Nidelva river through Trondheim Norway

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Focal length is the distance (measured in mm) between the surface of a lens and the focal point, when the lens is focussed at infinity. Smaller focal lengths indicate wide-angle lenses, larger focal lengths indicate a telephoto lens.

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1answer
90 views

General rules when compression in the background looks good (like with longer focal lengths)?

Is there any general set of rules or guidelines on when would the background compression generated by a long focal length look good in a picture? Example : in a headshot, I really like the background ...
2
votes
1answer
124 views

Possible to lock focal length on zoom lens? (SELP1650)

(This could turn out to be a bone, practical, product-specific query, but this is the internet so the worst that could happen is a 0 rather than a 1.) Anyhoo: is it possible to lock a zoomable lens ...
2
votes
2answers
124 views

Do I need the 18-55mm lens that comes with the camera, or should I instead get a 55-250mm lens?

I'm a novice so don't know whether I need the 18-55mm lens that comes standard with the Canon EOS Rebel T6i or should I instead get the 55-250 mm lens - or both? I'll be using the camera primarily ...
0
votes
2answers
510 views

Effective focal length of kit 16-50mm lens on A6000 (APS-C 1.5x crop factor) [duplicate]

This is likely a tedious question for you guys but, as a camera noob, I'm miffed, so please bear with me. I have a: Sony A6000 (APS-C 1.5x crop sensor). With kit lens: SELP1650 lens (16-50mm) So, ...
40
votes
11answers
16k views

Which focal-length lens is usually used for portrait photography, and why?

What focal length or range of focal lengths are usually used for portraits? What is used by professionals? Why would one select a certain focal length? What are the advantages and disadvantages of ...
5
votes
4answers
464 views

How do manufacturers come up with focal lengths for lenses?

There are a lot of lenses for each camera, and I understand that each lens caters to a different use case, but my question is on how they arrive at the specific focal length numbers. For example, ...
2
votes
2answers
265 views

Panasonic Lumix FZ1000 - How does it compare to binocular magnification?

I know almost nothing about photography. But I am interested in learning. My dad just purchased a Panasonic Lumix FZ1000. I own a pair of Leica 10x50 binoculars. I asked him how the maximum zoom or ...
3
votes
1answer
95 views

Which lens size will generate more detail for equivalent field-of-views in an image snapshot?

We are getting ready to purchase a 3 megapixel IP camera. It comes with either a 4mm or 6mm lens. We will only be using the camera for still image snapshots on a specified interval. Basically, it's an ...
2
votes
4answers
362 views

Are wide angle lenses suitable for portraiture of children?

Wide angle lens tend to make faces more "chubby" than they appear otherwise, and are therefore not used often for portraits, unless the landscape is an important part of the frame. I'm curious as to ...
1
vote
3answers
201 views

What focal length is recommended for photography for social media, like groups of people in weddings?

I want to get a lens for social photography (groups of people in weddings, or a close up for a bride). What focal length range would be recommendable? Also would it be good to get a wide angle lens ...
0
votes
1answer
125 views

What's the ranges of ratios of Focal Length to Sensor Height to approximate a human eye's view? [duplicate]

Given this formula for calculating the distance to an object as long as you have a picture of the object and know the actual height of the object... distance to object (mm) = focal length (mm) * real ...
15
votes
2answers
2k views

Why does a 50mm lens appear to give a human perspective, rather than a normal lens?

I grew accustomed to the notion that what one sees through a normal lens equates (or is close to) what can be seen with the naked eye (although that is not the "pure" definition of a normal lens, ...
2
votes
3answers
381 views

Is the Canon 70-200mm or 24-70mm better for convention photos? [closed]

I've decided I want to upgrade to a better lens, but I'm really torn between the Canon EF 70-200mm f/2.8L IS II USM and the EF 24-70mm f/2.8L II USM. I like to take convention photos, where space is ...
2
votes
2answers
248 views

How do you calculate the focal multiplier of a non-full frame camera?

I'm currently using a Sony RX100 Mark 3 camera and want to buy a Canon 6D + 24-105 F4 L lens from an online retailer, which is not in my country. (before continuing I'd like to state that there are ...
43
votes
9answers
24k views

Do professionals really never use a 24-70 lens?

I was reading lens reviews on the Rockwell site — mostly because it came up as first result in Google search — and he was saying professionals don't need and don't use mid-range zoom lenses like 24-70 ...
2
votes
3answers
216 views

Why isn't my computation of the actual size of an object in a photograph matching the expected value?

