Questions tagged [distortion]

a lens defect which causes straight lines to be curved or bowed

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Exactly why does length of an object seem to distort as we change prespective?

Suppose we take photos of a object from varying distances (all of which we can see the edge of an object), then one would see that in each photo the dimensions of the objects are distorted from each ...
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Scanner accuracy

There are cases where you want to remove the paper texture when you scan. An often mentioned technique is to do two scans, rotating the paper 180° between the two. Then in an image editor you load ...
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Is it possible to calculate field of view and aperture given focal length, k1 and k2?

I have some data coming from an API that looks like this: "camera_parameters": [0.785028, 0.032519, -0.053622] and the data structure that I would like to obtain should look something like ...
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1 vote
3 answers
536 views

What is the name of this distortion or artifact?

What is the name of this distortion or artifact? This is usually found in smartphone cameras, Nikon and Sony point-and-shoot cameras. This is not found in Canon point-and-shoot cameras, in Canon point-...
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11 votes
6 answers
5k views

Is it normal for RAW files to have lens distortion? How best to deal with it?

I noticed it for the first time when I took an image with the camera set for RAW+JPG mode. Because, I could see the 2 images side by side. The distortion is low enough that if I just looked at the RAW ...
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1 answer
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How do cameras distort the ratios of objects?

I measured this tiger's shoulder height to body length ratio (the yellow lines) to be at 56.3218391%. Is this figure accurate? If it is distorted, would the actual ratio be higher or lower?
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2 votes
3 answers
560 views

Photography tricks for widening objects or reducing narrowness?

I have a narrow face and feel this may negatively affect my streaming captures, especially with poor quality cameras, low lenses, poor sensors, etc. Are there any givens in getting a robust, wider-...
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3 answers
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How do cameras undistort photos?

I have an image data set consisting of pairs of JPG and RAW files. I was tasked with transforming JPG pixel coordinates (x, y) to RAW pixel coordinates (x_raw, y_raw). By comparing RAW and JPG images ...
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How does camera firmware obtain lens distortion correction parameters?

I use an Olympus MFT system and one thing I notice is that for most Zuiko MFT lenses there is significant barrel distortion as seen in the raw images. However, if you look at the jpg's, often they ...
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5 votes
4 answers
256 views

Why are flatbed-scanned images warped when compared to itself scanned & rotated 90 degrees?

This has been absolutely baffling me. I scanned an image both vertically and horizontally on the flatbed of my HP Color LaserJet Pro MFP M277dw using Windows Fax and Scan. I then used Gimp to rotate ...
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How to transform a picture with reference points on another picture?

I don't exactly know how to describe the problem. I have two maps that partly show the same extent of a place, but on the whole, the scale, rotation and protection might be different. I still want to ...
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Is crop and longer focal length equivalence not valid with rectilinear ultrawides?

The common assumption is that a crop will equal a longer focal length in perspective. However, rectilinear ultrawides will very visibly distort faces and spherical/cylindrical objects that are well ...
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Why is the person in the corner of this photo distorted? [closed]

Is it just me, or does the guy in the bottom left look really weird? What is causing the distortion? Anti-UK protesters outside the British embassy in Tehran on January 12, 2020. Atta Kenare/AFP/...
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3 answers
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How to find out what part of image is less lens-distorted?

I'm developing an application which uses a Canon DSLR to sequentially shoot an object from different views. Often the object is too big to fit in frame so I have to make more than one series of photos....
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Why aren't multi-aspect sensors commonplace on high-end cameras?

I found existing questions(1)(2)(3) about square sensors, but those would be excessive for the purpose described here. Introduction For low aspect ratio photos, e.g. 1:1, 6:5, 5:4, and 4:3, the 3:2 ...
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4 answers
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How do I get rid of distortion in pictures of distant objects photographed with a telephoto lens?

Here is a terrible example of my issue: Technical data: Canon EOS 70D + Canon EF 100–400 mm f/4–5.6 L IS, ISO 320, 400 mm, 1/500 sec, f/10. Is this issue caused by air turbulences over the water? ...
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What makes these white stars appear black?

This is partial screenshot from an episode of the TV (Netflix) show Daredevil (season 2, episode 7): Note how the normally white stars of the US flag are showing up as black - albeit quite out of ...
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24 votes
6 answers
14k views

What is the farthest a camera can see?

