Hi guys,

Up to now, using a grey card is still, well, in the grey area for me. I have a grey card but I do not know hot to use it. What do you do? I know you have to expose it in the same lighting as your subject. But how? Do you set your camera in Aperture Priority mode, Shutter Priority mode, or Manual? I am using a D70 and in my viewfinder, I see the following image:

http://www.f3mphotography.com/images/DigiPhoto/ManualExposure.gif

It says in the user guide that when using Manual mode, you have to adjust the Shutter and Aperture settings until you get Optimal Exposure. So do you have to expose your grey card until you reach this setting? I know wedding photographers don't have any time to tinker with this, but I am just asking this as a general photography question.

I also saw somewhere that grey cards are used to correct white balance? Paano yun?

And how about light meters, I'd like to buy this one (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=368226&is=REG&addedTroughType=search). But I don't know how useful it would be if I do not know how to use it. Do you set the shutter speed and then let it figure out the aperture and ISO? Or vice versa?

But the thing is, with all the advancements in DSLR technology, with all these different types of metering modes, auto white balance, do we still need these things? And with the ability to shoot RAW, do we need to think about white balance anymore? I know you still have to get your exposure right. Well, a little under-exposure they said is still okay, but not over-exposure where details will already be gone in the over-exposed areas.

Shine a light on me please...

Thanks,

Marco

Here you go Marco: You should read this (http://www.luminous-landscape.com/columns/determining-exposure.shtml). Cheers. :)

There is elegance in the simplicity of how you use a gray card. You have to put the gray card beside or near your subject and make sure that the same amount of light hitting the subject is also hitting the gray card. You then take a meter reading off the surface of the gray card. Try to ensure that the gray card fills the frame and you do not cast a shadow on its surface as you are taking your meter reading.

I recommend that you use manual exposure mode. You either select an aperture setting and adjust your shutter speed setting until your camera's meter tells you that you are properly exposed. Or you could also select a shutter speed setting of your choice and adjust the shutter speed setting.

Your camera's lightmeter will always recommend an exposure setting so that what it is reading will come out the tone of middle/neutral/18% gray. You don't always have to use a gray card. What you have to be conscious of is what the meter is reading.

For example, if you are shooting a subject wearing a white shirt and you inadvertently take a meter reading off the white shirt, the camera's lightmeter will think that it is bright and recommend an exposure setting that will make that white shirt come out the tone of middle gray. Hence, your shot will be underexposed.

A similar meter reading off a black shirt will give you a shot that is overexposed.

This is because the lightmeter in your camera takes a reflected meter reading. It measure the amount of light bouncing off a surface.

The Sekonic L-308s is a good lightmeter. It has all the basic features that you will need for the long haul. The Sekonic L-308s is an example of an incident lightmeter. It measures the intensity of light hitting the subject. Hence, its exposure settings recommendations aren't affected by factors like the ones stated above (i.e. white or black shirt).

Shooting in RAW affords you more precision in setting your white balance setting during RAW conversion and post processing. So I suppose in this sense that you should have more concern about your white balance settings.

Some photographers take a shot of their subjects holding either a gray card with either the white or gray surface facing the camera. They then use the white balance tool of Adobe Camera RAW to sample the white or gray surface as an aid in setting the white balance.

Please bear in mind that you can use this as a starting point to further tweak and fine tune your white balance settings to taste.

Cheers!

Jo Avila

Hi guys,

Up to now, using a grey card is still, well, in the grey area for me. I have a grey card but I do not know hot to use it. What do you do? I know you have to expose it in the same lighting as your subject. But how? Do you set your camera in Aperture Priority mode, Shutter Priority mode, or Manual? I am using a D70 and in my viewfinder, I see the following image:

http://www.f3mphotography.com/images/DigiPhoto/ManualExposure.gif

It says in the user guide that when using Manual mode, you have to adjust the Shutter and Aperture settings until you get Optimal Exposure. So do you have to expose your grey card until you reach this setting? I know wedding photographers don't have any time to tinker with this, but I am just asking this as a general photography question.

I also saw somewhere that grey cards are used to correct white balance? Paano yun?

And how about light meters, I'd like to buy this one (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=368226&is=REG&addedTroughType=search). But I don't know how useful it would be if I do not know how to use it. Do you set the shutter speed and then let it figure out the aperture and ISO? Or vice versa?

