72mm Vs. 58mm Lens at DVinfo.net

Joel Corral · January 4th, 2005, 10:32 PM

Sorry for the novice sounding question but is a 72mm lens, for instance the one on my HDR-FX1 at 12x zoom Equivalent to, Greater than or Less than (meaning zoom distance) than my 58mm Canon Gl2 at 12x (the Gl2 can Zoom To 20x but hypothetically speaking @ 12x for comparison). I would think that the 72mm at 12x would zoom in closer than a 58mm at 12x. am I not correct? If so what is the equation if there is one.

thanks

joel

Stefan Scherperel · January 4th, 2005, 10:52 PM

The diameter of the lens has nothing to do with the focal length. A 50mm lens projected on a 1/3 inch chip will have the same field of view and focal length whether it have a 32mm diameter or 132mm diameter. The only thing that will change your filed of view would be the sive of the sensor that it is being projected on. Therefore, if you have a 1/3 in chip it is a telephoto field of view, whereas a 50mm lens on a medium format camera will be slightly wide angle.

Barry Green · January 5th, 2005, 12:00 AM

Right -- you have to compare focal length, and the field of view at that focal length, which is dependent on chip size. You can't just directly compare them because the FX1 is a 1/3" chip, and the GL2 is a 1/4" chip.

At any given equal focal length, the GL2 would look more "telephoto" than the FX1 would, because of the chip size.

The FX1 at 12x zoom would have about the same field of view as the GL2 lens at 10x zoom.

Joel Corral · January 5th, 2005, 12:10 AM

thank you for making that clear to me.

damn i really need a telephoto lens that isn't 1,000 bucks!!!

joel

January 4th, 2005, 10:32 PM	#1
Joel Corral Major Player Join Date: Nov 2003 Location: Brea, CA Posts: 356	72mm Vs. 58mm Lens Sorry for the novice sounding question but is a 72mm lens, for instance the one on my HDR-FX1 at 12x zoom Equivalent to, Greater than or Less than (meaning zoom distance) than my 58mm Canon Gl2 at 12x (the Gl2 can Zoom To 20x but hypothetically speaking @ 12x for comparison). I would think that the 72mm at 12x would zoom in closer than a 58mm at 12x. am I not correct? If so what is the equation if there is one. thanks joel

January 4th, 2005, 10:52 PM	#2
Stefan Scherperel Major Player Join Date: Dec 2003 Location: Seattle WA Posts: 209	The diameter of the lens has nothing to do with the focal length. A 50mm lens projected on a 1/3 inch chip will have the same field of view and focal length whether it have a 32mm diameter or 132mm diameter. The only thing that will change your filed of view would be the sive of the sensor that it is being projected on. Therefore, if you have a 1/3 in chip it is a telephoto field of view, whereas a 50mm lens on a medium format camera will be slightly wide angle.

January 5th, 2005, 12:00 AM	#3
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Right -- you have to compare focal length, and the field of view at that focal length, which is dependent on chip size. You can't just directly compare them because the FX1 is a 1/3" chip, and the GL2 is a 1/4" chip. At any given equal focal length, the GL2 would look more "telephoto" than the FX1 would, because of the chip size. The FX1 at 12x zoom would have about the same field of view as the GL2 lens at 10x zoom.

January 5th, 2005, 12:10 AM	#4
Joel Corral Major Player Join Date: Nov 2003 Location: Brea, CA Posts: 356	thank you for making that clear to me. damn i really need a telephoto lens that isn't 1,000 bucks!!! joel