Exposure, interlacing & filter questions??? at DVinfo.net

Steve Nunez · June 10th, 2002, 01:21 PM

Hello everyone- hope everyone is having fun using their XL's.....

I always have fun using my XL1S- but seem to be fighting the "exposure" battle....when I shoot manually (usually -3 gain as rec. by most) I can't seem to balance the exposure for the main subject- if I adjust aperature or shutter to properly expose the subject- then I either get blown out highlights and if I adjust (according to the zebras) to reduce overexposed highlights, the subject becomes too dark...is there a filter I can use to reduce overblown highlights yet preserve the subjects exposure (this would seem the best solution)??

I was shooting my daughter at the playground and getting beautiful video but overblown highlights on light surfaces- herself as the subject was perfectly exposed but surrounding objects were overexposed- how are you guys getting the best all-around exposure?

Is there any benefit to de-interlacing video if final output is to TV? I know video for computer improves as there are no discernable interlacing frames- but if final output is for TV (NTSC) is there any benefit?

Thanks guys----have fun.

Barry Goyette · June 10th, 2002, 07:02 PM

I think you could probably find a substantial improvement in your highlights by using a circular polarizer...this will allow you to lower of the intensity of reflected highlights from the skin and other shiny objects while keeping your overall exposure high enough to give pleasing skin tones. Also try the -3 gain setting. Many users also adjust the black setup upwards a couple of points to open up the shadows a bit.

Regarding the interlacing...(I'm not sure if you are referring to the Frame mode, or software interlacing--although the both give similar results)...there is a very noticeable difference on NTSC television. The best way to understand it is to film something in normal and frame mode and play it back..the frame mode will look less "video-ey" than the normal mode...many would say it looks more like film (including me). There is a slight loss of sharpness..but then that also is something that can be a positive...It really comes down to your personal taste. The above also applies to the use of a smart de-interlacer like Re:vision Effects Fieldskit.

Steve Nunez · June 10th, 2002, 08:26 PM

I'll give that circular polarizer a shot.

Regarding de-interlacing- I was referring to actually running a de-interlacing filter to a project once it's been completed- is there any benefit to doing this if the intended video is to be shown on tv sets as opposed to de-interlacing for screen use (computer monitor screens that is)..the reason I ask is because when watching raw dv footage to TV looks great- was wondering if a benefit at all exsists for TV use.

Thanks

Barry Goyette · June 11th, 2002, 10:57 AM

Many NLE's stock deinterlacing filters do little more than allow you to choose one field and eliminate the other...in this case you will see a substantial degradation of quality on an NTSC television.

As I stated in my previous post, using a smart deinterlacer will give you results similar to the Frame mode...and whether it is an improvement is really a judgement based on personal taste. I like it because it make the footage less video-ey, and even casual viewers looking at my stuff have noted how it doesn't look like it was shot on a video camera.

The best way to decide is to run a test with the same footage interlaced and deinterlaced and play it back on a TV to see which you like best.

Steve Nunez · June 11th, 2002, 11:18 AM

Thanks......is such a "smart deinterlacer" available using Final Cut Pro 3?
Would it be a plug-in or after-market program?

Barry Goyette · June 11th, 2002, 11:41 AM

Here's the one I have used

http://www.revisionfx.com/rsfk.htm

I use it in with FCP 2...I'm not sure its osX compatible..there's a downloadable demo that you can try. Again, you can get an extremely similar result just using the Frame mode on the xl1s.

good luck!

Bill Ravens · June 11th, 2002, 12:51 PM

A polarizer, circular or otherwise, will only have marginal effects in helping your exposure problems. Current prosumer level CCD technology doesn't have anywhere near the exposure latitude that film has. The result is the problem you've brought up. To make matters worse, if your NLE is automatically clamping the highlights to NTSC standard of 100 IRE, the hotspots will be made a lot worse. Be sure to set your zebra for about 90 IRE to provide a margin for error, then expose for the highlights, and let the shadows fall where they will. There's not much more you can do unless you want to carry round a light set to use as fill for the shadows. This is basically a video CCD shortcoming.

