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-   -   Low light ideas (https://www.dvinfo.net/forum/sony-hvr-z1-hdr-fx1/140017-low-light-ideas.html)

Dana Salsbury December 20th, 2008 11:44 AM

Low light ideas
 
I film low light wedding receptions, where I can only provide so much light without annoying the guests. I keep shutter speed at 60 and also leave the gain alone while opening the iris appropriatly. I don't touch the gain (set to manual so it doesn't move). My thinking is that it's easy to add gain in post. Usually there is so much going on with sound, etc., that it's easier, but am I losing quality by not using the FX1's gain?

Oren Arieli December 20th, 2008 11:53 AM

You can only brighten a dark image so much in post before everything gets pushed to grey. Better to add a bit of grain 6 or 9db and get the photons recorded. You can use a noise-reduction program to smooth out the grain in post (expect long render times). Better yet, get a tall light stand, a dimmer and a bit of diffusion. A light that is placed very high (and is softened somewhat) becomes less distracting than on-camera lighting...especially if its already on when the reception begins. Using a dimmer, I often keep the light at 40% and bring it up ever so slowly before the first dance. Haven't had complaints...although I do my best not to use the light at all. Still, you need photons to make an image. You can't 'add' photons in post.

If need be, drop the shutter speed to 1/30th...but expect motion blur.

Greg Laves December 20th, 2008 09:13 PM

Dana, I would experiment with the amount of gain you can add without getting excessive grain. I usually don't want to go past 6 db gain, personally. You can also pick up some more light by going to 1/30 sec shutter speed. But at 1/30 sec shutter you need to have slow pans and limited fast motion on screen or you will get some motion blurring. But it works pretty well otherwise.

Dana Salsbury December 20th, 2008 09:30 PM

Great info. It's tough to mess with shutter speed, as the low light part of the night is dancing.

I'm going to try upping camera gain a bit to help. When I up the gain in post I also up the saturation to simulate good lighting.

I have a boom stand that I use for our third camera that has an adapter for mounting my soft-box. It's essential for back yard weddings, though I basically need to camp out next to it for consistent light.

Vito DeFilippo December 20th, 2008 10:24 PM

Hi Dana,

I asked the same question about gain in camera vs. gain in post a while back. The responses convinced me that gain in camera is better. The concept that gain in camera is BEFORE the image is compressed to tape makes sense to me. Gain in post is AFTER, so the image is degraded further.

Since then (with a Z1, which should give the same result as an FX1) I've been much less shy about using camera gain. Up to 15 and even 18db sometimes. These cameras are amazingly clean under gain. And the result has been great. I also routinely use a shutter speed of 30 at receptions, and have never had one comment on the look. No one notices.

For dance footage, I lower the shutter speed even more, though this is for effect. I like the blurred look. I will shoot some at 60, then some at lower shutter as an option.

For dance footage, I also use the Sony 10/20, though always at 10 Watts. I diffuse it with a bit of diffusion paper taped in front, which works great.

I never understood the concept of bringing lights on tripods to increase the light level of the room. Why not just ask the hall to turn it up a bit? Though maybe others have tried this and got a bad response, I don't know.

Dana Salsbury December 20th, 2008 10:39 PM

Actually, though, isn't gain artificial to begin with? What difference would it make for the FX1 to create it than my Mac?

Vito DeFilippo December 20th, 2008 11:36 PM

Because, the image is compressed (into HDV format) after the gain is added.

Your Mac adds gain to an already compressed image, further degrading the image.

But really, the only way to figure out what you like better is to do a test. Shoot a scene with no gain, and repeat with gain added in camera. Add gain with your Mac to the flat image, and see what looks better to you.

Boyd Ostroff December 21st, 2008 01:17 PM

Shooting our operas I often have to deal with really dark scenes where I can't change the lighting. What is your final product? Standard definition? If so then I think 9dB of gain is still quite acceptable. I frequently must use 12dB, even 15dB. True that it adds noise, but that's what you have to accept when shooting in the dark ;-)

Black stretch helps a bit on the Z1, but of course that's not an option for the FX1. Since I've never shot a wedding (I don't even GO to weddings) I don't have to deal with that sort of customer. But perhaps a little up-front education would help, where you explain that you can still shoot video in a dark place, but they should expect some noise in the picture?

