Quote:
Originally Posted by olgap
I was hoping for a chart that would show how different focal lengths relate to subjects, shown in meters/cm.
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Don't know of anything that precise, but for vague generalties
, there's
a little Canon focal length demonstration that's a good ballpark guesstimate.
Another good source for basic lens information/descriptions, and what all the numbers and acronyms mean is this
lens primer.
Quote:
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While wanting to understand the subject, perhaps I should just have asked which lens for the D90 would be best for extreme closeups (flowers, insects, mosses, lichens, fungi) and which would be best for 'normal' shooting. From your explanation, I gather should I should buy the widest angle lens I can afford for closeups.
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Um... no. As Mr. Guy explained, you probably want a macro lens, which is optimized for close-focus work (I'd go into a tedious description of floating elements, but I don't want your head to explode
). A wider lens will let you get closer, but the perspective may make it look farther away and there can be distortion and vignetting (light falloff in the corners). With macro lenses, you may even want a longer focal length so you'll have more working distance.
Where you might want a wider lens is if you're planning on adding further magnification by reversing a lens in front of your macro lens. Magnification when reversing lens x on lens y will be y/x. So, if y is 100mm, and x is 50mm, you'll get 2x magnification; if x is 35mm, you'll get almost 3x. I think. It's been a while since I looked that stuff up.
As for general purpose shooting, most folks prefer a walkaround zoom, in the wide-to-normal range. The 18-55 kit lens that ships with my dSLRs is limited, but low-cost, and a good example of a walkaround zoom. But it won't come close to doing "everything else."