balancing light/contrast at DVinfo.net

Connla Lyons · August 29th, 2007, 05:26 AM

Hello

i work for a community television programme in Dublin Ireland.

We are using a JVC pro 100 HD as our standard camera.

Due to HD not being supported by our broadcaster we are shooting in standard.

Now for the most part (thanks to DVinfo) I've been able to handle the camera fine and get as much out of it as I can. But I am not the main camera operator and with the recent good weather the other two cameramen have back with issues of getting light sources to balance while filming in very bright weather.

The situation in question was filming some fishing trawlers in a bay in a bright cloudless day, the cameraman wanted to keep the sky from being over exposed but to keep the sky blue he found that the trawlers loose alot of detail and contrast.

The second cameraman ran into a similar situation on another sunny day, but believes it could be an issue with the camera not being able to deal with high amounts of light.

Now I wasnt present on either situation so was not able to check if there were any details to explain the issue or fix it (such as shutter speed/exposure etc)

The camera is set up in standard definition shooting with with Paulo Ciccone's true colour V1 set up.

Any advice as to how I can tweak the camera to help this, or set ups I can pass on to ensure these issues can be avoided in future?

If I can I will post up a screen capture of the shot in question.

Brian Luce · August 29th, 2007, 08:14 AM

Maybe I'm wrong but I've always had the idea that to optimize your SD image you should shoot in HD and downconvert at the last possible moment in post. This will preserve more color space.

Regarding matching the sky to the subject in terms of exposure, you might try using graduated filters. They're cheap and work good.

Todd Norris · August 29th, 2007, 01:26 PM

I'm using a jvc HD250, and I have been able to get good images in bright contrasty exteriors by doing some or all of the following:

1)On sunny days, using a circular polarizer really helps cut the brightness of the sky, giving it a deep blue. This allows me to open up the iris another stop or so, therefore allowing more information to expose in the darker areas of the frame without overexposing the sky.

2)Brian Luce's idea above of using graduated filters is absolutely correct. Also, I find that the built in ND filters of the JVC are not nearly enough, so again using a polarizer or an ND filter in front of the lens helps get better images out of bright exteriors.

3) Also, lowering the Knee setting as low as it will go (80?) and using Black Stretch will give you lower contrast images which will help bring out shadow detail while also controlling highlights.

However, sometimes you just have to make an artistic choice. Sometimes a well-exposed sky with darker elements below the horizon looks cool. This is especially true in "magic-hour" and sunset shots where the foreground can be silhouetted.

Adam Letch · August 29th, 2007, 07:32 PM

that comes with digital, and even film though not to such a degree, the only way around this is a grad nd filter, if you use a polariser it will richen your colour and reduce glare, but you difference in exposure between sky and subject will still be the same.
I made this mistake originally when I started shooting outdoors, I previously only shot in a controlled lighting environment, and I wanted the sky to look blue along with a well exposed subject. Well this is why the film industry use big bright lights in the middle of the day! Needless to say a lot of underexposed footage.
So you expose for the 'middle grey' to get the best mix if you don't have a grad nd, but its a compromise. Basically the sky gets second seat to the subject matter your shooting.
cheers

Adam

Connla Lyons · August 30th, 2007, 03:29 AM

This is the shot in question:

Brian Luce · August 30th, 2007, 05:12 AM

Quote:

Originally Posted by Connla Lyons

This is the shot in question:

If you could figure out a way to get more clouds in the sky this problem would go away.

Stephan Ahonen · September 2nd, 2007, 03:31 AM

A polarizer can darken your sky a bit (and contrary to what another poster stated, a polarizer can reduce the brightness of the sky relative to the rest of the scene because of the polarization of light from the sky), but the best solution I've found in practical shooting (especially with a non-IF lens, what a pain!) is to frame your shots so the subject you're exposing for dominates visually.

