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

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5answers
496 views

What is a good focal length for street photography?

With a long lens you don´t disturb people but you are left "out of the scene", while with a short focal lens you are "inside the scene" but you may disturb people. What is a better alternative for ...
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3answers
121 views

How can I get a 12ft wide field of view at 3ft distance?

Is it possible to get 12ft wide image from a 3ft distance? I am a beginner and have very little knowledge on the field of view of cameras. I calculated that a Go Pro would need a lens with 1.5mm ...
1
vote
2answers
68 views

How does “designed for APS-C” affect focal length? [duplicate]

If a lens is designated by manufacturer as "designed for crop sensor" (i.e. DC in Sigma, DX in Nikon, DT in Sony), how would that affect the calculation of practical focal length (equivalent focal ...
0
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1answer
50 views

What's the full frame equvialance of this phone lens?

I took a photo with my phone, and here is the EXIF: F/2 4mm 1/14s ISO-1250 I searched on the Internet and found that the sensor is Sony IMX134, 1/4 inch. Then how to calculate the equivalent focal ...
6
votes
5answers
3k views

Why do Canon EF and EF-S lenses exhibit the same crop factor?

I have a Canon 7D, which has a crop factor of 1.6x. When using a Canon EF-S lens I get the focal length stated on the lens, when using a Canon EF lens I get the focal length times 1.6 when used on ...
0
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5answers
219 views

Is it worth getting a zoom lens which overlaps with lenses I already have?

I want your experience in choosing a new lens. I already have a couple of lenses with focal lengths as follows: 18-55mm, 70-300mm (MF), and 55-300mm (AF) - regardless the 18-55mm. All my zoom ...
2
votes
4answers
339 views

What kind of lens is typically used for these type of night street shots?

I've been trying to duplicate the depth of field like in these photos on snowy nights and I'm not getting comparable results. I'm using a 35mm prime lens at f/1.8 on a D3100. So my question is: Are ...
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2answers
8k views

How can I find a compact camera with an ultra-wide lens?

I'm looking to buy a compact camera, and having a very wide angle is important to me. I know that review sites often list the real focal length of the lens, but what I'm looking for is something that ...
0
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1answer
84 views

How do prime lens allow variance of focal length when focusing? [duplicate]

If the definition of prime lens says that their focal length is fixed, then how come you can still alter the focal length when focusing? (either MF or AF)
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1answer
101 views

How to calculate the focal length of cell phone cameras when none of the required parameters are available?

There are many camera phones for which the focal length, aperture size, and sensor size are not available. Is there a formula to calculate these parameters or a site which provides these details for ...
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4answers
67 views

Does the crop factor affect the field of view (FOV)? [duplicate]

I'm working on smartphone cameras. I want calculate Field Of View of different smartphone cameras using the formula : FOV = 2 arctan(SensorSize/2f) where: f is the focal length sensor size is the ...
2
votes
2answers
397 views

How does physical aperture size relate to f/stop?

There are two lenses on the market I am comparing AF Micro-Nikkor 60mm f/2.8D AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED If I use the formula for calculating apertures of both the lenses I will use ...
0
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2answers
69 views

Actual Focal Length on APS-C cameras [duplicate]

I'm aware that actual focal length of a lens on APS-C cameras is longer than what is written on the lens. My question is, for lenses that are specially designed for APS-C cameras (like a Nikkor DX ...
4
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2answers
1k views

Is it worth to buy old Sigma lens instead of Nikkor?

I'm amateur and I want to try something new. I have Nikon D3100 with Nikkor AF-S DX VR 55-200/4,0-5,6 G ED and I'm shooting everything - animals, landscape, people, sport, ... (like real amateur :D ). ...
0
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3answers
212 views

Is an 18-200mm lens sufficient for an Alaska trip? [closed]

I am an amateur photography enthusiast, mostly for vacation shots. I have a Nikon D80 body and the 18-200mm lens which I use as my "walking around" lens. I have a trip to Alaska coming up this ...
5
votes
4answers
269 views

Can a telephoto lens have a wide field of view?

