Photography Lesson One- Exposure Basics

Before I bought my camera, I totally underestimated how overwhelming learning how to use it would be.  Of course, it's easy to use it on the automatic mode, but I wanted to really learn how to use it.   When I bought the camera, I also bought the book Digital Photography by Ben Long.  I started reading the book when a I first got the camera but haven't touched it in several weeks.  Now that I have had a little practice, I am getting back to it. With so much material to learn, I'm using this blog to take notes and really process what I'm learning.  Though overwhelming, I am loving learning how to use my camera and learning how to edit photos.  I'm even loving the process of learning how to learn it-- the challenge of balancing practicing taking/editing photos, reading the "text book", and reading websites(mainly Pioneer Woman).  I thought that there would be a linear process for learning, but I haven't found one and am still loving the process.

This morning I woke up at 6am to head to a hot air balloon festival.  I have wanted to check out this festival since I moved to Baton Rouge seven years ago, but it's in August and hot as hell outside.  The early morning turned out to be the perfect time to go.

I read the "Exposure Basics" chapter last night and tried different settings this morning.  In a nutshell, there are three mechanisms that control exposure: the ISO setting, shutter speed and aperture.

ISO Setting.  "ISO is a standard for measuring the sensitivity of film....When you increase the ISO setting on your camera, you're essentially making the sensor more light sensitive.  As it becomes more sensitive, it will require less exposure to be able to see a scene."  (Long, 109)

Shutter Speed.  "Shutter speed is a measure of how many seconds the shutter stays open.  When the shutter is open longer, moving objects in your image will get blurrier (Long, 19)."  "...a longer shutter speed exposes the image sensor to light for a longer time than a shorter shutter speed (Long, 110)." 

Aperture.  Aperture is basically how wide the lens opens.  It affects how much light gets in the picture and the depth of field.  My understanding is the depth of field is what's in focus (i.e., is the thing right in front focused on and the background blurry or is everything in focus).   Aperture is measured in f-stops.  The lower the f-stop number, the wider the lens is open, the more in focus the thing in front it (and background blurry), and the "larger" the aperture.  Yes, a low f-stop number means a larger aperture.  Confusing, right?  That means the higher the f-stop number, the less wide the lens opens, more things are in focus, and the "smaller" the aperture  (I know my grammar on that explanation is horrible, but I'm not going to bother fixing it). 

This figure from the Long book (taken on my iPhone) summarizes these mechanisms.

These mechanisms need to be balanced to take good pictures.  (Long talks more about the "reciprocal nature of exposure parameters" but Pres's movie is almost over and I'm running out of time to "dither."  Dither is Pres's term for anything I do on the computer that he isn't interested in or thinks is silly)

Okay, so this morning I played with shutter speed and aperture. I mainly kept the ISO setting at 100, but took a few photos in auto mode.  Below are a bunch of photos with their ISO setting, shutter speed and aperture identified. 

ISO 100, f/3.5, 1/500 sec

ISO 100,  f/7.1, 1/20 sec

ISO 100, f/7.1, 1/50 sec

ISO 100, f/6.3, 1/160 sec

ISO 100, f/5.0, 1/100 sec

ISO 100, f/7.1, 1/200 sec

ISO 100, f/9.0, 1/100 sec

ISO 100, f/9.0, 1/100

ISO 100, f/5.6, 1/200 sec

ISO 100, f/3.5, 1/640 sec

ISO 100, f/7.1, 1/200 sec

ISO 100, f/3.5, 1/60 sec

ISO 100, f/5.6, 1/250 sec

ISO 100, f/7.1, 1/200 sec

ISO 100, f/5.6, 1/100 sec

ISO 100, f/8.0, 1/250

ISO 400, f/11, 1/400

ISO 100, f/5.6, 1/100 sec

I 

ISO 100, f/8.0, 1/250 sec

The light did not change much while I was there, and all of these photos are straight out of the camera (i.e., not edited in photoshop).   It is easy to see how the aperture and shutter speed affect the picture when looking at the photos with the settings identified. 

As tedious as it was, I really enjoyed this exercise of trying to understand how exposure works.  I'm going to edit some of this morning's photos now.  I should keep track of the functions I use in Lightroom, but I just don't think I have enough patience :)