Questions tagged [lens-design]

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

Filter by
Sorted by
Tagged with
60
votes
5answers
2k views

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 ...
49
votes
3answers
8k 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 ...
46
votes
7answers
10k 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 ...
41
votes
4answers
37k 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 ...
37
votes
3answers
4k 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 ...
31
votes
8answers
4k views

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

And which one is more effective?
31
votes
2answers
6k 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 ...
30
votes
3answers
7k 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 ...
27
votes
4answers
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
25
votes
5answers
7k 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 ...
23
votes
4answers
21k 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 ...
22
votes
2answers
3k 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 ...
21
votes
0answers
601 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, ...
20
votes
2answers
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?
19
votes
5answers
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.
19
votes
2answers
9k 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, ...
17
votes
8answers
8k 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 ...
17
votes
2answers
2k 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 ...
16
votes
9answers
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 ...
16
votes
4answers
72k 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 ...
16
votes
4answers
1k 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. ...
15
votes
2answers
6k 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 ...
15
votes
3answers
513 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 ...
14
votes
5answers
607 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?...
14
votes
3answers
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 ...
14
votes
3answers
4k 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 ...
14
votes
1answer
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?
14
votes
6answers
4k 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?
13
votes
6answers
8k 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 ...
13
votes
4answers
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 ...
13
votes
3answers
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 ...
13
votes
2answers
920 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 ...
12
votes
4answers
4k 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 ...
12
votes
4answers
3k 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 ...
12
votes
4answers
3k 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 ...
12
votes
5answers
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?
12
votes
1answer
502 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 ...
12
votes
2answers
562 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 ...
12
votes
4answers
6k 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 ...
11
votes
5answers
2k views

Is a two-prime lens possible? E.g. 35mm and 50mm

I really like prime lenses for their simplicity, zooming with my feet. I prefer it to a zoom lens because of this simplicity. But I do carry both a 35mm and 50mm because I do two different things ...
11
votes
3answers
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 ...
11
votes
3answers
4k 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
3answers
781 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 ...
11
votes
4answers
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,...
11
votes
2answers
1k 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 ...
10
votes
3answers
5k 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 ...
10
votes
5answers
108k views

What is the difference between Nikkor D type and G type lenses?

I recently bought a Nikon D5100. And along with this camera, I got the AF-S DX NIKKOR 18-55mm f/3.5-5.6G VR lens as kit. It's "G" type lens, right? One of my friend suggested to buy a 50mm f/1.8D ...
10
votes
3answers
407 views

How can I know if two lenses have interchangeable elements?

This simple question might have a not so simple answer, and I want to ask it about a single lense, but assume that would be off topic, because I'd basically be asking 'should I buy this to repair my ...
10
votes
1answer
1k views

How do I design a conceptual lens schematic?

I would like to attempt to create a schematic for a simple or small compound lens, but the process seems very daunting. I have thoroughly read 'Science for the Curious Photographer: An Introduction to ...
10
votes
3answers
158 views

What useful information can one gain from a lens element diagram?

On many photo gear review sites, cutaway diagrams of lenses are featured which show the layout of the elements in each lens. Here's the style of diagram I'm talking about, taken from Nikon's website ...