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56 votes
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Why do photo cameras lose focus when you zoom, when movie or TV cameras keep it?

The effect's name is parfocality, we are speaking of parfocal lenses. Lenses that change their focus when zooming are called varifocal lenses. Like reducing focus-breathing (change in focus also ...
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53 votes

How to zoom with Canon 77D with Canon 50mm 1.4 lens?

How to zoom with Canon 77D with Canon 50mm 1.4 lens To zoom in, step forward. To zoom out, step back. It's often called zooming with your feet.
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51 votes
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Why buy prime super telephoto lenses instead of zoom super telephoto lenses?

Who in the world buys large primes? Wildlife and sports photographers, mostly. I'm struggling to see how one would find use in a long focal length prime, 300mm and above for example: without zoom, ...
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42 votes
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How to zoom with Canon 77D with Canon 50mm 1.4 lens?

You can’t. The 50mm f/1.4 is a prime lens, which means it has a fixed focal length, or fixed field of view. This is what some people call a “sneaker zoom” lens, where you as the photographer have to ...
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41 votes

How to photograph distant objects (10km)?

You can't. I don't care what you've seen on CSI, this just isn't possible in the real world. Even taking Canon's ridiculously big (and now discontinued. Oh, and $100,000) 1200mm lens, The Digital ...
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32 votes
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Why doesn't the picture become darker the more you zoom in?

The answer to this question revolves around explaining how zoom lenses function because you are correct in your observation: As you zoom to higher and higher magnifications the image dims unless ...
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  • 36.3k
31 votes

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

You are not required to purchase any lenses at all. It all depends on your photography needs and what you're willing to spend your money on. Regarding range, the superzoom 18-200 mm covers the same ...
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29 votes

How to photograph distant objects (10km)?

By specifying that you want to do your surveillance photography in "good sun light", you have already shot yourself in the foot. The best time to do this kind of photography is at night or in the very ...
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  • 1,017
26 votes

Do photographers avoid using zoom?

do most photographers avoid using zoom No. If "most photographers" avoided zoom lenses with variable aperture, there'd be fewer zoom lenses with variable aperture on the market. Furthermore, there ...
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24 votes

Is replacing all my Fujifilm gear with this Canon zoom lens an upgrade?

The 24-70 is an incredibly good lens - it's as sharp wide-open as just about any prime at every focal length across just about its entire field. But it's only 24-70. As you're talking about a full-...
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21 votes

How do zoom lenses restrict their widest aperture at the telephoto end?

The entrance pupil is limited by the diameter of the front element, and that is what usually restricts the maximum aperture of telephoto zoom lenses - not the physical size of the aperture diaphragm. ...
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20 votes

How to photograph distant objects (10km)?

The general consensus in this thread is that detailed photography of a subject at a range of 10km is exceedingly difficult, and probably impossible using commercially available equipment — and there's ...
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19 votes

Is it safe to zoom while taking a photo for the effect?

Provided your lens isn't a power zoom (fairly rare, these lenses have motors that drive the zoom mechanism), then no you will not damage either camera or lens.
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17 votes

How should I approach deer to photograph them?

The only ethical ways to get closer is to either use a lens with a longer focal length ("more reach"), or to view them in captivity, such as in a zoo. Trying to get closer to wildlife will only ...
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16 votes
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Why does this lens lose focus when you zoom in but not when you zoom out?

The lens is not parfocal in either direction. What you have discovered is the difference between narrow Depth of Field (DoF) at longer focal lengths and deeper Depth of Field at wider focal lengths. ...
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15 votes
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What is a pump zoom lens?

It just means you push / pull the front of the lens to zoom, rather than twisting a zoom ring. The mechanism is simpler to design/manufacturer but is less precise and has a reputation for sucking ...
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15 votes
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Is replacing all my Fujifilm gear with this Canon zoom lens an upgrade?

Would switching to full frame Canon and getting that lens be an upgrade over my Fujifilm gear? For some shooters it would be. For others it would not. For a true photographer it shouldn't make a ton ...
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15 votes
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What does "AUTO-ZOOM" mean on my Zuiko lens?

Your lens dates back to a time when some lenses were still completely manual, and the aperture had to be manually closed for stop down metering. Your zoom lens has a more modern feature that allowed ...
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14 votes
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Any tricks to escape the zoom lens trap?

I think this is a great exercise and can really help you with your photography — even if you end up using zoom lenses in the future. And, there is a commonly-used "trick" here — it's called One Lens, ...
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  • 140k
14 votes

How to photograph distant objects (10km)?

As others have said, 10 km is not feasible due to the physics of light and atmospheric distortion. However, I'd like to address another aspect of this that hasn't been mentioned yet: if someone is ...
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14 votes

How do manufacturers get to high (83x) zoom levels on hybrid cameras?

I think the use of the term 83X while true, is most misleading. The Coolpix does a remarkable job when it comes to its optical range which is 83X. This is actually called the zoom range. The math is: ...
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13 votes

Why do photo cameras lose focus when you zoom, when movie or TV cameras keep it?

A lens that maintains the same distance of focus as it is zoomed is said to be parfocal. This is a highly desirable quality in a lens if one is shooting film or video and wishes to maintain focus ...
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  • 168k
12 votes

What difference is there between the 50mm in a zoom lens, a 50mm prime lens, and a 50mm macro?

Let's start with what is similar with all three of these lenses: They all have a focal length of 50mm. You should also be able to have a lot of overlapping focusing distances and aperture values. ...
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11 votes

Longer Zoom Lens

The rule is learn to get closer. Really the best wildlife shots are made by people who have learned to get closer to wildlife ( a tricky skill ) and to wait ( find a spot you think they'll come near ...
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10 votes

Difference between zoom and focal length?

The technical terms and colloquial usage are a bit different here: Focal length is a technical characteristic of a lens that directly influences its angle of view, i.e. how much of the entire field ...
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10 votes
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What is the shot called where it goes from telephoto to wide-angle without a zoom?

That effect was made famous in Hitchcock's Vertigo. It's called by various names: Hitchcock/Vertigo zoom, dolly zoom, reverse tracking shot. To achieve this effect, the camera zooms in or out, while ...
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10 votes

How much zoom would make a camera suitable for imaging railcar seals from 100 feet away?

As the other answers do a good job of giving you the fish, seeing as you're an engineer, this answer will teach you to fish. The angle of view of a lens & camera combination is simply determined ...
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10 votes
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Is it exactly true that doubling the focal length makes everything look twice as big?

Your intuition is right. To validate it, we can dig into basic high-school geometry. Although a camera lens is actually a complex lens made from many elements, conceptually and mathematically for ...
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  • 140k
10 votes

How can I magnify ≤1mm objects onto a display for under $200?

There are a few considerations here: How are the objects illuminated? Small objects typically need quite good illumination to see them properly. Without good light there is little point in magnifying ...
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