How to choose between a Grey Card, Expo Disk or Light Meter?

[nikonusersince2007]

What is the difference between a grey card, an expo disk and a light meter?

Do I need all 3 or a cobination of 2 or just 1?


*Does a light meter set custom WB or do I set custom WB with a grey card and then take the light measurement with the light meter with the camera now set with the custom WB...do the grey card and light meter work together or do I just need 1 of them to take a correctly exposed image?

So confused. Thank for the help!

 

[cbarbero]

A grey card and light meter works best for me. This also depends on the light meter used. There are some cameras out there with better meters than some of the lesser handhelds.

 

[MLeeK]

If I can only have one? The light meter is the most useful. The grey card is the cheapest and you can toss it in your bag for setting white balance as long as it is true neutral gray.

 

[Big Mike]

Two different issues here. Getting proper exposure and getting proper White Balance.

A light meter is the best tool for getting proper exposure...mainly because most (hand held) light meters are incident meters. They measure the light falling on the scene, not the light reflecting off of the scene. This gives you accurate exposure settings. A hand held light meter is also good for metering different parts of a scene, or lighting ratios etc. Also, if you need to meter flash/strobes as well, many hand held meters are flash meters as well.
You don't set White Balance with a hand held light meter. You could get a hand held color meter, and then dial in that setting to your camera, but that is for super accurate white balancing (and it's expensive) so it's usually only something you'd see on a movie set.

A grey card is a calibrated target for when using a reflected light meter. The meter in every camera is a reflected light meter. The way a reflected light meter works, the reflectivity (brightness) of the scene/subject will influence the reading, which can cause you to get improper exposure. By 'metering' on the grey card, you are using the tone that the camera is calibrated for, thus you will get setting for proper exposure.

Also, because a true grey card is color neutral, you can use it for setting a custom white balance.
There are also white balance targets that might have white/black/grey areas or even a patch of color swatches. You can use photos of these targets to set your WB/color on the computer, after the shoot. (shoot in RAW).

There are WB aids, like the expodisk, which help to set a custom WB.

 

[KmH]

The Expodisc fits certain size lenses (they make 7 sizes). So you may need several of them to accommodate the lenses you have. Expodisc is just a white balance tool, which is how they advertise it.

Or you can get just one gray card that works will all your lenses.

 

[GeorgieGirl]

The Expodisc fits certain size lenses (they make 7 sizes). So you may need several of them to accommodate the lenses you have. Expodisc is just a white balance tool, which is how they advertise it.

Or you can get just one gray card that works will all your lenses.

I have an expo disc and I still can't figure out how to work it. Custom WB no problem.

 

[480sparky]

I have an expo disc and I still can't figure out how to work it. Custom WB no problem.

Adjust camera to set custom white balance, install Exposdisc. Aim at light source, snap shutter. White balance now set.

 

[GeorgieGirl]

Adjust camera to set custom white balance, install Exposdisc. Aim at light source, snap shutter. White balance now set.

So it's the receiving light not the reflecting light with the expo?

 

[480sparky]

So it's the receiving light not the reflecting light with the expo?

The camera is set using the light coming through the Expodisc. The disc goes on the front of the lens, just like any other filter (that's why they're sold in common filter sizes).

 

[nikonusersince2007]

Does setting a custom WB with a grey card help to get correct skin tones?
What does setting a custom WB do? It affects all colors not just white-correct?

 

[480sparky]

Does setting a custom WB with a grey card help to get correct skin tones?
What does setting a custom WB do? It affects all colors not just white-correct?

A gray card is usually used to set the WB in post. Exposdiscs (and similar devices) allow precise WB setting before you shoot.

A 'Custom WB" means just that... the WB is set precisely to the color temperature of the light source. If the light is 5818°K, the camera sets itself to that. Not something close, like 5800 or 5825, but 5818.

WB affects all colors in the frame.


The difference between an Expodisc and a gray card is when you set the WB. If you use something like an Expodisc, your WB is set at the beginning of your shoot. As long as the light doesn't change, you won't have to fiddle with any WB issues again........ either in the field or in post.

A gray card is used to correct WB in post. You take a photo of it during your shoot, and use an 'eyedropper' in your post software to adjust the WB.

 

[MLeeK]

I use my grey card for setting WB in the field-not post. Especially when I am working in a particularly crappy gym.
Fill the frame with the grey card, take the shot, set the WB.
No matter what way you are using it (for setting in camera or in post) you have to make sure the shot of the grey card is not getting any reflection from a color cast onto it, it is exposed well in the light you will be shooting in. If your light begins to change... you need to re-set.
When you are using it for setting WB in camera fill the frame with the grey card.

 

[nikonusersince2007]

I have the sekonic light meter model 300something-how do I get my WB to be correct using a light meter instead of an expo disk? Or do I need to use both the light meter and an expo disk?

Does setting a custom WB with a grey card help to get correct skin tones?
What does setting a custom WB do? It affects all colors not just white-correct?

A gray card is usually used to set the WB in post. Exposdiscs (and similar devices) allow precise WB setting before you shoot.

A 'Custom WB" means just that... the WB is set precisely to the color temperature of the light source. If the light is 5818°K, the camera sets itself to that. Not something close, like 5800 or 5825, but 5818.

WB affects all colors in the frame.


The difference between an Expodisc and a gray card is when you set the WB. If you use something like an Expodisc, your WB is set at the beginning of your shoot. As long as the light doesn't change, you won't have to fiddle with any WB issues again........ either in the field or in post.

A gray card is used to correct WB in post. You take a photo of it during your shoot, and use an 'eyedropper' in your post software to adjust the WB.

 

[Derrel]

A gray card works quite well at the time of shooting...

I've also taken custom white balances off of a white cloud in the sky, using a tele-zoom, and defocusing the image...works like a charm...works a lot like the expodisc works...

 

[480sparky]

I have the sekonic light meter model 300something-how do I get my WB to be correct using a light meter instead of an expo disk? Or do I need to use both the light meter and an expo disk?

99.9999999% of light meters are only capable of reading the amount of light.... so they are only used for setting exposure. There are color temperature meters available, but they're very pricey! 4-digit price tags to start with.

If you want to be accurate, use a light meter and an Exposdisc. Gray cards can be thrown into the mix if you want, especially given they're relatively inexpensive.