Hot answers tagged

51

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 ...


48

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 ...


39

It depends. In many cases, it may actually be possible without any further visual aids in the picture. Many lenses, if not most, will show different longitudinal chromatic aberration in front of and behind the focus plane. If you scroll down just a little bit on the linked page, you will see this demonstrated with a picture of a focus test chart. With this ...


35

Actually, this is intentionally done and can be duplicated with any camera and flash combo (ish). To me, the second and third image seem indicative of a technique known as second curtain / rear curtain sync. The first appears to be good ol' flash during a long exposure...(more below)... In all of the examples, a decently long exposure (for the event) was ...


24

shutter speed 0.5 seconds This is likely to be a bit of your problem. The shutter causes vibration of the camera. So, too, does your hand pushing the release button. At faster speeds, this vibration does not affect the shot. Likewise, at very slow speeds (a few seconds +). But there’s a sweet spot somewhere between a second or two and ~1/30 where that ...


20

The blur is caused by the shutter being open for much longer than the duration of your flash. The orange color of the blur is due to the ambient lighting being much warmer in color than the light from your flash. Since the camera has almost certainly set white balance automatically to match your flash, the much dimmer and warmer ambient light has a very ...


20

When the aperture is positioned to minimize vignetting, the bokeh shapes for objects that are too far is rotated by 180° compared with objects that are too near. (The aperture image is reflected through its center point.) If the arrangement of your aperture blades is not symmetric around the center point, you can try finding "reference bokeh" that are ...


18

Use more light. Open windows, turn on more room lights, bring in extra portable lights. Use a flash. You say there is "no chance" to use a flash, but since you gave no justification for that it remains valid advice. Added: I just looked at the manual you linked to, and right on the front page it clearly shows a popup flash. A spot light from almost ...


16

You appear to be using your lens (100-400/5-6.3) with the aperture wide open. I would expect the glow in your photos to be significantly reduced or absent stopped down to about F8. Many lenses "glow" when used wide open, especially in bright light with high contrast. It is likely associated with spherical aberration and is typically reduced or completely ...


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.


13

There is definitely something very wrong here. That's not a focus or DOF issue, but looks like the lens suffers from extremely strong field curvature. It's normal for a lens to be sharper in the center than around the edges, and this effect gets stronger with wide open aperture and at the extreme ends of the zoom range (your last sentence indicates that you ...


13

First, I'll talk about what cameras do normally, then about how motion affects this operation. In order for an image to be sharp and in focus, all light coming from a single point on the object being photographed must fall on a single point on the film or sensor. If you take a picture of a face, you want all of the light reflecting off the left eye fall on ...


12

No, a higher resolution sensor does not increase the difficulty of handheld shooting. It does mean that is is more difficult to realize the full potential of the higher resolution sensor, but that doesn't mean the results are worse than they would be with a lower resolution sensor.


12

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. Bokeh is often considered better or ...


12

From the comments, it seems like this is your problem — you're probably focusing past infinity. See Why do some lenses focus past infinity? Or, if you're not turning the ring all the way and instead relying on the marking, it may just be that the marking isn't precise enough. Try the suggestions at Where to focus when shooting landscapes? instead.


11

The fact you're seeing this with two very different bodies suggests to me it's in the lens. Long zooms tend to have a bunch of elements (anywhere from a dozen to twenty, in my experience). No lens coating is perfect, and no lens surface is perfect. Every time light passes through an air-glass or glass-glass interface at an element surface, there's a small ...


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 ...


9

The softness at the edges is definitely caused by a decentered lens. This just means one of the internal glass elements is not properly aligned with the others. Like so; (It could be any of the elements...this is just an example of the far left being off.) I'd recommend that you immediately send it in for repair to Canon. You can start here: http://www.usa....


9

The short version is you need not the "biggest aperture possible" but the right aperture given the distance and desired depth of field. There are a number of online depth of field calculators available (search for it, since these answers live a long time I hesitate to put specific links). Put in your focal length, distance, sensor information as ...


9

From the information provided in your comments, it sounds very much like the shutter speed was too low, possibly because your ISO was too low and the subject was moving faster then the shutter, hence the blur. I'd suggest increasing ISO and shutter speed. Point of note. The light may seem OK to a human eye, but an eye is considerably more sensitive then a ...


9

A diopter lens* like this is really only supposed to work at VERY close distances, which your unmodified phone or camera lens won't focus to (otherwise, there is no need to use a diopter). From the picture, it looks like you are holding the camera a two feet or more away from the subject - the phone can likely focus on that just fine without a diopter. Try ...


8

As tenmiles stated, post-process defocus correction is not a solution for lack of good focus. Getting good focus in camera is a critical aspect of good photography. That said, there are some solutions, and we all make mistakes sometimes, and it's reasonable to expect an option to recover when you make such a mistake. While Photoshop CS6 has a basic deblur ...


8

All in all for the shutter time and subject matter you did very well to get a photo as clean as you did. Here are the causes of the imperfections you notice in your photo: The people in the photo are moving too fast for the shutter time of 1/80 second. Don't be afraid to push the ISO up to 400 or even 800 so that you can use a shutter time of 1/320 or 1/...


8

... I thought it could have been caused by either poor lens quality, bad auto-focus, or motion blur, or is it perhaps something else? If the problem is motion blur, you typically see a slight double-image or slight translucent "ghosting" around moving parts. You'll also notice more blur where there's motion vs. where there isn't any. There may be some ...


8

Yes, this precisely what Photoshop CC's Shake Reduction filter does. Adobe first publicly demonstrated their prototype feature at Adobe Max 2011. The crowd was pretty wowed by the demo. While it was demonstrated in 2011, Piccure actually introduced the feature before Adobe in 2013, as a plugin to Photoshop. See also: Adobe's help page for the Shake ...


7

One of the lens elements is badly decentred, send it to your nearest Canon service centre for repair.


7

The reason the background is not dark is because there is light shining on it. The same light sources that you are attempting to record directly are also illuminating the areas around the light and those areas are reflecting some of that light to the camera. Additionally, The highlights of the lights themselves are so overexposed that they appear almost pure ...


7

I’m using a bridge camera Fujifilm s7000. This is the root of your problem. The S7000 was announced in 2003, and discontinued in 2005. And while the camera might work just as well as it ever did, digital cameras have evolved significantly over the last 15 years, and that has changed our expectations of what we should be able to do with them. The other ...


7

I've run into that when taking pictures of Raku ceramics in and just out of the kiln. I think it's a heavy dose of near IR overwhelming (or at least leaking through) the camera's IR blocking filter. With a phone this may be more of a problem than with a high end SLR- the IR block filter may not be as efficient. If it -is- IR then whatever lens coatings the ...


Only top voted, non community-wiki answers of a minimum length are eligible