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Old Jul 1, 2010, 1:19 PM   #1
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Default Question about mm

Yet another question that popped to my head...but before I ask it i really want to thank all the members for the knowledge they are sharing.

Now to the question.

I have a p&s camera that says on the lens 6mm-60mm. Does a 70-300mm lens goes 5 times farther than my p&s? Can anyone explain it to me? Thanks.
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Old Jul 1, 2010, 1:43 PM   #2
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The focal length of a lens is an indication of how much it bends light. But the angle of view is determined not just by the focal length, but also the size of the image sensor. dSLRs have large image sensors, so they need longer lenses to get the same angle of view as a camera with a smaller image sensor and a shorter focal length.

See 'Focal Length' and 'Crop Factor' for more info.
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Old Jul 1, 2010, 2:32 PM   #3
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Quote:
Originally Posted by TCav View Post
The focal length of a lens is an indication of how much it bends light. But the angle of view is determined not just by the focal length, but also the size of the image sensor. dSLRs have large image sensors, so they need longer lenses to get the same angle of view as a camera with a smaller image sensor and a shorter focal length.

See 'Focal Length' and 'Crop Factor' for more info.

Gotcha. Now, how can i know the equivalent of the 60mm on my p&s on my dslr?
I need to know the size of the sensor in my p&s, right?
let's say it's 1 inch. so for a camera with a 2 inch sensor i would need a 120mm lens?
How can i find out the size of the sensor on my p&s?

Hope I got it right
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Old Jul 1, 2010, 2:37 PM   #4
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Well, in general, it's actually easier to get the 35mm equivalent focal length from the EXIF data in an image, or from the manufacturer's specs. Do you have a program that can read the EXIF data, or do you have an image you've posted somewhere that has it's EXIF data intact. or can you say what the manufacturer and model number of your camera is?
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Old Jul 1, 2010, 2:42 PM   #5
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Its a SX100is Canon.

About the photos, I'm still quite shy about posting. Hope it'll go away soon.
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Old Jul 1, 2010, 3:44 PM   #6
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From Canon's website on the SX100is:

Focal Length 6.0-60mm f/2.8-4.3 (35mm film equivalent: 36-360mm)
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Old Jul 1, 2010, 4:19 PM   #7
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So in order to match the reach on my T1i which is a 1.6 crop body, i need what lens?
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Old Jul 1, 2010, 6:13 PM   #8
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A 35mm Equivalent focal length of 360mm on the Canon T1i, which has a crop factor of 1.6, would take a 360mm/1.6, or 225mm focal length lens.
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Old Jul 2, 2010, 2:01 AM   #9
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Got it. Thanks!
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