Tagged Questions
3
votes
2answers
108 views
What's the difference between real and effective aperture?
I understand that the simple idea that f-stop is focal length divided by aperture really applies to a simple single-glass lens, not the compound lens systems used to provide good image quality in ...
3
votes
1answer
242 views
How do I properly understand what f-stop is? [duplicate]
I don't quite understand why most lenses seem to have approximately the same diameter aperture regardless of focal length.
F-stop is, by definition, a ratio of focal length to diameter, so a 20mm ...
15
votes
2answers
395 views
Does a specific f number across all lenses denote same amount of light?
When we say a light source emits 1500 lumens of light, it does not really matter if the light source is incandescent, CFL, diode etc. Similarly, when I say f/1.8 can I assume that all lenses pass the ...
10
votes
2answers
471 views
How to stop a high F number from appearing blurry?
I have been out taking some evening photos (just after sunset) and I have noticed that in a number of instances the higher f numbers ( 14+ ) are appearing more blurred than the lower f numbers ( < ...
2
votes
2answers
215 views
Why are the area of aperture, focal length, and amount of light specified in these terms?
So I'm looking at the wikipedia article on Aperture, and I'm a bit confused. I understand aperture to be the diameter of the hole that lets light in. In the article, someone states that
The ...
7
votes
3answers
327 views
What is the limiting factor in lens construction when it comes to f-stop values?
This widely praised Nikon 105mm macro lens has a maximum f-stop value of 2.8. I've held it in my hands, it's a big lens. Meanwhile, this 50mm Nikon lens can go up to f/1.2, despite being 25% cheaper ...
12
votes
6answers
523 views
Why are only certain shutter speeds or apertures available?
For the exposure control function DSLRs there are specific shutter speeds available. For example there are 1/4, 1/100, 1/500. Why, even in high end DSLRs, is there no option to use a custom shutter ...
14
votes
5answers
6k views
What is an easy way to remember the full stop scale?
If you were teaching someone new to photography the full stop scales, is there a better way then flat out memorizing these values? Does anyone have an easy way that they remember the scale? Would it ...
5
votes
4answers
7k views
What shutter speed to use when shooting video?
My camera is Canon 60D and I will be using it to shoot a short parkour video, that means:
a lot of motion, moving subjects, moving camera
focal length usually from 24 mm to 75 mm, but there will ...
11
votes
5answers
910 views
How can aperture be f/11 on a lens with an aperture range designation of 3.5-5.5?
I made a series of outdoor shots with Nikon D5000, with the 18-55mm 1:3.5-5.6G VR kit lens.
On some shots, I see in the EXIF info f/11, and in another shot, f/9.
How can that be, that the f-number ...
18
votes
4answers
2k views
Why do compact digital cameras not have the aperture range of DSLRs?
Why is it that on compact digital cameras the aperture never seems to go any smaller than about F8 ? Even on high-end compacts such as the Cannon G10 or Panasonic LX5. Is there some practical or ...
0
votes
2answers
335 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.
5
votes
7answers
944 views
Is there any way to stop down the aperture of a Canon PowerShot SD780 IS?
I have a Canon PowerShot SD780 IS point-and-shoot which I use as my carry-around-everywhere camera when I don't want to drag my SLR about. This tiny little camera works great and takes fabulous ...
17
votes
4answers
2k views
How do you find out the “sweet spot” of a lens?
I've tried googling this, but have never found a satisfactory answer.
I've heard the term "sweet spot" thrown around by some photographers to mean the f-stop of a lens which results in the highest ...
38
votes
2answers
12k views
What does f-stop mean?
What does f-stop mean? Is it the same thing when people say "2 stops" for example?
