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Old Jan 2, 2006, 7:21 AM   #1
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I feel stupid not knowing.

How does a macro lens differ from a normal telephoto lens?

Also when they say the lens takes life size close ups, what does THAT mean? If I take a photo of an ant I want it to be bigger than life size. Does it mean it appears life size on the sensor?
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Old Jan 2, 2006, 8:28 AM   #2
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I'll take a whack at this one...
Others can then laugh and correct me. :shock:
Macro basically means that the lens will focus closer than a normal lens. If you can focus closer, then the subject will appear larger in the frame. 1:1 is life size, and 1:2 is half life size. I am not aware of any lens that will focus larger than 1:1, but I have not looked for one either.
If you want to fill the frame with that ant, your lens will need assistance. The easiest way is probably to use extension tubes. This moves the lens farther from the sensor and the result is that you have to move the camera closer to the subject in order for it to be in focus. When you move closer, the ant becomes larger in the frame, and with the right extension tube(s), the ant will fill the frame.
Of course, there are trade offs. The major one is that, (for simplicity), the closer you get to the subject, less of it will be in focus - maybe only 1mm.
Hope this helps.
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Old Jan 2, 2006, 12:33 PM   #3
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Adding tosurfnron'scomments - macro lenses are usuallynot formulated to focus at infinity. Many normal lenses canfocus fairly close but notas close as 1:1. The 1:1 is image size to object size. If you had a stamp that measured 24x36mm ( the same size as a 35mm filmframe) it would be at 1:1 if its image was 24x36 on the film. At 1:2, it would be captured as 12x18 etc. If you wanted the stamp image recorded larger than its actual size, say 4:1, you could either move the lens further from the film or sensor oruse magnifier or microscope attachementsto produce a larger than life size image. One other point- the focal length of a macro lens doesn't change its range(eg.1:1).Itchanges theworking distance from the front of the lens to the subject. If you photograph an object like a stamp or coin, theFL affects howeasily you can illuminate the subject. However, with a live subject like a butterfly, a longer FL helps keep you from scaring it away.
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Old Jan 3, 2006, 3:54 PM   #4
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Ahhh. Thankyou both.I understand now.
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Old Jan 4, 2006, 11:34 PM   #5
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Canon does have a 5:1 macro, a 65mm manual focus? Check their lens lineup. It costs $800 though. You'd need a flash to illuminate your subject but it will fill your screen with an ant, or grain of rice, whatever. Fun!
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