Questions tagged [lens-design]

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

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6
votes
2answers
315 views

What are the production cost breakdowns for lenses?

I am very curious to know what the breakdown is for lens production costs. This information is hard to come by, and I am unable to find any reliable sources. Obviously, I can't just email Canon to ...
-2
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2answers
137 views

Is there a universal “safe” torque to use on the focus and zoom rings of all cinema lenses?

Is there a single torque amount that can be used at which all focus rings on all lenses can be moved that will allow a stepper motor to move the focus ring to adjust focus of all lenses without ...
10
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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 ...
1
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3answers
3k views

What does a megapixel designation on a lens actually mean?

I know that in a CMOS sensor the megapixels give you an idea of how many pixels are actually there to capture the light. In terms of a lens however, I cannot find any relation between the megapixels ...
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 ...
3
votes
4answers
489 views

Why are all the mirrorless full-frame 35mm f/1.4 lenses so big?

The Sony FE, Nikon Z and Canon R mounts all have flange distances shorter than the Leica M mount, yet Leica has the compact Summilux 35m f/1.4 design whereas the above's comparably speced lenses are ...
9
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4answers
724 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?
1
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4answers
275 views

Are all prime lenses designed so that the same DoF scale applies at any focusing distance? If so, why?

This question is about the mapping between the angular position of the focusing ring and the focusing distance. This mapping could be anything but the design of prime lenses seems to be such that a ...
4
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2answers
451 views

Where can I find a mechanical drawing of the Canon EF Mount?

This is my first question-post. First of all my final goal is to build a simple but functional objective. I was inspired by this video: DIY Camera Lens (I don't hope to make something so neat the ...
2
votes
3answers
483 views

Why not separate a tilt shift lens into two separate lenses?

When using a tilt shift lens I find myself using the two features of tilting and shifting for separate photos. If I want to control the depth of field such as in a portrait or macro shot I will tilt ...
4
votes
3answers
610 views

Why are phase detect lenses adapted onto contrast detect bodies so much slower?

The Sony A7 is able to adapt almost any type of auto-focus lens (Canon/Nikon/etc) and use autofocusing, but the auto-focusing is much slower than the same focal lengths native for the A7. Why would ...
8
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4answers
3k views

Why did manufacturers stop including DOF scales on lenses?

Seriously why? I hate it and I hate memorizing it or check my phone app for the depth of field of the current aperture. I find it so useful in old lenses. The DOF preview doesn't help that much ...
1
vote
3answers
270 views

What does the value of 'exit pupil' represent on a lens datasheet?

On this datasheet of the Kowa LM25HC lens I have access to, there is a number called exit pupil, which equals -57.9 mm. What does this number represent? This is not a question about what the exit ...
12
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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 ...
3
votes
4answers
465 views

What tiny lens to shorten the focus on a tiny camera?

I'm trying to set up a tiny camera for a tiny science experiment. The camera is an OmniVision OVM6211: It's pretty much a 3mm cube, containing the image sensor and all the lenses. It has a 90º FOV ...
3
votes
2answers
339 views

Is having a lens with vignetting a real world negative for portrait lenses?

After reading this answer for another post: I don't mind the vignetting as it actually improves the look of portraits however if you're doing astrophotography what's the point in a lens that's f/1....
6
votes
3answers
171 views

How does sensor size affect minimum front element size for a given f-stop and focal length?

Does the sensor size affect the needed size of the front element given a focal length and f-stop? My intuition tells me that a bigger image circle would require a bigger front element to maintain the ...
2
votes
1answer
1k views

What does “Di III” in a Tamron lens model name mean?

A Tamron "Di" (Digitally Integrated) lens is a lens optimized for digital cameras including those with 36x24mm 'full frame' sensors. A Tamron "Di II" (Digitally Integrated II) lens is a lens ...
7
votes
1answer
5k views

What are STF lenses?

What are STF (smooth transition focus) lenses? How much do they differ from other fast lenses? What artistic techniques are done with them? For example Sony has an a-mount 135mm F2.8 [T4.5] STF. What ...
5
votes
3answers
382 views

Why would lens be much longer than its focal length?

I accidentally saw Nikon 17-35mm f/2.8 lens and noted that it is rather large for its focal length. Here's the first review of this lens search offered - looks like it's 107 millimeters long. Given ...
0
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2answers
651 views

What does “Kit DFIN III” means in CANON EOS 750D?

I have search around for "Kit DFIN III", but didnot find any reference. What is the difference between CANON EOS 750D Kit DFIN III SLR 24.2 Megapixel with lens 18-55 mm f / 5.6, 7.7 cm Touchscreen, ...
5
votes
4answers
336 views

A thin camera and a thin lens with a large glass element

After seeing these 3D designs, I was wondering if a camera that is thin could possibly have such a large piece of glass in the lens (given the lens piece doesn't expand when powered on). As far as I ...
1
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2answers
2k views

I am getting a complete vignetting on my new canon 6D but only with the 18-270mm lens

I had been using the Tamron 18-270mm lens with my old canon rebel camera and it worked just fine; but now I have the canon 6D camera and when I use it with the same lens it comes out with a complete ...
4
votes
2answers
2k views

What influences the shape of a lens flare?

