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48

Bokeh is specifically the out-of-focus areas of an image. Gaussian blur is an algorithm to fog selected image areas, to hide details or make them look out of focus. The main differences: bokeh is created optically, gaussian blur in post-production; in bokeh, the amount of how wide an out-of-focus point will be smeared is determined by its relative distance ...


31

Depth of field depends not only on aperture but also on distance to the subject. Depth of field increases as the subject gets farther away. If the wave and boats were all relatively far from the camera, but not terribly far from each other, then it's not surprising that they were all reasonably sharp. You can use DOFMaster to run the numbers yourself. Some ...


27

It's probably a combination of two factors, firstly as you rightly suggest the focus screen plays a role - the view you see in the viewfinder effectively passes through a second aperture and so appears to be stopped down to about f/2.4 - f/2.8 So you can see bokeh through the viewfinder, it will just be much less pronounced due to the smaller effective ...


26

This photo is taken with a petzval lens which corrects all aberrations decently except for, well, petzval aka field curvature. Because the edges are in focus at a further distance, the blur is smaller there. Because the lens is fairly highly vignetted, the lens also effectively has a larger f number towards the edges, again reducing the blur. The result ...


21

Yes you are looking at clipping by the mirror box, I'm afraid it's unavoidable when using a lens with large aperture and exit pupil close to the film plane at certain focusing distance. Even if the mirror box doesn't clip the light cone the lens barrel will (for off axis points of light) leading to cat eye bokeh. Here's an example from a full frame camera ...


19

No. The sensor size plays a major part in bokeh. Sensor dimensions of your dSLR are about 3 times bigger than sensor of the compact, so a photo taken with compact's 5.1mm f/2 will look similar to one taken at 16mm f/6.3 using APS-C sensor. Also, the shorter focal length will reduce bokeh effect, because wider angle of view means more background has to fit ...


19

I think the main problem is one of dynamic range, your algorithm is probably right but you're working on the wrong type of data. A point lightsource that would otherwise clip and go pure white gets spread over a larger area by a defocussed lens, so that it forms a disc that isn't as bright and therefore doesn't clip. That's why you get those nice circles ...


17

The Japanese word Boke (ボケ) or the American spelling Bokeh, refers to the out of focus areas of a photograph. It does not necessarily mean only the background blur, it refers to foreground blur as well. Bokeh is often used to refer to the quality of out of focus blur more so than its presence. In Japanese, Boke Aji (ボケ味) is used to specifically refer to the ...


15

You don't actually need a tilt-shift lens to do this. This particular image was taken with a standard lens (50mm f1.2 according to the filename of the image on Ryan's website) rather than with a tilt-shift. The extreme bokeh effect here was achieved by using a freelensing technique, where the lens is detached from the camera body and held at a tilted angle ...


15

It is a property of the lens. the bokeh highlights image not only shape of the aperture, but it also gets a profile. It can be a square profile, have sharp edge and then attenuate, have dots inside it, show cats eye, or be smooth like yours. The way the lens is corrected for spherical aberrations affect this. Vintage lenses typically make sharp bokeh rings. ...


15

Bokeh is formed by many points of light spreading out, passing through the aperture and being projected onto the image plane as series of overlapping discs (assuming a round aperture). This can lead to harsh textures and effects when there are strong contrasts in the out of focus parts of an image, especially when lenses feature overcorrected spherical ...


15

The non uniformity of the bokeh leads me to believe that the background has been Photoshopped. Exactly how it was done is anyone's guess - but the sharp lines through the bokeh may indicate a liquify or similar brush that "grabs" the colors and drags them. I do think a bit of manual brush work was done, in addition to some filters. However, do be aware that ...


14

It's not appropriate to use the term "Gaussian blur" for the out-of-focus parts of an image, because "Gaussian" refers to a specific blurring function. It's the same Gaussian curve that you may know from the "normal distribution" or "bell curve" in statistics. A bright point that's smoothed by a Gaussian will taper smoothly from a bright center to a dark ...


14

This is field curvature. Simple lenses naturally project a curved field, not a flat one to match film or digital sensors. Modern lenses attempt to correct for this, but many older designs do not. In fact, it's sometimes called the "Petzval effect" after a classic design famous for this look. Interestingly, just this week Sony showed prototypes of a curved ...


