maximum f-stop at DVinfo.net

Bill Porter · April 6th, 2007, 10:16 PM

"Max. F/Stop: f/1.8-3.0mm (when tapes are used)"

??

Ken Ross · April 7th, 2007, 06:50 AM

Bill, maybe they mean the HV20 doesn't record well without tape? ;)

Lloyd Coleman · April 7th, 2007, 08:41 AM

Bill, the quote by itself does not make sense to me. Where are you taking the quote from? Is it part of a heading or section with other specifications, referring to things that may change depending on if you are recording to tape or the memory card?

The specs section in the manual simply says "f=6.1-61mm, F/1.8-3.0, 10x power zoom" Besides the reference "when tapes are used", the quote you posted does not make sense using "mm" after the 3.0. The lens has a focal length that is traditionally measured in mm, but the f/stop is a fraction that represents the size of the aperture in relation to the focal length and does not reference or depend on the units used to specify the focal length.

The camera will function differently in some respects (portion of sensor used, options available, 35mm focal length equiv. etc) when recording video to tape versus still pictures to the memory card. Let us know if your quote was part of a section that was also describing some of these things that are dependant on the recording mode you are using.

UPDATE: I see that the specs section for the HV20 on Canon's website has the quote that Bill posted. I think it is just a mistake. As mentioned above, not only does the "tape" reference not make sense, neither does the "mm" after the 3.0. The only explanation I can think of that would make it work is if in the largest photo mode when the camera is using the full sensor area, the lens would not project an image that is large enough to cover the corners of the sensor when set at its widest setting. They could limit how wide the lens could go in this mode to prevent vignetting, which could also limit the maximum aperture. This explanation is a stretch and the spec as posted is probably just a mistake

Bill Porter · April 12th, 2007, 01:57 AM

Whether it's a mistake or not, we can't say.

However, "f=6.1-61mm, F/1.8-3.0" does make sense. It means "f(ocal length)=6.1-61mm, F/1.8-3.0".

April 6th, 2007, 10:16 PM	#1
Bill Porter Major Player Join Date: Mar 2005 Location: Ventura, California, USA Posts: 751	maximum f-stop "Max. F/Stop: f/1.8-3.0mm (when tapes are used)" ??

April 7th, 2007, 08:41 AM	#3
Lloyd Coleman Major Player Join Date: Oct 2003 Location: Salt Lake City, UT Posts: 256	Bill, the quote by itself does not make sense to me. Where are you taking the quote from? Is it part of a heading or section with other specifications, referring to things that may change depending on if you are recording to tape or the memory card? The specs section in the manual simply says "f=6.1-61mm, F/1.8-3.0, 10x power zoom" Besides the reference "when tapes are used", the quote you posted does not make sense using "mm" after the 3.0. The lens has a focal length that is traditionally measured in mm, but the f/stop is a fraction that represents the size of the aperture in relation to the focal length and does not reference or depend on the units used to specify the focal length. The camera will function differently in some respects (portion of sensor used, options available, 35mm focal length equiv. etc) when recording video to tape versus still pictures to the memory card. Let us know if your quote was part of a section that was also describing some of these things that are dependant on the recording mode you are using. UPDATE: I see that the specs section for the HV20 on Canon's website has the quote that Bill posted. I think it is just a mistake. As mentioned above, not only does the "tape" reference not make sense, neither does the "mm" after the 3.0. The only explanation I can think of that would make it work is if in the largest photo mode when the camera is using the full sensor area, the lens would not project an image that is large enough to cover the corners of the sensor when set at its widest setting. They could limit how wide the lens could go in this mode to prevent vignetting, which could also limit the maximum aperture. This explanation is a stretch and the spec as posted is probably just a mistake Last edited by Lloyd Coleman; April 7th, 2007 at 09:03 AM. Reason: Update

April 7th, 2007, 06:50 AM	#2
Ken Ross Trustee Join Date: Jan 2005 Location: New York Posts: 1,945	Bill, maybe they mean the HV20 doesn't record well without tape? ;)

April 12th, 2007, 01:57 AM	#4
Bill Porter Major Player Join Date: Mar 2005 Location: Ventura, California, USA Posts: 751	Whether it's a mistake or not, we can't say. However, "f=6.1-61mm, F/1.8-3.0" does make sense. It means "f(ocal length)=6.1-61mm, F/1.8-3.0".