Questions about specific terms used within photography
11
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5answers
2k views
What is the meaning of “stopped down”?
Was reading this answer (emphasis mine):
It also tells us that the lens was stopped down, as if it were wide open there would be no corners to cause diffraction, regardless of the number of ...
11
votes
4answers
2k views
What is a “fast” lens?
I've been reading lots of camera reviews lately and have ran across several references to "fast" lenses.
What exactly is a fast lens and what are its advantages compared to other lenses?
11
votes
5answers
1k views
What is a portrait lens?
I hear this term used pretty often. Does it refer to a specific focal length? Or very low F-number? What does a lens need to have in order to be considered "portrait lens"?
11
votes
2answers
1k views
What is T-number / T-stop?
Usually, when discussing aperture of a lens, F-stop and F-number are used for quantifying. But some photographers, and especially videographers, also mention T-stop. The concept and numbering used ...
11
votes
5answers
2k views
What is “infinity focus”?
I have been reading a bit about astrophotography and the term infinity focus keeps coming up. What is infinity focus and how do you set the camera to infinity focus?
11
votes
4answers
610 views
What does 'Equivalent to 1.6x the focal length of the lens' mean?
In the specifications of Canon 550D, about the lens the following is mentioned
LENS
Lens Mount EF/EF-S
Focal Length Equivalent to 1.6x the focal length of the lens
Now this is really ...
11
votes
4answers
2k views
Why are effective pixels greater than the actual resolution?
This page compares Canon EOS 550D and Canon EOS 500D cameras and mentions
18.7 million effective pixels
for 550D. However the best resolution possible using this camera is
5184 * 3456 = ...
11
votes
5answers
694 views
What is the difference between a soft and sharp image?
I have seen several questions talking about images being soft or sharp. What is the difference? Is soft simply the opposite of sharp in this context, or is there something more to it?
Sample images ...
11
votes
1answer
493 views
What is “exposure safety shift”?
I ran into the term "exposure safety shift" in this answer. What is exposure safety shift, and what is its intended purpose?
11
votes
2answers
493 views
What exactly is “base ISO” and how do I find what is base ISO on my camera?
If I understood correctly, base ISO is in full stop steps from the lowest possible ISO setting on my camera. For example if the lowest setting on my camera is ISO 100, than the following table would ...
10
votes
4answers
875 views
How important is ISO speed?
My wifes Canon EOS 450D has various speed settings and an auto mode.
The quickest one is 1600.
She photographs mainly birds, both stationary and in flight and mainly still insects.
What are the ...
10
votes
1answer
343 views
What's it called when two photographs are printed on triangles so you see a different one from different angles?
This is kinda hard to explain, but I've seen it several places before. I'm looking for a special way that two photographs are printed — they're printed so you from each angle can see just one of the ...
10
votes
2answers
188 views
What is “photometric exposure”?
What is "photometric exposure," and how is it related to what is commonly called "exposure" and "exposure values"?
I have also seen the term "radiometric exposure" used to describe a similar ...
9
votes
2answers
843 views
What is the meaning of W and T on a camera's zoom buttons?
On every conventional digital camera (excluding the models with detachable lenses), there are buttons to zoom in and out with W side and T side.
When you press W, the lens zooms out. The lens zooms ...
9
votes
4answers
696 views
Do any other manufacturers other than Canon use the terms Av and Tv?
Canon uses "Av" (aperture variable) for the automatic exposure mode that entails the user choosing the aperture and the camera body choosing the shutter speed. This mode is called "A" by Nikon, and I ...
9
votes
4answers
706 views
Why is sensor sensitivity called “ISO”?
I was curious to know how the term "ISO" was coined for referring the image sensor's sensitivity. Is there any reason or circumstance that contributed for terming "ISO"?
Also, does ISO has a literal ...
9
votes
2answers
1k views
Why don't comparisons of aperture take sensor size into account?
