Hello LLC members,
In three previous posts I covered Aperture (f-stop) , Shutter Speed (Time Value) and ISO (film/digital sensor sensitivity) these are the key settings to obtaining a proper Exposure Value.
But wait, these are also the key settings to creative photography as well. Once you get a handle on the trade-offs when using these settings in combination the creative possibilities are endless.
The simplest way to show this relationship of Aperture, Shutter Speed & ISO is the Exposure Tri-angle
As you can see in this graphic which shows ISO at the top, Shutter speed to the lower left and Aperture lower right. All of them in various combinations influence Exposure Value in the center.
Your ISO is set to 100, Shutter Speed is 1/30 & Aperture is at f/1.8 Your Exposure meter indicates a value of +1
Which is Over Exposed!
So what do you adjust to obtain a proper exposure value of 0 ?
Ah, here is where your creative side steps in, if you want shallow depth like this
This photo is shot at f1.8 notice how the background is blurred aka shallow Depth of Field (DOF)
you would keep the f/1.8 setting and adjust your shutter speed to?
Yes, that’s it you would raise the shutter speed to about 1/60 ( faster shutter speed = less light is hitting the Digital Sensor ) which should provide a proper exposure.
Ok, is this starting to make sense yet?
Same scene same light ISO 100 , shutter speed 1/30 but instead you want more Depth of Field (Larger f/# = less light entering the lens ) so you set the Aperture to f/4 effectivly cutting the light by 1-Stop and bringing the exposure to 0
This photo is shot at f4 notice how less of the background is blurred and more of the scene is coming into view.
The best way to learn is to put your camera in Manual Mode and play with the settings.
Here is a suggestion:
Put your camera on a tripod in Manual Mode, take some object(s) from around the house put them in different lighting conditions (bright,dim,& dark) and shoot some photos, adjusting only shutter speed, then adjusting only Aperture, then only adjusting ISO so your light meter shows a perfect exposure value ( 0 )
There is one catch:
If the scene is Extremely Under or Over Exposed you may have to adjust two of the three settings to achieve a proper Exposure Value.
I also can suggest a great book by Bryan Peterson ” Understanding Exposure “ which I know for a fact is at the Palm Beach County Library because I have checked it out multiple times myself 🙂
Check out my photography site dapontephotography
P.S. Please feel free to leave comments or questions