DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Sony HVR-Z5 / HDR-FX1000 (https://www.dvinfo.net/forum/sony-hvr-z5-hdr-fx1000/)
-   -   Low light video (https://www.dvinfo.net/forum/sony-hvr-z5-hdr-fx1000/239127-low-light-video.html)

Pete Crawford July 16th, 2009 08:45 AM

Low light video
 
Thanks for all the input from you all a few weeks ago. If I can get this video on here, this track has very challenging light. In the feature race the video is brighter than the actual lighting looks. I shot in manual, 120 (or so) shutter speed, 21 on the gain, auto focus, I tried to keep the iris wide open, and I still haven't a clue what I'm doing. In the auto mode it shot pretty close to the same.

Hanks Vs Beeler 7 11 09 Atoka Raceway Park

This video is on youtube.com

Thanks for all of the advice!

Don Bloom July 16th, 2009 09:30 AM

First the LCD is not the best way to determine exposure. A production monitor is still the better way to go. Having said that, I know that it is mostly impossible to use one for event work so what I've been doing for years is adjusting the brightness of the LCD to match as closely as possible the lighting conditions. IOW, if it's bright outside I set the brightness of the LCD brighter, if it's dark inside I set the LCD to match as close as I can get it. Not perfect but it helps me to at least get into the neighborhood.
Then of course there are the Zebras which will help get you to the right address and generally between the 2 you can get to the 'house'.
I have to ask though if you were using a shutter speed of 120th why did you kick the gain to 21? That's really high and honestly outside, especially if using a higher shutter speed there is no reason to use positive gain. If anything and the camera can do it you might need to go to negative gain. Again that's if the camera can do it. Most prosumer types can't but some do. At the very least use 0 gain and if need be use the ND filter. This will help open the iris. BTW, you didn't mention the f/stop you were at but I'll assume it was pretty closed with 21 gain on the meter. Gain helps to gather more light in a sense so with a higher shutter speed, the iris should be opened up a bit depending on the conditions but with 21 gain and an open iris you'll probably be overexposed or at least right on the edge.
I suggest you play around with the camera a bit more, very bright conditions at different shutter speeds, f/stops and ND filter settings then do the same in dark conditions. There is where you'd probably need some gain. Use a tape write down and or talk into the mic to record the different settings and then you'll know what the camera is capable of and you'll know when to use what seetings for what conditions.

Pete Crawford July 16th, 2009 10:04 AM

Thanks Don. I used the histogram just to try and keep the light in the right area. I say I had the iris wide open, I was saying that because I kept the f stop as open as possible (1.6 to 4 ish).

The video looked really good. Obviously I have a lot to learn.

Pete

Pete Crawford July 16th, 2009 10:09 AM

With changing light at the track, karts moving to the dimmer areas in turns, is it best to stay in auto mode?

Khoi Pham July 16th, 2009 10:17 AM

Quote:

Originally Posted by Pete Crawford (Post 1172462)
Thanks for all the input from you all a few weeks ago. If I can get this video on here, this track has very challenging light. In the feature race the video is brighter than the actual lighting looks. I shot in manual, 120 (or so) shutter speed, 21 on the gain, auto focus, I tried to keep the iris wide open, and I still haven't a clue what I'm doing. In the auto mode it shot pretty close to the same.

Hanks Vs Beeler 7 11 09 Atoka Raceway Park

This video is on youtube.com

Thanks for all of the advice!

First I would adjust your lcd brighness as close as possible to your editing monitor, never use gain unless you have too, standard shutter speed is 60th of second for 1080 60i video, open your apperture as wide as possible, use your zebra or if it is still dark then you can use your gain up, gain is the last thing you want to bring up, so for low light, go in this order, always:
1. keep apperture open as wide as possible
2. keep shutter at 60th of a second max.
3. gain up.

I bet you could have use about 6db or less if you were using 60th of a seconds and you would have much less video noise.

Pete Crawford July 16th, 2009 10:28 AM

Khoi, I did drop the shutter speed and the gain with success, but I was afraid that if I got too low on the shutter speed the Karts would be blurred. I thought 1/60th wouldn't capture the action and was afraid that the 1/120th area wouldn't be fast enough.

DV exposures must be different than using a still camera to catch action.

Khoi Pham July 16th, 2009 10:34 AM

Quote:

Originally Posted by Pete Crawford (Post 1172508)
Khoi, I did drop the shutter speed and the gain with success, but I was afraid that if I got too low on the shutter speed the Karts would be blurred. I thought 1/60th wouldn't capture the action and was afraid that the 1/120th area wouldn't be fast enough.

DV exposures must be different than using a still camera to catch action.

It would not be as clear if you are doing slomo with the footage, but it would not be blur if you are watching at normal speed, with the Z5, 12db is probably the max I would use on it.

Pete Crawford July 17th, 2009 05:40 AM

Khoi....thanks, I've been playing with those things the last couple of days. We race again tomorrow night, I'll do those and see how it does. I was actually pleased with how little noise I had with the z5u.

Pete

William Ellwood July 20th, 2009 10:26 AM

Can anyone confirm that when I run the Z5 in auto mode, it will add gain after it has got the iris wide open? I set the max gain to 12db via the menu to stop the gain going too far.

Jeff Harper July 21st, 2009 03:03 AM

Yes it will add gain if conditions warrant, which is why you set the gain limit. 12db is a good place for it.

Martin Wiosna July 27th, 2009 12:19 AM

wouldn't it be easier to go with full manual so the camera doesn't adjust the gain?

Zach Love August 4th, 2009 12:51 AM

Quote:

Originally Posted by Martin Wiosna (Post 1177130)
wouldn't it be easier to go with full manual so the camera doesn't adjust the gain?

Easier? Never! I want my camera to use auto gain, auto iris, auto shutter, auto focus and even auto record. You pay more for a pro camera because it does everything for you so you don't have to work. Heaven forbid that we be smarter than the objects we're using.

In all seriousness, learn the camera, be smarter than the camera and your video will show it. I agree to the above, when shooting 1080i60 I always have the shutter at 1/60 (unless I'm going for a certain look), when 1080p30 I'm at 1/30, 1080p24 1/24.

I'm really wondering if you had an ND filter on, because I have gotten good results with my Z7 at night under street lights and I have seen a lot of venue lights that are MUCH brighter than the standard street light.

To repeat what is above:

0. Check ND filters.
1. Open up your shutter.
2. Open up your iris.
3. Add gain.


All times are GMT -6. The time now is 06:48 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network