Questions tagged [zoom]

An optical 'zoom' or 'variable focal length' lens is one that has a range of focal lengths at which it can operate. "Digital zoom" is a technology which simulates optical zoom by cropping the image.

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73
votes
7answers
428k views

How do I convert lens focal length (mm) to x-times optical zoom?

What is the rule to convert the 'mm' notation to the 'optical zoom' notation? I searched a bit and found this one: optical zoom = maximum focal length / minimum focal length For example a 18-55mm ...
49
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3answers
11k views

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

In photo cameras, i.e. (D)SLRs, digital cameras, etc., when you focus on an object and then you zoom (in or out), the object gets out of focus. On the other hand, in movie or TV cameras, the focus is ...
46
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7answers
11k views

How do constant aperture zoom lenses work?

Cheaper zoom lenses usually are faster at the wide end and slower at the long end (for example, the $150 Canon EF-S 18-55mm f/3.5-5.6). More expensive constant-aperture zoom lenses have the same ...
42
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12answers
8k views

Is digital zoom really useful?

I've always wondered what is the use of digital zoom, apart from viewing the subject clearly on the LCD display. We can take a photo with the optical zoom and crop the photo to the desired region of ...
38
votes
2answers
7k views

Why no zoom lenses with a maximum aperture wider than f/2.8?

I can understand that a zoom lens with a maximum aperture wider than f/2.8 would be difficult and costly, but it seems like something pros would kill for. Surely it can't be more expensive (if its ...
37
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3answers
4k views

When you zoom in with a lens on an SLR why does the lens go in then out?

I guess this is more a question of optics than photography but I just got an SLR with a basic 18-55 lens. I noticed that when going from 18 to 55 or 55 to 18 the lens physically comes back in and ...
31
votes
10answers
119k views

What is the difference between a telephoto lens and a zoom lens?

Looking at the product page for Nikon lenses, I notice a distinction between telephoto lens and zoom lens. What is the difference between the two? Why would I want one over the other? I wiki'd ...
29
votes
4answers
11k views

What is focal length and how does it affect my photos?

What is focal-length? Are focal-length and zoom synonymous? How does the focal length of a photo affect it? Are there common uses for different focal lengths, and how can I decide what to use when?
24
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4answers
5k views

Why buy prime super telephoto lenses instead of zoom super telephoto lenses?

35mm and 50mm primes make perfect sense to me: sharper images, simple operation, and framing can usually be handled by taking a few steps forwards and backwards. I'm struggling to see how one would ...
23
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5answers
7k views

Why doesn't the picture become darker the more you zoom in?

As your lens's focal length gets longer, fewer photons pass through the lens to hit the mirror/sensor. Why don't you see darkening when you look into the viewfinder and zoom in with a zoom lens, and ...
23
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7answers
3k views

Which scenarios are better shot with a prime lens versus zoom lens or macro lens?

What scenarios are better shot with a prime lens? A zoom lens? A macro lens?
21
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5answers
4k views

Why choose an 80-200mm over an 18-200mm lens?

Being a beginner, I can't see why I must choose an 80-200 over an 18-200. Are there scenarios where an 80-200 would be preferable over an 18-200? I will be buying a D7000 soon and am looking at these:...
21
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3answers
6k views

Fast prime vs. expensive zoom for indoor sports photograhy?

I plan to try shooting my kids' indoor activities (Tae Kwon Do and Figure Skating). I can get pretty close to the action for TKD, and I have access to ice/board level positions for shooting at the ...
20
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2answers
5k views

Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?

Why does a camera's maximum (allowed) aperture get smaller when you increase its zoom?
19
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10answers
5k views

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

Question updated/clarified I'm looking to perform feature identification on small tick/bug/mite-like creatures approximately 0.3mm to 1mm in size. I'd prefer to be able to project magnified images ...
18
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5answers
12k views

How does changing focal length affect depth of field?

I'm curious about how my "area of acceptable focus" changes when the focal length of the lens I'm using changes as I zoom (or switch lenses). In particular, I'd like to know how the front & back ...
18
votes
6answers
9k views

Why are push/pull zooms relatively rare?