At what distance can a face no longer be identified using a camera? At what distance can a figure of a person no longer be captured?
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2 votes
3 answers
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What are some causes for an oblate image of the Moon during total solar eclipse?

I took a few pictures during the total solar eclipse of 2019. I noticed in my images that the "width" of the Moon is greater than the "height". I know that the Moon is oblate by about 0.0012 (...
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Is distortion still significant at the distance of a selfie stick?

I'm trying to get an accurate sense of what I look like with the following methods: 1) Phone Selfie, outstretched hand - horrible distortion 2) Phone Selfie, outstretched hand + Selfie Stick, total ...
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Does the DJI Phantom 4 advanced has the fisheye effect on taking videos from above?

I make research on transportation systems. I'm going to use a Dji Phantom 4 Advanced in order to take videos from above and then I will georeference multiple frames. Should I take into account the ''...
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2 votes
3 answers
826 views

In photo taken with a prime lens, what is the cause of the "zoomed" bokeh appearance?

This image was taken with a Vivitar 24/2 (Kiron) prime lens. The lens is sharp. The focal plane is reasonably flat, and there is barrel distortion. The bokeh balls have an oval shape in which the ...
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3 votes
2 answers
380 views

How to reduce landscape curvature?

My camera is a Nikon D610 which I used with a Sigma 12-24 wide angle lens. Can anyone recommend a software product to straighten up horizons with? I have attached an example where I have a curved lake ...
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Were there ways to deal with distortion in the darkroom ages? [duplicate]

When people used early ultrawide angle lenses that had visible distortion, did they simply accept the fact and print it too ... or were there mitigations for things like critical architecture ...
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8 votes
2 answers
6k views

Lens correction in darktable when my lens isn't known?

I took some raw (CR2) photos and want to edit them in darktable. The focal length is quite low and the distortion high. Usually I correct the distortion by using darktable's lens correction module ...
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4 answers
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Distance-creating "lens"?

On another recent question I noted that it's theoretically possible to take "short-range" pictures that have the perspective as if they were taken at a distance, by means of a system of mirrors: To ...
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6 votes
2 answers
3k views

How can I get headshot portraits with pleasing, natural perspective if I'm constrained to a short distance?

I know in a portrait photo we use distance between camera and the subject in such a way as to create a pleasing and hopefully natural-looking perspective. I think it's good on 1 ~ 1.5 meter to get a ...
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2 votes
1 answer
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Will a clip-on zoom lens correct the distortion of a wide-angled smartphone lens?

My friend wants to shoot a vlog style series and she doesn't currently own a DSLR, so she was going to shoot with her smartphone. I am aware of the natural distortion of features (noses, foreheads, ...
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4 votes
5 answers
7k views

How is focal length facial distortion different on an APS-C sensor compared to a full frame? [duplicate]

From my understanding (and research) focal length affects how a face will end up looking on a photograph. Here's an example of focal length distortion on a full-frame sensor: My question is: will a ...
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3 votes
2 answers
1k views

Distortion towards the edges/corners of the field of view in an image

I am taking a picture keeping the camera horizontally in landscape mode from a height of roughly 3-4 ft, acquiring the top-view of the scene. It was seen that the objects placed towards the centre of ...
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1 answer
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What is the cause of this speed-dependent distortion? [duplicate]

I took this shot using a Sony Xperia SP with OpenCamera, here are some details: Exposure: 1/800 ISO: 50 Aperture: f/2.4 focal length: 3.0 The photo was taken out of a train, at around 160km/h, the ...
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2 votes
1 answer
1k views

How to measure field-of-view of a camera with fisheye Lens? [duplicate]

For a camera with a rectilinear lens a simple measurement would consist of taking images from known distance of an object of known size. For example using a sheet of paper as an object set on a wall ...
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1 vote
1 answer
179 views

How to fix the phenomena where photos add 5 / 10 lbs or kgs to your face? [duplicate]

So, they say that photographs make you look a little heavier or fatter by 5 to 10 lbs or kgs. It does appear to be true as most of my photographs make my face look "fuller / rounder" than as it is ...
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10 votes
4 answers
1k views

What is the reason for a ripple effect on photos taken from a helicopter?

