18% gray card vs white card

[Alexr25]

its hard to read color in white.

Only if one or more channels clips but if you take your exposure reading from the white target your channels aren't going to clip and for that matter the target will no longer be white as far as the camera is concerned, it will be grey.
The reason some authorities say use a gray card rather than white paper or fabric is that many white papers and fabrics have fluorescent dyes added to give them that whiter than white appearance. These dyes in theory could upset the white balance reading in the camera, in practice I have not had any problems using white targets. Photographic grey cards on the other hand are supposed to be colour neutral, that's what you pay the money for.

 

[W.Y.Photo]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral. If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

 

[Ysarex]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral.

Tee shirts and paper are a poor choice as a WB reference. Styrofoam is not and should not be grouped with fabric and paper. Styrofoam is as good or better than any commercial product. I trust and prefer Styrofoam over my color checkers for setting WB.

See this old TPF post: 18 gray card prices Photography Forum Look at the graphs in Helen's post #13 and note that Polystyrene cup out performs all other items tested including commercial products. This has been my experience as well. The coffee cup rules!

Joe

If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

 

[W.Y.Photo]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral.

Tee shirts and paper are a poor choice as a WB reference. Styrofoam is not and should not be grouped with fabric and paper. Styrofoam is as good or better than any commercial product. I trust and prefer Styrofoam over my color checkers for setting WB.

See this old TPF post: 18 gray card prices Photography Forum Look at the graphs in Helen's post #13 and note that Polystyrene cup out performs all other items tested including commercial products. This has been my experience as well. The coffee cup rules!

Joe

If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

Okay, I see your point, Styrofoam does seem to be an exception. A very good one as well.

But would you use a chicken wing box over a color checker in a high profile still life shoot for a crayola advertisement? Even if you would be the only person who knew you did so?

 

[Ysarex]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral.

Tee shirts and paper are a poor choice as a WB reference. Styrofoam is not and should not be grouped with fabric and paper. Styrofoam is as good or better than any commercial product. I trust and prefer Styrofoam over my color checkers for setting WB.

See this old TPF post: 18 gray card prices Photography Forum Look at the graphs in Helen's post #13 and note that Polystyrene cup out performs all other items tested including commercial products. This has been my experience as well. The coffee cup rules!

Joe

If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

Okay, I see your point, Styrofoam does seem to be an exception. A very good one as well.

But would you use a chicken wing box over a color checker in a high profile still life shoot for a crayola advertisement? Even if you would be the only person who knew you did so?

If I was the only person who knew -- absolutely. If the client was watching I'd make sure a colorchecker was laying around. I keep a colorchecker with my camera because I occasionally build my own input profile. But with both a colorchecker and a coffee cup at hand I'd use the coffee cup for WB over the colorchecker. I don't need to "look competent" to convince myself.

Joe

 

[Buckster]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral.

Tee shirts and paper are a poor choice as a WB reference. Styrofoam is not and should not be grouped with fabric and paper. Styrofoam is as good or better than any commercial product. I trust and prefer Styrofoam over my color checkers for setting WB.

See this old TPF post: 18 gray card prices Photography Forum Look at the graphs in Helen's post #13 and note that Polystyrene cup out performs all other items tested including commercial products. This has been my experience as well. The coffee cup rules!

Joe

If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

Okay, I see your point, Styrofoam does seem to be an exception. A very good one as well.

But would you use a chicken wing box over a color checker in a high profile still life shoot for a crayola advertisement? Even if you would be the only person who knew you did so?

If I was the only person who knew -- absolutely. If the client was watching I'd make sure a colorchecker was laying around. I keep a colorchecker with my camera because I occasionally build my own input profile. But with both a colorchecker and a coffee cup at hand I'd use the coffee cup for WB over the colorchecker. I don't need to "look competent" to convince myself.

Joe

LOL! Reminds me of a photographer I knew many years ago who placed a LOT of value on "looking the part" and, to that end, insisted on always wearing a photographer's vest, even in the studio, even though he kept nothing in the pockets. He also kept a light meter hanging around his neck even though, as far as I could tell, he never actually used it.

 

[W.Y.Photo]

I might be mistaken but I thought a WB card is for accurate white balance setting while the 18% grey card is for accurate metering.

Well, This is true, that's what they are made for. But the fact of the matter is that an 18% gray card or splotch from a reputable color checker is just as good at white balance as a white card from a reputable WB card company. So why buy both?

White Tee shirts, Styrofoam cups, or pieces of printer paper may work fine in most situations but they tend to be slightly less than neutral.

Tee shirts and paper are a poor choice as a WB reference. Styrofoam is not and should not be grouped with fabric and paper. Styrofoam is as good or better than any commercial product. I trust and prefer Styrofoam over my color checkers for setting WB.