Most of the time the shape of the flare is close to a circle, but recently I saw a movie where the lens flare was elliptically shaped. The stills below, taken from the movie Die Hard, show the effect ...
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 ...
1
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2answers
253 views

Why do we not see super zoom lenses starting in wide angle?

While a common zoom lens might be 24-70mm and there are super zooms with ranges like 24-240mm I have yet to find a lens that starts in ultra wide angle and goes up to normal focal range. For example a ...
11
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5answers
110k 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 ...
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, ...
1
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2answers
309 views

Why is the kit zoom lens for Olympus so much smaller than that for Nikon?

I am currently considering buying either an Olympus OM-D EM-10 mark ii or a Nikon D3400. As a beginner I thought I would stick to the kit lenses for a while, and have seen that the specs of both kit ...
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 ...
2
votes
1answer
119 views

What focal length make compact lens design easiest?

What is the focal length where it is easiest to build compact lenses? I have seen, when looking for compact lenses for several systems, that they tend to be in the normal to moderate wide angle range....
2
votes
1answer
160 views

What type of lens element is this?

I pulled apart a microscope objective lens to clean it. I was using it to take photos and noticed they were coming out blurry/cloudy. Turns out the first two lens elements were "cemented" together. ...
6
votes
4answers
2k views

Why do lenses for larger sensors tend to have shallower angles?

Why do different (mirrorless) cameras + provided lenses all seem to end up with a 24 mm 35-mm-equivalent focal length? The fixed-lens Canon Powershot G5X has a 1" sensor (actually 8.80 mm high) with ...
1
vote
3answers
281 views

Is focal length internal or external? [duplicate]

I just wanted to check because I've encountered various distinctly different assertions. I was originally taught that focal length referred to the optimum distance from subject| ←→|lens, where ...
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?
4
votes
1answer
460 views

Helios 44 M - knurled knob with red W or M marking - purpose?

Edit: question modified for future googlers after discovering it's an M not a W. I recently bought one of the many varieties of tricked-up Helios you can find on eBay - fake anamorphic bokeh & ...
8
votes
4answers
1k views

Why there are so few lenses with small minimum focus distance?

My superzoom compact camera Canon Powershot SX60 HS has advertised minimum (closest) focus distance of 0 cm, and many other compacts have this in a couple cm range. But for my micro four thirds ...
2
votes
4answers
2k views

How can I increase the flange focal distance (back focal length) of DSLR lens?

I am working on a custom setup where I am using a DSLR lens (Canon 50mm f/1.8) to project an image onto an image sensor (image plane). For my application, I require a very large distance between the ...
1
vote
1answer
109 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 ...
1
vote
0answers
113 views

What causes swirling in bokeh? [duplicate]

The East German antique lens, Zeiss Biotar 75mm, is famous for producing a swirling, water-like bokeh as illustrated in the photo below: What optical materials and/or design cause this effect, which ...
11
votes
3answers
5k 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 ...
8
votes
2answers
893 views

Why did typical number of iris blades decrease from the 1950s to the 1970s and 80s?

I have in my collection a number of 1950s "silver" lenses, and they all have a high number of iris blades: 10, some even 12. On the other hand lenses from the end of manual focus era (late 1970s to ...
-1
votes
2answers
467 views

Projector Design and lenses

I am working on a project where I need to project a single image onto an object, Originally I was looking at the digital projector route but due to cost and complexity this has been ruled out. I found ...
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 ...
0
votes
6answers
314 views

Why is there no lens that is perfect for any situation? [duplicate]

My friend was talking about the 28mm, 70mm, and 200mm Nikon primes that he considers to be the "holy trinity" of lenses. Another friend asked why not just make a single 28-200mm zoom lens instead? I ...
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 ...
5
votes
2answers
255 views

Do lens optics/formulas, of the same lens model number, get updated as it is being produced?

Context I've noticed that the Nikon 105/2.5 has a long history of having many different versions from Sonnar v Gauss design to coatings and different blade counts for the aperture. Most of these ...
1
vote
2answers
218 views

What are the technical limitations that prevent lens manufacturers from producing 70-300mm f2.8?

70-300 f2.8 lenses don't seem to exist. What are the reasons behind that?
1
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3answers
3k views

Are there any 24-70 2.8 lens with no length change in zooming?

I'm planning to buy a 24-70 f/2.8 lens for my Canon 7D. I need a lens that won't increase its length while zooming (like the Canon 70-200mm series). Is there such a lens in any brand?
3
votes
3answers
1k views

Why do some telephoto zoom lenses physically extend while others don't?

The kit lens that came with my canon is an 18-135mm lens, but I hardly ever use it because I prefer my prime lens (I know a lot more about prime lenses than zoom lenses). One of my friends has a 24-...