Questions tagged [lens-design]

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

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3
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1answer
367 views

Is there any rhyme or reason to the order of zoom and focus rings on lenses?

I have 3 zoom lenses, 2 Nikkors & a Tamron. AF-S NIKKOR 24-120mm f/4G ED VR AF-P DX NIKKOR 18-55mm f/3.5-5.6G VR [the kit lens] Tamron AF 70-300mm F/4-5.6 Di LD MACRO 1:2 All except the 24-...
2
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2answers
2k views

What is the highest (slowest) f-number in a produced lens?

Kind of what it says on the tin. There's plenty of questions on Photography.SE about the fastest lens out there, but let's go the other way - what's the highest (non-infinite) f-number on a production ...
0
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1answer
441 views

Is there a List of Canon EF Push/Pull zoom lenses?

Is there a list of all push/pull zooms that Canon has manufactured for the EF mount? I do know the following ones: EF 100-400mm f/4.5-5.6 L IS USM EF 28-300mm f/3.5-5.6 L IS USM EF 35-350mm f/3.5-5.6 ...
0
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3answers
2k views

Below which focal length are lenses considered to be wide angle?

Focal length is the only factor that decides whether a lens is described as being normal or wide angle. Below which focal length are lenses considered to be wide angle? Is this focal length the same ...
8
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3answers
2k views

What are groups and elements in lenses?

I hear people talking about groups and elements in lenses, but I am not sure what they mean. Could someone please explain?
11
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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 ...
8
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2answers
10k views

What does “Flat Field Focus” mean?

Looking at lenses, specifically sigma macro lenses, I noticed that it had a ""Flat Field" front lens element". What does this mean? And how is it different to the norm?
1
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1answer
242 views

Which lens coatings reduce internal reflection?

I've used the Pentax Super Takumar 50 f1.4 and love the lens but notices that in certain lightning situations I get a yellow blur in the shape of the a lens blade. Using my hand I can sometimes stop ...
2
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1answer
228 views

What would be the reason to not include VR/IS in a telephoto lens?

A recently released Nikkor AF-S 105mm f/1.4E ED doesn't have VR. It surprises me a lot. I understand that there is little interest in having VR/IS in fast 35mm or 50mm lenses, but here, we are talking ...
1
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1answer
355 views

Why do old-school catadioptric lenses have a fixed aperture?

Pretty much what it says on the tin. As far as I can tell, catadioptric telephoto lenses (operating on a similar principle to many telescopes; using mirrors rather than refraction) fell out of favour ...
2
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1answer
1k views

How does a focus ring bring a subject in or out of focus?

When you manually adjust your focus ring on the lens, what actually happens inside the lens? Is this changing simply the point at which the lens is focusing, so that anything at this distance away ...
3
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3answers
271 views

What's the purpose of these notches where the front of the lens case meets the side?

Here's a close-up of a Leica DC Vario Summilux. Note where the arrow points. This part is not movable—it's just a part of the lens's casing structure. The side surface is crossed by the front surface ...
3
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1answer
357 views

Limits of camera lens capabilities [closed]

I read that the canon 35mm f/2 IS is the lowest aperture lens that also has IS. Is this because a stabilizer at any lower F-stop is not possible, or just because it is just currently outside of our ...
60
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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 ...
0
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2answers
1k views

What are the advantages of Tamron SP 85mm f/1.8 over the Nikon 85mm f/1.8G?

What are the advantages of Tamron SP 85mm f/1.8 Di VC USD over the Nikon AF-S 85mm f/1.8G and why Nikon is about $200 cheaper than Tamron? They are both similar on the specs. except for elements/...
16
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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 ...
1
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2answers
1k views

Why do modern aspherical lenses have so much coma?

The Nikon Noct 58mm f/1.2 from 1997 is famous for having excellent coma control wide open. Sources generally credit this to its being one of the first lenses that used an aspherical element, which had ...
31
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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 ...
4
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1answer
526 views

Is there a difference in the image produced from a 50mm rangefinder or slr lens?

Particularly, I am interested in the performance on film for Canon leica thread mount (LTM) 50mm lenses versus their FL/FD SLR lenses, in aperture size 1.2/1.4/1.8. Their performance on full frame ...
4
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1answer
1k views

Why do zooms have small apertures even around 50mm?

A 50mm f/1.8 prime from one of the major manufacturers can easily be found for $200 or less, but zooms that include 50mm in their range always seem to have much smaller apertures even at 50mm until ...
15
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3answers
520 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 ...
1
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1answer
315 views

Could someone please give simple explanation of “Principal plane” & “Nodal plane”?

I have read "cardinal point" on Wikipedia for number of times but still I can't get it. My English is not perfect. could someone please explain it in simple English?
12
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2answers
567 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 ...
8
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4answers
2k views

Why is my large format lens so much smaller (in length) than my 35mm-format lens?

In general I have found that as the focal length of 35mm (or APS-C) lenses increases, the physical length of the lens increases as well. However, my large format lens is much thinner than other 35mm ...
4
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2answers
281 views

Why do superzoom designs keep expanding on the telephoto rather than wide-angle end?

