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Old Jul 24, 2009, 7:16 AM   #1
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Default Going nearer to the subject Vs. Zoom

I am about to buy a DSLR body and a lens. Was deciding whether to buy a prime or a zoom lens. Prime lens look good since it is faster. However, I would like to ask in order to compensate for the lack of zoom, can we just move closer to the object and get the same result, in terms of field of view? For example, if your subject is a man standing behind a church and you want to cover his full body, you can use a zoom lens and still able to capture the background which is the church. However, I am afraid if you used a prime lens and move nearer to the subject, your background will be gone. Thanks.
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Old Jul 24, 2009, 8:33 AM   #2
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It's called "zooming with your feet."

With a fixed focal length lens, you can't adjust the angle of view, but what you can do is adjust your vantage point, and frequently you can adjust the position of your subject.

For instance, in the example you give, you can pick a vantage point that gives a good perspective of the church, and then position the man within the frame so you get the composition you want.

What makes shooting with a fixed focal length lens a good learning experience is that it forces you to take your time and consider everything that makes an image. A zoom lens, on the other hand, lets you take the shot and move on. Both techniques have their advantages, but if you want to take photographs instead of snapshots, you will learn the difference faster with a fixed focal length lens.

Get one of each! The newer kit lenses are all relatively good, and large aperture fixed focal length lenses can be relatively inexpensive. Get the 18-55 kit lens and a 50mm f/1.8, and shoot with both.
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Old Jul 24, 2009, 9:04 AM   #3
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TCAV has given you good advice. I would also STRONGLY recommend getting a kit lens. One of the areas where you'll suffer with just using a prime is wide angle. The kit lens in any system will give you that capability. It simply isn't always possible or practical to move far enough away to get the framing you want with the equivelant of 50mm lens (or whatever focal length you choose).
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Old Jul 24, 2009, 9:28 AM   #4
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One of the main reasons for getting a dSLR camera is so you CAN change lenses to get different effects. While I find myself using primarily prime lenses, I won't do without a couple of zooms. The kit lenses are usually excellent value for your money - reasonable quality for not very much money are are always a good buy. And yes, there are times when you can't get the shot you want with a prime lens and zooming with your feet - you'd have to either use a zoom or a different prime lens. For instance, a 50mm f1.8 lens won't help you much if you want to shoot pictures of wolves in Yellowstone National Park. There is a time and place for both zooms and primes, and half the fun of photography is trying to figure out which will work the best for what you have in mind.

I also agree with TCav, that zoom lenses can make a photographer lazy (it's easy to stand in one spot, twirl the zoom and snap some pictures). That can often lead to missed opportunities, where if they had moved a bit to one side or another, they would have gotten a much better composition. Primes do force one into walking around their subject and really LOOKING at a scene, to figure how best to capture it. Always a good habit to get into, regardless of what type of lens you are shooting with.
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Old Jul 24, 2009, 9:47 AM   #5
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Quote:
Originally Posted by maisatomai View Post
...However, I would like to ask in order to compensate for the lack of zoom, can we just move closer to the object and get the same result, in terms of field of view? For example, if your subject is a man standing behind a church and you want to cover his full body, you can use a zoom lens and still able to capture the background which is the church.
Your distance to the subject will impact Perspective.

If you use a wider focal length lens and move closer for the desired framing, you'll notice that the closer subject will appear to be larger (out of proportion) compared to the size of the background portions of the frame. That can be helpful for exaggerating subject features. Shooting from a closer distance to your primary subject can help something in the background appear to be further away (as in the church in your question).

If you shot from further away using a longer focal length lens, framing so that your closer primary subject occupied the same percentage of the frame, you'd end up with a more compressed background (flatter appearance to the image). Depending on how far away the church is compared to the person closer to the camera, you may not be able to fit all of it into the frame that way either.

So, the focal length you use is important in order to get the desired perspective, even if you're using your feet for zoom.

If you scroll down on this wikipedia page, you'll see some examples showing the impact of shooting at different distances with different focal length lenses, while keeping the framing so tha the foreground subject occupies the same percentage of the frame.

http://en.wikipedia.org/wiki/Perspective_distortion_(photography)

Here's an interesting thread where we were discussing the pros and cons of different focal lengths and shooting distances for automobile shots. You'll find some links to examples of shooting from a closer distance with a wider lens, as in the screen capture showing a shot of a Ferrari.

http://forums.steves-digicams.com/wh...ar-dealer.html

But, you may not always want to shoot that way (deliberately exaggerating the closer portions of the image for effect by using a wider focal length and shooting from a closer distance). So, having more than one focal length lens can be a good idea.
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Old Jul 24, 2009, 10:45 AM   #6
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Of course, you're also constrained by your surroundings. You may need to use a wider focal length lens to fit what you need to into the frame, since you may not be able to back up far enough with a longer focal length lens.

Here's an example of a shot using a 24mm zoom setting with a Sony A700 with an APS-C size sensor (giving you roughly the same angle of view you'd have using a 36mm lens on a 35mm camera). Had I tried to use a longer focal length, I may not have been able to get the desired framing (as the room was not that large). I did take some more from different angles, as well as head and shoulders type shots of the same subjects (and some outside where had some room).

This shot just stood out as having more issues with perspective and I figured it would make a good example here. Note the impact shooting from a closer distance with that focal length had in the attached image.

You've got an undesirable perspective with the closer portions of the image appearing to be larger than they should be in comparison to the size of the background portions. For example, the boot that's closer, and the apparent size of the closer legs and knees compared to the subjects' torsos.

But, you can't always back up enough for the desired framing and perspective. So, having more than one focal length lens is a good idea.

As already pointed out, I'd get the kit lens with any camera you choose. Most dSLR models are available with an 18-55mm kit lens that doesn't add much to the cost of the camera. That way, you'll have more flexibility in more conditions. That would also give you a chance to learn more about what you may want in lenses (focal lengths you may want to use more often, etc.) so you can make better informed decisions on future purchases.
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