14

No photoshop necessary for that background. That's simply what happens when shooting a telephoto lens, f/2.8 or larger, and having the subject closer to the camera and much further from the background. I don't see anything inherently special about the tone. We'd expect cool tones from the shade and that's what we've got. The nice part, imo, is the contrast ...


13

It's called "Nisen Bokeh" and is mainly due to the lens design (though the background plays a part, it's possible to "provoke" this effect with any lens with the right background). Overcorrected spherical aberration (blur disks which are brighter in the periphery than the centre) is usually to blame. It's showing up more often with the A7 due to the use of ...


13

I was always wondering if theres anyway to get bokeh that looks something like this (vertically distorted bokeh). This vertically-oval bokeh is the result of an anamorphic lens, which "squeezes" an image horizontally to fit a laterally-wide field of view into a relatively narrower film or sensor format. The image must be "unsqueezed" in post-processing or ...


12

Yes, it is possible - however, a quick experiment shows that it's a little tricky and that the results aren't as good as what you can from a bigger camera. The bokeh discs are just out of focus lights - so all you have to do is place some lights and "defocus" them. Here's what you do: You need an iPhone 3GS or later, earlier models are not capable of ...


12

The problem with the prime 35mm is that in order to frame your shot properly, you'll need good mobility. Which you may not always have in a busy and crowded car show. So I would give one point to the 18-200 for that: It'll let you frame your shots even if you can't get yourself at the exact right position you'd need with the 35. Then, the thing is: it's a ...


12

First of all, in optics, only light adds up and darkness does not. Make sure that your algorithm does not bleed dark pixels outwards their original location. Resulting pixels should rather resemble maximum of nearby source pixels than average. Or, to be even more exact, you'd be summing up logarithms of affecting source pixels. Another possible cause why ...


11

Okay, so, really, two aspects here. First, would an 85mm lens let you blur the background more? Probably, because the framing for a longer focal length decreases the apparent depth of field, and because there are reasonably-priced and readily available 85mm prime lenses with wide apertures and generally nice technical image quality . But it's not a ...


10

Bokeh is a word we use to describe the appearance of out-of-focus blur. It comes to us from the Japanese phrase boke-aji (ボケ味), which literally means "the flavor or taste of the blur". In English, the phrase was shortened while "h" was added to aid in pronunciation. Almost all photographs have bokeh — not just images with shallow depth of field. Since ...


10

As has already been pointed out, out of focus highlights will (mostly) reflect the shape of the aperture. That may be the most obvious element of bokeh. There is quite a bit more to bokeh than just that though. Spherical aberration correction is another important element. If a lens corrects spherical aberration perfectly, an out of focus highlight will ...


10

Cell phone cameras don't have moving parts, such as aperture blades. So they will be working at a fixed aperture, their widest. And they'll have a very short focal length, meaning a very wide depth of field. So to get a blurred background will be very tough. You'd need to focus on a subject very close, with a background very very far, and even then, it's ...


10

In general "high quality" bokeh is viewed by most photographers as out of focus areas that are smooth rather than harsh. Most lenses that produce smooth bokeh also produce out-of-focus highlights that are round rather than an equiangular regular convex polygon. Since lenses that produce round out of focus highlights with soft edges also tend to produce ...


10

Good or bad bokeh is in the eye of the beholder. Michael Clark thinks the highlights have to be round, usually meaning a fully open aperture, but I don't agree. I don't mind 7-gon or 9-gon highlights, though round one do look nicer. An aspect of bokeh which bothers me more than the general shape is the light distribution. For me the best bokeh is when the ...


10

From the other question: Here's the list of things that influence depth of field the most (in this particular order): Subject distance, the closer the subject is, the shallower the DOF (think of macro) Focal length, the more millimeters, the shallower the DOF Aperture, the smaller the f-number, the shallower the DOF (written by Karel)...


9

Light propagates in a line, unless you make your photo near a black hole or a giant sun. Consequently, as soon as the light converges into the focal point and arrive at your sensor, you have similar cones from the aperture to the focal point and from the focal point to the sensor. The upper circle is in the shape of your aperture, the bottom circle is the ...


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