Linked Questions

0 votes
2 answers

Does Zooming the lens Changes the Aperture? [duplicate]

Hello Photographic Lovers, Aperture is what the power of lens to open and close so as to control the light. So When we Zoom in the lens and see the far objects, then it changes the aperture. So ...
Rupesh Shinde's user avatar
46 votes
7 answers

How do constant aperture zoom lenses work?

Cheaper zoom lenses usually are faster at the wide end and slower at the long end (for example, the $150 Canon EF-S 18-55mm f/3.5-5.6). More expensive constant-aperture zoom lenses have the same ...
Ken's user avatar
  • 5,058
14 votes
2 answers

How do apertures which seem too large to physically fit work? [duplicate]

A 400mm f4.0 lens is supposed to have a maximum aperture diameter of 10cm. Looking at such a lens they don't seem big enough to fit that kind of aperture including all the mechanics for control inside ...
LuLeBe's user avatar
  • 143
3 votes
4 answers

Why does illuminance stay the same for a given f-stop even when focal length changes?

I'm trying to wrap my head around the math/physics of how illuminance on the film/sensor plane remains equal for a given f-number regardless of the focal length of the lens. Since a longer lens will ...
the_meter413's user avatar
1 vote
1 answer

I can't get the aperture to stay at f/4 and shutter speed at 1/1000 in manual mode on a sony a6000

When I set the aperture and shutter speed on my a6000 in manual mode the aperture always changes when I take the photo. I am using a sony 24-240mm lens f/3.5-6.3. It does the same in aperture mode. ...
Kerry Spong's user avatar
1 vote
1 answer

Why does aperture change when I zoom my lens even in manual mode? [duplicate]

I have my Nikon D7500 set to Manual Mode. I can change the shutter speed and it maintains the setting. When I change the aperture, the setting is not maintained and varies depending on the zoom of ...
lestat1978's user avatar
1 vote
2 answers

Relationship between f-number and amount of light being let into the lens system [duplicate]

Why does smaller f-number imply greater aperture diameter and consequently, greater amount of light entering the lens of a camera? As evidenced from my study across a number of resources, an absolute ...
LumosMaxima's user avatar
2 votes
3 answers

focal length to aperture relation while zooming - is my russian lens lying to me?

I have this old soviet/russian "Granit" 80-200mm lens, connected to my Canon 550d DSLR through M42 adapter. I also have "modern" kit 18-55mm lens. What I don't get is how aperture ...
kao3991's user avatar
  • 23
1 vote
1 answer

New but old Canon 20 - 35mm f3.5 - 4.5 will no longer stop down to f 3.5

Need some info/help please. I have a 6dmk2. I bought a brand New/Old Canon 20 - 35mm f3.5 - 4.5 Love this lens, inexpensive, light and exactly what for my needs. PROBLEM: it will no longer stop down ...
Fred Parczewski's user avatar
1 vote
2 answers

shooting in Av (Aperture Priority) Mode, but set Aperture deviates from what I set

I am shooting with a Canon 6D and an f4 24-105 L-series lens. I am pretty certain I set the aperture at f4. After inspecting ...
Walter's user avatar
  • 333