The Canon EF 100-400mm f/4.5-5.6 L IS USM has a push/pull zoom mechanism instead of a zoom ring. Other lenses, like the Nikon 80-200mm f/2.8 AF that was released in 1988, use this type of zoom too, ...
17
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10answers
3k views

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

I'm a hobby photographer. I like taking portraits, which I often do at festivals and conventions. I usually take the following gear: Fujifilm X-T2 (an APS-C sensor mirrorless camera), a 16-55mm f/2.8 (...
17
votes
11answers
7k views

What is the best lens for taking photos of birds?

I was using a Panasonic Lumix, now I finally got a Canon EOS 60D, but I was used to that 18x zoom that my old camera has, because you can't get too close from the birds to take pictures, since they ...
17
votes
5answers
70k views

What's the advantage of buying a fixed 50mm f/1.8 lens when my camera has an 18-55mm zoom lens?

I've got a Nikon D3100 with an 18-55mm zoom lens. I'm keen to experiment with some other lenses and a friend of mine recently reccommended I purchase a fixed 50mm f/1.8 lens as he said it's good for ...
16
votes
4answers
37k views

Why prefer the 18-55mm and 55-250mm lenses vs 18-200mm?

There seems to be a preference for to have the 18 mm - 55 mm 55 mm - 250 mm lenses, but no mention of why they're better than a single 18-200mm. Could someone please explain why the two separate ...
16
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6answers
4k views

Why do we talk about focal-length when frame sizes are different?

I keep seeing people talking about focal-length of lenses without saying how large the frame is. Is there a more sensible way to talk about how much a lens “zooms”? (I have seen so many adverts etc ...
15
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2answers
47k views

What is the meaning of W and T on a camera's zoom buttons?

On every conventional digital camera (excluding the models with detachable lenses), there are buttons to zoom in and out with W side and T side. When you press W, the lens zooms out. The lens zooms ...
15
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6answers
1k views

Overlapping vs. Complementary lenses

I'd like to know if anyone has any advice or experience they can share about using a pair of zoom lenses that have overlapping focal lengths; or a pair of zoom lenses that have adjacent focal lengths. ...
15
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3answers
18k views

What is the technical difference between focus and zooming?

This may look like a silly question but I don't know what the difference between zooming and focusing is. Zooming in will usually let me have fewer subjects in the scene while zooming out will allow ...
15
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8answers
2k views

Would a prime be redundant with a fast zoom?

Now that I am finally getting a fast zoom (Tamron 17-50mm 2.8) I've been considering a fast prime to go with it, specifically a Sigma 50mm 1.4. Despite its shortcomings, it still does really nice ...
14
votes
2answers
7k views

What differences between point and shoot zoom versus DSLR zoom cause the price disparity?

I'm just getting into the world of photography, stepping up from a point-and-shoot. I've just purchased a Nikon D3100 and it should be here in a couple of days. I've done lots of research, but ...
13
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10answers
4k views

Do photographers avoid using zoom?

Because most lenses do no have a fixed aperture, do most photographers avoid using zoom as to avoid messing up their settings and their established exposure?
13
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4answers
4k views

How can a lens like a 18-55mm have more than one focal length?

How can a lens have a range of focal lengths? Shouldn't it be a single number? Isn't focal length supposed to be fixed for a lens of a particular shape and geometry? What am I missing? How many ...
13
votes
4answers
1k views

Other than speed and weight, what advantages might a prime lens have over a zoom at the same focal length?

At the same focal length, apart from speed and maybe weight, what other advantages does a prime lens like the 50mm have over a zoom lens like the 24 - 70mm? To put it better, If I set my 24-70mm lens ...
13
votes
3answers
2k views

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

Does the aperture ring lock the apertures beyond, say 5.6 at length lens's telephoto end? Does the lens introduce an obstacle to the aperture ring so the lens can't be opened anymore beyond the ...
13
votes
4answers
19k views

How do zoom, magnification, and focal length relate?

Zoom lenses and cameras with superzooms are often sold with a times ("×") zoom number — like a 12x zoom or 30x zoom. The question How do I convert lens focal length (mm) to x-times optical zoom? ...
12
votes
4answers
4k views

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

Obviously the biggest hybrid zoom on the market (Nikon Coolpix P900 I think) does not range from actual 24 mm to 2 meters in physical length, but what kind of optical systems do manufacturers use to ...
12
votes
11answers
4k views

How should I approach deer to photograph them?

