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Old Jan 17, 2010, 12:19 AM   #1
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Default DX format and 1.5x crop factor

Does the 1.5x crop factor apply to DX format lens?

In other words, is the focal length for a 18-70mm DX lens shown in 35mm equivalent?
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Old Jan 17, 2010, 12:37 AM   #2
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actually it applies to all lens if the sensor is a aps-c sensor. It does not apply if your camera is full frame.
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Old Jan 17, 2010, 12:58 AM   #3
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okay, so even on DX lens you have to multiply 1.5 to get the 35mm equivalent?
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Old Jan 17, 2010, 1:13 AM   #4
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Quote:
Originally Posted by NothingRare View Post
okay, so even on DX lens you have to multiply 1.5 to get the 35mm equivalent?
yes, all lenses from all manufacturers (even micro 4/3 system lenses) are rated at their 35mm full frame, so you must apply the appropriate crop factor to any lens.
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Old Jan 17, 2010, 1:19 AM   #5
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Hards

You beat me to the answer.
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Old Jan 17, 2010, 7:14 AM   #6
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The Focal Length of a lens is a physical property of that lens, and doesn't change with the size of the sensor that it projects an image onto.

The 'Crop Factor' is a crutch that people with experience in 35mm film photography use to associate what they know about the angle of view of a lens on a film SLR with the angle of view the same lens would provide on an APS-C dSLR. If you don't have any (or even much) experience with 35mm film SLRs, 'Crop Factor' is meaningless to you.

A DX Format Lens is a lens that can project a complete image onto the smaller APS-C size image sensor, but when it is used to project an image for a 'Full Frame' dSLR or a 35mm film SLR, will produce severe vignetting on the areas of the frame outside the image it can project. When using an APS-C dSLR, there is no difference between a DX format lens and any other lens.
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Last edited by TCav; Jan 17, 2010 at 8:46 AM.
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Old Jan 18, 2010, 11:41 PM   #7
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I understand now, thanks for your replies
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