Thursday, February 17, 2011

The Triangle of Proper Exposure!!!!

The first thing I say to people who want to take better pictures is TURN YOU FLASH OFF. Back a few thousand year ago when my Lily was a baby the only camera I had was a Cannon power shot...a point and shoot, and I was able to get really good pictures with that camera simply by turning off the flash and making the camera work for me. One of the super gals over in my Flickr teaching group took a nearly perfectly composed image, however I think she can truly make it into an art image by simply turning off her flash and making her camera work harder :) {hopefully she will let me post the images once she is done with them}
There are three things that your camera does to expose an image,
I am going to explain them to you in the order I set them on my camera.
ISO~This goes back to old film speed for those of you old enough to remember film. Remember if you were going to take pictures outside you would 100 speed film and if you were indoors you would use 400 speed or higher. Well ISO on your digital camera is how sensitive the light gathering sensor will be. If your ISO is set to 100 you would be in very bright lighting conditions, If you were in a low light room your would set your ISO to 1000. OK so get your Camera manual or Natural Light for dummies :) and find the section on ISO and read it I am going to go fill my coffee cup {whistling} keep going I'll wait >>>>OK do you know how to set that on camera the case of the sample image the ISO was set to 1600 seems a bit high. The thing about high ISO is that>>>> the higher the # the grainier the image. Now the better your camera the better it can handle the higher numbers. But I always try to keep the number as low as possible!!!SO in the sample image I think I would hang around 1000, but you will need to get as much light as you can open curtains, the front door...but turn off light bulbs they just make everything yellow and add very little light :)
OK the second thing I set on my Camera is my F-stop or aperture, I am going to call it Fstop, OK??
Fstop is a function of your with different lenses you have different options. Fstop is how closed or open the "pupil" of your lens is at a setting. So pick up your camera....yeah go get it :} take the lens off and look at the back of the lens, look in and see the little black flower inside that is the aperture that determines how much light will be let into the lens....make sense??? so if we set the camera to say F4.5 we are telling the lens to not open up as much and let less light in >>>>buuuut if we set it, to say F1.8, we are telling the lens to OPEN WAY UP and let in TONS of light!!! now all lens have a limit to how high or low their Fstop can go I have a 18-200mm lens that only goes down to F3.5 so this lens is best for outside or lighting situation that have LOTS of light. But my 50mm opens up to F1.4>>> I can shoot in the house at night with no flash. Your Fstop also determines how much of the photo will be in focus, this is called depth of field.
Here are three samples>>>> this first image is ALL in focus and its Fstop is F8
This image was shot at F5.6 notice she is all in focus and the background is blurry she is sitting a ways from the background as well so that adds to the blur of the background.
and finally this one is shot at F2 and the only thing in focus is her face.

So to recap>>> ISO determines how sensitive the sensor will be and Fstop determines how much light will reach that sensor by how far the "pupil" will open, and how much of the image will be in focus>>> so that bring us to SHUTTER SPEED
Shutter speed is ‘the amount of time that the shutter is open’.
In film photography it was the length of time that the film was exposed to the scene you’re photographing and similarly in digital photography shutter speed is the length of time that your image sensor ’sees’ the scene you’re attempting to capture.
You this on your camera as 1/60, 1/250 etc. the lower the number the more time the shutter will be open, seems a little backwards but this because it is measuring in factions of a second. If you have a low light situation you would want to set your shutter speed lower like 1/125 or if you are in a high light area you could be all the way up at 1/6400. Your camera can meter for what you need to set that shutter speed at. Again go to your manual and read about how to meter for shutter speed. If your shutter speed gets below 1/60 you are likely to get blurriness from your hands moving {or even your heartbeat} So a good rule for now is not to go below 1/60, if the meter is asking for a lower shutter speed then move your ISO up to the next setting {if you were at ISO 200 move up to ISO 250.
OK final recap :) TURN YOUR CAMERA TO M....not auto :) and make sure your flash is off!!
Set your ISO to your lighting
  • Low light>>>High number{like 400-1000 or more} 
  • High light>>>Low number {100-320}
  • High number= grainier images>>>Low number=sharper images
Set your Fstop for lighting and what depth of field {or focus} you would like
  • Wide open Fstop {like 1.4-2.8}>>>> lets in lots of light, and less of the photo is in focus
  • Tighter Fstops {like 3.2-22} >>> let in less light, and more of the photo are in focus
Set your Shutter Speed to what your Camera meter tells your to set it at.

Generally once I set my ISO and my Fstop for a photo session I don't change them too much, what I am changing for each pic is the shutter speed. Sometimes I will change the ISO at say Sunset where I started the session at 100 and by the end as the sun moves down, I am at 320. And I change my Fstop depending on how may ppl are in the image, more ppl the more of the photo I need to be in focus, with less blur.

This was a ton of info!!!! Thanks for making all the way to the end:) please ask question!!! and play with your camera :)
Miz Wildflower!!!


  1. I can never read this info enough! thanks so much!

  2. Super Info!! It is nice to read this info when it is written a bit different than in my manual!! I have ready it several times but it seems like I have trouble applying it:) I think I got a handle on F-stop but now I need to work with the others more!! I really want to move from shooting in auto or aperature to manual!! Time to play!