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Optics is the science of light, and in photography often refers more specifically to to the properties and construction of lenses or the technical aspects of light sensors.

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126 views

Does a lens exist that is parfocal, has a linear zoom throw, and is affordable?

I'm working on a project to create, essentially, a servo-powered zoom lens, using a (D)SLR zoom, a zoom ring gear, and a stepper motor. After mounting the zoom ring gear, I'll attach a pinion gear to ...
2
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0answers
87 views

How to obtain 180° FOV and little optical errors?

I'm thinking about building an all-sky camera, i.e. an automated camera that points straight up to the zenith and that captures the entire sky down to the horizon. The idea is to capture celestial ...
3
votes
1answer
117 views

Do nano coatings actually make a difference?

Nikon famously has "nano coatings" on it's higher ended lens, and many photographers online swear that this visibly improves their images. However, it's not clear what the actual improvement is ...
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2answers
46 views

Nikon J1, takes pictures but they are all black, doesn't seem to “see” things, lens not the problem

I have a nikon J1, it has always worked well. Today I wanted to take a picture and the screen appeared black, like something was blocking the light completely or I was trying to take a picture of a ...
2
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2answers
103 views

How do universal clip-on iPhone lenses work?

So, recently I see a lot of clip-on Universal iPhone lenses like this (aliexpress link). I have a CCTV camera at home. It has a lens which looks like this from m12lenses.com. Can I clamp these iPhone ...
0
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2answers
67 views

Distortion Removal=Parallax Removal?

So, as the title suggests: does distortion removal caused by lenses means that the parallax is also removed from the pictures?
10
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2answers
141 views

What model does Lightroom use for lens correction?

I use Adobe Lightroom to remove the barrel distortion from GoPro images. Does anyone know if this software uses the Brown-Conrady model to achieve the lens correction? If not which model does it use? ...
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4answers
105 views

Does aperture effect the “depth” of faces in a portrait? Wide aperture make noses look shorter, wrinkles less pronounced?

Having a debate with myself that F/10 makes my portraits look better by making faces have less "depth." What I mean is I feel like wider apertures such as f/4 make my nose look longer and wrinkles ...
2
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4answers
135 views

How can I fire two cameras simultaneously with different settings but the exact same view?

I have an idea I want to play around with and I was hoping something already exists for it but google has turned up nothing. I want to use two cameras synchronized to fire at the exact same time and ...
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0answers
77 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?
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1answer
54 views

If a lens has a 4% Barrel Distortion, what does that mean for images?

I know what barrel distortion is, but how do I take a 4% rating and relate that to an image?
2
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3answers
118 views

Light Capture of Full-Frame Lens on Crop Body [duplicate]

Given two lenses: a full-frame lens and a crop lens, both at focal lengths necessary to capture the same frame on their respective systems and at the same f/stop. The physical size of the aperture ...
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3answers
166 views

What factors make a lens brighter? [duplicate]

Let's say I have two lenses of 50mm, one with maximum aperture f/1.8 and another with f/1.4. I understand that when using maximum aperture, for the latter lens more light will get to the film or ...
21
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2answers
2k views

Why is infrared light's focus point different from that of visible light?

When reading about infrared photography, it's often mentioned that IR's focus point is slightly different from visible light. Why is the focus point of infrared light point different from the focus ...
2
votes
2answers
162 views

What is the “airy disc”, in simple language?

In my understanding, this is relevant to photography because if you are shooting light of a certain wavelength (or primarily so, and such as: a blue scene), your aperture size can affect the sharpness ...
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1answer
79 views

What is the fastest T Stop available?

What is the widest T Stop possible We are having f stops of below even 0.7 NASA lenses What will be the T stop of such lenses with f stop below ONE?
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1answer
178 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 ...
1
vote
1answer
134 views

How do wavefronts/wavelets propogate in three dimensions, and why is this important for photography?

The photography book I have talks about waveforms, but it doesn't do a good job of explaining them. So, here's my understanding from the book and google searches (it could be unbelievably wrong.) In ...
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3answers
322 views

Does focal length change when I adjust the focus? [duplicate]

When I adjust the focus of my camera, in general, does this affect the focal length? I have heard that it does.
4
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1answer
161 views

Can a teleconverter make lenses designed for a “crop” sensor cover full frame?

I have a crop lens. Can I fill a full-frame sensor adding an appropriate tele converter (focal length extender? Specifically, I have a 1/2" C-mount lens and terrible vignetting on a full frame camera. ...
3
votes
1answer
121 views

Is it possible to make your own focus distance scale?

I'm using a Nikkor 18-105mm kit lens and it doesn't have a distance scale on its focus ring, is it possible to create your own distance scale by knowing the 0 and the infinity focusing points on the ...
3
votes
1answer
258 views

What could cause this visible artifact which seems to a be a glowing inverse of something outside of the frame overlayed on this photograph?

An acquaintance recently posted an image to FB from his recent trip to the JFK Historic Site asking for an explanation of a visible artifact he states was not visible to the naked eye but was visible ...
0
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1answer
45 views

Recommended F-Stop for older Canon 35mm F/2 [duplicate]

I have a few year old Canon 35mm F/2 lens (Here it is on Amazon). I've been shooting wide-open, but I realize that doesn't make for the sharpest photos. What would you say would get me the sharpest ...
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1answer
118 views

Is the Panasonic Leica Summilux the same quality as a non-Panasonic Leica summilux?

Is there an advantage to having a Leica Leica lens vs. a Panasonic Leica lens? To my ability to examine them, they look like the same on the inside. Would this be correct? The Leica Leicas are ...
0
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3answers
168 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 ...
11
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3answers
663 views

Why are superzoom lenses small but giant telephoto lenses huge?

