I want to educate myself and am immersing myself in everything photography-related. I'm picking up the concepts fast because I was a physics major in college (and thus have some background in optics) and am good with math.

For practice I offer free event, wedding, whatever photography, and can't get enough, plus I make loads of people happy who would otherwise not have photos of their events.

I want to diversify my lens arsenal (fast), and wanted to know how I can best come up to speed on lenses, their various attributes, and what they mean as far as how they translate to real world photos.

Does anyone have a simple quick-start guide on the subject?

I'm looking to solve some holes in my photo-taking and am find conflicting info on the web. Some say 50mm is good for landscapes and portraits, others say 75-200 is their go-to for weddings and events. I'm trying to make sense of all this and get it clear in my head to the point I can make the correct selection in my next lens purchase.

Mainly, I'm looking for in-home or restaurant events — so, low light, people, and motion are involved. I'm a Nikon D7000 user.

Help me help myself....


There is one very simple way of looking at things: the picture you want is the one where your position in relationship to your subject and the background makes the subject look the way you want. The length of the lens can only change the framing.

The reason why something in the 85-105mm range for a full-frame 35mm camera is "good for portraits" is that it allows you to be three to eight feet away from the subject (a natural distance for social interaction) and get a head-and-shoulders to half-height sort of framing. There's nothing magical about the lens -- you'd get exactly the same picture if you used a 50mm from the same position and cropped afterwards -- including having the same depth of field at the same aperture and distance (modulo the effects of the physical layout of the sensor elements, which very slightly changes the game in the digital world). And you'd have to throw away a lot of data as well, whether you're working in the digital or film world.

The upshot is that the "right" lens is the lens that lets you take the picture you want to take with minimum cropping after the fact.

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    I am, of course, disregarding highly specialised lenses, like tilt/shift lenses, lenses that change field curvature, fisheyes and microscopic lenses -- if you need any of these, it's for a reason, and you'll know what that reason is going in. – user2719 Dec 20 '10 at 23:55
  • A 50 f/4 does not have the same depth of field as a 100 f/4. See photo.stackexchange.com/questions/4928/a/4952#4952 – Evan Krall Dec 21 '10 at 1:02
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    The lens-to-film distance changes with the focal length as well (meaning that the apparent size of the lens, and the "obliqueness" of the incident light) also changes. Until you get to focusing distances that require exposure compensation, yes, depth-of-field is a function of distance and aperture, not focal length. – user2719 Dec 21 '10 at 1:11
  • Not magic but the 70-100mm range is considered to give a flattering perspective most people. As you may know, longer lenses reduce the impression of distance and so it makes people's noses look shorter. I suppose they may not like that in Asia ;) but it least most North-American photography books describe it that way. – Itai Dec 21 '10 at 2:41
  • so with my beak i need a telephoto lens then? – kacalapy Dec 21 '10 at 14:12

Here is a lens buying guide that starts with the basics of lenses and explains how to chose a lens according to different needs. It's aimed at beginners.


You could check out my new site (shameless plug): http://lenshero.com, it lets you see all lenses compatible with a camera, and browse by type, for example low light lenses for the D7000.

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    great but for a noob its hard to make a good choice. im thinking my best bet would be to rent a few lenses and play with them prior to making any purchase, as i have no experience with lenses and would be buying my 1st non-kit lens. nice site, but my dilemma is not knowing good from junk, and i would save to get good lenses if i knew they were worth it and the results/ difference they produce compared with others. any thoughts on this? – kacalapy Dec 21 '10 at 14:25
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    Renting sounds like a great idea. – Alex Black Dec 21 '10 at 14:30

You definetly want to check out http://www.pixel-peeper.com/lenses/ where you can find out full-size sample photos from lenses. You can search pictures taken classified by lens model, focal length, aperture... and then compare them.


I suggest borrowing a range of lenses and trying them out. Get a sense of how they work in reality; a theoretical understanding can only take you so far. Try shooting in different conditions (bright sunlight, low-light, subtle shades and vivid colours), and play around with the range of apertures and focal lengths available for each lens.

The easiest and cheapest way of borrowing lenses is to find a local photography group. Try Meetup or searching the net. Most photographers would be happy to lend their gear out for an afternoon or evening.

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