Let's say I have a full frame camera (Sony A7) with a 50 mm lens (Canon FDn 50mm f/1.4) mounted on it. At a given object (a plane) distance I should be able to compute the size of the image in real ...
4
votes
3answers
578 views

Does focal length change when I adjust the focus? [duplicate]

When I adjust the focus of my camera, in general, does this affect the focal length? I have heard that it does.
3
votes
2answers
144 views

55mm on an 18-55 lens versus 55mm on a 55-250mm lens

I have two canon kit lenses which came with my 1100D. While experimenting casually with my lenses, I came across something that I find peculiar. When I am focused at an object at a certain distance on ...
0
votes
3answers
185 views

Do lens hoods need to be matched to focal length?

Is it true that not all generic lens hoods work on all lenses (provided the filter diameter matches, of course)? I read that the focal length plays a role in it - but I cannot find such readings on ...
17
votes
9answers
60k views

What lens focal length most closely resembles the perspective of the human eye?

For example, if I have a lens that is 16mm-50mm, which focal length would be the closest to the human eye's view? (I don't have a camera yet, so I'm just curious.) Would 50mm be more zoomed in than ...
4
votes
1answer
333 views

What are the advantages and disadvantages of zoom lenses with a wide range of focal lengths? [duplicate]

Are there some disadvantages of a zoom-lens with wide range focal length compare to a lens with narrow range both having the same max. aperture? For example, if we have two lenses: Sigma 18-55mm f4 ...
0
votes
1answer
39 views

Focal length of the sony DSC-H20 [closed]

I am working in finding the distance of the objects in a video taken using a Sony Camera model DSC-H20 and suppose that any lens or zoom distortions were applied. In order to know the position I need ...
0
votes
6answers
194 views

Is the wide aperture and bokeh of a 50mm prime more important than getting to the 70-90mm range for portraits?

I've a Pentax K-30 with the following lens: Pentax-M 50mm 1.7 manual focus Tamron 17-50mm 2.8 autofocus Pentax 55-300mm 4-5.6 autofocus Considering that : Pentax 50mm has the nicest bokeh and ...
3
votes
4answers
252 views

Given the same sensor size lens, will a higher megapixel sensor give more “reach” then a lower one?

I've been wondering this for a while now, and I can't seem to find a straight answer about this. If we are talking about the exact same sensor size, (lets say FX) and we are using a 50mm lens. ...
0
votes
1answer
175 views

How do lenses focus? (and zoom?) [duplicate]

My understanding of focal length is that it is the distance from the lens to the sensor; in my observations: higher focal lengths make for longer lens. Then I started thinking about how a lens ...
25
votes
6answers
10k views

How to capture the scene exactly as my eyes can see?

What settings of my DSLR camera will emulate the scene exactly as I can see through my naked eyes? I think it's not possible to get the contrast and colors exactly as my eyes can see, and it may vary ...
60
votes
6answers
21k views

What is “angle of view” in photography?

I read on the Lens Buying Guide @ neocamera: Focal-length determines the angle-of-view seen through a lens for a given sensor-size. With a full-frame sensor a lens gives the same angle-of-view ...
4
votes
3answers
25k views

What mm lens for distance shots?

If I am looking to take landscape and wildlife shots and some of those shots being from a decent distance what mm lens would I need? I am not sure what else I should be adding here, I am just looking ...
0
votes
2answers
195 views

What is the relationship between focal length and minimum focus distance?

If I know the focal length of a lens, How can I know the minimum focus distance? I have checked several webpage, but I am still wandering is there a formula? I know there is mark in the lens, but ...
27
votes
4answers
74k views

How do I calculate the distance of an object in a photo?

If I took a picture of a windmill on the horizon — given that I know the sensor size and the focal length of the lens and other factors to do with the shot — could I calculate how far away an object ...
0
votes
1answer
177 views

I have camera specifications but don't know the actual focal length

I'm trying to figure out the focal length of my camera. I'm trying to figure out the distance from my camera to an object using the equation listed here (How do I calculate the distance of an object ...
0
votes
0answers
32 views

Tamron 18-200mm super wide angle lens [duplicate]

I purchased this lense, it says that it is a wide angle lense also. I would like to know hiw i can tell for sure, is it a wide lense or not?
0
votes
6answers
426 views

Why does Sony say that a 35mm lens is “35mm equivalent when used with an APS-C camera?”

