ThreeCee Loc: Washington, DC

I see field of view and angle of view used interchangeably a lot in photo tutorials. I have always thought that they are very different. Field of view is what you see in the seen. It is more a function of the sensor size for a given lens.
Angle of view is more related to the focal length of the lens. A wider lens ie. 35mm will have a wider angle of view than a 100mm lens.
The reason it is important is because wider lenses tend to have more perspective distortion. One of the reason 85mm is used more for portraiture than the 35mm. You can get the same field of view with both lenses by changing your distance and cropping but the angle of view will be noticeably different. Thoughts?

BebuLamar

The angle of view is depended on the focal length and the sensor size. The field of view is depended on the focal length, the sensor size and also the distance between camera and the subject.

Ysarex Loc: St. Louis

fosis Loc: Pittsburgh, PA

Honestly, you can define a difference between these 2 terms, but the "reality" out there doesn't change regardless of which lens you're using. If you took a portrait from the same distance, and cropped the 35mm lens image to that of the 85mm lens, the relative sizes of the face to objects in the background would not be any different.

At the same time, the advantage of choosing varied focal lengths is to change the perspective from front to back, either to compress near/far image sizes or to enlarge the near and shrink the far, with roughly the same subject matter in the frame.

I perceive sensor size simply as "cropping" the field covered by a given focal length.

Longshadow Loc: Audubon, PA, United States

The field of view depends on the angle of view.

Field of view is an area, angle of view is a number.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

I don't usually refer folks to Google etc., I try to answer questions directly. This link, however, leads to is a great article/tutorial on this question. It is well-explained and has excellent diagrams.

https://photographylife.com/equivalent-focal-length-and-field-of-view#:~:text=The%20main%20difference%20between%20the%20angle%20of%20view,24mm%20f%2F1.4G%20is%20only%20for%20a%20full-frame%20camera.

Take a few moments to read it- it's well worth the time!

Architect1776 Loc: In my mind

Good explanation.
#2 & #3 paragraphs are all that is needed to explain the difference.

Longshadow Loc: Audubon, PA, United States

mikegreenwald Loc: Illinois

Thank for the reference. The article makes the difference very clear.

imagemeister Loc: mid east Florida

FOV measured in linear feet/meters from left to right - AOV measured in angular degrees of the light cone described by the diagonal of the sensor/film size......They are very closely related !

47greyfox Loc: on the edge of the Colorado front range

This is an excellent article! Thanks for sharing!

burkphoto Loc: High Point, NC

Good article.

Micro 4/3 users know that their native lenses are designed to cover an image circle just barely larger than the sensor. A 2X "crop factor" (really, a magnification factor) still applies for comparison with larger formats, but there is no crop. The lenses are designed and engineered specifically for the smaller format. This requires much less glass, both because the lens is smaller in diameter (to project a smaller diameter cone of light that covers less surface area on the sensor) AND it is half the focal length of full frame sensors for an equivalent field of view. There is much less distortion at wide angles due to the short flange-to-sensor distance, too. Weight is generally 1/3 to 1/4 that of a full frame lens of equivalent field of view and real aperture. Cost is usually half that of full frame equivalent lenses.

If you mount a full frame lens on a Micro 4/3 body with a "normal" adapter, the crop factor is 2X, and you are cropping slightly less than the center quarter of the projected image circle. A "speed booster" or "focal length reducer" adapter will reduce the magnification to shorten the real focal length, reduce the effective crop factor, and intensify the light projected on the sensor. Speed boosters are the opposite of teleconverters.

SuperflyTNT Loc: Manassas VA

Yes they’re related. FOV is determined by AOV at a given distance. AOV is constant for a given focal length on a given sensor, (with the caveat that the lens provides full coverage of the sensor).

PHRubin Loc: Nashville TN USA

fetzler Loc: North West PA

Lenses have have two properties: focal length and image circle diameter. A 90mm lens for a m4/3 only needs to cover the m 4/3 sensor. A 90mm lens for a 4 x 5 in view camera will cover at least a 5x7 in film because of the swings and tilts.

The angle of view (for a given camera sensor size) is the angle that the image covers along the diagonal of the sensor. The lens focal length that gives a given angle of view depends on sensor size. The field of view describes how much of the scene is included in the image. One could describe this by the vertical angle of view and the horizontal angle of view.

If one has lenses with minimal barrel and pincushion distortion then there is no image distortion no matter what the focal length is used.

If I use a 90mm lens on a 4 x5 view camera to make an image and cut out a piece of film the size of a 35mm frame. The object in the small piece will appear to be same as in the corresponding piece of the pre-cut film.

If one moves a camera closer or further from a subject then the perspective changes. If you could move close to subjects and still keep the wide angle image in reasonable focus you would see just what a wide angle lens sees. I could do this when I was young but alas no longer. In this sense all lenses have "perspective" distortion.