Linked Questions

2 votes
5 answers
3k views

Why do lower f-stop numbers mean larger apertures? [duplicate]

I thought this would have been asked before but it seems not. I don't understand how f-stops are numbered. From what I read, the lower the f-stop number, the larger the aperture. That is, f/2 is ...
CodyBugstein's user avatar
-1 votes
2 answers
2k views

What F means in lenses and how to find focus distance [duplicate]

I've found some camera sensors with very low resolution to use with electronics. Camera have 150x150px and can mount different lenses type: F2.7, F4.0, F6.0. I want to ask what F means and if I can ...
Singee's user avatar
  • 101
57 votes
9 answers
144k views

What is aperture, and how does it affect my photographs?

How does aperture affect my photographs? Why should I care about the aperture with which a photo was taken?
Dan McClain's user avatar
  • 2,087
34 votes
6 answers
48k views

What is one "stop"?

I always hear this term, e.g., I had to go down one stop Increasing X by Y raises Z by one stop I turned down the flash/the light two stops This lens/sensor/strobe/Photoshop tweak raises X by around ...
William C's user avatar
  • 1,524
32 votes
2 answers
27k 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 (e....
Imre's user avatar
  • 32k
26 votes
4 answers
6k 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?
Patrick Ritchie's user avatar
6 votes
4 answers
3k views

Why do camera manufacturers stick with the same awkward control layout imposed by film cameras? [closed]

You could replace the full set of controls with some much more intuitive and integrated click-wheel or touch-screen controls. But a good chunk of photography classes (my wife has taken a few courses) ...
WillC's user avatar
  • 197
14 votes
5 answers
37k views

What does the f-stop printed on the lens refer to?

I have read this,so I know what an f-stop is, but what does the number on printed the lens signify? Is this is the maximum f-stop, the ideal, or something else?
John's user avatar
  • 1,621
14 votes
6 answers
12k 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 ...
Billy ONeal's user avatar
  • 3,350
8 votes
6 answers
6k views

What reduces blur from camera movement more: large aperture or image stabilisation?

In the reviews of lenses with image stabilisation systems there are quite often written the quality of its performance represented by the number of f-stops (2-4 f-stops). As far as I understand, it ...
BartoNaz's user avatar
  • 183
10 votes
4 answers
7k views

What is the quantative relation between flash guide number and ISO?

I found that formula on the Internet: $$ \text{Guide Number} = \frac{\text{Shooting Distance}\times\text{Aperture}}{\text{ISO Sensitivity}} $$ Is it correct? If it is could someone please explain why ...
lanan's user avatar
  • 223
0 votes
2 answers
13k views

How is f-stop a measure of dynamic range?

As far as I have read f-stop is a measure of the aperture. This affects the amount of area in the foreground and background which is in focus. While having a look at the dynamic ranges of cameras I ...
jinkx's user avatar
  • 103
7 votes
3 answers
1k views

What is it called when aperture and exposure are previewed on the LCD screen before the shot is taken?

I have a Canon PowerShot SX120 IS. I would like to get a better comparable camera, but the singular feature I love the most about this camera is when in Manual mode, I scroll through shutter speed ...
Jason's user avatar
  • 71
6 votes
2 answers
1k views

What's the base f-stop when counting an ideal f-stop for lens?

I've read a lot around this site that an ideal quality of the lens is achieved when using f-stop roughly 2 stops slower than the fastest value of the lens. Firstly, I'm not exactly sure what "2 stops"...
Frantisek's user avatar
  • 2,683
1 vote
3 answers
2k views

How is the F stop number derived?

How are F Stop numbers derived? I have both a Canon 50d and a Panasonic DMC-LZ8k, a compact with full manual mode. When I set all settings but shutter speed identically between cameras, I end up with ...
Evan Pak's user avatar
  • 1,272
13 votes
2 answers
622 views

Does focus breathing make a lens slower when close focusing?

I've heard that focal length of some lenses will become noticeably longer when focusing to a close distance, an effect called "focus breathing". Since f-number is focal length divided by diameter of ...
Imre's user avatar
  • 32k
2 votes
1 answer
15k views

calculating aperture and shutter speed inversion [duplicate]

I'm taking a manual photography class, using my canon rebel t5. Any tips on how to calculate aperture and shutter speeds easily? (I know they have to be inverted). After I meter my photo (set at -0-)....
AngBrammer's user avatar
-1 votes
1 answer
3k views

What does the F number in a lens name mean? [duplicate]

Possible Duplicate: What does the f-stop printed on the lens refer to? I understand that for a DSLR you can modify the aperture(the F number) to allow more or less light to enter the camera. But ...
Ryan's user avatar
  • 151
-2 votes
1 answer
5k views

How does aperture affect exposure? [duplicate]

I've heard that aperture can change the exposure, but I would like to know if this is true, and how it does it. P.S. I hope this question isn't dumb like my last two.
J. Walker's user avatar
  • 1,201
0 votes
2 answers
500 views

True or False: A two full F/stop change to either side of the starting F/stop will either double or half the amount of light from the original F/stop

Explain. A two full F/stop change to either side of the starting F/stop will either double or half the amount of light from the original F/stop.
user avatar
0 votes
4 answers
704 views

How do you exercise depth of field in practice?

I'm really frustrated because many of my nicely framed photos are of poor technical quality, mainly because of the wrong depth of field or subject being out of focus. I always thought I know theory ...
dzieciou's user avatar
  • 533
5 votes
2 answers
343 views

How do dedicated light meters account for light transmittance?

Dedicated light meters seem to be well-regarded for their versatility and accuracy of metering. What puzzles me about them is how can they account for the different light transmittance of different ...
Imre's user avatar
  • 32k
0 votes
1 answer
455 views

Convert leica-m to c mount? Ideal lens for low light photography?

We are using a scientific camera which has c mount. We are dealing with very low light conditions so we are going to need to use a fast lens with large aperture. The Leica Noctilux-M 50mm f/0.95 seems ...
Adam's user avatar
  • 101
1 vote
4 answers
167 views

how many f stops should I allow for a given change in focal length - ISO and shutter speed remaining constant?

There are charts that show me what how many stops in shutter speed or ISO to allow when, for example, using an ND filter but given that a longer focal length reduces light available is there a chart ...
Gerald M's user avatar
1 vote
1 answer
292 views

Where can I find tables of common shutter speed and aperture values? [duplicate]

I'm working on image processing software (mind that I'm a programmer and when talking about photography, I'm "tabula almost rasa"). In this software, I'm using a RAW decoder that returns a data ...
mishan's user avatar
  • 252
2 votes
1 answer
273 views

How can I set up an off camera flash using the reading from the light meter?

I want to be able to blend ambient light with fill in flash, using off camera flash in manual mode. I don't understand how to translate the information from the light meter into settings to input into ...
Andy's user avatar
  • 53