DoF vs focus point? (Page 2): Actually, as the working distance decreases the depth of field changes to 50/50 front back. If you are shooting a crop sensor camera, you're looking at...

GTinSoCal Loc: Palmdale, CA

GoofyNewfie wrote:

Hard to tell, but it looks like the point of focus might be a bit in front. A lot of you probably know this, but for other readers, depth of field extends from about 1/3 in front of the point of focus and 2/3rds behind. Ie: you get more in focus behind than in front.

Actually, as the working distance decreases the depth of field changes to 50/50 front back.

If you are shooting a crop sensor camera, you're looking at around 1/2" depth of field.
Not much to work with to get 2 subjects in focus. At f16 you'd have about 2" to work with.

GT

SQUIRL033 Loc: Chehalis, WA

at 250mm and f/8, from 6-8 feet away, your total depth of field is gonna be about an inch with a crop body. in the photo you posted, it looks like the bird on the far right edge of the photo is the one that's in focus, and neither of the ones in the middle of the frame are sharp (your lens may be front-focusing a bit). given that and the shallow depth of field you're getting with that lens at that distance, there's really not a lot you can do. even at f/22, you'd only have about 3 inches at that distance.

RTR Loc: West Central Alabama

Here may be a helpful resource.
http://www.dofmaster.com/dofjs.html

adam1134

Here is a great site with a calculator to help you figure out the depth of field based on your aperture and distance from the subject. It is in meters....

http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

normanhall Loc: Leslie Missouri

I think you are correct on this, if you notice the bird that is slightly out of frame is in focus and it is in front of the main bird in the photo. so i have to agree with you if picked up the rock in front of the bird causing the one behind to be out of focus. if you also notice the rock in the very front of the photo is slightly out of focus also.

One Jughead Loc: Greene County, OH

The bird on the right side is in focus and it appears to be closer than the one in the center. My guess is that the focus was closer to being on the bird on the right side.

ephraim Imperio

CaptainC wrote:

F-stop issue. Either that or tell the far bird to move closer.

Ha! Ha! Ha! Very funny Captain!

:XD: :thumbup: :thumbup: :thumbup: :lol: :lol:

Indi Loc: L. I., NY, Palm Beach Cty when it's cold.

I looked at the picture really close by increasing the size on my monitor. It looks to me like your point of focus might be off because the center bird, and the white patches on the rock seem to be in focus.

Indi Loc: L. I., NY, Palm Beach Cty when it's cold.

GoofyNewfie wrote:

Hard to tell, but it looks like the point of focus might be a bit in front. A lot of you probably know this, but for other readers, depth of field extends from about 1/3 in front of the point of focus and 2/3rds behind. Ie: you get more in focus behind than in front.

Goofynewfie. Did you just make those examples, or capture them from the web?
Those are good examples for a handbook.

GoofyNewfie Loc: Kansas City

Yes, they are mine. I teach the Photography merit badge class for boy scouts in our area. The small photos in the handbook are not very good. Thanks

senad55verizon.net Loc: Milford, NJ

MWAC wrote:

How far were you from the subject?

DOF is caused a combination of the distance from the camera to the subject and the distance from subject to the background. The further away you are from the subject the smaller your plane of focus will be.

Small correction: The further you are from the subject the greater (i.e., deeper, thicker) your depth of field will be.

Incidentally, what is acceptably sharp focus is an arbitrary decision based on the optical phenomenon called "circle of confusion". If you're interested, check it out on Google or other sources.

GoofyNewfie Loc: Kansas City

"optical phenomenon called "circle of confusion"
I think that's in my brain.

twowindsbear

GTinSoCal wrote:

quote=GoofyNewfie Hard to tell, but it looks like... (show quote)

I'm really curious - how does the size of the sensor - i.e. crop sensor or full size sensor - affect the depth of field?

Cappy Loc: Wildwood, NJ

I think you focused on the rock in front of the birds. The bird to the right is in focus as is the one in the center (almost focused 100%).

Go back the same rock, same everything except use some toys to replace the birds and try different settings. Play & learn.

julesreyesmarko Loc: Los Angeles

I like that idea, second that vote.

Cappy wrote:

I think you focused on the rock in front of the birds. The bird to the right is in focus as is the one in the center (almost focused 100%).

Go back the same rock, same everything except use some toys to replace the birds and try different settings. Play & learn.