# Tag Info

50

You've run over the diffraction limit. Light rays passing through a small hole will diverge and interfere with each other and a pattern emerges--a sort of banding where different frequencies/placement can cause separate rays to add up or negate each other. The smaller the opening gets, the larger this divergence/interference becomes. This pattern is called ...

43

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

43

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 ...

42

Shooting blurred photos can be considered opposite of black and white photography - while black and white is about hiding colors to bring out shapes and shadows, blurring helps to reveal colors by hiding shapes and shadows. An interesting subcategory is a combination of the opposites - black and white blurs - where distractions by both details and colors are ...

40

As mentioned in the other answers, diffraction has led to unsharpness. To put this to the test, one can attempt to sharpen the image using deconvolution by using the point spread function that corresponds to F/29. For diffraction, we have (up to an overall normalization) P(s) = {J1[ πrs/(λF) ] / [ πrs/(λF) ] }2 where J1 is the Bessel function of the ...

31

What you are looking for is large depth of field. This is an optical property, not something applied as a special effect, so it's not something you can turn on or off. The raw image captures the light focused by the lens, and inevitably there will be parts of the scene which are either too far or too close — out of the range where the rays are tightly ...

24

There's a good answer from Brian Auer, which I'll reproduce here, as it pretty much covers the problem you're trying to solve: Ooh, good question. Yes, but how much will depend on the camera. If the camera has manual controls for aperture, that definitely helps. It also helps if the camera has zoom, as most P&S cameras do. The problem with ...

24

I used to think that blurring was one of those things that was impossible to recover from in post. Amazingly enough it's possible to take an image that is blurred beyond recognition: and recover all the original detail if you know the exact blurring function: So why isn't this done all the time? Well firstly you never know the exact blurring function ...

22

Unlikely to be Image Stabilisation @Dan, that's a good question. I suspect that most of us have a problem with blurry images more often that we would like. It's unlikely that Image Stabilisation is causing this problem. I have certainly never had this problem myself. However, IS reduces camera shake - that probably isn't your problem. So, what could ...

21

While using shallow depth of field is the most common technique to get blurred background, there are some other ways: using plain background so it would not need any blurring set up your own background - you'll have full control over color and pattern shoot against sky or some other plain surface (longer lens will help you by having smaller segment of ...

20

There is NO difference at ALL because the physical aperture has not changed. The Fuji Finepix S4000 simulates a small aperture using an ND filter. When you stop-down the ND filter slides into the optical path. The Aperture written in the EXIF data is adjusted to reflect the transmittance of the ND filter, but note that since the size of the opening has not ...

19

Ultimately, you want a shallow depth of field, which means a low fstop number (f/2.8 for example). The lower the fstop number, the more light that gets in, so in order to expose correctly, you need to increase your shutter speed (1/1000 is better than 1/25), lower your iso (100 is better than 400), and if all this is not enough, add a neutral density filter ...

18

Bokeh is subjective, and all cameras can create bokeh. One pre-requisite to pleasing bokeh is to have sufficiently out of focus areas. Most details that are only a bit out of focus don't look too pleasing. Something is more out of focus the further away it is from the plane of focus. In addition, the the shallower the depth of field, the quicker things ...

18

Image stabilization aims to fix the problem of a moving camera (camera shake). Your question and example photo aim to fix the problem of a moving subject. To reduce blur of a moving subject, you need a shorter shutter speed, or you need to freeze the motion with flash. If you also have camera shake, then image stabilization will help some. But first make ...

18

You've hit the diffraction limit. That link has some amazing answers with a lot of detail, so I won't be redundant, but in short, once the aperture gets to be below certain physical size, diffraction causes inevitable blur. For your camera (and any other camera with an APS-C-sized sensor), the limit is a little beyond f/11. The amount of light let in doesn'...

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 ...

17

Have you tried the High Pass Filter in Photoshop? Make a selection around the area of the image you need better focus on, press ctrl-J to jump this to a new layer. Then, in the Filter menu, scroll down to Other, and choose High Pass. Depending on how large your photo is, you might want to choose from 1-6 pixels. You will probably have to ...

16

Using lenses with IS can take a little practice to get used to and use effectively. There are times when IS/VR may actually add blur to your images, due to the way it functions. Generally, if you are using a lens with image stabilization, you need to make sure that IS is active and tracking before you fully press the shutter button. If you make the mistake ...

15

The bokeh behind the couple looks normal, the sides seem to have had a gaussian blur applied to give a fake tilt shift effect. The telling factor is the highlights. The light coming from the windows is much brighter and ought to have a sharp cutoff when rendered out of focus. Gaussian blur gives a soft edge to such highlights. edit: reading the text of the ...

15

This looks like the effect of noise reduction at high ISOs. Heavy NR is common in compact cameras with small sensors. Fujifilm does it better than most, but there's only so much blood you can get from a stone. On most modern high-megapixel point and shoot cameras, you'll see this even at low-ISOs if you pixel peep. It's important to note that in most cases, ...

15

Because of diffraction. f/29 is way too much for you to expect a sharp image. Try shooting the same thing at f/8 and you'll see the difference.

14

You're confusing the blur in the background that's due to having a shallow depth of field with motion blur from a long exposure. The exposure length has pretty much nothing to do with it here. It's all about the aperture. (And if you want to change your composition, the distance to the subject.) Depth of field has been covered in great length on the ...

14

Firstly I notice your aperture is set at 1.8. This will make DOF very narrow, making focusing very difficult. Also your camera is very good at higher iso, so try using 1600 / 3200 initially. Try setting the following. Use auto focus to focus on something with a defined edge (the tops of the trees?), then switch to manual to keep the focus. Use a higher iso,...

14

It is indeed a rule that comes from film cameras. On point 4 the answer is simple: Multiply the focal length with the crop factor of your sensor. Because the sensor is smaller than a full frame sensor, it will not cover the full image circle, cropping out a smaller image. This has the effect of looking like a longer focal length. E.g. on Canon, a 50mm ...

14

The simple recipe is to convolve with a Laplacian of Gaussian kernel (3x3, with 8 in the middle surrounded by -1 and take the abs(result)) . After this you get some artifacts if it is a jpeg image, and out of focus borders that have a high intensity difference will also "ping". The result you can threshold to detect the strongest edges and remove teh ...

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I find a long lens helps 200-300mm, as you have to move the camera more side to side, being closer and using a shorter lens will give you problems with the subject coming toward you and then going away. Being further away yields a more consistent side to side panning motion which is easier to perform consistently. A strong deliberate sideways motion also ...

13

One more suggestion: if the picture is meant to be a background for something else (like a computer desktop, a printed page or a work of art), then the "something else" forms the foreground of the resulting work, and the picture in the background should not excessively distract the viewer from it. Thus, a completely blurred or defocused picture may be ...

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It's more complicated than just depth of field. You can have two photos with identical depth of field, but one can have more background blur than the other. In addition to background blur, there is also "bokeh", which describes what kind of blur there is. Check out this article which describes it in detail, and gives you a tool for calculating the various ...

12

It's unlikely to be IS. If it is, then IS is seriously broken. It's generally safe to leave it on all the time except when you are using a (very firm) tripod. That said, with a moving child from close range, IS really isn't likely to have much of an effect. What it could be, from most to least likely: Subject moving in and out of focus. By the time ...

12

I did some quick Google Books searches, and while I can't pinpoint the origin, there are a number of references to it as a rule of thumb or general guideline in the early 1970s, and none that I can find before that. There are plenty of earlier references to the idea that a longer focal length requires a faster shutter but they're all general advice. The ...

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