August 29th, 2007, 05:26 AM	#1
Connla Lyons New Boot Join Date: Jun 2007 Location: Ireland Posts: 9	balancing light/contrast Hello i work for a community television programme in Dublin Ireland. We are using a JVC pro 100 HD as our standard camera. Due to HD not being supported by our broadcaster we are shooting in standard. Now for the most part (thanks to DVinfo) I've been able to handle the camera fine and get as much out of it as I can. But I am not the main camera operator and with the recent good weather the other two cameramen have back with issues of getting light sources to balance while filming in very bright weather. The situation in question was filming some fishing trawlers in a bay in a bright cloudless day, the cameraman wanted to keep the sky from being over exposed but to keep the sky blue he found that the trawlers loose alot of detail and contrast. The second cameraman ran into a similar situation on another sunny day, but believes it could be an issue with the camera not being able to deal with high amounts of light. Now I wasnt present on either situation so was not able to check if there were any details to explain the issue or fix it (such as shutter speed/exposure etc) The camera is set up in standard definition shooting with with Paulo Ciccone's true colour V1 set up. Any advice as to how I can tweak the camera to help this, or set ups I can pass on to ensure these issues can be avoided in future? If I can I will post up a screen capture of the shot in question.

August 29th, 2007, 07:32 PM	#4
Adam Letch Major Player Join Date: Feb 2006 Location: Perth, Western Australia Posts: 414	This is typical lack of latitude that comes with digital, and even film though not to such a degree, the only way around this is a grad nd filter, if you use a polariser it will richen your colour and reduce glare, but you difference in exposure between sky and subject will still be the same. I made this mistake originally when I started shooting outdoors, I previously only shot in a controlled lighting environment, and I wanted the sky to look blue along with a well exposed subject. Well this is why the film industry use big bright lights in the middle of the day! Needless to say a lot of underexposed footage. So you expose for the 'middle grey' to get the best mix if you don't have a grad nd, but its a compromise. Basically the sky gets second seat to the subject matter your shooting. cheers Adam

August 30th, 2007, 03:29 AM	#5
Connla Lyons New Boot Join Date: Jun 2007 Location: Ireland Posts: 9	This is the shot in question: Attached Thumbnails

August 29th, 2007, 08:14 AM	#2
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Maybe I'm wrong but I've always had the idea that to optimize your SD image you should shoot in HD and downconvert at the last possible moment in post. This will preserve more color space. Regarding matching the sky to the subject in terms of exposure, you might try using graduated filters. They're cheap and work good.

August 29th, 2007, 01:26 PM	#3
Todd Norris Regular Crew Join Date: Jul 2003 Location: Overland Park, Kansas Posts: 48	I'm using a jvc HD250, and I have been able to get good images in bright contrasty exteriors by doing some or all of the following: 1)On sunny days, using a circular polarizer really helps cut the brightness of the sky, giving it a deep blue. This allows me to open up the iris another stop or so, therefore allowing more information to expose in the darker areas of the frame without overexposing the sky. 2)Brian Luce's idea above of using graduated filters is absolutely correct. Also, I find that the built in ND filters of the JVC are not nearly enough, so again using a polarizer or an ND filter in front of the lens helps get better images out of bright exteriors. 3) Also, lowering the Knee setting as low as it will go (80?) and using Black Stretch will give you lower contrast images which will help bring out shadow detail while also controlling highlights. However, sometimes you just have to make an artistic choice. Sometimes a well-exposed sky with darker elements below the horizon looks cool. This is especially true in "magic-hour" and sunset shots where the foreground can be silhouetted.

September 2nd, 2007, 03:31 AM	#7
Stephan Ahonen Major Player Join Date: Apr 2005 Posts: 512	A polarizer can darken your sky a bit (and contrary to what another poster stated, a polarizer can reduce the brightness of the sky relative to the rest of the scene because of the polarization of light from the sky), but the best solution I've found in practical shooting (especially with a non-IF lens, what a pain!) is to frame your shots so the subject you're exposing for dominates visually.