Questions tagged [distortion]
a lens defect which causes straight lines to be curved or bowed
130
questions
1
vote
1
answer
65
views
Close up photos obscure the outside edges of vertical objects in the scene. How can I fix this? [duplicate]
I'm shooting laboratory photos of small (60mm) sized objects. It is essential for me to use the entire camera sensor to achieve adequate spatial resolution, so I am putting the camera as close as ...
0
votes
0
answers
105
views
What are these bands called? [duplicate]
I wanted to know what this sort of distortion / artefact is called?
0
votes
1
answer
57
views
Imagemagick distort values for GoPro Hero3+ Black lens correction
I am trying to use ImageMagick to correct an image from the lens of a GoPro Hero3+ Black camera. I see here that ImageMagick has both instructions and code parameters here for a GoPro Hero 3 but ...
1
vote
0
answers
42
views
Field of view calculation by camera parameters + radial distortion [duplicate]
I am a software developer with focus on computer graphics but being poor in the topic of camera hardware.
I try to implement a physical camera for simulation purposes and having some parameters to ...
0
votes
4
answers
385
views
Which is the cause of Barrel and Pincushion distortion?
Barrel and Pincushion distortion are due to the fact that the magnification of the lens changes as you get further off axis.
Let's consider a single thin lens with an aperture stop. These two pictures ...
0
votes
3
answers
81
views
What is it called when a short vs tall object gets distorted when it moved towards the edge of the image?
If I have a camera pointing "straight" down towards a table and put a pack of gum on the table, it will look the same no matter where I move the pack of gum in the image.
If I put a bottle ...
0
votes
2
answers
126
views
Weird colour artifacts with Sony a7 III. What's the cause and how can I fix it?
I took some photos with my a7 iii and a Tamron 28-75 lens yesterday and one of the subjects was wearing a shirt made with pink and white fibers. I'm seeing some weird artifacts in the colors that I've ...
3
votes
2
answers
155
views
Does "Field of view" include radial lens distortion?
When manufacturers state the "field of view" of a camera, is that including lens distortion or not? I work a lot with CCTV and dashcam footage which always has barrel distortion. For a given ...
1
vote
1
answer
79
views
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 ...
1
vote
1
answer
133
views
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 ...
0
votes
0
answers
76
views
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 ...
1
vote
3
answers
587
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-...
12
votes
6
answers
6k
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 ...
0
votes
1
answer
183
views
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?
2
votes
3
answers
571
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-...
6
votes
3
answers
3k
views
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 ...
8
votes
2
answers
1k
views
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 ...
6
votes
4
answers
382
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 ...
1
vote
3
answers
1k
views
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 ...
-1
votes
2
answers
102
views
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 ...
0
votes
1
answer
401
views
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/...
0
votes
3
answers
340
views
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....
2
votes
2
answers
374
views
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 ...
5
votes
4
answers
3k
views
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? ...
0
votes
2
answers
208
views
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 ...
25
votes
6
answers
15k
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?
2
votes
3
answers
123
views
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 (...
0
votes
2
answers
303
views
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 ...
0
votes
1
answer
162
views
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 ''...
3
votes
3
answers
889
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 ...
3
votes
2
answers
388
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 ...
2
votes
0
answers
57
views
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 ...
8
votes
2
answers
8k
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 ...
5
votes
4
answers
325
views
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 ...
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 ...
2
votes
1
answer
393
views
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, ...
4
votes
5
answers
8k
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 ...
3
votes
2
answers
2k
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 ...
0
votes
1
answer
74
views
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 ...
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 ...
1
vote
1
answer
254
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 ...
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):
...
2
votes
2
answers
333
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 ...
0
votes
3
answers
3k
views
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)
2
votes
1
answer
288
views
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 ...
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?
0
votes
1
answer
339
views
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 ...
2
votes
3
answers
2k
views
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 ...
1
vote
1
answer
858
views
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 ...
2
votes
4
answers
3k
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 ...