View Full Version : Settings for low light video


Bert Na
June 18th, 2007, 10:53 AM
I'd like to be able to duplicate the quality of the sample video in this post (http://dvinfo.net/conf/showpost.php?p=622574&postcount=1), but it's not clear to me what the poster meant by ".. 1-3 clicks from 100% zebras..", does anybody know what he was referring to?

Neil Groundwater
June 18th, 2007, 12:01 PM
The 'Assist Func.' entry on page 43 of the HV20 manual explains how to turn on the zebra indicator. Then the display shows whether brighter portions of the image are 'blown out'. You can use that to manually lower the exposure until the zebras are gone and highlights are preserved. (I think the zebras only show when you are in "P" mode.)

Ed Khang
June 18th, 2007, 03:25 PM
The footage comes from an HV10.

Wow, and no vertical banding.

-Ed

Bert Na
June 19th, 2007, 12:24 AM
Thanks, Neil. I read the section on the zebra pattern settings in the manual and found another post from Tim Le (http://dvinfo.net/conf/showpost.php?p=622330&postcount=11), where he described his technique in more details.

Don Miller
June 20th, 2007, 05:48 PM
I'd like to be able to duplicate the quality of the sample video in this post (http://dvinfo.net/conf/showpost.php?p=622574&postcount=1), but it's not clear to me what the poster meant by ".. 1-3 clicks from 100% zebras..", does anybody know what he was referring to?

The issue/trick is to keep the camera from cranking up gain. On the HV10 there is no control or readout of gain. So the choice is to set the aperature wide in AV mode, or set the shutter slow in TV mode. Which you do depends on the situation.
Another mode on the HV10 that may help is night mode. Night mode lets the shutter drop below 1/60. The other modes seem to go to max gain before dropping the shutter low.
Gain is why some HV10/20 low light shots look great, and some show a lot of noise.

Oh, what Tim said about exposure compensation and noise really doesn't make a lot of sense. Bring up exposure in post is going to add the noise back in.

Ed Khang
June 20th, 2007, 06:26 PM
The issue/trick is to keep the camera from cranking up gain. On the HV10 there is no control or readout of gain. So the choice is to set the aperature wide in AV mode, or set the shutter slow in TV mode. Which you do depends on the situation.
Another mode on the HV10 that may help is night mode. Night mode lets the shutter drop below 1/60. The other modes seem to go to max gain before dropping the shutter low.
Gain is why some HV10/20 low light shots look great, and some show a lot of noise.

Oh, what Tim said about exposure compensation and noise really doesn't make a lot of sense. Bring up exposure in post is going to add the noise back in.

Apeture and Shutter Priority are my preferred modes for shooting with my DSLR. Will be an easy transition for me.

-Ed

Bert Na
June 20th, 2007, 11:24 PM
Tonal adjustment in post processing won't add noise unless it's overdone. Whatever noise that's present in the video does become more noticeable because of the increase in dynamic range.

Avoiding electronic gain boost will help keep the overall noise down so it will be less obvious after post processing. Tim's explanations seem to make sense, but more importantly, the results he achieved speak for themselves.

Oh, what Tim said about exposure compensation and noise really doesn't make a lot of sense. Bring up exposure in post is going to add the noise back in.

Don Miller
June 21st, 2007, 07:12 AM
The amount of gain determines noise.
The scene has a EV. Getting to that Ev is a function of aperture, shutter speed, gain, and exposure changes in post. The gain and exposure changes determine noise. Increasing gain in the camera probably produces less noise that increasing exposure in post.
True tonal adjustments may somewhat increase or decrease apparent noise, but there are no tricks here.

Bert Na
June 21st, 2007, 09:09 AM
I disagree. Brightness and contrast adjustments in post processing don't add noise, they merely make the noise more apparent. There's no electronic gain involved here.

Ed Khang
June 22nd, 2007, 04:32 PM
Please see my post here:

http://dvinfo.net/conf/showthread.php?p=701223#post701223

I tried Tim Le's settings, but I get a lot of vertical banding.
:(

-Ed

Betsy Moore
June 26th, 2007, 11:53 PM
Is there any way to just completely disable gain all together if you wanted to?

James Bresnahan
June 27th, 2007, 09:40 AM
[QUOTE=Betsy Moore;703471]Is there any way to just completely disable gain all together if you wanted to?[/QUOTE

For the HV20 (not sure about HV10), Spotlight mode locks the gain at 0db, while letting shutter and aperture auto-adjust. Try toggling TV, AV, Cine, and Spot when you are indoors--the Spot mode is always darker (but cleaner) because of the gain limiting. I still don't use Spot mode very often--anyone else?

The more common (HV20 only?) method is locking the exposure at a known amount of gain, as discussed in numerous posts in this forum.

Tony Moskal
June 27th, 2007, 10:11 AM
I find using Cinemode to be the best for low-light. It appears to at least limit the gain, if not turn it off. I find noise level is quite low, and more than acceptable for low light situations

Ed Khang
June 27th, 2007, 11:43 PM
I'm talking about the HV10 here, folks.

Oh. and I can't believe I missed this post!
http://dvinfo.net/conf/showpost.php?p=618759&postcount=9

Keep it secret: keep it safe! :)

-Ed