of the controls, he thought that he might be in over his head!
All tripods are the same
After he got into the camera store, the sales person started offering to sell him all sorts of stuff like filters, extended warranties, other lenses, etc. He didn’t really know what to buy. He just knew that he wanted a better camera than the present one he had. The above quote, or perhaps paraphrase, is from the employee that he was talking to. Obviously, this employee has never mounted his camera on a tripod before, and if he has, it certainly wasn’t the least bit breezy outside!
A helping hand
So I thought, why not offer a running series of posts just for the Newbies? While I was walking Hobbs this morning, I thought about some topics that I think might be useful to the uninitiated:
- Deciding between point-and-shoot and DLSR
- Choosing a DSLR camera:
- Choosing a point-and-shoot camera:
- Extended warranty. Should I get one?
- Tripod: Do I need one? How to choose one
- Pixels! Pixels! Pixels! – Explaining and showing the difference between different cameras/megapixels
- What type of lenses do I need?
- Accessories: What do I need? How many CF cards? Filters?
OK, now that I’ve chosen one, how do I use it? What are all of these strange markings on the camera?
- RAW? JPG? What should I use? (Uh oh!). That ought to be a fun one!
- Aperture
- Shutter Speed
- Exposure
- Manual mode
- Composition
So, those are the items that popped into my head immediately. That’s a lot of information that needs to be disseminated. Sure, you can find it all over web, so why not here, too. I rather like the community here. There are lots of experienced folks around here and I’m sure that they can add value to any article that I post, so after a post has cooled down, I’ll make changes to the post and promote it to a ‘page’.
Looks like I have a lot of work to do! If you are a Newbie, or an experienced person and can think of anything else that might be helpful to a beginner, please chime in! If you have any suggestions, let’s hear ‘em!
Frequent Flier
Pretty light stuff today. Just a picture to share, really. This fellow, a White-Breasted Nuthatch, kept visiting my feeder the other morning. He’d fly in, grab seed, fly to a nearby tree, crack it open, return the feeder and repeat the entire process. He was fun to watch, but it sure seemed like an awful lot of energy to expend for that little seed. I guess that’s why they have to keep on eating all day!
He was a bit challenging to photograph because they do not stay in one place for very long at all. As a matter of fact, I had to focus manually and do a bit of pre-focusing because by the time that the auto focus could react, he’d already grabbed the seed and flown off. After a couple of auto focus failures, I gave up and kicked it old school with a bit of pre-focusing! Sometimes the old school beats the new school!
I identified this bird at my favorite bird identification site, Whatbird.com. If you are interested in identifying birds, give them a try.
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