Questions tagged [lens-design]

Of and relating to the specifics of lens construction and manufacture.

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62 votes
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Is there development in the world of lenses?

Now, I'm not an expert, so if this post makes you laugh, you're welcome. Still, as far as I know there are basically two components that determine the potential quality of a camera's photos: Sensor ...
Bart van Heukelom's user avatar
51 votes
3 answers
10k views

What image-quality characteristics make a lens good or bad?

When reading lens reviews on the Internet, I often find subjective statements about the image quality that a lens produces, such as "good contrast" or "sharp". The problem is that I don't think I am ...
Caetano Sauer's user avatar
46 votes
7 answers
13k 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
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44 votes
4 answers
43k views

What does the number of elements and groups in a lens mean?

All lens specifications include a statement of how many elements the lens contains, and in how many groups, for example: Nikon AF-S VR Zoom-NIKKOR 70-300 mm 1:4,5-5,6G: 17 elements in 12 groups (two ...
Kiril Kirov's user avatar
  • 1,335
38 votes
3 answers
5k views

When you zoom in with a lens on an SLR why does the lens go in then out?

I guess this is more a question of optics than photography but I just got an SLR with a basic 18-55 lens. I noticed that when going from 18 to 55 or 55 to 18 the lens physically comes back in and ...
zgirod's user avatar
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33 votes
8 answers
4k views

What is the difference between in-lens image stabilizing and sensor-based image stabilizing?

And which one is more effective?
spinodal's user avatar
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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
  • 4,645
31 votes
2 answers
7k views

What is a pancake lens?

I've read about a "pancake lens" but don't really understand what that means. What the pros and cons of having a pancake vs. another type of lens? I'm thinking of getting a Panasonic Lumix DMC-GF1 ...
David Collie's user avatar
28 votes
3 answers
3k views

Is it physically possible to build a long zoom (17-300 mm for example) at an aperture value of around 1.4 or 1.2?

I'm curious if the physics allow a company to build such a lens of course with good IQ, minimal color aberration, maximum sharpness, and little to none lens vignetting or edge softness
dassouki's user avatar
  • 1,299
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 ...
Lazer's user avatar
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24 votes
4 answers
22k 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
23 votes
2 answers
4k views

Are there any secrets in lens design?

Lens manufacturers usually share diagrams like this for their products. However, they conspicuously omit specifications that would allow one to completely analyze the optical system, like the power ...
feetwet's user avatar
  • 3,593
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
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21 votes
2 answers
12k views

What is the benefit of an internal focus lens?

The "IF" in Pentax DA★ 200mm f/2.8 ED (IF) SDM stands for "Internal Focus". I know what this means: the lens doesn't change in size as I focus. (And it's true; it doesn't.) What's the point of this, ...
mattdm's user avatar
  • 143k
21 votes
0 answers
606 views

Is Image Stabilization better in the lens or the body? [duplicate]

Possible Duplicate: What is the difference between in-lens image stabilizing and in-sensor image stabilizing? Some DSLR manufacturers have image stabilization (IS) in the body of their cameras, ...
Hamish Downer's user avatar
19 votes
11 answers
4k views

Are all kit lenses poor? (And if so, why?)

Kerri Shotts says (emphasis mine): Also, if you already have great glass, there is little reason to get more (unless you need it for a certain reason). E.g., if you have a 70-200 f/4, don't rush ...
Billy ONeal's user avatar
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19 votes
5 answers
10k views

What's the difference between the Canon and Nikon lenses mounts?

I was wondering what, if any, are the technical differences between the two mounting systems. Does one auto focus faster? Can one hold more weight? Things along those lines that make them different.
Elfudge's user avatar
  • 195
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
18 votes
2 answers
3k views

In what way does the lens mount limit the maximum possible aperture of a lens?

In many answers to questions about different aspects of really large aperture lenses it's pointed out that the lens mount sets a hard limit on the maximum possible aperture of the lenses to that ...
Hugo's user avatar
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17 votes
2 answers
8k views

Retrofocus lens? What's that?

I saw that in Why do some people prefer 50mm to 35mm prime lenses, even for a crop sensor? , in @MattGrum's answer: ... The 50mm is a simpler design compared to the retrofocus 35mm ... What's ...
Kiril Kirov's user avatar
  • 1,335
17 votes
4 answers
75k views

How does a spherical lens differ from an aspherical lens?

Many lenses (like the Pentax DA 15mm f/4 Limited, or the Nikon AF-S 35mm f/1.4G) are described as having "aspherical lens elements". Does this mean that regular lenses are spherical lenses? What's the ...
user avatar
17 votes
3 answers
6k views

Why are 50mm Lenses Cheaper?

There is no doubt that 50mm lenses, if all other variables are held equal, will beat any other lens when it comes to value for price (lower f/number). I want to know why. Possible theories I have ...
Daniel Smith's user avatar
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. ...
Chinmay Kanchi's user avatar
15 votes
5 answers
4k views

How can a lens like a 18-55mm have more than one focal length?

How can a lens have a range of focal lengths? Shouldn't it be a single number? Isn't focal length supposed to be fixed for a lens of a particular shape and geometry? What am I missing? How many ...
Lazer's user avatar
  • 4,029
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
15 votes
1 answer
2k views

How does a macro lens focus so close?

How does a macro lens focus so closely and how is the system different to that of a non-macro lens?
damned truths's user avatar
15 votes
6 answers
8k views

What is the Leica look?

What is the Leica look that fans of the company claim is unique to them? What concrete differences are there that are most obvious to a layman?
Jonathan Winters's user avatar
15 votes
3 answers
584 views

What lens design limits derive from the width of the lens mount?

