Mitchell
June 27th, 2004, 08:14 PM
Hello Folks
This is the first of my tutorials. If I get a good response I will continue...If nobody cares, then I wont waste anymore of aj's bandwidth.
Let's begin
I'll start by defining DOF
Depth of field is the distance between the nearest and farthest part that appear in sharp focus .
A few factors have a role in the DOF
The aperture of the lens
The focal length of the lens
The Distance from the camera to the subject
APERTURE
In a camera lens there are blades which open when the shutter is depressed. The amount that these blades open, determine the amount of light hitting the film.
Apertures or F stops( as they are also referred to as) are however a bit confusing.
The SMALLER the number the MORE light hits the film.
As in diagram below notice the small number has the large opening where as the large(higher) number has the smallest opening
http://www3.sympatico.ca/mitchell.b/Tutorials/lens_aperture.gif
The "maximum" aperture refers to the smallest number as the smallest number is the biggest opening allowing the "maximum" light to hit the film.
The "minimum" aperture refers to the largest number.
Confused yet ...I was... LOL
lenses with really low numbers like 2.8 are called "fast" lens's as they can shoot in lower lighting situations.
So in a nutshell you will receive a very shallow depth of field when you shoot with an f stop of 2.8 as in this picture
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo28.jpg
Notice how I have focused on the one zoo. Anything in that plane or zone will be in focus. Everything else is a blur. This is how I like to shoot. personal preference I guess but it does make your eye go to where I want it to go.
Here is a shot with an f stop of 11. Middle of the road for my lens
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo11.jpg
That plane or acceptable zone of focus just got bigger
Now here is the last pic with the lens at F stop 32
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo32.jpg
Pretty much everything is in focus.
The focal length of the lens
Depth of field also is reliant on the lens used.
Meaning a 28mm lens will have a much better depth of field than a 100mm lens .
The shorter focal length can capture more of the scene in focus than a longer focal length lens.
The above photographs were taken with a 90mm macro at
F stop 2.8, 11, 32.
Below is a series of pictures with a 28mm lens
at f4
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo284.jpg
at f11
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo2811.jpg
at f29
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo2829.jpg
Now compare all three shots to the shots above with the longer lens. You can see that the shorter lens allows for more to be in acceptable focus. This is why shorter focal lengths are good for landscape photography.
The Distance from the camera to the subject
In my opinion, this factor is not really important as we are generally in close to the aquarium.
For those that want to know though, the rule is
The further you are away from the subject the zone of sharpness become greater in the foreground and background and usually even greater in the background.
SO
What does this all mean .
DOF is a matter of personal taste, I tend to go on the shallower end of things and sometimes too much.
Like the pipe fish I shot, I received critiques that MORE depth of field was required. Personally I like it the way it is. Like I said...personal taste.
So go out and shoot, try the different apertures on a still subject, record what aperture was used on each and make up your own mind.
I hope this was of SOME help. I know aperture can be confusing with the larger number smaller number thing but after time it will make sense.
here is a last pic...
VERY shallow DOF but I like it !!!
http://www3.sympatico.ca/mitchell.b/boardpics/IMG_3340.jpg
This is the first of my tutorials. If I get a good response I will continue...If nobody cares, then I wont waste anymore of aj's bandwidth.
Let's begin
I'll start by defining DOF
Depth of field is the distance between the nearest and farthest part that appear in sharp focus .
A few factors have a role in the DOF
The aperture of the lens
The focal length of the lens
The Distance from the camera to the subject
APERTURE
In a camera lens there are blades which open when the shutter is depressed. The amount that these blades open, determine the amount of light hitting the film.
Apertures or F stops( as they are also referred to as) are however a bit confusing.
The SMALLER the number the MORE light hits the film.
As in diagram below notice the small number has the large opening where as the large(higher) number has the smallest opening
http://www3.sympatico.ca/mitchell.b/Tutorials/lens_aperture.gif
The "maximum" aperture refers to the smallest number as the smallest number is the biggest opening allowing the "maximum" light to hit the film.
The "minimum" aperture refers to the largest number.
Confused yet ...I was... LOL
lenses with really low numbers like 2.8 are called "fast" lens's as they can shoot in lower lighting situations.
So in a nutshell you will receive a very shallow depth of field when you shoot with an f stop of 2.8 as in this picture
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo28.jpg
Notice how I have focused on the one zoo. Anything in that plane or zone will be in focus. Everything else is a blur. This is how I like to shoot. personal preference I guess but it does make your eye go to where I want it to go.
Here is a shot with an f stop of 11. Middle of the road for my lens
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo11.jpg
That plane or acceptable zone of focus just got bigger
Now here is the last pic with the lens at F stop 32
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo32.jpg
Pretty much everything is in focus.
The focal length of the lens
Depth of field also is reliant on the lens used.
Meaning a 28mm lens will have a much better depth of field than a 100mm lens .
The shorter focal length can capture more of the scene in focus than a longer focal length lens.
The above photographs were taken with a 90mm macro at
F stop 2.8, 11, 32.
Below is a series of pictures with a 28mm lens
at f4
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo284.jpg
at f11
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo2811.jpg
at f29
http://www3.sympatico.ca/mitchell.b/Tutorials/zoo2829.jpg
Now compare all three shots to the shots above with the longer lens. You can see that the shorter lens allows for more to be in acceptable focus. This is why shorter focal lengths are good for landscape photography.
The Distance from the camera to the subject
In my opinion, this factor is not really important as we are generally in close to the aquarium.
For those that want to know though, the rule is
The further you are away from the subject the zone of sharpness become greater in the foreground and background and usually even greater in the background.
SO
What does this all mean .
DOF is a matter of personal taste, I tend to go on the shallower end of things and sometimes too much.
Like the pipe fish I shot, I received critiques that MORE depth of field was required. Personally I like it the way it is. Like I said...personal taste.
So go out and shoot, try the different apertures on a still subject, record what aperture was used on each and make up your own mind.
I hope this was of SOME help. I know aperture can be confusing with the larger number smaller number thing but after time it will make sense.
here is a last pic...
VERY shallow DOF but I like it !!!
http://www3.sympatico.ca/mitchell.b/boardpics/IMG_3340.jpg