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#1 |
Junior Member
Join Date: Jan 2007
Posts: 3
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Hi, i'm pretty new to the photography world, so be excuse my incompotence.
i would like to know what the numbers on the lens mean? i've done some research on the camera, Canon PowerShot SD700 IS (Digital IXUS 800 IS).. i found that the zoom wide is 35 mm and zoom tele is 140mm .. But on the camera it says 5.8-23.2mm 1:2.8-5.5 Can someone please kindly explain? thank you |
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#2 | |
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Join Date: Jan 2004
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jappy88 wrote:
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So your Canon's lens has a real focal length range of 5.8 to 23.2 mm, but since the sensor is a tiny 1/2.5" size, when you look through the viewfinder and consider the field of view produced on that tiny sensor, it's comparable to what you would see if you looked through a 35mm film camera 's viewfinder with a 35 to 140 mm zoom lens attached. So basically, for any of this to make sense you have to have some familiarity with the field of view produced by various lenses on a 35mm film camera. |
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#3 |
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Join Date: Aug 2004
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Yep, everything Norm said is in order.
The only thing I didn't see was an explanation of 1:2.8-5.5 Those are the aperture values. Most digicams (and many slr zoom lenses) cannot maintain a constant maximum aperture as you zoom. What these numbers mean is that when you are at 35mm the camera has a max aperture of 2.8. But by the time you zoom out, the max aperture becomes 5.5. |
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#4 | |
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JohnG wrote:
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#5 |
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Join Date: Dec 2002
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And as a touch more info, the human eye is roughly the equivilent to a 50mm lens. What this means is that the sizes of things in the image will generally match with what you see with your eyes.
So a 35-140mm zoom is a bit of a wide angle at 35mm. And the 140mm is about 3 times more powerful than your eyes. Eric |
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#6 | |
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Join Date: Feb 2005
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JohnG wrote:
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#7 |
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Join Date: Jan 2007
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thank you so much of the explanation guys. It is more apparently me now =)
Just one more question. What lens ranges are consider "good"? for example comparing with a lens that has 35-140mm zoom and 38-114mm zoom.. which one is better? thank you again |
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#8 | |
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Join Date: Jul 2005
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Howeverthere is no "best" range for anything. Choose whats best for your needs, they will not necessarily be best for everyone. 35-140 would be good for the casual snapper, its a good rangefor a smaller compact. I use an H1 with 36-432mm reach because I like telephoto. Others would prefer a wider camera for landscapes, say starting at 24mm or so. |
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#9 |
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Join Date: Jan 2007
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ok.. great.. thank you so much for your reply
=) |
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#10 |
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Join Date: Jan 2007
Posts: 154
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Since we are discussing lenses, is there a formula to convert mm to magnification? I know what 8x binocsprovide but I cannot relate magnification to a 200 mm lens for example.
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