I took a trip on a helicopter and took many pictures with my iPhone 6 plus. One of the images was distorted with a sort of wavy ripple blur effect (other images did not exhibit the same distortion): ...
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2 votes
2 answers
276 views

Why do the spokes bend in this photo?

This is obviously a high frame rate photo of a very close cycling race finish. What gets me is not the closeness of the race (although the closest I've ever seen). Rather, it's how the spokes appear ...
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3 answers
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What is the origin of the hexagonal artifact of direct sunlight/spotlight photos?

Sometimes direct sunlight or spotlight appears hexagonal on photos/videos. What is the origin of this artifact? (source)
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0 answers
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How to determine the projection (Stereographic, equidistant etc.) of my fisheye lens?

I have a Fujinon FE185C057HA fisheye lens and I want to know its projection. Is there a software tool I can use to do this? I have the lens with me so I can take some pictures with it. I just need a ...
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8 votes
6 answers
2k views

How can I keep lines straight when taking photos of my artwork for printing reproduction?

How to take photos of my artwork for printing reproduction? I have a Canon EOS 700D and cannot seem to get them 'straight'; they always seem askew?
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1 answer
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Bendy distortion of straight lines in infinite mirror

I was in one of those mirror mazes where they have massive mirrors in a maze structure. However, these mirrors were lined with LED light strips, which were straight, because they were on the edge of ...
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2 votes
3 answers
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Is there a difference between increasing focal length vs. cropping? [duplicate]

Other than the difference in the quality of the image (increased focal length will produce more quality than the equivalent cropping of the image), is there a difference? For example, if I increase ...
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1 vote
1 answer
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How can I convert RAW files with proper distortion correction from the command-line?

I'm close to fully automating a process of stacking bursts of pictures into one image thanks to Hugin's command-line tools, however there's one part I can't automate yet, it's converting RAW into ...
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2 votes
4 answers
2k views

How do i take a photo of an object perfectly vertical like a top view?

I'm creating a set up that allows me to take photos of any object to capture its outlines for computer controlled cutouts. I'm no photography expert :D. I use a 60 x 60cm LED Light panel to ...
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-4 votes
2 answers
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Why does my forehead look big in pictures vs. reality? [closed]

My forehead in reality is small—normal. Everyone I ask tells me it is normal, not big. In photos it seems too big—not even normal. I am a man. My hairstyle doesn't hide the forehead, it is up. Why in ...
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3 votes
4 answers
2k views

Does distortion change with focus?

I'm interested in writing some software to eventually replace the current photogrammetry system I use at work. Distortion correction (among other calibrations) is an important factor in getting high ...
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2 votes
1 answer
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Physical Distances at the edge of a photo compared to the center

If I take a photo with a camera facing straight down onto a flat surface (no tilt), will 1 cm of the surface be represented by the same number of pixels at both the edge of the camera and the center ...
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2 votes
3 answers
675 views

Why do I get converging vertical lines even when using a normal perspective lens?

was shot with a Mamiya 645E with a 80mm lens. I'm surprised at the lack of parallelism of vertical elements. I was pointing up at a diagonal to avoid a fence; is that all there is to it?
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0 votes
2 answers
325 views

Can lens correction help distortion caused by getting too close for headshots?

I am using a Nikon 50mm 1.8D, but with an APS-C on a D7200, it gives me 75mm focal length. It's as sharp as a $700 85mm lens, and I paid $135 brand new for it. I am currently using this setup for ...
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17 votes
4 answers
6k views

What is the difference between perspective distortion and barrel or pincushion distortion?

I've heard of: perspective distortion barrel distortion pincushion distortion mustache distortion What are these different types of distortion, and how do they relate? What causes them, and can they ...
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5 answers
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Focal length on Full frames and cropped sensors

Yes, this subject again. But I have a slightly different question and I was unable to find an answer here or anywhere else. I understand a 50mm lens is a 50mm lens ALWAYS. I understand that "...
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1 vote
0 answers
511 views

Where can I find Adobe Lens Correction Profile (.lcp) files for RawTherapee?

The latest versions of RawTherapee can apply corrections from Adobe Lens Correction Profile (.lcp) files, but where can these be found? I've tried Adobe's Lens Profile Downloader, but it doesn't list ...
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