KenR
Well-known
If we can get back on topic - I think that shallow depth of field is popular now because of snob appeal - photographers are telling the world several things a) I have an expensive large sensor camera, not one of those cheap small sensor types with unlimited depth of field that the masses use and b) I have an expensive f/1.4 lens that I can use wide open because my expensive full frame camera has shutter speeds to 1/8000 sec. Trends in art often come down the artist trying to show how he/she can differeniate him/her self from everybody else.
Gabriel M.A.
My Red Dot Glows For You
wolves3012
Veteran
I'd hazard a guess that almost all members of RFF know full well the intent of the post. To be utterly pedantic, since no lens is perfect then nothing is ever perfectly in focus. However, with a short focal length lens and in the real world, it translates to everything is in acceptable focus and differential focus becomes difficult if not impossible. DOF is indeed related to the sensor/frame size for a given field of view.
jbot
Jared Krause
I definitely agree, but sometimes people just don't really care about taking technically and compositionally impressive photos. They just want something that looks nice, and can afford to support their hobby. Bokeh does look nice..
Perhaps, although perhaps they are just wanting to emulate what a 4x5 or 8x10 can do with ease, without having to resort to all the effort. Maybe they just like the look?
JHutchins
Well-known
I'm more skeptical about the snob appeal explanation for a taste for shallow depth of field than I usually am about snob appeal explanations (and usually I'm pretty skeptical about them). A lot of the art of photography is learning to simplify -- to cut away everything that might distract so that the viewer sees the thing or relationship between things that caught your eye and prompted you to take the photo. A lot of technique is just a bag of tricks that photographers can use to simplify a scene. Control of depth of field is one of them. By throwing everything not in the plane of focus into a deep blur you've sharply limited the number of things in the image that can hold an eye so the resulting pictures are often powerful. If the eye can be held by the thing the camera is focused on, it will be. People like the results they get wide open, they shoot wide open. That's all the explanation one really needs, isn't it?
Yeah, please all go ahead and bash bokeh. I´m waiting for Nocti prices to come down back to 1000$ each and then buy a dozen!
Remember "The dose makes the poison." (Paracelsus)
Remember "The dose makes the poison." (Paracelsus)
timor
Well-known
Not really. Field of view or rather angle of view is a lens function and has nothing to do with the size of medium on which the image is projected. Differentiate between focus and DOF has a practical meaning. Mike Johnston is talking about creative use of DoF according to need of situation or idea of the photographer.( Nothing new, this topic is discussed for at least the last 100 years. ) But if someone does not know how DoF is created around the exact point of focus, very simple thing, then how he can use it consciously ? Whoever is using tilt/shift lenses can not be oblivious to it. And there are still restrictions on using apertures. Did anyone notice that P&S lenses mostly go to f8 top ?
When comes to bokeh the whole excitement was most likely invented and implemented by Nikon or Canon agents embedded in early photographic forums in order to sell to amateurs expensive, high speed lenses. And it works ! Simple propaganda mechanism. Questions regarding pleasant for the eye out of focus areas in the photographs are know also for very long time. This aesthetics where not invented with the down of digi era.
timor
Well-known
Very well said. You have a talent to simplified not only in photography. I agree with you 100 %.
Sparrow
Veteran
I still remember when bokeh was a fault induced by the photographer not stopping the lens down far enough ... ah, happy days ...
Sparrow
Veteran
... that would be your personal circle of confusion then
semilog
curmudgeonly optimist
wolves3012
Veteran
Sorry, I disagree. Basic optics says the sensor/frame size is related. Read this:
http://en.wikipedia.org/wiki/Angle_of_view
Specifically (I changed the symbols to make them type-able and the emphasis is mine):
For a lens projecting a rectilinear image, the angle of view (a) can be calculated from the chosen dimension (d), and effective focal length (f) as follows:
a=2 arctan (d/2f)
d represents the size of the film (or sensor) in the direction measured. For example, for film that is 36 mm wide, d=36 mm would be used to obtain the horizontal angle of view.
timor
Well-known
Still the same. This is just a calculation of what your medium gonna use from lens field of view. DoF obtained from let say 50mm Rokkor MD will be the same for my 35mm negative as for your four third sensor. (Yes, I can see, that you are rather film photographer.) Just your image will be smaller cause mounting 50mm Rokkor on four third camera will not change in any way lens field of view or covering power. For the same field of view on small sensor one has to use shorter lenses. Shorter lenses are projecting narrower circles of confusion, thus producing deeper DoF. But still no matter, the image from four third camera and mine from 35 mm neg enlarged to the same size will sport approximately similar DoF.
TXForester
Well-known
Originally Posted by wolves3012
DOF is indeed related to the sensor/frame size for a given field of view.
Interesting. Wolves3012 made a statement about the relationship between medium size and DoF and you countered the comment with a statement about the relationship between angle of view and medium size. Two different concepts. Not only that, but you got it partially wrong. While angle of view is a function focal length ("lens function" in your words), apparent angle of view is a function of both focal length and medium size. Hence the phrase "cropped sensor."
TXForester
Well-known
I'll agree, but sometimes the things for which you want to show a relationship are not in the same plane of focus (or close enough for practical purposes). Take the Sam Abell branding photo mentioned in the article. The photo needed visual depth to show relationship. While simplification often helps to mentally focus on the subject, shallow focus is not the right technique for all photos.
timor
Well-known
All I am saying is that DoF depends rather on optical qualities of lens rather then on the size of the medium.
About the use of DoF ; shallow depth or deep, that tool one can use depends on situation and intention. Most good quality lenses come with exact description of DoF for each aperture setting. It has some purpose I guess.
wolves3012
Veteran
Exactly the point I was making. Angle of view depends on sensor/film size. Small sensor needs a short lens for a given angle of view, therefore large DOF. Obviously there are other, small factors involved but essentially this is true. As for making enlargements to the same size, the acceptable focus changes, obviously.