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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 ...


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

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 light source 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 ...


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

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

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

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) and this is my ...


10

The doughnut bokeh of catadioptric ("mirror") lenses is not caused by the rear mirror or long focal length, but by the obstruction (front mirror actually) on the front element. You can achieve it with any lens if you put a round sticker on the front lens. Or better: on a clear (e. g. UV) filter in front of it. With a little practice you could even achieve ...


10

You appear to be seeking to maximize the amount of background blur. Factors that increase background blur are: Distance to subject (closer) Distance to background (farther) Focal length (longer) Aperture (larger opening; smaller F-number). Sensor size in and of itself is not a factor. However, it influences focal length choice and working distances. ...


9

Bokeh means the visual looks of out-of-focus areas of a photograph taken using real world optics. For perfect optics an out of focus point of light (e.g. an out of focus start) would be a perfect disc. Real world optics are not perfect and a single point of light will not show up as a perfect disc in the photograph. Gaussian blur is a digital filter that is ...


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 ...


9

High quality is when it fits the vision and intent of the photographer and it enhances the aesthetics of the image. Bad quality is when it subtracts from the overall quality/aesthetics of the photo and for technical reasons does not match the photographer's intent. In general, the intent of bokeh is to make a smooth background against a sharp foreground. ...


9

This is a swirl-y bokeh, an often desirable flaw commonly found in some vintage lenses and lenses. There are some lenses known for this this characteristic, most notably the soviet made Zenit Helios 40-2 85mm F1.5 which is still being manufactured. You can find this lens on ebay for ~$600. If you are adventures enough you can convert the Cyclop night vision ...


9

This bokeh effect is known as (soap) bubble bokeh. Along with a "glowing" look, this type of bokeh is seen in lenses that have over-corrected spherical aberration. It is associated with Cooke Triplet lenses, which have three elements in three groups. Myer-Optik Trioplan lenses, such as the 100mm F2.8, are particularly known for their bubble bokeh.  This ...


8

Instead of trying to describe it by mere words, I'm posting this to show the size of those bokeh balls. They are quite small, as you can see. Bright ones are made of several overlapping "balls" but some dim ones appear individual. Actually all background blur is made of these circles, but only those created by a point light come up visible. Photo taken with ...


8

In trying to take a suitable image to use as a full example, I removed the UV filter I have on the end to act as protector - problem apparently solved. Lesson learnt: cheap glass is cheap for a reason.


7

I'm no expert, but my understanding is that the primary thing that causes bokeh-circles to be sharp is the (apparent) size of the light source. Smaller light-sources will cause sharper bokeh-circles. To understand why that is, you must first understand what causes bokeh; please see this answer for a detailed explanation. Once you've read that, it's easy ...


7

Simple version, because the aperture blocks out any rays of light that would have corresponded to that point that don't pass through it. Each point of light is actually the same shape as the aperture as some of the light coming from all of the aperture goes in to producing it, the only difference is that when properly focused, it all appears to be one point....


7

If you have a fast lens, create a circular cover over it, and it should swirl the background. It's best seen with foliage.


7

I assume you mean the "bokeh balls" phenomenon, where out-of-focus highlights become large, bright circles: The answer to this is simple: the non-bright areas are also diffused into large circles, but since photography is capturing light, that's what you see. A large circle of no-additional-brightness doesn't change the result.


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