June 10th, 2002, 01:21 PM	#1
Steve Nunez Trustee Join Date: Jan 2002 Location: Pembroke Pines, Florida Posts: 1,418	Exposure, interlacing & filter questions??? Hello everyone- hope everyone is having fun using their XL's..... I always have fun using my XL1S- but seem to be fighting the "exposure" battle....when I shoot manually (usually -3 gain as rec. by most) I can't seem to balance the exposure for the main subject- if I adjust aperature or shutter to properly expose the subject- then I either get blown out highlights and if I adjust (according to the zebras) to reduce overexposed highlights, the subject becomes too dark...is there a filter I can use to reduce overblown highlights yet preserve the subjects exposure (this would seem the best solution)?? I was shooting my daughter at the playground and getting beautiful video but overblown highlights on light surfaces- herself as the subject was perfectly exposed but surrounding objects were overexposed- how are you guys getting the best all-around exposure? Is there any benefit to de-interlacing video if final output is to TV? I know video for computer improves as there are no discernable interlacing frames- but if final output is for TV (NTSC) is there any benefit? Thanks guys----have fun. __________________ Steve Nunez-New York City www.stevenunez.com

June 10th, 2002, 08:26 PM	#3
Steve Nunez Trustee Join Date: Jan 2002 Location: Pembroke Pines, Florida Posts: 1,418	I'll give that circular polarizer a shot. Regarding de-interlacing- I was referring to actually running a de-interlacing filter to a project once it's been completed- is there any benefit to doing this if the intended video is to be shown on tv sets as opposed to de-interlacing for screen use (computer monitor screens that is)..the reason I ask is because when watching raw dv footage to TV looks great- was wondering if a benefit at all exsists for TV use. Thanks __________________ Steve Nunez-New York City www.stevenunez.com

June 11th, 2002, 11:18 AM	#5
Steve Nunez Trustee Join Date: Jan 2002 Location: Pembroke Pines, Florida Posts: 1,418	Thanks......is such a "smart deinterlacer" available using Final Cut Pro 3? Would it be a plug-in or after-market program? __________________ Steve Nunez-New York City www.stevenunez.com

June 10th, 2002, 07:02 PM	#2
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	I think you could probably find a substantial improvement in your highlights by using a circular polarizer...this will allow you to lower of the intensity of reflected highlights from the skin and other shiny objects while keeping your overall exposure high enough to give pleasing skin tones. Also try the -3 gain setting. Many users also adjust the black setup upwards a couple of points to open up the shadows a bit. Regarding the interlacing...(I'm not sure if you are referring to the Frame mode, or software interlacing--although the both give similar results)...there is a very noticeable difference on NTSC television. The best way to understand it is to film something in normal and frame mode and play it back..the frame mode will look less "video-ey" than the normal mode...many would say it looks more like film (including me). There is a slight loss of sharpness..but then that also is something that can be a positive...It really comes down to your personal taste. The above also applies to the use of a smart de-interlacer like Re:vision Effects Fieldskit.

June 11th, 2002, 10:57 AM	#4
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Many NLE's stock deinterlacing filters do little more than allow you to choose one field and eliminate the other...in this case you will see a substantial degradation of quality on an NTSC television. As I stated in my previous post, using a smart deinterlacer will give you results similar to the Frame mode...and whether it is an improvement is really a judgement based on personal taste. I like it because it make the footage less video-ey, and even casual viewers looking at my stuff have noted how it doesn't look like it was shot on a video camera. The best way to decide is to run a test with the same footage interlaced and deinterlaced and play it back on a TV to see which you like best.

June 11th, 2002, 11:41 AM	#6
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Here's the one I have used http://www.revisionfx.com/rsfk.htm I use it in with FCP 2...I'm not sure its osX compatible..there's a downloadable demo that you can try. Again, you can get an extremely similar result just using the Frame mode on the xl1s. good luck!

June 11th, 2002, 12:51 PM	#7
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	A polarizer, circular or otherwise, will only have marginal effects in helping your exposure problems. Current prosumer level CCD technology doesn't have anywhere near the exposure latitude that film has. The result is the problem you've brought up. To make matters worse, if your NLE is automatically clamping the highlights to NTSC standard of 100 IRE, the hotspots will be made a lot worse. Be sure to set your zebra for about 90 IRE to provide a margin for error, then expose for the highlights, and let the shadows fall where they will. There's not much more you can do unless you want to carry round a light set to use as fill for the shadows. This is basically a video CCD shortcoming.