85mm-135mm lenses are great for portraits because of compression perspective distortion, meaning they flatten facial features. However at those focal lengths, you have to step back a few meters from ...
0
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2answers
435 views

How does focal length change perspective? [duplicate]

@MichaelClark answered a question I posted about zoom using focal length (emphasis added): You are correct that a focal length twice as long (2X zoom) as the original one will make objects appear ...
0
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1answer
67 views

Do I get more detail from a shorter focal length by being physically closer?

Let’s say I want to shoot a static scene and have a free hand regarding the focal length. If I ignore the geometric distorion for a while, do I get some image quality advantage by shooting from a ...
24
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3answers
44k 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 ...
3
votes
5answers
11k views

If I have an 85mm lens for portraits, is a 50mm useful as well?

I recently got my Canon EF 85mm f1.8, after lot of thought over if I should buy Canon EF 85mm f1.8 or Canon EF 50mm f1.4, I decided on 85mm so that I can shoot portraits of people even from a ...
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2answers
290 views

What type of lens is more suitable for this type of portrait shot on railroad tracks?

Posted on FaceBook looking for volunteers to model for me for free and I give them the photos for free and some people agreed to that so I want to be prepared and at least take the right gear to the ...
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4answers
315 views

Will a 50mm EF lens give the same result as a 50mm EF-S lens? [duplicate]

edit: ^^ the answer to that question talks about the lens being the same and but not how or why this is the case, and does not answer the question about resultant image, First of all, to let you ...
0
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1answer
53 views

camera mobile phone takes pictures at constant focal length if 3.5 mm.supposed to have autofocus and touchfocus [duplicate]

This is a cheap Chinese landvo l200 Android mtk65xx mobile The onlything it keeps Changing is IS0 from 150 to 800 + And exposure time I wondered how can it autofocus and touch Focus when it keeps ...
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1answer
358 views

Why doesn't exposure change when changing focal length?

With a Canon 550D camera and a Tamron 18-270 mm zoom lens, I tried to fix shutter time, aperture (f/8.0 to cover all zoom range), and ISO, so the exposure meter read 0.0 with 18 mm focal length and ...
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0answers
25 views

Relationship between the focal length and sensor size [duplicate]

What is a relationship between the focal length of the lens and the sensor size to achieve the same image area ?
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3answers
11k 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 ...
2
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4answers
1k views

35mm vs 40mm: Does it matter?

I want to buy the lens Voigtlander Nokton 40mm F1.4, $449 Voigtlander Nokton 35mm F1.4, $629 I am asking, why the slightly difference in focal length, the price difference in so much as $180? ...
2
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3answers
178 views

Which EXIF tag to set for the 35mm equivalent focal length?

For a manual lens (*Rokinon 8mm f/3.5 Fisheye) I want to add the focal length information to the EXIF metadata in the resulting pictures with exiftool. I use the lens on a Canon 60D body. Obviously I ...
0
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1answer
316 views

Does the Canon EF-S 24mm f/2.8 STM Lens offer any significant advantage over the Canon 18-55mm IS II at a 24mm focal length?

Does the Canon EF-S 24mm f/2.8 STM Lens offer any significant advantage over the Canon 18-55mm IS II at a 24mm focal length (the kit lens for my T3i)? I'm looking for a cheap lens that offers a wide ...
2
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5answers
2k views

Does sensor size affect lens distortion?

There was recently a video posted about how different focal lengths affect portrait photography, specifically how distortion at smaller focal lengths have more distortion and are less flattering. So ...
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11answers
10k 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 ...
3
votes
1answer
97 views

How to calculate the correct focal length needed for a subject of a given size and distance?

I need to purchase my first ever lens. So far I've only used lenses that were built into a camera. This specific lens is for the BlackMagic Deign Pocket Cinema Camera (a video only camera, but one ...
2
votes
3answers
258 views

Why does getting closer or zooming in decrease depth of field?

I know that aperture changes the depth of field (DOF), but why is it that by making the image appear larger (by getting closer to the camera or zooming in) there is less DOF?
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4answers
954 views

Will a short focal length cut it for indoor event photography? (Context: It's Crowded, Dark, Has Mixed Lighting, and Requires Walking Around.)

