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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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4answers
367 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 ...
2
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3answers
340 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 ...
2
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3answers
412 views

Should I upgrade my camera or lens to shoot pro hockey games?

I've gotten the opportunity to shoot pro hockey games. My current gear doesn't cut it: Nikon D70 Nikon 18-70mm F/3.5-4.5 Kit lens Nikon 70-300mm F/4-5.6 D Nikon 50mm 1.8D Monopod From where i'm ...
2
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1answer
118 views

Why do DPReview's charts show the G7X II as having an aperture around f/8?

I have a Canon G7X II camera, which has a 24-100mm f/1.8-2.8 lens. Why does DPReview's chart show it having an aperture of around f/8 at a focal length of 100mm?
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2answers
125 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 ...
2
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3answers
478 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 ...
2
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2answers
600 views

Why are the area of aperture, focal length, and amount of light specified in these terms?

So I'm looking at the wikipedia article on Aperture, and I'm a bit confused. I understand aperture to be the diameter of the hole that lets light in. In the article, someone states that The ...
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3answers
8k views

What is the relationship of aperture, focal length, and ISO in a SLR?

I was using Nikon digital camera, and recently bought a Canon 550D. I am totally new to SLR. I am not familiar with SLR terms: Aperture, focal length and ISO, and their relation to one another. What ...
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4answers
440 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 ...
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3answers
813 views

Are there specific use-cases in mind that make the 70-200 F2.8 worth its weight/size?

I've been looking to upgrade my Mark iii's kit lens, and am comparing lens strategies. The 70-200mm canon F2.8 seems like an enduring and very popular lens. After holding one, i am left wondering why? ...
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2answers
3k views

DX 35mm vs FX 50mm

Will the picture taken from AF-S DX NIKKOR 35mm f/1.8G and AF-NIKKOR 50mm f/1.8G be one and the same because of the DX and FX format??
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2answers
276 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 ...
2
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2answers
232 views

What is the importance of the back focal length of a lens?

What is the effect and importance of the back focal length of a lens? For instance, if I look at these two lenses by Ricoh, they have the same focal length and aperture, but their back focal lengths ...
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1answer
162 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
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1answer
2k views

Can I build my own focal reducer by reversing a teleconverter?

Would it be feasible to reverse a 1.4x teleconverter's optics into a cross-system lens mount adapter & have it function as a focal reducer? For example, like this: Camera hacked adapter ...
2
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1answer
85 views

Will a focal length reducer help me image deep sky objects using an 8" newtonian telescope?

Will a 0.5x focal length reducer help me to reduce the exposure time if I am imaging deep sky objects? I'm using a 1200mm focal length optical tube (f/6), a 32mm super view telephoto extension ...
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2answers
279 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 ...
2
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2answers
841 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 ...
2
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3answers
585 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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3answers
490 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 ...
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3answers
842 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 ...
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1answer
207 views

Is 85-135mm really the best for every single kind of face?

They say that focal length around 85-135mm is the best for the head and shoulder kind portraits. I've done some tests myself, I can definitely see the differences. The face is more natural looking ...
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5answers
343 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 ...
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3answers
1k views

How to compare the focal length of a 50mm prime lens with the default lens of a point and shoot camera?

To imagine the 50mm focal length of a prime lens 1.4F, can I simply zoom the lens of my point and shoot camera up to 50mm? Will both the focal lengths be same? Any other way to imagine the focal ...
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4answers
2k 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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2answers
422 views

How to achieve full-frame look/view on a crop-sensor - without changing the lens?

I have a Canon 600D, which is crop-sensor camera. If you're shooting with a Canon EF 50mm, it'll be (50x1.6) = 80mm on a normal full-frame body right? I'm also a street-photography-kinda guy, which I ...
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3answers
483 views

What is the sweet spot of the Canon's 18-55mm IS STM lens?

I'm plannning to photograph negative film like this. And I would like to know what would be the sweet spot of my lens to achieve best sharpness possible, what f stop and at what mm I should be ...
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5answers
3k views

Keeping two subjects in focus (depth of field)

What is the best way to get two subjects in focus in a portrait (sometimes not at the same distance from the lens)? Obviously, this is a question of depth of field, but I am curious what some of the ...
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3answers
4k views

50mm lens=75mm on DX camera? [duplicate]

I'm looking for a 50mm lens for my nikon d3100 and I just came across an AF-S 50mm f/1.8G lens and it says in the description that if it's used on a DX camera, the angle of view is going to be 75mm. I ...
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2answers
554 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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3answers
699 views

Is it possible to calculate focal length if you know the aperture?

