To understand and calculate depth of field (DOF)

DOF (Depth of field-depth of field) is a portrait photography important factor when the bombardment. There are many questions surrounding the DOF, such as "why is the P&S again it is difficult to create thin DOF though aperture (f-number) open big?" And they told each other that capture the Portrait use FF because it clears better font, so the question is "the FF really deleting fonts better (than the crop)?" "Focal length affects DOF?", so on and so on ...

The fact is, when you have a tube 17-55f 3.5-5.6 and 70-200f4L or 50f 1.4, then your doctor will likely change how the DOF, clear fonts.

I think this is an interesting topic and cause "fog" (as I'm new at learn). I wrote a post talking about the DOF and the calculation of the DOF, both to the pro "guillotine" to learn more, just for the newbie (like me) have a chance to learn.

But do not know the Forum has one said me and yet cares not me writing out the being yelled at or "discounted" ^^. Anyone care to Comment, I would rely on it but decided to write it or not. The Dof is really very hard to calculate when shooting for someone like me, is also difficult to learn but do not control was correctly. I'm sharing what I know about the DOF. While children sit the actual pictures to post up, but honestly I don't know how to post now. Let me find out keep writing my post slices, to have new artwork "said that the book, tips have been" ^^ here are 3 pictures I snapped in place while writing this article, with your P&S the Canon G7. I have scored important parameters with the focal length and aperture.
All 3 panels of children are not moving air, which only change parameters.
-The first Sheet grabs 7mmF 2.8, Vrohto bottle is seen clearly, behind the blur, though 2 bottles set close together but the bottle after the blur shows DOF is quite thin (10 cm <).
-The next Plate was still 7mmF 2.8, but I change the focus point (using Flexizone mode of the G7, the SRL can select point autofocus). And the result is Vrohto bottle after bottle, longer strokes ago blurred.
So after two shots on one can see the DOF change according to the DISTANCE FROM the CAMERA (LENS) to the PLANE of FOCUS (i.e. the subject wants it most morphological)
-The last Plate I shoot at 7mmF8, one can see both the bottle VRohto bottle, strokes are more strokes before, because I focus in the bottle. So the DOF in this image has more depth than the 2 photos above.

And then, there's the example to visualize the story here. Now I'm going to "expertise"
DOF DEPENDING FACTORS?
Speaking in General, there are 3 elements:
1. Aperture (aperture) or f/stop, f-number, is the aperture of the lens. This factor is most of these medical doctors all know. Of larger guns (f-number as small, e.g. f 2.8 > f4 > f8 > f22 ...) then more thin DOF, and vice versa. That is the same in other elements, then shoot at F 2.8 for the F8 thinner DOF. Photo 7mmF 2.8 and 7mmF8 on the other end is the obvious example: F 2.8 thinner DOF, F8 deeper DOF.
Applications: want to get thinner strokes (remove tops) we open the wide border (F2, 2.8, 4). Like almost all of its us closing the password again (F11 .16)
2. the distance to the plane of focus. As close to the DOF as slim.
I would say a little bit about the plane of focus, it is cited quite a number of concepts, but also simple. The focus plane as POF (plain of focus), the flat surface on the plane that photo is the most strokes. Go away little about the 2 (near the shooting over and away from the take over) photo was still in a range that's eyes "," fade out till I found it "ceases its call". The closest that we accept as Dn (near) the farthest, denoted Df (far), so the DOF = Df-Dn. so, what the word "accepted" it says what? That depends on the viewers eye, i.e. the Df and Dn also depend on the evaluation of image viewers, someone says is approved, someone asked "what are you called upon the modernity". But of course not so that there is no "standard". I will discuss more about this later, it somewhat bipolar, says always the fear of a "fire pipe", hihihi.

The conclusion I newborn photography for two factors are: Want thinner DOF, approached the focus than the plane (or focus in the other plane near themselves over time, not necessarily forced the "footed zoom", just like in the 2 photos with 7mmF 2.8 children in focus in 2 bottles of different Vrohto thatI have the camera where to go, still change DOF), and of course, vice versa.