All Questions
16
questions
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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?
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"...
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 ...
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 ...
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 ...
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 ...