I need focal length (for my IA homework), but I didn't know that in real world I would only get the aperture. Ok, my camera is an Olympus X-21, and manual says: -----Olympus lens: 6.3 to 18.9 mm, f/3....
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4answers
420 views

What is the equivalent f/stop for 50mm?

If f/8 And Be There is the rule for 35 mm, what is the best f/stop if I am using 50mm? Context: Street Photography Note: Though one can say that "it depends", this is a very specific question. When ...
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2answers
590 views

Help me understand effective f-number

If I set a lens to, say, f/2 but my focus is set to its closest point, my effective f-number won't be f/2 any more but it will be higher by a factor that depends on focal length, image magnification ...
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2answers
194 views

What happened to multi-focal lenses?

Apparently multi-focal lenses such as the Tri-Elmar 16-18-21mm went out of fashion but I was wondering if the reasons for that were technical or commercial. Are multi-focal harder to build compared ...
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4answers
2k 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 ...
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3answers
177 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 ...
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3answers
1k views

How to shoot/capture the droplets of water being sprayed through a spray bottle

I am trying to capture the droplets of water while being sprayed on a subject through a spray bottle. What I mean here is - when I am spraying the water on my subject, I want to capture the droplets ...
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3answers
6k views

Is the formula for object image size given focal length, etc. independent of sensor size?

I am trying to figure out how big an object of, say, 50cm height at 100m distance and 600mm focal length would appear on a camera's sensor. The ubiquitous formula object size in image = focal length *...
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1answer
2k views

Canon 24-70mm 2.8f - Optimal aperture for sharper pictures

I always have trouble getting sharper images from my 24-70 lens. I have watched numerous YouTube videos to correct this and its improved but not completely corrected. I am going on a trip and don’t ...
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2answers
6k views

How do I choose among the following lens of 55-250 IS, 70-300 IS and VS 75-300?

Sorry by this specific question, but I'm pretty crazy here looking for a difference. I've got to buy a lens tomorrow (I leave my country in 2 days) I could see the difference between 55-250 and 70-300,...
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1answer
653 views

How do I calculate the maximum aperture at each focal length on a 35-200mm lens

I am looking for the linear maximum aperture of a 35-200mm 3.5/4.5 Nikon manual focus lens. I already know the max & min of the 35 & 200mm it's the 50, 70,105, & 135 that I am interested ...
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2answers
156 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 ...
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4answers
202 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 ...
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1answer
633 views

How to calculate the focal length for old lenses (m42 or m39) mounted on Sony Nex? [duplicate]

As far as I know, it is necessary to multiply the focal length by the crop factor. My Sony Nex 5 has a crop factor = 1.5 For lens Helios 77M-4 1.8/50 focal length will 50 * 1.5 = 75 Is this true for ...
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1answer
342 views

What is a 50mm focal length good for on an APS-C camera?

This is on a Sony NEX, so the 35-mm equivalent focal length is 75mm. What kind of photography is this focal length good for? I shoot low-light, landscapes / cityscapes, and the typical vacation ...
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2answers
249 views

What does different focal length offer me?

I have a beginner photographer and I have spent a lot of time learning the basics (exposures, lenses, focal lengths, crop factor etc). It's all good except I'm not so sure when I need to buy lenses of ...
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2answers
1k views

What are the technical camera specs for the HTC Wildfire S?

I am trying to do some CGI manipulations on pictures I've taken. In order to fake reality with some 3D object inserted in the picture, I need some information to configure my virtual camera so it can ...
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2answers
91 views

Does 4.0-72mm on the lens when equivalent focal length is 24-432mm mean crop factor of 6×?

The Samsung WB250F has 4.0mm-72.0mm printed on its lens, and its 35mm equivalent focal length range is 24mm-432mm. Does that mean it has a 6x crop factor?
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1answer
1k views

Size of the entrance pupil vs size of the aperture

I understand that the entrance pupil is the image of the aperture as seen from the front of the lens. However, is the size of the entrance pupil the same as the size of the effective aperture? In ...
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2answers
201 views

Will old K-mount lenses have the same field of view on Pentax K01?

Will old K-mount lenses have the same field of view on Pentax K01? Or, will 50mm lens (made for 35mm film) function as a 75mm lens?