Hot answers tagged terminology
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Most importantly: It's not just the disks rendered from a point source, even though that's the simplest way to describe it and see it. The disk is just a shorthand; the lens characteristics that produce these disks are always present; they're what determines the look of the out-of-focus areas in every photo you take!
On the one hand, it's quite ...
56
In layman's terms (assuming a layman who knows some very basic geometry), imagine your nose as the apex of a triangle. The left side of the triangle is the left edge of your peripheral vision, and the right side is the right edge. The horizontal angle of view is simply the angle between those edges, and the vertical angle of view is the same thing for up and ...
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There are two reasons why an ISO is not made part of the 'normal' range:
It is considered a non-trivial drop in quality and you do not want users complaining about its performance. In other words, if the quality difference between ISO 12800 and 6400 is stronger than the one from 3200 to 6400. Note that there may be more changes than simply more noise, ...
30
I think the best way to describe Bokeh is to show Bokeh:
Reference: In the Spotlight by Healzo
The blurry background "circles" are what we normally refer to as Bokeh, however in general it more simply refers to the quality of background blur. The picture above has some truly excellent bokeh, as the circles are truly round, generally evenly shaded across ...
30
Ok for a change I'm going to dispense with the formulas, photos of rulers and definitions of "magnification" and go with what you actually experience in practice. The major factors that actually matter to shooting are:
Aperture. Wide aperture lenses give you a shallower depth of field. This is probably the least controversial factor! This is important as ...
28
SLR - Single Lens Reflex, meaning that there is only one lens through which the viewfinder and the film are exposed to the image. This is in contrast to other types of cameras, like rangefinders, where the viewfinder was a separated optical path than the film, usually in the form of a small lens on the top-side of the body. The Reflex part comes from the ...
28
Short answer
So, not being quite satisfied, I did some research. Here's the tl;dr answer, but I hope you find the rest as interesting as I did.
In painting and in photography, the "key" of an image is the overall tendency of its tone scheme towards brightness or darkness.
When the key is bright, the image is high-key, and when it is dark, the image is ...
27
The hyperfocal distance is the distance at which everything from 1/2 the distance to infinity is in focus.
For instance, if the hyperfocal distance of a particular lens at a particular aperture is 100ft, then by focusing at 100 ft you can capture anything from 50ft-infinity in clear focus.
A more in depth explanation can be found at www.dofmaster.com
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It means the lens focal length doesn't change, but you can change the framing by moving your feet — which in this idiom are wearing sneakers (which, for non-native English speakers, are casual athletic shoes). I've more commonly heard "zoom with your feet", which is the same thing except not dependent on shoe style.
It important to be aware that changing ...
26
In practice, you're correct and it means that it's a fixed focal length lens.
Historically, the term "prime" derives from cine work, where it had a more literal meaning of the primary lens of a multi-lens system.
The concrete advantages are typically that they are much more compact, and have a much higher quality/cost ratio, as they're easier to engineer ...
25
Photography has borrowed the term "gel" (and the technology) from theater. The original colored "gels" were made out of gelatin (and tended to melt). Today, they are made out of other materials that are more heat tolerant (but can still melt....)
there's a nice writeup on this on wikipedia:
http://en.wikipedia.org/wiki/Color_gel
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This is an excellent question, and one that has different answers depending on context. You mentioned several specific questions each of which might warrant their own answers. I'll try to address them more as a unified whole here.
Q. Is it just a property of the lens?
A. Simply put, no, although if you ignore CoC, one could (given the math) make the ...
25
The aperture range on your lens only shows the maximum aperture for your lens at the extremes of the zoom range; i.e. f/3.5 at 18mm and f/5.6 at 55mm. There is nothing to stop you using a narrower aperture; remember a larger number is a smaller hole (the f number is the diameter of the hole as a fraction of the focal length).
25
STM stands for Stepper Motor and is a applied to a new range of Canon lenses which feature a new design of focus motors which, along with a new iris mechanism are designed to eliminate (auditory) noise during video recording.
Canon haven't revealed any information about how the new design works but it's probably the same type of motor used in mirrorless ...
24
I think, in general, you are considered a professional photographer if your primary source of income comes from your photographic work. For example, if you are a wedding photographer by trade, your job is to photograph weddings. You are a "professional" wedding photographer. The same would be true if you were a sports photographer, and sold your work to ...