See this old TPF post: 18 gray card prices Photography Forum Look at the graphs in Helen's post #13 and note that Polystyrene cup out performs all other items tested including commercial products. This has been my experience as well. The coffee cup rules!

Joe

If you're going for accuracy its best that you use a item that has been verified by a color scientist as neutral than an Item that may look neutral and in fact be Blue or Ultra-Violet in terms of the actual color of the light it reflects.

If you don't have a color checker or just didn't bring it with you, I'm sure a white piece of styrofoam board will work just fine though.

Okay, I see your point, Styrofoam does seem to be an exception. A very good one as well.

But would you use a chicken wing box over a color checker in a high profile still life shoot for a crayola advertisement? Even if you would be the only person who knew you did so?

If I was the only person who knew -- absolutely. If the client was watching I'd make sure a colorchecker was laying around. I keep a colorchecker with my camera because I occasionally build my own input profile. But with both a colorchecker and a coffee cup at hand I'd use the coffee cup for WB over the colorchecker. I don't need to "look competent" to convince myself.

Joe

Obviously you don't. I'm just trying to understand what the advantage is to these companies of not using Polystyrene for their white cards... The Macbeth line is certainly flatter throughout than the Styrofoam cup in almost every color of light except for purple. That's obviously a sign both that they know what they're doing and that there is some sort of Optical Brightener within the card. So in a situation where there is a lot of purple or close to ultraviolet light bouncing around (which is really any situation outdoors as the sun produces Ultraviolet light all the time) Polystyrene is the obvious choice.

My problem is regarding the fact that on all other spectrum's the Macbeth and Smethurst seem to do exceptionally well, couldn't they simply remove the OB's and/or replace their material's mix with polystyrene to create a much more effective color checker? And if so why don't they? It's not like they get their business from people who don't understand these types of things, they get their business from the very people who take interest enough to look into these sorts of things!!

 

[qleak]

Obviously you don't. I'm just trying to understand what the advantage is to these companies of not using Polystyrene for their white cards...

Polystyrene would survive much longer than paper.

So economically speaking you'd only ever need to sell one to each customer (unless they decided to boil it!).

 

[W.Y.Photo]

But if everyone starts using paper cups instead they are screwed anyways.

That's obviously a sign both that they know what they're doing and that there is some sort of Optical Brightener within the card.

I just reevaluated what I said based of the data and I now realize that its because they do not use OBs that the purple falls off... Curious....

 

[unpopular]

the 18% recommendation may be a precaution against saturation of the sensor.

I was wondering about this, too but couldn't articulate it. But doesn't the camera expose the white balance at zero bias? So wouldn't the exposure be middle grey regardless?

 

[spacediver]

no idea, I'm really new to photography and almost always shoot in manual as I'm doing technical imaging. My comment was just a guess - it may be the case that most exposure modes prevent saturation by adjusting exposure accordingly.

 

[Ysarex]

the 18% recommendation may be a precaution against saturation of the sensor.

I was wondering about this, too but couldn't articulate it. But doesn't the camera expose the white balance at zero bias? So wouldn't the exposure be middle grey regardless?

If you're setting a custom WB on the camera then most modern cameras now have a failsafe that refuses to proceed in the event of overexposure. That's actually unfortunate because a old down & dirty trick to set a functional UniWB custom WB was just to point the camera straight at a light and force an exposure that maxed all three channels.

In any case, as Alex noted above if you fill the frame with the card the camera exposure system is going to compensate and adjust it to grey anyway. If you're using it as a reference for WB later then it doesn't have to fill the frame and you just need to make sure it's not overexposed.

Joe

 

[unpopular]

the 18% recommendation may be a precaution against saturation of the sensor.

I was wondering about this, too but couldn't articulate it. But doesn't the camera expose the white balance at zero bias? So wouldn't the exposure be middle grey regardless?

If you're setting a custom WB on the camera then most modern cameras now have a failsafe that refuses to proceed in the event of overexposure. That's actually unfortunate because a old down & dirty trick to set a functional UniWB custom WB was just to point the camera straight at a light and force an exposure that maxed all three channels.

In any case, as Alex noted above if you fill the frame with the card the camera exposure system is going to compensate and adjust it to grey anyway. If you're using it as a reference for WB later then it doesn't have to fill the frame and you just need to make sure it's not overexposed.

Joe

Both of the cameras I use don't let you adjust exposure for WB. It's a mode that has no exposure control at all.

 

[W.Y.Photo]

The RAW file holds data on white balance as if it were a slider in lightroom. No matter what the white balance is set to in camera that effect is always reversible if you shoot RAW. You can easily see what an image would look like in the "Sunny" "Cloudy" and "Incandescent" white balance settings as you can change it in a Raw file post-capture.

It doesn't "expose" the white balance it just chooses a reasonable variable value that will then effect the color of all the pixels to match an image with our eye's method of adapting to the light source within that image.