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2 votes
3 answers
440 views

Is diffraction limited aperture independent of lens?

I have always understood diffraction limited aperture as a property of the camera and its sensor, not of the lens. The camera has a certain sensor size and a certain megapixel count, which together ...
juhist's user avatar
  • 6,835
0 votes
3 answers
173 views

Does a camera have to have a contiguous housing?

The lens group in this picture would have its own protective lens tubes like the one on a camera but one for each lens group. What would be an issue having a gap between the lens group and stray light ...
Muze's user avatar
  • 1
14 votes
2 answers
1k views

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
  • 243
1 vote
1 answer
198 views

Why is Auto on aperture rings near the smallest aperture?

This is something that has puzzled me for a while and it always seems counter-intuitive. When a lens has an aperture ring with an auto position (A), it is always (at least on 3 systems that I have ...
Itai's user avatar
  • 103k
15 votes
3 answers
2k views

How do zoom lenses restrict their widest aperture at the telephoto end?

Does the aperture ring lock the apertures beyond, say 5.6 at length lens's telephoto end? Does the lens introduce an obstacle to the aperture ring so the lens can't be opened anymore beyond the ...
user152435's user avatar
  • 1,515
2 votes
1 answer
969 views

Why don't all zoom lenses have variable f-numbers? [duplicate]

As I understand it, the f-number is a ratio between the focal length and the aperture diameter. A zoom lens can change focal length, but shouldn't the maximum aperture be a fixed size? If so, that ...
Brendan Abel's user avatar
12 votes
6 answers
8k views

What are the theoretical minimum and maximum apertures?

Is there such a thing as a maximum aperture that a lens can be open to? What about a minimum aperture that it can be closed to? Do these concepts even make any sense? Is there a lens with the ...
Sachin Kainth's user avatar
11 votes
3 answers
900 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 ...
Drew's user avatar
  • 2,465
31 votes
3 answers
8k views

Why do wide angle prime lenses have relatively small apertures?

I've noticed that many of the wide angle prime lenses (at least for Canon) have somewhat smaller apertures than their normal or telephoto counterparts. E.g. the regular Canon 24mm prime is f/2.8 while ...
ab.aditya's user avatar
  • 4,655
22 votes
2 answers
5k views

Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?

Why does a camera's maximum (allowed) aperture get smaller when you increase its zoom?
William C's user avatar
  • 641
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
9 votes
3 answers
6k views

What are the advantages of a lens having a fixed maximum aperture?

What are the advantages of a lens having a Fixed Maximum Aperture? Previous answers have indicated that "pros tend to want constant apertures in zoom lenses". While in general lenses with a fixed ...
fmark's user avatar
  • 2,641
24 votes
4 answers
23k views

Why is the aperture ring removed from new Nikon lenses?

Maybe I'm wrong, but I notice that Nikon's newer lenses don't have an aperture ring. For example, an older AF 35 mm f/2D is now replaced by AF-S DX 35 mm f/1.8G, or AF 50 mm f/1.8D is replaced by a ...
Arseni Mourzenko's user avatar
46 votes
7 answers
14k views

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
  • 5,088
18 votes
8 answers
9k views

Will using a lens at max aperture ("wide open") result in poor images?

I’m looking to add a second lens to my kit lens I got with my Nikon D7000. I have read several reviews on both the 35 and 50 mm lenses made by Nikon in particular that said using either lens at the ...
kacalapy's user avatar
  • 7,908

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