Till the cows come home ...

[Arbib]

Originally Posted by r_fredrick_smith

Thanks.

But we have to go "in depth" when talking about Depth of Field!

Cheers,
rfs

As an old timer in photography (since 1968), the terms of "OPEN UP" and "CLOSE DOWN" were (and still is) the "nomenclature" used by all old timers and those with formal photography education. The new Generation of Digital Photographers. like teenagers wanted to "make up" their own terms for their generation...The problem, as rfs pointed out, is that we don't need NEW TERMINOLIGY for evey new generation. IT adds confusion to the already not so complicated photographic nomenclature established many years ago that used terms to express what was happening mathematical in layman's terms...

Thanks for the explaination again, for why we should be using the established proper use of standardized photographic terms.

Let use Express NEW WAYS in our photographic output in being creative and inovating in how we express our ideas and feelings in print, not words.

DOF...Man, I missed that "Subject" in your lead photo

[Electricseashell]

Thanks for all the explanations I bought a photography book and actually knew what DOF was but someone reading this later might not.. My problem is that currently all I have to shoot with is a digital. I have an old 35 mil that I can't seem to make work, nor could I afford the film . So I'm still learning how to convert F stop to digital language since it isnt very clear, but want to better my photography.
This photo was a good example of DOF .. again thanks

[Arbib]

Originally Posted by Electricseashell

Thanks for all the explanations I bought a photography book and actually knew what DOF was but someone reading this later might not.. My problem is that currently all I have to shoot with is a digital. I have an old 35 mil that I can't seem to make work, nor could I afford the film . So I'm still learning how to convert F stop to digital language since it isnt very clear, but want to better my photography.
This photo was a good example of DOF .. again thanks

No need to change your terminology from from film to digital....An F/stop is an F/stop. The Sensor will effect this too, (Another topic that's has been fully explored.....
on a 100mm lens...f/4 will be 1/4 the focal length in it size, and f/8 will be 1/8 the focal length in its size...with film OR digital...

The SMALLER the Opening, the MORE DOF OF DOV....BUT...as you focus closer at the same f/stop, the DOF gets smaller. and Visa-Verse.

look at this link below
and play around with putting different "distances" in the box...but use the same f/stop.

then change the f/stop, but keep the Distance the same...The Chart on the right will will give you the "Near" and "Far" point of the DOF you will get with the distance/f/stop combo on the left you chose.

Also change the camera, and see how the sensor size also effects the DOF..Canon APS-C, (40D) or Canon FF (5D) You will see that the smaller the sensor gets, the more DOF there is, even for an adjusted lens FL to maintain the FOV for this experiment. (14mm = 28mm FOV on a 4/3's, and 17mm/18mm = 28mm FOV on a APS-C camera, and 28mm = 28mm FOV on a FF camera)

use a lens focal length of 50mm for a better comparison..Wide angle lens's will give you the near focus and INF for the far point above 5 feet. most of the time.

Depth of Field Calculator

[Electricseashell]

my head is swimming but that was a very cool lesson I've bookmarked it for more.

[PhotosbyChuck]

I like the shot, so don't take this wrong. But I'd say that most of what we're calling DOF in this photo is post process blur and not DOF. (I know RFS already indicated he changed the photo....I'm just saying most of the perceived DOF is post and less is optics). Firstly, it appears to be an impossible natural DOF since the furthest steer (which is in focus) is further from us than the person across the street (who is not in focus).

But, for more precise proof there are 2 major types of errors of selection in this photo:

1) The selection missed spots that should be blurry

Blurry background objects get sharply focused as you trace their outline closer to a steer. This is because the original was in focus and an imprecise selection was blurred to give the effect. Look at the yellow square-shaped item being held by a lady across the street. The item is fairly sharp as is her arm holding it. However her head and body are very blurry. Her backside and head are much blurrier than her front. If you scan the crowd on the far side, right where their bodies interset with the steers, you'll see this is true to some extent on them all.

Another example is the white hat we can only see the rim of in the lower right corner. It's worn by someone wearing a blue shirt. The shirt is blurry, but the hat is sharp. Hmm, that shoulder and the rim of the hat should be very similar in terms of focus and they're not.

Perhaps the most obvious is the tire we see under white SUV behind the yellow item. The lower edge of the car body and the tire are further away than all of the blurry people we see in front of the car -- but the edge of the tire is clean.

2) The selection blurred areas that should not be out of focus

Notice also that objects directly across from the camera are very fuzzy while things most distant from the camera are either sharp or less fuzzy. Take a look at the front hooves under the umbrella. They're out of focus, yet the hind legs and the horse in front of the steer are in focus. Again, that's optically impossible and therefore was due to post processing (assuming the photographer had a clean front lens element!) In this case, the selection blurred the hooves when it should not have blurred them.

In a newspaper the post processing done on the image would be tougher to notice. But I wonder -- is it photojournalism if the photograph has been manipulated...or does it become art?

Again, I like the photograph ... to me, it's more the latter. That's probably good news. Art prints sell for more!

[r_fredrick_smith]

Yes, as I had mentioned earlier in the discussion, I did do some selective blurring of elements in the photo to focus more attention on the cows. This is often done for journalistic photos (for example to obscure faces that might be recognized). It not should be used to portray a scene in a false manner, however (as we've seen done to photos from Iraq and other areas of the world). When I submit a shot to a newspaper, I often do some selective blurring and usually it is not very noticeable especially when being converted to B/W. But I don't worry about it much, since few will really notice the difference.
Also, consider my original purpose in posting the photo (DOF was not the reason, by the way).
cheers,
rfs

[digitalm]

I think the umbrella is a it bit distracting in this shot. I think it also hints to the fact that a blur effect was added in post-processing: the front hoof of the lead animal (and legs of the lead horse) are a lot more blurry than what would happen naturally.

[digitalm]

Sorry, I missed the whole thread. I see that Chuck spotted the same thing I did.

[Electricseashell]

The original post was an example of a photojournalist shot for local papers. I appreciate that some of the DOF was done manually.. Here is another question... Would you have submitted the photo without the manipulation? and when you submit a photo do they have the right to manipulate it? I ask because I would love to submit photos to my local paper, but would like to know what to expect.

[r_fredrick_smith]

Actually some of the blurriness of things like the cows legs or hooves should be obvious. These animals are in motion while I'm taking the shot and the shutter speed was not fast enough to freeze the action in all cases. And again, this shot was not about DOF but was about a small town newspaper and asking if anyone recognized the town. It was Bandera, Texas, by the way. It has led to a good discussion about DOF, but that was not the reason for the post, and it shows how threads can spin out of control when people do not read the initial post and the particular forum category that the shot is in.

If anyone wants to talk about DOF in more detail, I've posted a DOF shot here:

Depth of Field (DOF) - A discussion by Example

Cheers,
rfs