SD vs down converted HD

Pete Cofrancesco · July 12th, 2009, 05:03 PM

Quote:

Originally Posted by Boyd Ostroff

... all standard definition wide screen 16:9 is anamorphic...

That's not correct. Wide screen was first achieved by cropping SD and putting black bars on the top and bottom. As they advanced they switched to anamorphic which used all of the vertical resolution by squeezing the image when filmed, then was expanded by the dvd player. This then was called "true" wide screen.

Shaun Roemich · July 12th, 2009, 10:33 PM

Quote:

Originally Posted by Pete Cofrancesco

That's not correct. Wide screen was first achieved by cropping SD and putting black bars on the top and bottom. As they advanced they switched to anamorphic which used all of the vertical resolution by squeezing the image when filmed, then was expanded by the dvd player. This then was called "true" wide screen.

I believe what Boyd is referring to is that all 16:9 SD DV is RECORDED as "anamorphic", which is a "new" take on the original filmic process of placing a "squeezing" lens on the camera and a "stretching" lens on the projector.

By this I mean that REGARDLESS of whether one has native 16:9 sensors or a centre crop of a 4:3 sensor is performed (lowering resolution), BOTH are recorded to tape the same way which is writing the information to a 720 x 480 frame size (ASSUMING NTSC) with a pixel aspect ratio conversion so that during play back, the 720 x 480 (which is NOT 16:9 if you do the math...) BECOMES 16:9.

Of course, Pete knows this and my dissertation is solely for the benefit of future readers.

Shaun Roemich · July 12th, 2009, 10:34 PM

Quote:

Originally Posted by Pete Cofrancesco

Wide screen was first achieved by cropping SD and putting black bars on the top and bottom.

Actually, the process was to take a 16:9 shaped "bite" out of a 4:3 image and then stretch that vertically to fill 4:3 frame and record to tape.

Tom Hardwick · July 13th, 2009, 02:23 AM

Shaun's considered reply is correct but I have a small quibble about 'a centre crop of a 4:3 sensor is performed, lowering resolution.'

In fact the resolution isn't affected at all - a road sign is just as readable in the middle of a 4:3 frame as it is in a masked down 4:3 frame. On a 4:3 TV this is very clearly so - but if you then expand this cropped image vertically to fill a 16:9 TV it does appear to have less resolution. But the resolution is actually unchanged; sit further away and the sign is just as legible.

Pete's argument (anamorphic uses all of the vertical resolution) is not borne out in practice and the DVX100B clearly proves this. It's a 4:3 chipped camcorder that has the option of masking to produce 16:9 (whereupon the v'finder image is undistorted) or squeezing the image (then the v'finders show vertical expansion)

Both give the same end result on DVD - in resolution and aspect ratio.

tom.

Shaun Roemich · July 13th, 2009, 08:33 AM

Quote:

Originally Posted by Tom Hardwick

In fact the resolution isn't affected at all - a road sign is just as readable in the middle of a 4:3 frame as it is in a masked down 4:3 frame.

Again, my bad for not being clearer: resolution of a 4:3 sensor cropped to 16:9 is reduced COMPARED TO a 16:9 native sensor in SD when viewing on a 16:9 display (NOT letterboxed in a 4:3 display).

Jim Snow · July 14th, 2009, 03:06 PM

Another benefit to shooting in HD and converting to SD after editing is the ability to crop footage (zoom) to optimize framing and composition without losing SD definition. You can safely go in 20% without perceptible SD softening.

Leon Johnson · February 15th, 2013, 06:49 PM

I agree with Jim Snow about downloading HDV in HD, editing in HD, and converting as the last step.

What is still confusing to me is what method (workflow) of converting from HDV to SD is the best method before burning an SD DVD. I've tried exporting to Quicktime, then to Compressor/DVD Studio Pro. Have also used MPEG Streamclip and Toast.

The reason this is especially critical at this point in time is that I was hired to video tape series of fast paced soccer games. Just want to reduce the blur and get the best clarity to SD DVD.

Many thanks, everyone.

Leon

Chris Hurd · February 15th, 2013, 07:04 PM

Hi Leon, you might want to check whichever editing forum we have that best suits your workflow (Vegas / Adobe / Final Cut etc.) because I think you'll find much more info there rather than this camera-specific board. Hope this helps,

February 15th, 2013, 06:49 PM	#37
Leon Johnson New Boot Join Date: Jan 2009 Location: Raeford, NC Posts: 5	Re: SD vs down converted HD I agree with Jim Snow about downloading HDV in HD, editing in HD, and converting as the last step. What is still confusing to me is what method (workflow) of converting from HDV to SD is the best method before burning an SD DVD. I've tried exporting to Quicktime, then to Compressor/DVD Studio Pro. Have also used MPEG Streamclip and Toast. The reason this is especially critical at this point in time is that I was hired to video tape series of fast paced soccer games. Just want to reduce the blur and get the best clarity to SD DVD. Many thanks, everyone. Leon

February 15th, 2013, 07:04 PM	#38
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Re: SD vs down converted HD Hi Leon, you might want to check whichever editing forum we have that best suits your workflow (Vegas / Adobe / Final Cut etc.) because I think you'll find much more info there rather than this camera-specific board. Hope this helps, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 13th, 2009, 02:23 AM	#34
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Shaun's considered reply is correct but I have a small quibble about 'a centre crop of a 4:3 sensor is performed, lowering resolution.' In fact the resolution isn't affected at all - a road sign is just as readable in the middle of a 4:3 frame as it is in a masked down 4:3 frame. On a 4:3 TV this is very clearly so - but if you then expand this cropped image vertically to fill a 16:9 TV it does appear to have less resolution. But the resolution is actually unchanged; sit further away and the sign is just as legible. Pete's argument (anamorphic uses all of the vertical resolution) is not borne out in practice and the DVX100B clearly proves this. It's a 4:3 chipped camcorder that has the option of masking to produce 16:9 (whereupon the v'finder image is undistorted) or squeezing the image (then the v'finders show vertical expansion) Both give the same end result on DVD - in resolution and aspect ratio. tom.

July 14th, 2009, 03:06 PM	#36
Jim Snow Trustee Join Date: Mar 2009 Location: Santa Clara, CA Posts: 1,104	Another benefit to shooting in HD and converting to SD after editing is the ability to crop footage (zoom) to optimize framing and composition without losing SD definition. You can safely go in 20% without perceptible SD softening.