BetterPhoto Q&A
Category: New Questions

Photography Question 
Rachel 
 

exposure


which exposure will give greatest depth of field


To love this question, log in above
1/16/2008 3:07:17 PM

 
Alan N. Marcus   Hi Rachel,

Depth-of-Field

When the shutter opens the camera lens is permitted to briefly project an image of the outside world on the surface of the light sensing chip or film. During this brief play of light an image is recorded (exposure). Exposure speaks about our ability to control this brightness inside the camera and the duration (time) this light is allowed to play on the film or chip. Too much or too little light hitting the film or chip results in a substandard picture. Since the lens acts like a funnel gathering light, the larger the lensís diameter, the brighter the image. The working diameter of the lens is therefore a key control. We exercise control over the diameter of the lens by means of a variable restriction placed between the glass elements of the lens. Looking into the camera lens you can see this mechanical restriction it resembles a series of overlapping metal blades with a hole or opening in the center. This design is modeled from our human eye. Our eye has an iris that contracts and expands based on the level of the light. The iris is the colored portion of our eyes and itís named for the Greek goddess of the rainbow Iris. Doubtless, you have seen the iris widen and constrict.

If the lens is operated wide open (large diameter) the depth-of-field zone will be very shallow. If you close down the aperture down and cause the lens to operate with a tiny diameter the depth-of-filed zone will be stretched out.

Depth-of-field defined:
Depth-of-filed is that span (region) before and after the point of actual focus that provides acceptable sharpness. What you may not know is, this span is not split in the middle rather the depth-of-field region extent 1/3 toward you and 2/3 behind (away from you) from the point focused upon.

Hope this helps


Alan Marcus


To love this comment, log in above
1/16/2008 4:26:36 PM

 
Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
gregorylagrange.org
  Hey Rachel, do you know a Jackie Robins?


To love this comment, log in above
1/16/2008 4:54:59 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
Contact Carlton
Carlton's Gallery
carltonwardphoto.com
 
 
 
Hi Rachel, Alan is as always correct.
When I 1st started learning about DOF, I related it to the diameter of a pipe. f/2.8 is a large pipe that will let in a lot of light in a short amount of time which will also be very limiting to how much of the image is in focus. f/22 is a smaller pipe and it takes longer to let the light through but includes more detail of everything in the image. Ansel Adams used to shoot at f/94 which is why his Yosemite photos are so saturated and detailed. You could hit the shutter and go have lunch while the image was being recorded. The other 2 criteria are the shutter speed & ISO settings. You can select f/22 but you may need to set your shutter to 1.6 seconds at ISO100 or to get a faster shutter speed, you will need to increase your ISO setting to 400, 800 or even 1600. The higher the ISO, the grainier (called noise) the image will be -although the newer DSLRs are getting much better at high ISOs. You also have to consider the particular lens and distance you are from a subject. I took a photo of a falcon with lens at about 275mm and set my DOF at f/7.1, the falcon was about 20 feet away and the background was 100 ft behind the bird. This gave me good focus and detail on the falcon and the green background had a very nice blur which provided a nice contrast. I had an overcast day and used ISO200 and shutter speed at 1/125th second. Back in the 70s I used to carry the Nat'l Geographic field guide with me and when I started shooting again a few years ago, I picked up Bryan Petersons "Understanding Exposure" which is where I learned about Better Photo.
There are some fabulous courses here at Better Photo that will get you very familiar with Exposure and if you are serious about photography, you need to learn these fundamentals to provide a foundation for the rest of your photographic journey.


To love this comment, log in above
1/16/2008 5:52:51 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
Contact Carlton
Carlton's Gallery
carltonwardphoto.com
 
 
 
Hi Rachel, Alan is as always correct.
When I 1st started learning about DOF, I related it to the diameter of a pipe. f/2.8 is a large pipe that will let in a lot of light in a short amount of time which will also be very limiting to how much of the image is in focus. f/22 is a smaller pipe and it takes longer to let the light through but includes more detail of everything in the image. Ansel Adams used to shoot at f/94 which is why his Yosemite photos are so saturated and detailed. You could hit the shutter and go have lunch while the image was being recorded. The other 2 criteria are the shutter speed & ISO settings. You can select f/22 but you may need to set your shutter to 1.6 seconds at ISO100 or to get a faster shutter speed, you will need to increase your ISO setting to 400, 800 or even 1600. The higher the ISO, the grainier (called noise) the image will be -although the newer DSLRs are getting much better at high ISOs. You also have to consider the particular lens and distance you are from a subject. I took a photo of a falcon with lens at about 275mm and set my DOF at f/7.1, the falcon was about 20 feet away and the background was 100 ft behind the bird. This gave me good focus and detail on the falcon and the green background had a very nice blur which provided a nice contrast. I had an overcast day and used ISO200 and shutter speed at 1/125th second. Back in the 70s I used to carry the Nat'l Geographic field guide with me and when I started shooting again a few years ago, I picked up Bryan Petersons "Understanding Exposure" which is where I learned about Better Photo.
There are some fabulous courses here at Better Photo that will get you very familiar with Exposure and if you are serious about photography, you need to learn these fundamentals to provide a foundation for the rest of your photographic journey.


