Linked Questions

6
votes
3answers
1k views

Is focal length measured relative to the sensor or the lens? [duplicate]

I'm very (very) new to photography world.. I've been trying in the past few days to explore very deeply to this world.. But the more I dived in the more confused I became. For example most of the ...
1
vote
3answers
274 views

Is focal length internal or external? [duplicate]

I just wanted to check because I've encountered various distinctly different assertions. I was originally taught that focal length referred to the optimum distance from subject| ←→|lens, where ...
1
vote
0answers
68 views

Where is the focal point of a camera lens? [duplicate]

If the distance between the center of the lens and the film is called Focal length, does that mean the focal point of the camera lens is located on the film?
25
votes
5answers
4k views

What is the shape of the focal plane?

This is something I just realised I don't entirely know the answer to, so I'm going to ask it here as I think it's interesting. In most non-scientific writing on depth of field, diagrams generally ...
7
votes
3answers
4k views

Since it's not “focal length”, what is the term for the distance at which things are in focus?

I was under the impression that the “focal length” of a lens is the distance at which stuff appears in-focus. (E.g., perhaps I set the camera so that objects 3 meters away appear sharp, ...
1
vote
3answers
2k views

How is Focal Length defined for 180-degree fisheye lenses?

The definitions of Focal Length I saw seem to implicitly assume that the field of view is finite, which isn't true for 180-degree lenses, or presume parallel transport of certain rays passing through ...
2
votes
1answer
2k views

Is it wrong to call the image plane the focal plane?

I'm from France and I would ask a question on a point that I don't understand, as it seems that so many people confuse (or may be I'm wrong). On the camera, there is a symbol (a theta or phi) which ...
0
votes
2answers
2k views

Where is the image sensor located in a camera with a fixed-focus lens?

I am working on some research on the Kinect for XBOX One. I am looking into the depth measurements of the device. I have read that the depth values are calculated from the devices focal plane. So i ...
2
votes
3answers
471 views

When a lens and camera are callibrated together, which is changed, and might other lenses be adversely affected?

I wonder what exactly is the calibration of a camera body and a particular lens. I know the effect, but how it is achieved? I recently bought 80-200 (the two-ring version), I was waiting for too long ...
1
vote
1answer
70 views

What defines an “objective”?

I'm not experienced in photography and would like to get some knowledge about the terminology. My question is: What defines an objective? Or: When would you define something as an objective? I mean, ...
0
votes
2answers
71 views

Measure in photo formula help

Good Day I am trying to measure the width of an object in a photo as accurate as possible using the formula found in a previous question. Distance to object(mm)=f(mm) x real height(mm)x image ...