All Questions
Tagged with aperture lens-design
34
questions
1
vote
1
answer
213
views
what is the barriers of making fast lenses? [duplicate]
I know there are lenses like f/0.7
However as a beginner I'm wondering what's the barrier of making ultra fast lenses like f/0.01 ?
Also if lens manufacturers willing to make wide aperture lenses, ...
5
votes
2
answers
416
views
How does the Sony 135 F2.8 [T4.5] STF twin aperture lens design work?
I stumbled across the Sony 135 F2.8 [T4.5] STF other day.
I have read through the review but I can't for the life of me figure out what the twin-aperture setup is supposed to do!
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 ...
16
votes
4
answers
2k
views
Why aren't lenses designed with extra large apertures for autofocus beyond what's used for imaging?
Historically, designing large-aperture lenses has been difficult because correcting the optical aberrations that arise from large apertures requires complex designs and very large amounts of glass. ...
3
votes
2
answers
4k
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 ...
8
votes
1
answer
781
views
Why does my Zeiss Hasselblad Distagon lens have a 5 blade diaphragm?
As we are all aware, the more blades there are in a lens’s diaphragm, the rounder the resulting hole can be made, and in turn this gives a more natural looking bokeh.
So on receiving my recent ...
3
votes
2
answers
323
views
Is there a difference in sharpness between aperture stops?
Is there a notable difference in sharpness between aperture stops of a lens?
If so, where can I find that information for my Canon 550d Kit lenses?
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 ...
12
votes
4
answers
7k
views
Is overall light gathering of a lens only dependant on aperture?
My impression is that the aperture value of a lens determines its light gathering ability, but I'm not sure I understand how it works...
When considering light gathering in telescopes, it is ...
31
votes
3
answers
9k
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 ...
9
votes
4
answers
1k
views
Why do filter sizes vary for lenses of the same focal length?
I have a Nikkor 18-55 kit lens that has a 52mm filter, and recently I was looking that the 17-55 lens has a 77mm filter.
Is it because the latter is a better quality lens? I assume a bigger circle ...
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 ...
26
votes
5
answers
8k
views
What is special about lenses with f-number < 1?
Talking about fast lenses, Wikipedia mentions
Nikon TV-Nikkor 35mm f/0.9-Fastest Nikon lens ever made
Why don't, for example, f/0.5 lenses exist?
Is there some special construction that comes ...