This week I've read two news stories about two different camera lenses that can magnify things that are very far away. The first is the Nikon Coolpix P900, which is a point-and-shoot camera that ...
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4answers
158 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 ...
0
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2answers
321 views

Is there a formula to calculate the physical size of an image?

I'm trying to figure out the size of the physical space an image represents (IE, how many meters long/wide the real world in the image is), but I can't seem to find a formula that works with only the ...
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2answers
270 views

What causes barrel distortion?

Here are some scenarios for barrel distortion: When a target is too close to a camera, the photo will show barrel distortion. My flip cell phone's camera often produces barrel distortion. Some ...
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1answer
69 views

Why can a lens still function when subject to severe physical degradation?

Consider the following two modifications to a camera lens: Obstructing the about 75% of the lens's front element with an opaque filter as shown here: https://www.youtube.com/watch?v=43W159gPpdQ. ...
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3answers
474 views

Equivalent focal length and aperture of 150mm medium format lens on a 35mm camera

I'm mounting a Hasselblad Sonnar C 150 mm f4 on a 35mm sensor (43mm diagonal) camera. What is the calculation to get the new angle of view and equivalent focal length? Does this also affect the ...
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4answers
210 views

How can I compare different lenses in terms of quality?

I am currently looking to buy a new lens to replace with kit lens, having an extra reach, faster, better image quality and also better video quality. Without buying all the lenses I have shortlisted, ...
2
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3answers
238 views

Is a quartz lens necessary to prevent UV blocking on full spectrum enabled cameras?

I have read that in order to operate a "full spectrum" camera properly, so as to not block light in the ultraviolet portion of the spectrum, that one needs to acquire quartz lenses for one's camera. ...
0
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0answers
112 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 ...
5
votes
1answer
151 views

Background warping through foreground defocus

I came across this effect the other day, and have spent the better part of the last week trying to figure out exactly what is happening. When photographing two layers, with the foreground in front of ...
0
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2answers
131 views

Why does the same f-number mean same amount of light? [duplicate]

Intuition tells me that a bigger lens will collect more light with the same f-number than a small lens. But photographers tell me I am wrong. I cannot understand why. There are quite a few posts both ...
2
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2answers
201 views

What is the importance of the back focal length of a lens?

What is the effect and importance of the back focal length of a lens? For instance, if I look at these two lenses by Ricoh, they have the same focal length and aperture, but their back focal lengths ...
0
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1answer
134 views

Lenses round ..Photographs square shaped why? [duplicate]

If camera lenses are round then why is the photograph taken by the camera is square-shaped? photography
14
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4answers
4k views

How can a super tiny iPhone 6 Plus lens produce significant DOF?

According to Apple specs the iPhone 6 Plus thickness is 0.28 inch (7.1 mm) and the lens length is only a part of that. And according to an article I found, Depth of Field is a function of "aperture ...
3
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2answers
495 views

What do resolution figures mean in lens specifications?

I'm working in computer vision and choosing the right lens is obviously as critical as having a good sensor if you're going for quality inspection (for example). Sadly I have very little experience ...
3
votes
2answers
530 views

How to determine if a new lens is a subpar copy?

I have read some posts like the ones below about testing a lens to determine how well it performs optically. What I didn't see was anything on determining whether the lens performs as it should and is ...
2
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1answer
223 views

Why does the “fisheye effect” look stronger or weaker with different scenes taken with the same lens?

It seems that the fisheye effect can look different with the same lens. So I want to understand how it works. For example, I use a Dji Phantom vision 2 drone to take pictures, all of my pictures have ...
7
votes
1answer
334 views

How is Nikon's PF optics different from and similar to Canon's DO optics?

Nikon has just announced a new 300 mm lens featuring a new technology called "PF" or "Phase Fresnel." This has been compared to Canon's existing DO (Diffractive Optics) lenses such as the 400 mm f4 ...
3
votes
1answer
154 views

How can I calculate the effect of a supplementary close-up lens (a.k.a macro filter)?

If I have a +1, +2, +4, or +10 close-up lens which attaches to the front of my regular lens, how can I calculate its effect on close focusing distance, figure out how much magnification I can get from ...
1
vote
1answer
275 views

How do add on macro smartphone lenses allow you to take macro photos?

It may sound obvious, but how exactly does an add on macro lens allow you to take close up photos? Can someone give technical reasons? I'd like to know the physics behind add on macro lenses and how ...
2
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1answer
110 views

Why do I need an add-on lens to take smartphone macro photos?

Why do you need an external macro lens for a smartphone to take macro photos. Why can't the smartphone lens itself take macro photos?
1
vote
1answer
133 views

Where do rays of light from one point strike the film?

I am a programmer and I am doing a camera simulation, I am stuck in a matter of how to know where does every ray of light incident after traveling through the lens, every point of the object will give ...
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0answers
61 views

Where is the focal point of a camera lens? [duplicate]

If the distance between the center of the lens and the film is called Focal length, does that mean the focal point of the camera lens is located on the film?
4
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3answers
174 views

How to estimate the minimum magnification to capture features of a certain size?

What is the correct way to estimate the minimum magnification (maximum subject distance) at which features of a certain size are resolved? My thinking is that given a system capable of resolving a ...
3
votes
3answers
359 views

How can the focal length of a lens be many times greater than the lens's physical length?

I bought a Tamron 16-300. Question is: how can it have a focal length 0f 300 mm when it is only about 30 mm long? Doesn't the lens have to be 300 mm from the sensing element?