To love this comment, log in above
1/16/2008 5:53:28 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
Contact Carlton
Carlton's Gallery
carltonwardphoto.com
 
 
 
Hi Rachel, Alan is as always correct.
When I 1st started learning about DOF, I related it to the diameter of a pipe. f/2.8 is a large pipe that will let in a lot of light in a short amount of time which will also be very limiting to how much of the image is in focus. f/22 is a smaller pipe and it takes longer to let the light through but includes more detail of everything in the image. Ansel Adams used to shoot at f/94 which is why his Yosemite photos are so saturated and detailed. You could hit the shutter and go have lunch while the image was being recorded. The other 2 criteria are the shutter speed & ISO settings. You can select f/22 but you may need to set your shutter to 1.6 seconds at ISO100 or to get a faster shutter speed, you will need to increase your ISO setting to 400, 800 or even 1600. The higher the ISO, the grainier (called noise) the image will be -although the newer DSLRs are getting much better at high ISOs. You also have to consider the particular lens and distance you are from a subject. I took a photo of a falcon with lens at about 275mm and set my DOF at f/7.1, the falcon was about 20 feet away and the background was 100 ft behind the bird. This gave me good focus and detail on the falcon and the green background had a very nice blur which provided a nice contrast. I had an overcast day and used ISO200 and shutter speed at 1/125th second. Back in the 70s I used to carry the Nat'l Geographic field guide with me and when I started shooting again a few years ago, I picked up Bryan Petersons "Understanding Exposure" which is where I learned about Better Photo.
There are some fabulous courses here at Better Photo that will get you very familiar with Exposure and if you are serious about photography, you need to learn these fundamentals to provide a foundation for the rest of your photographic journey.


To love this comment, log in above
1/16/2008 5:56:49 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
Contact Carlton
Carlton's Gallery
carltonwardphoto.com
 
 
 
Hi Rachel, Alan is as always correct.
When I 1st started learning about DOF, I related it to the diameter of a pipe. f/2.8 is a large pipe that will let in a lot of light in a short amount of time which will also be very limiting to how much of the image is in focus. f/22 is a smaller pipe and it takes longer to let the light through but includes more detail of everything in the image. Ansel Adams used to shoot at f/94 which is why his Yosemite photos are so saturated and detailed. You could hit the shutter and go have lunch while the image was being recorded. The other 2 criteria are the shutter speed & ISO settings. You can select f/22 but you may need to set your shutter to 1.6 seconds at ISO100 or to get a faster shutter speed, you will need to increase your ISO setting to 400, 800 or even 1600. The higher the ISO, the grainier (called noise) the image will be -although the newer DSLRs are getting much better at high ISOs. You also have to consider the particular lens and distance you are from a subject. I took a photo of a falcon with lens at about 275mm and set my DOF at f/7.1, the falcon was about 20 feet away and the background was 100 ft behind the bird. This gave me good focus and detail on the falcon and the green background had a very nice blur which provided a nice contrast. I had an overcast day and used ISO200 and shutter speed at 1/125th second. Back in the 70s I used to carry the Nat'l Geographic field guide with me and when I started shooting again a few years ago, I picked up Bryan Petersons "Understanding Exposure" which is where I learned about Better Photo.
There are some fabulous courses here at Better Photo that will get you very familiar with Exposure and if you are serious about photography, you need to learn these fundamentals to provide a foundation for the rest of your photographic journey.


To love this comment, log in above
1/16/2008 6:02:32 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
Contact Carlton
Carlton's Gallery
carltonwardphoto.com
  OK, in my attempt to attach a photo, I must have submitted my response 4 times and I still dont see my photo ?


To love this comment, log in above
1/16/2008 6:04:41 PM

 
Oliver Anderson
BetterPhoto Member Since: 11/16/2004
  Don't worry Carlton....we see your photo. You're wearing a purple shirt.lol


To love this comment, log in above
1/17/2008 11:20:46 PM

 
Log in to respond or ask your own question.