# Tag Info

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### 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
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### 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 ...
• 4,223

### 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.
• 21.7k
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### 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 ...
• 176k
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### 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

### 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) ...
• 39.4k

### 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]) ) ...
• 6,478
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### 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 ...
• 5,414

### 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
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### 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

### 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

### 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

### 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 ...
• 22.1k
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### 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

### 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

### 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 the Sun appear in the sky as a disk, they image exactly the same as to size. Both are 1/2 degree of arc disks. ...
• 39.4k
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### 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. Instead of computing angle of view, we can use a simpler rule of thumb. Using the ...
• 33.2k

### 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
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### 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.
• 1,591

### 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 ...
• 5,158

### 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 ...
• 25.2k
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### 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 ...
• 5,990

### 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 ...
• 25.2k
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### Finding focal length from image size and FOV

It's basic geometry: you have a right angle triangle, with half the FOV as one of the angles (a), and half your image size as the opposite side (A). To calculate the focal length F, use tan(a) = A/F, ...
• 3,181
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### How is wide field-of-view possible using a tiny sensor?

It seems that 1/2.3 sensors would produced fields-of-view that are tiny, even at the shortest focal lengths. You're not completely wrong — you're just underestimating the limit. The relationship ...
• 143k
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### Calculation of Distance of an object given the field of view of camera

Your math is unnecessarily complex, no need to compute or use angles (and therefore, no need for any trigonometry). Using the lens magnification formula M = ƒ/(do - ƒ), where do is the distance from ...
• 33.2k

### Does field of view change for different lens model for the same focal length?

There are at least two issues involved here: Focal lengths, particularly with zoom lenses, are approximated to the nearest "standard" number. You'll almost never see a lens marked as a 242mm or 256mm ...
• 176k
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### How to find an angle and a distance for clicking picture of a distorted artwork to achieve 3D effect?

As this is the photography forum I will try to make a good approach using one. You need a camera with some kind of live view preferable. Get a tripod and position your camera pointing to the sheet of ...
• 25.2k
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### How do I select a fixed lens for my APS-C sensor camera for a specific field of view/zoom

There is no calculation required. If you are happy with 50mm now, just buy a 50mm "fixed' lens, as 50mm is always 50mm regardless of what the sensor size is. Yes, the field of view changes with ...
• 12.3k