I currently live in suburbia and there's a large field behind my house. Since yesterday I've noticed 3-4 deer grazing there. I've approached them three times at varying times of day and haven't been ...
12
votes
5answers
3k views

Is it problematic to mount a Canon EF 100-400mm f/4.5-5.6L lens on Rebel XSi (450D) body?

I have a Canon Rebel XSi (450D) and I'm going on a two week trip to Argentina and Patagonia where I want to try some wildlife photography. I have the kit 55-250 f/4.5-5.6 lens which I like, but I ...
12
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2answers
4k views

Does a greater optical zoom range on a lens mean less image quality?

I have read that big optical zooms of let's say 10X do not produce excellent image quality. Is this true even nowadays, as there have been many technological improvements in this area? For example, ...
11
votes
6answers
4k views

What are the pros and cons of non-extending zoom lenses?

Apart from the obvious benefit of not changing the center of gravity, what are the technical pros and cons of zoom lenses that do not change "physical length" when changing the focal length? For ...
11
votes
6answers
533 views

On smaller prints, will a high-quality zoom lens provide near equal image quality compared to primes?

Let's say I shoot with Canon EF 35mm f/1.4L, Canon EF 50mm f/1.4, and a Canon EF 85mm f/1.8. Can these 3 primes be replaced with a Canon EF 24-70mm f/2.8 for the convenience of not needing to change ...
11
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5answers
2k views

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

I'm an engineer, and we have a need to take pictures of railcar seals (steel ties as pictured) from on top of the building. What I need is a camera with sufficient zoom so we can clearly see whether ...
11
votes
4answers
344 views

What are important considerations when purchasing a zoom lens?

What should I be aware of when buying a zoom lens (other than that it will fit my camera)? What specs should I pay close attention to?
10
votes
11answers
10k views

How to photograph distant objects (10km)?

How to photograph distant objects like man and cars, with resolutions enough to identify face and car numbers? I'm looking for suggestions and cost, 10km range, with good sun light. Thanks. Please ...
10
votes
6answers
1k views

Why are 50mm no longer the default kit lens for prosumer SLRs?

Every time someone asks me for a kit recommendation I point them towards some sort of prime lens with a standard focal length. Similarly, almost anyone I talk to about the ideal budget kit swears that ...
10
votes
4answers
3k 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 ...
10
votes
5answers
2k views

Why do fixed lens cameras have a motorized zoom while interchangeable lens cameras don't?

I would like to know why motorized zoom (controlled by a W/T lever) is always on fixed-lens cameras and never on interchangeable lens cameras.
10
votes
7answers
18k views

How do I get the best results for sports with a 70-200mm f/2.8?

Can anyone help? I am using a nikon d7000 for sports photography. My husband kindly bought me a sigma 70-200mm telephoto lens 2.8 as I shoot a lot of low light indoor sports. I have only just started ...
10
votes
4answers
662 views

Would a fixed or zoom telephoto lens be better for learning?

My daughter has a Nikon D-90 camera body and two prime f1.4 lenses 50mm and 35mm. She is interested in learning more, and I am curious which of a zoom or fixed telephoto lens would help her best? Is ...
10
votes
2answers
646 views

Max aperture on zoom lenses - stepwise or linear?

When zooming with lenses without a fixed max aperture, the change in aperture* that the camera displays is stepwise, usually in steps of thirds. But, is the max aperture really the same all the way as ...
9
votes
4answers
10k views

What does 'how much zoom' mean?

I have Canon 18-135 and 70-300 zoom lenses. People ask me how much zoom my camera supports. What am I supposed to tell them? "135 ÷ 18 = 7.5" and "300 ÷ 70 = 4.2"?
9
votes
7answers
1k views

Should I postpone buying a zoom lens until I've learned to zoom with my feet?

After several years of shooting with my point-and-shoot, I upgraded to an NEX-5R, with two prime lenses — a 35mm f/1.8 and a 19mm f/2.8. I don't have a zoom lens, not even the kit lens. I've been ...
9
votes
3answers
1k views

What is the technical name for a zoom lens which has a fixed maximum aperture?

What is the technical name for a lens which has the same maximum aperture throughout the entire zoom range?

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