Why do bridge/semipro/superzoom camera manufacturers keep increasing the telephoto end rather than the wide-angle end? For example, the Nikon P900 has a 35 mm-equivalent focal length of 24 to 2000 mm....
2
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1answer
101 views

What are the (dis)advantages of moving the entire lens for focusing vs. only parts of it?

There's a lens adapter available that adapts Leica lenses to Sony mirrorless cameras. It's called TECHART PRO. The key feature is that it allows to use autofocus with the manual lenses. This works by ...
0
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2answers
177 views

How much have tele-prime lenses improved over the years?

Context I'm considering the Nikon 500mm f4 AIS P lens as a way to get longer reach that's better than my current setup Nikon 300mm f4 AF with 1.4x TC to get birds and related wildlife. I've heard ...
1
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5answers
1k views

Why are filters only added to the front of the lens and not the back, too (or even the camera)?

I see how some filters have to be attached to the front of the lens, because they require some amount of interaction, like a graduated neutral density or circular polariser filter. But what about the ...
2
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2answers
232 views

How do I design a secondary lens for my fixed-lens camera to narrow its field of view?

My goal is to put a lens or an array of lenses in front of my actioncam to use its high resolution for recording of undistorted normal-eyed footage, to avoid having to buy two cameras for the ...
0
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1answer
345 views

Nikon Lens: A (Auto-focus) vs. A/M (Auto-focus/Manual)

I have two lenses which are 18-140 VR and 50 1.8G. On the 18-140 VR I got a button showing A and M while on the 50 1.8 I got a button showing A/M and M. I understand that A is for auto-focus and M is ...
9
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2answers
8k views

What are ED elements?

I find that some lenses are indicated with the letters "ED", referring to some special type of lens element. What are ED elements, and what advantages do they bring? Note that this question isn't ...
1
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2answers
2k views

Does Apple make its own lenses for iPhone cameras?

Does Apple make its own lenses for iPhone cameras? Or, does it at least design them? If not, does it source from a lens maker like Zeiss, or a camera maker like Canon?
4
votes
1answer
485 views

What is meant by 'centering quality'?

I'm reading lens reviews and I have encountered the term 'centering quality' a few times (e.g. http://www.photozone.de/sony_nex/720-sony50f18nex?start=1). What does this term mean? What are the ...
4
votes
4answers
726 views

Which focal length lens generally has the sharpest lens? 24, 35, 50 or 85?

Context I realize that the above four focal lengths lend to having a different perspective that make them all unique. It might be possible to use one as the other but that isn't always true with the ...
2
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2answers
130 views

Have lens/camera bodies been repairable by the consumer/user back in the day?

Context I've been skimming LensRental and related websites and I see most all modern lens are extremely complicated, intricate, expensive but they work, mostly. I see that with a7rII, there is an ...
30
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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 ...
1
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4answers
2k views

Why does crop factor apply with APS-C lenses, and why aren't these brighter than FF ones at same aperture?

I know that the image circle of FF-lenses is bigger than it needs to be on APS-C sensors, thus the FOV spears narrower. I've heard that APS-C lenses sit closer to the sensor, thus projecting a smaller ...
5
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4answers
962 views

How do manufacturers come up with focal lengths for lenses?

There are a lot of lenses for each camera, and I understand that each lens caters to a different use case, but my question is on how they arrive at the specific focal length numbers. For example, ...
2
votes
1answer
95 views

Does the type of lens adapter matter for manual focus?

Context I use a cheap adapter that has an Aperture Ring for the new Nikon G lens but also works for older lens as well. I use a Sony a6000 which has focus peaking and related. Question Assuming ...
1
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1answer
851 views

How do lenses focus? (and zoom?) [duplicate]

My understanding of focal length is that it is the distance from the lens to the sensor; in my observations: higher focal lengths make for longer lens. Then I started thinking about how a lens ...
0
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3answers
404 views

Why don't we have a single lens e.g. say a 18-200 f/1.2 lens for the SLR camera? [duplicate]

Right now we have multiple interchangeable lenses. So why don't we have a single lens, say a 18-200 f/1.2 lens? Are camera manufacturers deliberately avoiding that or it is that it is physically ...
22
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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 ...
3
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6answers
287 views

Should lenses of equal quality for smaller sensors be cheaper?

In theory do we expect lenses of identical specs and quality to be cheaper when designed for smaller sensors? My expectation is that the answer is yes, because all of the things that lenses struggle ...
5
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2answers
379 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!
4
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1answer
1k views

How is focus-breathing controlled in lens design?

Answers here note that minimizing focus-breathing is especially desirable for cine lenses, and that it is one of the common features of those higher-end lenses. How is it achieved? Also noteworthy ...
11
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3answers
786 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 ...
8
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4answers
5k 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 ...
0
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2answers
7k views

What kind of lens are used in mobile phones?

Usually what kind of lens are used in mobile phones. I mean of the types similar to convex, concave etc.. Are they fixed focal length usually? How do we get the focal length of camera from digital ...
1
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4answers
672 views

What lens designs are sharper than a pinhole lens but also allow for multi-month exposures?

I have a homemade pinhole camera (film) that I use for taking super long exposures (multiple months). And while the results are fun, I would like to improve the sharpness of the image. Is diffraction ...