16
votes
Accepted
As a blind person, how can I better understand how wide or narrow a field of view is?
When a field of view is described as 120°, that refers to the total angle. So, 60° to the left of center and 60° to the right.
Most camera lenses show a very restricted subset of the field of view ...
- 143k
14
votes
Accepted
Does aperture affect field of view?
Answer with an image : the guy on the left represents your (vertical) field of view and its image on the sensor is inverted on the right (in other terms, the guy fills your entire image).
As you can ...
- 4,163
13
votes
Shouldn't the diameter of the moon with a 600mm lens be double what it is with a 300mm lens?
Assuming both lenses are being used on the same size sensor, the area in the frame with a 600mm lens should be one quarter the area in the frame with a 300mm lens. The linear dimensions should change ...
- 175k
13
votes
What focal length do I need to get the same field of view as an iPhone SE?
According to this the iPhone SE has an 29mm-equivalent lens, so on a Fuji with a 23.6x15.6 sensor (Fuji XT-3)(crop factor 1.53) you need a 29/1.53=19mm lens for the same field of view.
- 20.6k
12
votes
Accepted
does focal length change across an image?
There's really no such thing as a 'theoretically perfect' rectilinear lens with a perfectly flat field of focus and no geometric distortion. Even a lens that perfectly matches its blueprint would not ...
- 175k
11
votes
Accepted
Is it exactly true that doubling the focal length makes everything look twice as big?
Your intuition is right. To validate it, we can dig into basic high-school geometry.
Although a camera lens is actually a complex lens made from many elements, conceptually and mathematically for ...
- 143k
8
votes
Is a 30mm lens a good general purpose lens on an APS-C sensor?
A “normal” lens is one that is not telephoto and not wide-angle. This works out be a lens with a focal length about equal to the diagonal measure of the format frame. The Advanced Photo System (APS) ...
- 38.7k
7
votes
What is the focal length on your typical cell phone camera?
Focal length does not change with sensor sizes - what actually changes is the field of view:
FOV [°] = 2 * arctan ( d [mm] / (2 * f [mm]) )
...
- 6,467
7
votes
Accepted
How do I find the focal length when stitching images made with an unknown lens in Hugin?
No, you need to enter either the field of view (FOV), or the lens and crop factor information.
Luckily for you, for the Apollo mission images, the camera and lens information is well documented. The ...
- 32.3k
7
votes
Accepted
Why is the field of view angle from exiftool different from Apple's official values?
In the linked tables, FOV refers to horizontal field of view, according to the key. The discrepancy would be due to the fact that the values calculated by exiftool ...
- 5,404
6
votes
Accepted
Is a 30mm lens a good general purpose lens on an APS-C sensor?
IMHO, 30mm would be ok for general purpose photography.
I have a sigma 18-35 and I often find myself using the long end of this lens (from 28 and onwards). Distortion depends a lot on the specific ...
- 178
6
votes
Buying a Nikon DSLR Camera body only, is a 35mm and 55-200mm lens enough for most cases?
35mm is not wide enough for many types of general photography. With any group shots, (especially indoors) or any large outdor landscape scenes, you will need something like 16mm to 18mm to get ...
- 12.2k
6
votes
Can I optically zoom in but still capture the content seen when zoomed out?
No. Zooming in works by moving the optics of the lens so that the focal length is longer, resulting in a reduced field of view and greater magnification actually projected on to the sensor. This isn't ...
- 143k
6
votes
Is it exactly true that doubling the focal length makes everything look twice as big?
It's not exactly true, but it's a first approximation and easily good enough for many practical purposes.
Let's consider an ideal thin lens. We're already introducing one level of errors, because ...
- 1,497
6
votes
Distortion towards the edges/corners of the field of view in an image
This is perspective distortion, and it is an inevitable outcome of projecting a three-d world onto a flat surface. See What is the difference between perspective distortion and barrel or pincushion ...
- 143k
6
votes
What is this notation for Diagonal Angle of View units in this lens specification?
