Understanding Aperture

Below you will find an excerpt from my book “Understanding the Basics of Exposure”. This will help you get a better idea of the books content as well as teach you a little about the Aperture and how it is used. If you know of anyone into photography please share this post. I believe that the book can help those just getting started as well as reinforce the basics for those who have been doing this for awhile. You can find out more about the book here: 

http://eldridgestudios.blogspot.com/2012/10/exciting-news.html 

and here: 

http://eldridgestudios.blogspot.com/2012/11/quick-reminder.html.


Enjoy this excerpt and please leave a comment and let me know what you think.
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What is the Aperture?

Aperture in its basic definition is a hole in which light travels through. This opening is increased or decreased using a series of blades within the lens of a DSLR. The number that is used to indicate the size of the opening is called an f-stop. The f-stop number is determined by dividing the focal length of the lens by the diameter of the pupil (or opening). Luckily in the camera world we just have to pay attention to the numbers after the “f” to know the f-stop. Smart people somewhere already did the math.

How the Aperture is Used?

The aperture is used when determining proper exposure. If you think of the aperture as a faucet and light as water it might be easier to understand. If you turn a faucet on full blast it is letting a large amount of water flow. That would be the equivalent of a wide open aperture i.e. f2.8. If you turn the water on just slightly where there is only a trickle then you have a small aperture i.e. f22.

Not only is aperture used to help determine proper exposure but it is used to determine depth of field.

• Depth of Field (DOF)

• DOF is the distance between the nearest and farthest objects in a photograph that appear reasonably sharp. Think of this area as the focal plane as well. Lenses can precisely focus on a given point. However, anything closer or further away from that point begins to leave the focal plane. This is how you get the nice blurry backgrounds you see in some photographs or the tack sharpness in others.
• The smaller the opening (higher the f-stop number) the greater depth of field. Think of it like squinting your eyes.
• The larger the opening (smaller the f-stop number) the shallower the depth of field.

•Aperture is one of the most powerful tools in a photographer’s arsenal to creating compelling images. It vital to your photography that you fully understand what changing aperture numbers will do to your photograph.

Below is a list of typical f-stops you typically see on modern lenses and a graphical representation of what happens to the depth of field as the f-stop number changes. I highly recommend that you memorize these apertures as it will help you later when you are determining manual exposures and depth of field.

A Great Local Place (Gold Coast Railroad Museum)

I decided to check out a new local place.  Each time the family and I took a trip to the Miami Metro Zoo I had seen a sign for the Gold Coast Railroad Museum.  I didn't pay much attention to the place because I figured it was just a small walkthrough museum.  There is this really cool iPad app (FREE) out there called Stuck on Earth.  You really need to check it out if you haven't.  It lets you check out local places and see photos from that place.  That is when I really got interested in the Railroad Museum.

So, this past Saturday we (the family) journeyed to the museum.  To say the least I was impressed.  There is so much history stored away for you to see and interact with.  Besides, being a guy it was AWESOME to set foot on the massive pieces of mobile metal!!!!!

The clouds were out in full force which gave me the idea to do some HDR shots.  The first photograph is my favorite of the bunch with the dramatic clouds in the background and the old rusted hunk of metal in front.  The second shot was of a very old steam engine which had to be done in black and white of course.  Lastly, I just couldn't pass up the leading lines down the side of passenger cars.  All and all it was a great trip and I was not even there that long.  The next time I will plan for some addition time!

The Switch

My first computer was a Commodore 64 but since then I have always been a PC guy. Why? Well, they were the cheapest and the most versatile… I owned my first PC 21 years ago (DOS and eventually Windows 3.1). Since my first PC I have had many variants of the PC. The timeline (or stages) of PC ownership has always been the same.

Year 1 - Thrilled: Happy that I didn’t spend a HUGE amount of money but managed to get good performance. Later in the year you upgrade the RAM and maybe the video card.

Year 2 – Denial: Your computer begins crashing fairly often and you begin to have issues with disk space (for unknown reasons). You check for virisus, delete everything you can, take off programs, and run system clean up after clean up. But, hey this is still a great computer right? You begin to search websites on occasion looking for a new one.

Year 2.5 – Realization: This is the realization that your PC is in full “Windows Flail” mode. Constant crashing (blue screens), no disk space (don’t know why), simple programs take forever to load and are buggy at best. The fans begin to make noise and system tools to help improve your computer just don’t work anymore. Finally, you reformat your heard drive and clean install the operating system.

Year 3 – Waiting for Trash Run Thursday: If you have made it this far you are on the verge of a nervous breakdown if you ever have to do work on the computer. The clean install worked for a few months but it passes quickly. You buy another computer and you start the cycle back at Year 1. The old computer gets stripped of any usable parts and tossed in the trash.

I am trying to break the cycle.

I used to look down at Mac users because they had systems that couldn’t run EVERYTHING (I was mostly concerned with games). I would laugh and talk about how inferior their operating systems were and how much faster my processor was. Here was the deal… They always seemed to hold onto the same computer for a very long time. Being a photographer I also noticed that most of the professional photographers I followed used Macs. I started the research and quickly realized that from a photographer’s perspective the Mac platform stands above the rest. I use the computer for one primary purpose and that is post processing my images. You guessed it… I bought an iMac 27”. No, I can’t play all the games I used to but that is why we have console systems. I would say the photographic processing performance of the Mac is as good as (maybe a little better) an equivalent PC but I am hoping that at the Year 3 stage I will not be waiting for the trash to run. Stay tuned for some photography specific reviews as it relates to the Mac platform.