Dave Blackhurst December 21st, 2008 02:04 PM

Switching the shutter to 1/30 is the quickest way to gain low light performance - Sony consumer handycams have been using the trick to keep "acceptable" low light performance - yes, you have blur potential, just be thoughtfull and keep it in your option list - it's a powerful trick.

I second the "in camera gain" vs. trying to gain up in post - you might look at noise reduction plug ins if gain is too objectionable - seen pretty effective results in post.

As for light, an on camera light goes a long way - the Sony 10/20 (HVL-20xxx, with the "xxx" being the specific model # designating the battery option), with a sto-fen diffuser, is an old standby that has served many HD shooters quite well, myself included. You can't go wrong with having one or more in your kit for when the lights go down.

The Sima 20LX LED light that recently came out is a bargain too, and as soon as I rig up a few homebrew diffusers, that will be my new light - my test results with it have been quite good, and a pair of them cuts through a surprising lot of darkness - so far, two seems like the optimal array, but you can stack the things as desired.

Marcus Martell December 22nd, 2008 05:53 PM

Excuse me guys, where can i get a noise-reduction program to smooth out the grain in post?
thx

Steve Phillipps December 22nd, 2008 06:06 PM

Quote:

Originally Posted by Dana Salsbury (Post 981605)
Actually, though, isn't gain artificial to begin with? What difference would it make for the FX1 to create it than my Mac?

And because using gain in camera allows to capture info in the shadow areas, in post you can't put anything into the shadows that the camera didn't see in the first place.
Steve

Oren Arieli December 22nd, 2008 07:21 PM

Quote:

Originally Posted by Marcus Martell (Post 982579)
Excuse me guys, where can i get a noise-reduction program to smooth out the grain in post?
thx

Neat Video, and Boris are one place to start. Depends on your platform and price range.
All will be render-intensive (as far as I know). So don't use it as a shortcut to brighter images unless you have plenty of render time to spare.

Kevin Richard December 22nd, 2008 09:22 PM

Quote:

Originally Posted by Dave Blackhurst (Post 981899)
The Sima 20LX LED light that recently came out is a bargain too, and as soon as I rig up a few homebrew diffusers, that will be my new light - my test results with it have been quite good, and a pair of them cuts through a surprising lot of darkness - so far, two seems like the optimal array, but you can stack the things as desired.

I used two of these at a party this weekend and I forgot to bring my gel packs so I had no diffusion paper to put on them (last minute throw together)... I quickly looked around my partner's place and grabbed some styrafoam(sp) paper that his surround sound speakers came in, then I needed tape. He had a lint roller sitting right there and I thought "that will work" then as I'm grabbing it it dawns on me that it might be all I need. It fit perfect on two of the lights and didn't look bad at all (lint roller paper straight on the light)! Worked pretty well as a diffuser and I didn't get any cooky looks when I fired them up that night... granted it was mostly drunk hoochies but still, it felt just right.

Don Miller December 22nd, 2008 09:47 PM

With the Simas you can use gaffers tape to add a gel for tungsten lighting. Usually when its dark color temperature is low too.
The litepanels are nice but expensive. The micro model for on camera has a dimmer and a gel holder. But $300US versus -$30 for the Sima.
Those of us starting to use the 5DII are able to shoot 1080 30p in low light without problem. But the camera is very limited in function compared to regular camcorders. The future seems to be big sensor with better low light performance.

Dana Salsbury December 22nd, 2008 11:45 PM

drunk hoochies...lol

I have two of the Litepanels and two of the Sony duo lights. I love the gain control on the Litepanels, but haven't found a good diffuser (besides the one included) that can spread the light enough. My Sonys do that masterfully, and when I use both Sonys together I'm rockin.

Per lumins, I look forward to selling my three FX1s for a card-based system. Capturing is a huge waste of my day, and if I could get better low-light I could actually start showing off my receptions.


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