24
Don't feel bad. Color theory isn't easy.
First, many of your terms come from the many different ways to express a color. What we typically call a "color" (like, 'red' or 'orange') can be expressed in a variety of different ways:
RGB: The combination of red, green, and blue light that forms a color. This is also called additive color (when you add more ...
23
Pancake lens is a lens which is designed to be physically very thin and compact, relatively pocketable when combined with a slim body. Current pancakes have fixed focal length, from moderate wide to moderate telephoto, they're usually relatively slow for a prime lens (f2.8 and slower) although exceptions exist. Pancake lenses don't alter the image in any ...
23
Basically all "expanded" means is that this is not part of the standard recommended range. Often the expanded ISOs are implemented in software rather than hardware (which is bad)
With ISO 50 you might be getting an overexposed ISO 80 (the native, unamplified ISO) so could end up with less dynamic range. This is done by metering for ISO 50 but actually ...
23
ISO is the short name for the International Organization for Standardization.
The applicable standard for colour print film speed is ISO 5800:2001, and for the digital still camera imaging equivalent it is ISO 12232:2006. The numbers used in the linear system (there is also a logarithmic equivalent) and procedures used are nearly equivalent to the former ...
22
True macro lens gives you a 1:1 magnification -- that is a ratio of size of the subject and its image on the sensor. With 1:1 magnification on APS-C sensor (22×15 mm), you can fill whole picture with area of this size.
Other properties of macro lenses include that they have fixed focal lengths, usually very low distortion (see distortion figures of ...
22
Bokeh, in its most technical definition, is the shape produced by taking an out of focus picture of a single point of light. The overlapping bokeh from all the myriad points of light that make up a scene creates the blur in out-of-focus areas.
People may have different preferences, but there are really just a few different measurable qualities of bokeh.
...
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Different light sources have different color temperature and when you want natural colors, you need to correct them for that particular light source. Basically white balance says what is rendered as neutral gray. You can find a more thorough explanation here: http://www.cambridgeincolour.com/tutorials/white-balance.htm. Wikipedia lists different light ...
22
The definitive answer for the word in English is Mike Johnston's article on the topic at Luminous Landscape. Mike says "it is properly pronounced with bo as in bone and ke as in Kenneth, with equal stress on either syllable." He's the person responsible for the h on the end in English — he thought it would ward off the most egregious mispronunciation, ...
22
Exposure fusion is a process that takes multiple images and combines them to create a single image while only keeping the properly exposed elements. In contrast to HDR images, exposure fusion is more basic, gives a more realistic effect, and requires fewer steps.
The exposure fusion(fusion, or EF) process takes each individual pixel and assigns a weight to ...
22
These letters refers to zooming depth as follows,
W = Wide angle
T = Telephoto
Read more about wideangle and telephoto in the tags.
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The aperture affects not only the amount of time required to take a photo, but also the depth of field within it.
With a wide aperture (so a low number, like f/1.8) gives a shallow depth of field - sometimes less than a millimetre with a macro lens. Because a lot of light is reaching the sensor (be it film or digital), this allows for fast shutter speeds
...
19
Parfocal lens is a lens which remains in focus when you change the focal length. The non-parfocal lens is called varifocal.
It is very convenient to focus at the maximum focal length and change the zoom afterwards. It is more important for manual-focus lens because a well functioning auto-focus can quickly adjust the lens to keep it in focus.
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Fundamentally a telephoto design is used to make a lens body shorter than it's focal length, for practical reasons [what if your 18-300 ultrazoom was actually 30cm long?], a retrofocus design is the opposite, and makes a lens longer than it's focal length in order to leave space for the mirror on an SLR.
You can tell if your lens is a retrofocus or ...
18
It means "through the lens" and generally it hooks your flash into the exposure system of the camera since the metering of the scene is through the lens. This allows the camera to exert control over the flash, including power, distance, etc. based on the scene and focal length, if the flash supports that functionality with your camera. Usually true for ...
18
Definition of SLR
SLR consists of:
SL
Single lens. That is, it does not have a separate lens for a viewfinder. If it has a viewfinder, the viewfinder looks through the main lens.
R
Reflex. This means it has a mirror (called a "reflex mirror") that allows light from the main lens to be bounced upwards onto a ground glass screen. Modern SLRs usually ...
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