When one compares focal length, many times we use the 35mm equivalent length. A 50mm lens on an APS-C sensor camera(1.6x) would be a 80mm equiv. length on a full frame camera.
But when we state the ...
9
votes
3answers
7k views
What is flat light and how to counter that?
I have often heard people saying that the light in the picture X is appearing "flat". I want to understand what exactly does that mean, and what are the possible ways to counter that?
9
votes
6answers
1k views
What does small depth of field mean?
Can anyone clarify for me the various terms used to describe depth of field?
There are so many it's hard without a photo dictionary to relate in my head what's actually being said to me about the ...
9
votes
2answers
798 views
What is a vertorama and is it really different from a panorama?
Is "vertorama" a real photography term, or is it simply something that people use to describe a vertical panorama? I never thought that panorama was limited to horizontal landscape oriented images, ...
9
votes
4answers
736 views
Lens “family” names - what do they mean and should I care?
Some lens manufacturers have special names for their lens designs/families. Just to name a few:
Leica - Summar/Summarit/Summilux, Elmar/Elmarit, Noctilux
Carl Zeiss - Planar, Tessar, Sonnar, ...
9
votes
2answers
2k views
What is “pixel density”?
Apparently megapixels aren't a good way to measure the camera quality, so some people are referring to a relative measuring system called "pixel density".
What specifically is this? What information ...
9
votes
1answer
331 views
Is there a name for the type of portrait composition where the subject is looking out of the frame?
I'm wondering if there's a specific term to describe a portrait where the main subject is looking at something outside the frame that we (the viewer) can't see. I like it as a composition technique: I ...
9
votes
1answer
2k views
What is the difference between depth of field and depth of focus?
Reading this answer I realized that I didn't know the difference between the two depths (of field and focus). Browsing related questions didn't reduce the blur (!) between the two...
Wikipedia ...
9
votes
1answer
326 views
What does it mean to “mount” slide film for processing?
I just finished my first roll of a 35mm slide film and it is time to get it processed. I checked few places online and the options are to get them processed "mounted" or "unmounted".
So what do ...
8
votes
4answers
2k views
What is the difference between a telephoto lens and a zoom lens?
Looking at the product page for Nikon lenses, I notice a distinction between telephoto lens and zoom lens.
What is the difference between the two? Why would I want one over the other? I wiki'd ...
8
votes
3answers
366 views
What do you call the technique for removing uninteresting parts of photo by combining two images?
I'm looking for the name of a technique to cut out an "uninteresting" part of a photograph. The example I'm thinking of is of a guy on the left of a photograph and a tower on the right. The middle ...
8
votes
3answers
736 views
Image processing & editing: what is an “unmanipulated” image?
What is considered an "unmanipulated" image? As defined by photo.net:
Unmanipulated
a single uninterrupted exposure
cropping to taste
common adjustments to the entire image, e.g., ...
8
votes
2answers
540 views
What is DRI? And how does it differ from HDR?
I recently came across the term DRI meaning Dynamic Range Increase.
What exactly is it and how does it differ from HDR or High Dynamic Range (or is it the same thing just different terminology?
8
votes
3answers
647 views
How can a 24-70mm and a 10-22mm both be “wide angle” lenses?
I've been looking at a 10-22mm lens for my Canon T2i. I've also come across some other "wide angle" lenses, like the Sigma 24-70mm F2.8.
I don't understand how a wide angle lens can have such high ...
8
votes
1answer
1k views
What is the 'Maximum Reproduction Ratio' of a lens?
A review of a Sigma 19mm f2.8 lens contains the following line
It has a minimum focusing distance of 20cm /7.9in and a maximum reproduction ratio of 1:7.4.
So, as in the title, what is 'maximum ...
8
votes
1answer
262 views
8
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1answer
581 views
What is a focusing screen?
I've seen a couple other questions such as this one talk about focusing screens. What is a focusing screen? Where is it located?
8
votes
2answers
783 views
What is the difference between a Nikon “Micro” lens and a “Macro” lens?