Short version: What primes are good walk-around lenses for an indoor, dark, crowded environment where you'll be taking pictures of individuals or small groups ad-hoc, walking around and stopping in ...
36
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9answers
10k 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 ...
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2answers
4k views

So my iPhone 6 camera lens is as wide as my full frame 35mm DSLR lens?

I am trying to understand what is the deal with "full-frame" and what difference it makes, so did a silly test: I sat at my bed and aligned the iPhone 6 camera with the door of the room and took a ...
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7answers
28k views

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

For example, if I have a lens that is 16mm-50mm, which focal length would be the closest to the human eye view? (I don't have a camera yet, so I'm just curious). Would 50mm be more zoomed in than ...
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0answers
60 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?
3
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3answers
489 views

Phone camera (Samsung S4): is it possible to determine the distance to the object in focus on jpg picture?

I took a picture with Samsung S4 phone. Is it possible to determine the distance to the object on the picture? The object is in focus. I looked at the JPG picture properties but could not find ...
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2answers
1k views

How do I take good portraits with a bridge camera and superzoom?

I'm an absolute beginner with regards to photography. I did some research on portrait photography today. From what I learned, a long-telephoto lens (70mm-135mm or more focal length (35mm ...
0
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2answers
90 views

Valid value for shutter speed based on Focal Length [duplicate]

I was listening to Ben Long videos and he was saying a safe value for shutter speed is 1/focal length So if I have a 35mm prime 1.8 lens, does that mean 1/35 = 0.02 so in my camera panel do the values ...
2
votes
4answers
3k views

What is the relationship between focal length and shutter speed?

I am very new to photography and am trying to grasp the basics of it these days. Can someone please help me understand the relationship between focal length of a lens and shutter speed of camera?
0
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1answer
42 views

Why does the FoV of adapted lenses seem to be the same as kit lenses with the same focal length?

I have a NEX-6 with a number of legacy lenses and the two NEX "kit" lenses. If I fit the 16-50 kit lens, setting it to 50mm, and view the image through the viewfinder, noting the width of the image, ...
2
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3answers
300 views

Will a 18-140 lens be good for basketball stadium photographs? [closed]

I am absolutely new to photography and have just started learning the basics. I have got a Nikon D-610 with a 18-140 lens for now. I just want to know if I can take this to a basketball game and get ...
3
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3answers
485 views

Is lens focal length specified considering the effect of barrel distortion on field of view?

Given a Nikon 14mm f/2.8D ED AF Ultra Wide-Angle Nikkor Lens on a full-frame sensor, in theory the field of view is HFOV: 104° x VFOV: 81°. However this lens exhibits noticeable barrel distortion ...
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4answers
1k views

What exactly is focal length when there is also flange focal distance?

If focal length is the measure between the rear element and the sensor then how can you have different flange focal distances? Is the focal length not literally the measure between the rear element ...
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4answers
2k views

Do I need other camera lenses if I have an 18-200mm or other super-zoom?

I wanted to ask that once you have purchased a lens of say 18-200mm, then is it required to purchase other lenses — say 24-70mm, 24-105mm, 18-105mm, 28-135mm,etc. Does 18-200mm lens satisfy all the ...
2
votes
2answers
318 views

How to estimate camera sensor size?

I am using a smartphone for capturing photos and I need to estimate the camera sensor size (mm*mm). I have the resolution (in pixels) and the focal length (in pixels). I can also measure the size of ...
3
votes
3answers
207 views

How can the focal length of a lens be many times greater than the lens's physical length?

I bought a Tamron 16-300. Question is: how can it have a focal length 0f 300 mm when it is only about 30 mm long? Doesn't the lens have to be 300 mm from the sensing element?
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5answers
3k views

What is a normal lens?

I've heard people call 50mm lenses "normal lenses". For a lens to be considered normal, does it have to be exactly 50mm or is there some leeway? Does the normal focal length depend on crop factor of ...