I'm familiar with the lens design limitations imposed by the flange-to-focal-plane distance. But what constraints are caused by the width of the lens mount (that is, the size of the hole in the ...
James Youngman's user avatar
14 votes
5 answers
5k views

Why isn't my camera body white?

If I leave it in the sun for a few minutes, even in winter, it gets pretty hot. In summer, I'd have to shade it as it has been too hot to touch. This makes remote-triggered wildlife photography and ...
Knob Scratcher's user avatar
14 votes
6 answers
11k views

Do lenses lose sharpness when they age?

I was reading this answer where it mentions, "..it's a lens that can lose sharpness as it ages.." and was wondering if this is true and if yes, true for all lenses. Reasons as to why this happens and ...
Regmi's user avatar
  • 1,640
14 votes
5 answers
650 views

Why don't today's lenses come with a polarizer by default?

As I am now looking for a decent polarizer for my 18-105mm and 50mm (Nikon D80) I realized how important they are for outdoor photography. So why aren't they directly hard-mounted on every modern lens?...
Der Papst's user avatar
  • 143
14 votes
4 answers
3k views

How would a curved sensor change camera and lens design?

I've read that lenses are designed to project an image onto a flat surface and that as image sensors grow larger, lenses will grow correspondingly larger and by some additional factor. Flat imaging ...
Knob Scratcher's user avatar
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
  • 143
14 votes
3 answers
9k views

How does an apodization filter improve bokeh?

The new Fujifilm Fujinon XF56mmF1.2 R APD has an "apodization" filter, which Fujifilm says "smoothes the outline of the subject to create a more natural bokeh effect". The Wikipedia article on ...
mattdm's user avatar
  • 143k
13 votes
4 answers
5k views

How do manufacturers get to high (83x) zoom levels on hybrid cameras?

Obviously the biggest hybrid zoom on the market (Nikon Coolpix P900 I think) does not range from actual 24 mm to 2 meters in physical length, but what kind of optical systems do manufacturers use to ...
Chimel31's user avatar
  • 131
13 votes
6 answers
1k views

What lens characteristics contribute to attractive lens flare?

Some lenses give really harsh and unwanted flares. Some gives beautiful flares that add depth to an image. What's the science behind this?
jp89's user avatar
  • 2,561
13 votes
2 answers
621 views

Does focus breathing make a lens slower when close focusing?

I've heard that focal length of some lenses will become noticeably longer when focusing to a close distance, an effect called "focus breathing". Since f-number is focal length divided by diameter of ...
Imre's user avatar
  • 32k
12 votes
6 answers
7k 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
12 votes
4 answers
4k views

How close can a lens focus?

From my understanding, if you want to do some macro photography it is better to have a lens that can focus when it is really close to the subject. Sometimes people buy extension tubes to help them ...
Tom's user avatar
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12 votes
3 answers
5k views

Does a large mount diameter really allow design advantages for large aperture lenses?

To keep the conversation simple, please focus only on native lens design for the mount. So with the recent Nikon mirrorless announcement, Nikon has been touting the bigger mount. I am no expert in ...
georgekhaidas's user avatar
12 votes
1 answer
551 views

Can anyone identify this lens?

I read once, in a book, about a lens that was an "inverse fisheye". Basically a hemispherical mirror mounted at one end of a glass tube. I can't remember what it was called, nor can I find any ...
Tom O'Connor's user avatar
12 votes
2 answers
2k views

What are the constructional differences between a macro and a regular lens?

I understand that to reduce minimum focusing distances, macro lens design must focus on maintaining certain distances between the lens and the sensor. However, is the placement of the lens and its ...
user1266515's user avatar
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 ...
asc99c's user avatar
  • 223
11 votes
3 answers
1k views

What effect does the lens hood have on pictures and how does its shape impact that? [duplicate]

I have a Sigma 50mm lens f1.4 and it has a lens hood that has a sine wave shape going around the perimeter of the lens. I imagine this particular shape is useful for getting a particular effect and ...
WilliamKF's user avatar
  • 1,715
11 votes
4 answers
2k views

Why do prime lenses have multiple lens elements?

If I look up the specifications of my 50 mm lens, it says that it has 8 lens elements, in 7 groups. Why is this, why not just a single lens element with a 50 mm focal distance?
Orbit's user avatar
  • 1,530
11 votes
3 answers
6k views

Are all DSLR lenses made of glass?

This question is about lenses to "big" DSLRs, not system or compact cameras with interchangeable lens. Are all lenses made of glass in DSLR? And if not, is there a notable difference between: kit ...
Tschareck's user avatar
  • 787
11 votes
3 answers
897 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
11 votes
2 answers
3k views

Why aren't more lenses white?

So high end Canon lenses are white. This is to reduce heat, correct? If so why is this something that only appears in really high end Canon lenses. I wouldn't think that painting a lens white ...
Taylor Huston's user avatar
11 votes
3 answers
2k views

What is a pump zoom lens?

While browsing for cheap second hand lenses I found the Cosina 70-210mm f4.5-5.6. The seller notes that it's a pump zoom. Googling the term does yield some results, ...
Saaru Lindestøkke's user avatar
11 votes
4 answers
5k views

Lens "family" names - what do they mean and should I care?

Some lens manufacturers have special names for their lens designs/families. Just to name a few: Leica - Summar/Summarit/Summilux, Elmar/Elmarit, Noctilux Carl Zeiss - Planar, Tessar, Sonnar, Distagon,...
Karel's user avatar
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