back focus and 1.6 x extender at DVinfo.net

Bruce Moore · May 9th, 2002, 06:55 PM

I seen a few people on these topics state that the 1.6 x is "softer" than Canon's 2x for 35mm( if you use it on an XL-1).
So my questions are:
1.) Why would canon do that?
2.) Could it be the back focus of the standard 16x and the camera.

I know when you send the XL-1 in for an annual cleaning, they check the back focus BUT does the 1.6x throw it out of focus by a hair since it is not part the back focus adjustment.

Chris, don't be shy, please add your 2 cents.

Bruce

Chris Hurd · May 9th, 2002, 07:36 PM

I'm not shy, just ignorant! This is a question for those more learned than me.

Bruce Moore · May 9th, 2002, 08:16 PM

YODA, I don't think I heard you!

Jeff Donald · May 19th, 2002, 06:43 PM

Hi,

I have played with the video 1.6X converter and I own the Canon 1.4X and the 2X converters. The 1.6X does not appear as sharp to me. My personal opinion is that it is not a back focus issue. I believe the two 35mm converters are sharper for two reasons. The 35mm converters cover more than the 1/3 inch chips. Only the center portion of the converters are used. The center of a lens is always the sharpest and best corrected portion of the lens. The second reasons is the quality of the lenses placed in front of the converters. The 35mm Canon EOS lenses run rings around the video lenses for sharpness, contrast, resolution etc. Canon now publishes MTF graphs for their 35mm lenses. I have not been able to find them for their video lenses. Why? Because the 35mm lenses are much better and Canon probably does not want that kind of comparison being made. Kind of an apple and oranges thing.

Jeff

Bruce Moore · May 19th, 2002, 06:48 PM

jeff,

Thanks, makes sense.

Bruce

May 9th, 2002, 06:55 PM	#1
Bruce Moore Regular Crew Join Date: Oct 2001 Location: Glendale, AZ Posts: 57	back focus and 1.6 x extender I seen a few people on these topics state that the 1.6 x is "softer" than Canon's 2x for 35mm( if you use it on an XL-1). So my questions are: 1.) Why would canon do that? 2.) Could it be the back focus of the standard 16x and the camera. I know when you send the XL-1 in for an annual cleaning, they check the back focus BUT does the 1.6x throw it out of focus by a hair since it is not part the back focus adjustment. Chris, don't be shy, please add your 2 cents. Bruce

May 9th, 2002, 07:36 PM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	I'm not shy, just ignorant! This is a question for those more learned than me. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 19th, 2002, 06:48 PM	#5
Bruce Moore Regular Crew Join Date: Oct 2001 Location: Glendale, AZ Posts: 57	jeff, Thanks, makes sense. Bruce __________________ There are only three things that will kill you: Bad Luck, Stupidity, and Time.

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May 9th, 2002, 08:16 PM	#3
Bruce Moore Regular Crew Join Date: Oct 2001 Location: Glendale, AZ Posts: 57	YODA, I don't think I heard you!

May 19th, 2002, 06:43 PM	#4
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Hi, I have played with the video 1.6X converter and I own the Canon 1.4X and the 2X converters. The 1.6X does not appear as sharp to me. My personal opinion is that it is not a back focus issue. I believe the two 35mm converters are sharper for two reasons. The 35mm converters cover more than the 1/3 inch chips. Only the center portion of the converters are used. The center of a lens is always the sharpest and best corrected portion of the lens. The second reasons is the quality of the lenses placed in front of the converters. The 35mm Canon EOS lenses run rings around the video lenses for sharpness, contrast, resolution etc. Canon now publishes MTF graphs for their 35mm lenses. I have not been able to find them for their video lenses. Why? Because the 35mm lenses are much better and Canon probably does not want that kind of comparison being made. Kind of an apple and oranges thing. Jeff