Okay, now that we've got the technical issues worked out, lets move on.
You should have a copy of the Ultimate Guide to Digital Nature Photography, right? Let's skip over the Equipment Chapter, which is chapter number 1. Equipment is important, but I just didn't want to waste too much time on it. Go ahead and read it anyway and if you have any questions about that chapter, just post them here. Don't be bashful or embarrassed to ask a question - ANY question. You might just ask the same question that everyone else was wondering about but was also too afraid to ask. Ask away about anything in Chapter One.
So we will go right to Chapter Two - Exposure. I feel this is much more important than equipment, particularly for beginning photographers and I think most here fall into that category.
For this first part, I really want you to focus (excuse the pun) on pages 54-57 which are exposure basics, plus pages 60 and 61, which deals with histograms. Please read it all - it's good stuff, but I really want to emphasize the ideas on concepts on these pages. Read them more than once if you have to!
Shutter Speeds and f-stops are the two primary components to exposure, which is simply the amount of light that reaches the image sensor in your camera. Longer shutter speeds allow more light to reach the sensor (making a brighter image) while shorter shutter speeds allow less, making a darker image. Read how the shutter speeds are displayed by your camera and how you read them - fractions of seconds and whole seconds.
F-stops are a little more complicated, as the numbers are not nearly as intuitive. The whole stops are listed in green on page 54 showing the smaller numbers (such as f2.8 and f4) allowing more light and the larger numbers allowing less. The numbers themselves represent a ratio of aperture (which is the physical size of the lens opening) and the focal length. A 100mm lens with an aperture size of 25mm is a ratio of 4:1 or f4.
So these two variables affect the amount of light that reaches your sensor, determining how bright or dark it is. Combine the two and you have an exposure value, which represents the lightness or darkness of the image. (page 57)
But these two variables also affect the aesthetic nature of the image. Fast shutter speeds freeze movement while longer shutter speeds blur it. Neither is right or wrong, it just depends on your individual interpretation of the scene. Lets call it creative vision!
f-stops also have an aesthetic value, namely depth-of-field. (second paragraph on page 57) f2.8 or f4 will have "shallow" depth of field while f16 or f22 will have much greater depth of field. Again, neither is right or wrong.
Before Thursday, I would like you to post an example of an exaggerated shutter speed (very fast or very slow and it's aesthetic effect) and the same for an f-stop and its depth-of-field, either very shallow or very great. If possible, give the data that was used (i.e. f16, 1/2 second) I'll comment on each and give you my feedback.
Should be fun!
Read about ISO as well, although it is not technically a component of exposure, but merely a measure of how sensitive the sensor is to light. Ask if you are unsure.
Post 4 images. One fast shutter speed, one slow shutter speed (showing the effects) and one small f-stop and one large f-stop )also showing the respective effects)
Sorry Richard, It's been a super hectic week. It sounds like an excuse but the fact that it gets dark so early these days, I barely get to see the sun. I'll post my pictures on the weekend if thats ok with you.
I agree with Anjanita. During the week it is hard to get out and get shots. And yes I have a question about the aperature and shutter speeds. I dont quite understand about when you open up you get twice the light and when stopping down you get half the light. Could you explain?
You don't have to go out and take photos for the assignments (although you can if you want). You can go through photos you already have and use these as examples.
Michelle: I think you just answered your own question. When you go from f8 to f11, for example, you reduce the exposure - or amount of light - by 1/2. If you go from f8 to f5.6, on the other hand, you increase the exposure - or double the amount of light. Both of those examples are changing the exposure by one stop. One stop darker and one stop lighter.
The same is true for shutter speeds. 1/30 second is one-stop brighter than 1/60 second. It doubles the amount of light. 1/125 of a second is a stop darker - or 1/2 the amount of light.
Richard, I'm not too sure I know how to figure out which of my photos would correspond to the specifications of this assignment. So far, I've been taking pictures without really paying atenion to these things. Please clarify as it would make this assignment much easier to complete. Thanks!
Discussion
8 repliesYou should have a copy of the Ultimate Guide to Digital Nature Photography, right? Let's skip over the Equipment Chapter, which is chapter number 1. Equipment is important, but I just didn't want to waste too much time on it. Go ahead and read it anyway and if you have any questions about that chapter, just post them here. Don't be bashful or embarrassed to ask a question - ANY question. You might just ask the same question that everyone else was wondering about but was also too afraid to ask. Ask away about anything in Chapter One.
So we will go right to Chapter Two - Exposure. I feel this is much more important than equipment, particularly for beginning photographers and I think most here fall into that category.
For this first part, I really want you to focus (excuse the pun) on pages 54-57 which are exposure basics, plus pages 60 and 61, which deals with histograms. Please read it all - it's good stuff, but I really want to emphasize the ideas on concepts on these pages. Read them more than once if you have to!
Shutter Speeds and f-stops are the two primary components to exposure, which is simply the amount of light that reaches the image sensor in your camera. Longer shutter speeds allow more light to reach the sensor (making a brighter image) while shorter shutter speeds allow less, making a darker image. Read how the shutter speeds are displayed by your camera and how you read them - fractions of seconds and whole seconds.
F-stops are a little more complicated, as the numbers are not nearly as intuitive. The whole stops are listed in green on page 54 showing the smaller numbers (such as f2.8 and f4) allowing more light and the larger numbers allowing less. The numbers themselves represent a ratio of aperture (which is the physical size of the lens opening) and the focal length. A 100mm lens with an aperture size of 25mm is a ratio of 4:1 or f4.
So these two variables affect the amount of light that reaches your sensor, determining how bright or dark it is. Combine the two and you have an exposure value, which represents the lightness or darkness of the image. (page 57)
But these two variables also affect the aesthetic nature of the image. Fast shutter speeds freeze movement while longer shutter speeds blur it. Neither is right or wrong, it just depends on your individual interpretation of the scene. Lets call it creative vision!
f-stops also have an aesthetic value, namely depth-of-field. (second paragraph on page 57) f2.8 or f4 will have "shallow" depth of field while f16 or f22 will have much greater depth of field. Again, neither is right or wrong.
Before Thursday, I would like you to post an example of an exaggerated shutter speed (very fast or very slow and it's aesthetic effect) and the same for an f-stop and its depth-of-field, either very shallow or very great. If possible, give the data that was used (i.e. f16, 1/2 second) I'll comment on each and give you my feedback.
Should be fun!
Read about ISO as well, although it is not technically a component of exposure, but merely a measure of how sensitive the sensor is to light. Ask if you are unsure.
Michelle: I think you just answered your own question. When you go from f8 to f11, for example, you reduce the exposure - or amount of light - by 1/2. If you go from f8 to f5.6, on the other hand, you increase the exposure - or double the amount of light. Both of those examples are changing the exposure by one stop. One stop darker and one stop lighter.
The same is true for shutter speeds. 1/30 second is one-stop brighter than 1/60 second. It doubles the amount of light. 1/125 of a second is a stop darker - or 1/2 the amount of light.