This is the standard minute and second of arc notation for fractions of a degree; one minute (′) is 1/60th of a degree and one second (″) is 1/60th of a minute.
(I am slightly suspicious that the ...
- 21.8k
5
votes
Accepted
Why do photographs make a place look bigger than it is?
Short answer:
Lenses and field of view.
Long answer:
Your eyes work very much like a camera, with field of view for binocular vision at about 115 degrees.
According to this site, the true central ...
- 492
5
votes
Buying a Nikon DSLR Camera body only, is a 35mm and 55-200mm lens enough for most cases?
It depends.
This is why getting a blanket lens recommendation almost never works. Everybody has a different set of priorities on what and how they want to shoot and how much they have to spend.
...
- 51.4k
5
votes
Accepted
Camera handling - right handed, left eye dominant
Do what is most comfortable to you. I am also right handed and for whatever reason got used to using my left eye to look thru the view finder.
Personally, I find having both eyes open quite ...
- 17.4k
5
votes
does focal length change across an image?
There are "barrel" and "pincushion" distortion optical aberrations which involve variation in magnification across the image -- this isn't discussed in terms of a change in focal length.
With barrel ...
- 4,026
5
votes
Accepted
How big is the sun in an image made with Canon APS-C and 300mm focal length?
As Alan Marcus mentions, the sun (as well as the moon) are very close to the same size in the sky, at 0.5° of arc.
The angle of view 𝜃 of a lens with focal length ƒ, as seen by a camera with sensor ...
- 32.3k
5
votes
Why are lenses characterized by focal length and not the effective field of view?
This question is predicated on a misconception. The flange distance is included in the focal length in lens labels — it is the distance from the optical center of the lens focused at infinity to the ...
- 143k
5
votes
Accepted
Does a Canon 18-135mm have a wider field of view than a Canon 24mm?
If using it on the same camera yes.
As long as the sensor size remains fixed the angle of view is determined by the focal length. And 18 is lower than 24 so it is wider.
- 1,581
5
votes
What is this notation for Diagonal Angle of View units in this lens specification?
In trigonometry, degrees are subdivided into 60 minutes (indicated with a single quote or apostrophe). Each minute is further subdivided into 60 seconds (indicated with a double quote). So 74 degrees ...
- 5,138
4
votes
What is the relationship between field of view and focal length for fisheye?
Michel Thoby's webpage has the following formula for the equal-area projection:
r = 2 f sin(θ/2)
where r is the distance from ...
4
votes
Buying a Nikon DSLR Camera body only, is a 35mm and 55-200mm lens enough for most cases?
portrait, landscape, macro
If these are the kinda of photography you intend on doing then maybe the kit lens is the better choice over the 35 prime. I assume you are going with the 55-200 regardless ...
- 612
4
votes
Why don't lens manufacters just label their lenses in 35mm equivalent terms?
A mm unit does NOT describes the field of view. A mm unit on a lens is a focal leingth. It does not matter if you project it on a "full frame" camera, dx sensor or a sheet of paper.
But ...
- 24.1k
4
votes
Can I combine a pinhole bodycap with macro extension tube to adjust focal length?
Can I combine this with a macro extension tube to adjust the focal length?
Yes, you can.
You can make some extension tubes with cardboard too to make some preliminary tests.
P.D. Just make sure you ...
- 24.1k
4
votes
Accepted
Can I combine a pinhole bodycap with macro extension tube to adjust focal length?
Yes, you can.
But keep in mind that the optimal performance of a given pinhole is related to focal length used. More on the theme can be found here: How to calculate the optimal pinhole size?.
Using ...
- 6,010
4
votes
How big is the sun in an image made with Canon APS-C and 300mm focal length?
With your camera and existing 70 - 300 lens, shoot pictures of the moon. The moon and sun appear in the sky as a disk, they image exactly the same as to size. Both are 1/2 degree of arc disks.
...
- 38.7k
Only top scored, non community-wiki answers of a minimum length are eligible