I'm thinking of getting a Sony A6000 with a Sony SEL35F18 Lens. I'm a little confused about the actual focal length (and/or field of view) of the lens when attached to an APS-C sized sensor. The ...
0
votes
1answer
699 views

Camera sensor size vs pixel size and focal length [closed]

I've already seen the answer about the crop factor. I'm writing a small software for motion tracking (from two cameras, videos) in 3D space and research. To do that, I need some information about ...
33
votes
6answers
11k views

What software can show my most frequently used focal length?

Many people recommend a focal length of 35mm, 50mm, and sometimes even 85mm and upwards for those interested in purchasing a prime lens. I, however, would like to figure out what focal length(s) I use ...
0
votes
1answer
88 views

how to calculate “FocalLenIn35mmFilm” with limited metadata

Im creating an app that uses "FocalLenIn35mmFilm" to calculate feild of view(FOV). unfortunately not all photographs contain this property in their meta data, the Motorola Nexus 6 is an example. The ...
0
votes
0answers
23 views
10
votes
3answers
2k views

Does the size of the front glass mean anything?

Considering the Nikon lenses: Prime lenses: AF Nikkor 14mm f/2.8D ED has a huge front glass (●₃), AF-S Nikkor 50mm f/1.8G has a tiny little front glass, deep inside the body (∙₁), AF-S VR Nikkor ...
1
vote
1answer
131 views

Why don't all zoom lenses have variable f-numbers? [duplicate]

As I understand it, the f-number is a ratio between the focal length and the aperture diameter. A zoom lens can change focal length, but shouldn't the maximum aperture be a fixed size? If so, that ...
18
votes
3answers
27k views

How do people shoot very large moon views?

I see pictures of the moon that looks like it is very close to the earth; I am wondering whether they are real or is there a trick to show the moon that big? Here is an example: ...
5
votes
2answers
6k views

How can I calculate focal length from a photograph?

I posted this question over on Stack Overflow, but someone suggested this site might be of more help to me. I'm doing a college project where I'm trying to calculate the focal length of a camera ...
0
votes
1answer
110 views

Comparing focal length [duplicate]

Hello I want to move from my compact camera to a dslr. I am fan of landscape photos so I want to buy an ultra-zoom lens. My camera supports 14x optical zoom. I know that for compact cameras it's just ...
1
vote
3answers
1k views

How far away can I be and still get a sharp subject with a 100mm lens?

If I have a 100mm lens, how far away can I shoot the subject? If I am shooting basketball, how far can I shoot the subject and still get a sharp picture?
8
votes
2answers
11k views

How to calculate the FOV in degrees from focal length or distance?

How does one to calculate the field of view (or angle of view) in degrees from the following details: sensor size (for example, 1") distance to target (for example, 7 feet) focal length (for ...
1
vote
2answers
1k views

How can I know the focal length and sensor size of my webcam?

I have this webcam: QHM495LM WEB CAMERA and I need to know its focal length and its sensor size, but in the specs of the webcam, it only gives me this information: • Inbuilt sensitive microphone and ...
2
votes
3answers
163 views

If the zoom number doesn't tell me magnification, what does? [duplicate]

I've read How do I convert lens focal length (mm) to x-times optical zoom?, and learned that the times-zoom number doesn't tell you much. So, how do you determine the magnification — the amount a lens ...
2
votes
3answers
300 views

Will a macro extension tube eliminate the cropping of an APS-C lens on a full-frame sensor?

I understand using an A-mount lens intended for APS-C sensors on a full-frame camera results in cropping of the image. According to a tech at Sony, you lose 1/3 of pixels (APS-C is a 2/3 sensor so it ...
0
votes
3answers
2k views

How do I convert focal length to maximum distance?

I would like to know whether there is any relation between focal length and distance. For example, what is the max distance I can shoot from a 55mm-300mm lens?
0
votes
1answer
89 views

How do I measure the distance from an object to fit it in the screen? [duplicate]

I'm curious if there is any math formula for this. Let's take a close-up of a human face for instance, given the human face is about 20cm/8 inches, how do I choose the right focal length and from ...
0
votes
1answer
98 views

I want to know about the relationship between focal length and aperture [duplicate]

I have Nikon D7000 and I know the basic relation of shutter speed, aperture, and iso. All I want to know is focal length and aperture relation. As I zoom in the camera the f/stop increases (e.g. it ...