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56

The "times zoom" notation is simply the big number divided by the small one, so the examples you give are correct. "3x zoom" simply means the longest focal length is three times the shortest. This number really isn't very useful, though. On point and shoot cameras, it became popular because the starting focal length was generally about the same across all ...


46

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, isn't your shot composition always at the mercy of how close or far away your subject is, meaning heavy cropping is almost always necessary in post? It's ...


43

No, it does not have much use. Digital zoom is a restricted form of cropping: It is always done around the center. It is constrained to certain fixed increments. It is limited in quality by the firmware of the camera. On the other hand, cropping can: Be of arbitrary size. Be taken from any part of the image. Be processed using a variety of state-of-...


29

There is no simple relationship between the physical length of the lens and its focal length. For example, a retrofocus wide angle is generally longer than its focal length, while a telephoto lens is shorter than its focal length. Inside a zoom, you have several lens groups that move independently. The focal length of the zoom depends on the relative ...


29

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 range as the other four lenses you mentioned. All of the other lenses focal ranges are parts of the large range of the 18-200 mm lens. The 18-200 can surely ...


27

These letters refers to zooming depth as follows, W = Wide angle T = Telephoto Read more about wideangle and telephoto in the tags.


26

The focal length of a lens determines its field of view on your camera. If it has a long focal length, it has a narrow field of view, making the things in front of you appear large in the photograph. If it has a short focal length, it has a large field of view--it's a "wide angle" lens that takes in a large area, making objects appear small. A "zoom lens" ...


26

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 are plenty of fixed aperture zoom lenses available at a range of focal lengths, so it's safe to say that photographers don't have to avoid zooms just to have ...


25

The biggest reason for difference in the two lenses is aperture. The 80-200mm is a constant f/2.8 throughout the focal range and the 18-200mm varies from f/3.5 to f/5.6, so substantially slower, especially at the far end. All this really means is that the 80-200 can let in more light at the same focal length over the other. Also, generally, zooms with ...


23

Technically 'Telephoto' means that the focal length [the mm] is longer than the lens is. In my experience, people in the photography world usually don't talk about it under that definition. Most of the time people say 'Telephoto' they just mean 'zoomed in' or in other words 'high mm' or 'long focal length' As has been mentioned, Nikon seems to say that 85mm ...


22

At 50mm on your 18-55, the max aperture is f/5.6. On the 50mm f/1.8, the max aperture is - obviously - f/1.8. It is perhaps not immediately obvious, but f/1.8 lets in 10-12 times more light than f/5.6. That is the difference between shooting at 1/10 second shutter speed (which is absolutely a no-go for moving subjects) and shooting at 1/100 (which is a ...


20

A range of focal lengths indicates a zoom lens. There are two major classes of lenses. Primes, or primary lenses, have a single focal length. They tend to be higher quality, as there can be fewer lens elements, and fewer moving element groups. One exception to this rule is super telephoto prime lenses, particularly faster lenses (f/2.8), which are some of ...


20

I think an important advantage is saving time. When you happen to shoot hundreds of photos in a row stuck with a lens wider than would be optimal, cropping each one of the images into a smaller size in post processing would be quite tedious - usually you can't do that in batch unless you really don't care about resulting framing. Framing on spot, on the ...


20

The short answer is because it is cheaper to manufacture such lenses. The longer the lens and the wider the aperture, the larger the optical elements in the lens - thus larger the expense to produce them. A lens like 70-200/2.8 must have a front optical element of 200mm/2.8=72mm, which is quite a chunk of glass. On the other hand, the 70-300/4-5.6 needs to ...


20

Presumably because the people who buy their first DSLRs mostly come from the point-and-shoot world and care about the versatility afforded by the zoom more than about image quality. Also, a 50mm is way too long to be a good "default" lens with an APS-C camera, and good-quality ~30mm lenses are, due to certain quirks of optics, much more complex (and thus ...


19

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.


19

The entrance pupil can not be any larger than 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. The physical size of the diaphragm is only part of what determines the maximum aperture, expressed as an f-number, of a lens. Magnification ...


17

Focal length is a measure how the lens focusses the light into a point. When light enters a 50mm prime lens, the light converges into a point the camera sensor after 50mm. In addition the focal length determines the magnification of the object you photograph. A long lens (e.g. 300mm) magnifies the images a lot (useful for birding) while a short (wide angle) ...


17

I'll tackle this from the assumption you're looking for the best lens, money no object (as you indicate). The best lens will be the Canon 500L f4 IS, 600L f4 IS or 800L f5.6 IS mounted on a gimbal mount on a very solid tripod rated in the 20+lbs area. Which of these is the one for you comes down to a couple things. Focusing speed: The 800mm will have ...


17

Since your question is "What am I supposed to tell them?", I'm going to go a little bit off the literal math with my answer. What you should say is: The more "times-zoom" a lens has, the more compromise on image quality it has to have. Since my camera allows me to change lenses, I can have the flexibility of a huge zoom range without compromising on the ...


17

Same photo will result from using digital zoom or cropping. Advantage of digital zoom: you don't need a computer to crop it. You can upload straight to Facebook, print it out, etc. Cropping is a very common post-processing technique and this lets you do it easily, on the fly. Advantages of cropping after the fact: you can take more time to compose the crop ...


17

Image quality. The wider the range of focal lengths on one lens, the more design compromises are made and the more correction must be applied deal with things like geometric distortion, chromatic aberration, and light fall off in the corners. Aperture. Even though the EF-S 18-200mm f/3.5-5.6 has the same maximum aperture of f/5.6 as the EF-S 55-250mm f/4-5.6 ...


16

As an owner and user of both the 450D and the EF 100-400mm, I can offer some help here. From a construction, durability, and handleability perspective, using the 100-400mm on the 450D will definitely not be a problem. Both the camera and the lens are durably built, and the lens mount can handle a considerable amount of rugged use and rough handling. The ...


16

If your camera only saves in JPEG, using digital zoom instead of cropping later avoids IQ loss from compressing twice. This is usually minor, but there it is.


16

A prime likely still has several advantages over a zoom at a given focal length. (Well, depending upon your needs and habits.) A less complex optical design. All else being equal, a less complex design is likely to have fewer compromises, which means the prime is more likely to have less distortion of any sort -- pincushion, barrel, coma, and chromatic ...


15

Constant-Aperture Zoom Lens.


15

The two generally control two different aspects of the image projected by the lens. Focusing sometimes has the effect of changing "zoom" a little as well, however its purpose is different. To keep it simple: Focus adjusts the Focal Plane The focal plane is the thin plane of reality that is focused clearly on the imaging medium Focusing moves this plane ...


15

No, the lens does not zoom automatically. Almost all SLR zoom lenses are zoomed using the zoom ring, very few have a motorized zoom mechanism.



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