When it comes to macro photography and Nikon, what is the difference between a Micro and a Macro [Nikkor] lens?
Is the answer as simple as to say that Nikon uses Micro in its nomenclature for its ...
8
votes
1answer
4k views
What does the magnification ratio number mean on a macro lens?
I'm looking for a macro lens. I have 28-105mm Nikkor which gives me "1:2 Magnification Ratio" (whatever that means). I found another lens, Tamron 90mm Macro, which has magnification ratio of 1:1.
...
8
votes
1answer
731 views
What does “viewfinder magnification” mean?
Viewfinders (both optical and electronic) typically come with two stats: magnification and coverage. The latter measuring how much of the actual exposed area (film or sensor) one sees. But what is ...
7
votes
4answers
378 views
What does IQ mean?
I see a lot of questions which mention IQ. The only meaning I know outside photography is "intelligence quotient" but obviously IQ has some other meaning here.
IQ is used for example in
"Lens with ...
7
votes
3answers
2k views
What do the AF-A, AF-C, and AF-S autofocus settings mean?
My camera has these settings for autofocus, and I don't know what they mean. I suspect "A" is "Auto", and "C" is "continuous", but I have no idea what "S" is.
7
votes
2answers
196 views
What is the Term for “Positional Photography”?
I’m wondering if there is a term for the kind of photos where the subject and the background together form an optical illusion that they are connected.
The classic example is a photo of a person ...
7
votes
2answers
797 views
What is “solid angle” and how does it relate to photography?
So, I was hanging out in the chat room, and hear mention of something called "Solid Angle". What is this, and how can it be important?
7
votes
3answers
331 views
What are ED elements?
I find that some lenses are indicated with the letters "ED", referring to some special type of lens element. What are ED elements, and what advantages do they bring?
Note that this question isn't ...
7
votes
2answers
157 views
What does it mean to excite aliases?
I recently came across the phrase 'excited aliases.' The phrase seems to be related to lens sharpness in some way. While a web search turns up the phrase a few times, I am unable to locate a decent ...
7
votes
3answers
4k views
What is the definition of portrait photography?
Can we talk about a portrait photograph if, let's say, a grandmother and her 3-year-old grandchild are in the picture? Or, must it be only one person in the photograph?
7
votes
2answers
487 views
What does “lifted blacks” mean?
What does "lifted blacks" mean? How does it affect your image? How do I do it in Lightroom?
6
votes
4answers
3k views
What does “long exposure” mean?
Very often, when people are talking about photography, they use the expression "long exposure". Here's a quote from a recent answer:
A tripod and long exposure were required for this shot.
Where ...
6
votes
4answers
341 views
What is a “small” aperture?
It happens a lot. People refer to the aperture being small (or big!). By default does this imply a small opening of the iris (literal aperture), or a small f-value (how the aperture is measured, for ...
6
votes
2answers
275 views
What is a kit lens?
I am new to photography and am looking to purchase my first DSLR or mirrorless camera. While reading Buying a digital SLR on Digital Photography Review the author keeps referring to the camera's kit ...
6
votes
3answers
502 views
Why is the Nikon 35mm f/2D AF considered a Wide-Angle lens?
What makes the Nikon 35mm f/2D AF Wide-Angle Lens lens be considered wide-angle as compared to the Nikon 35mm f/1.8G AF-S DX Lens which isn't advertised as wide-angle?
6
votes
3answers
177 views
Why is the amount of light a lens lets in called the 'lens speed'?
It seems very counter intuitive that the amount of light let in by a lens is referred to as the lens speed. This term confused me for a while because I couldn't logically see how a speed would be ...
6
votes
2answers
1k views
What does “Non-Mfg Zoom Lens” mean?
When I was surfing keh I found "Non-Mfg Zoom Lenses" and "Non-Mfg Fixed Focal Length Lenses"? What is the meaning of "Non-Mfg"?