But the thing is, with all the advancements in DSLR technology, with all these different types of metering modes, auto white balance, do we still need these things? And with the ability to shoot RAW, do we need to think about white balance anymore? I know you still have to get your exposure right. Well, a little under-exposure they said is still okay, but not over-exposure where details will already be gone in the over-exposed areas.

Shine a light on me please...

Thanks,

Marco

This is the most concise explanation about the proper usage of a gray card I've ever read.

Thanks Sir Jo. :)

There is elegance in the simplicity of how you use a gray card. You have to put the gray card beside or near your subject and make sure that the same amount of light hitting the subject is also hitting the gray card. You then take a meter reading off the surface of the gray card. Try to ensure that the gray card fills the frame and you do not cast a shadow on its surface as you are taking your meter reading.

I recommend that you use manual exposure mode. You either select an aperture setting and adjust your shutter speed setting until your camera's meter tells you that you are properly exposed. Or you could also select a shutter speed setting of your choice and adjust the shutter speed setting.

Your camera's lightmeter will always recommend an exposure setting so that what it is reading will come out the tone of middle/neutral/18% gray. You don't always have to use a gray card. What you have to be conscious of is what the meter is reading.

For example, if you are shooting a subject wearing a white shirt and you inadvertently take a meter reading off the white shirt, the camera's lightmeter will think that it is bright and recommend an exposure setting that will make that white shirt come out the tone of middle gray. Hence, your shot will be underexposed.

A similar meter reading off a black shirt will give you a shot that is overexposed.

This is because the lightmeter in your camera takes a reflected meter reading. It measure the amount of light bouncing off a surface.

The Sekonic L-308s is a good lightmeter. It has all the basic features that you will need for the long haul. The Sekonic L-308s is an example of an incident lightmeter. It measures the intensity of light hitting the subject. Hence, its exposure settings recommendations aren't affected by factors like the ones stated above (i.e. white or black shirt).

Shooting in RAW affords you more precision in setting your white balance setting during RAW conversion and post processing. So I suppose in this sense that you should have more concern about your white balance settings.

Some photographers take a shot of their subjects holding either a gray card with either the white or gray surface facing the camera. They then use the white balance tool of Adobe Camera RAW to sample the white or gray surface as an aid in setting the white balance.

Please bear in mind that you can use this as a starting point to further tweak and fine tune your white balance settings to taste.

Cheers!

Jo Avila

Sometimes in a worse case scenario that you forget your grey card... You can also take a meter reading on your own hand; not as accurate though but it may get the job done... :)

@Jo, thanks for the concise tip... Very useful indeed. :)

I read somewhere that a red surface can also be used to take a meter reading. :)

Sometimes in a worse case scenario that you forget your grey card... You can also take a meter reading on your own hand; not as accurate though but it may get the job done... :)

@Jo, thanks for the concise tip... Very useful indeed. :)

The surface can be of any color actually - just as long as its tone is equivalent to middle gray. Most people forget that we are talking about tones and color when we discuss middle gray :D

Cheers!

K

I read somewhere that a red surface can also be used to take a meter reading. :)

Your camera built-in reflected meter is calibrated to set an exposure that will produce 18% gray, meaning if you point your meter to any white subject it will produce a tone of 18% gray or if you point to black it will produce 18% black ,not black -black or white - white . So what happen if you point your meter that is already 18% reflectance like the "gray card". When you point your meter at an 18% greycard the meter will give you a suggested exposure that would produce an image of this card that will print in exactly the same tone. Meaning the light that the meter is reading on the card is the same light that is hitting your subject. because you are not pointing your meter to any subject , the meter is not reading any tone in the scene . It does not know if you are photographing a beautiful caucasian face , pinoy face or negro face, bright sky, white snow or jet coal black. All it know is what it sees is the 18% light reflecting from the card. Based on this reading it will recomends an exposure that will reproduce this tone in a finish print of 18% gray.

So , since the 18% -gray tone in the card will be faithfully reproduced as an 18% gray tone in the finish print, all other tones-darker or lighter- will also be faithfully reproduced in the printed image. All other tones! darker, lighter, black will be black ,white will be white, all tones will be reproduce in print as exactly as ther are in nature.
but make sure that the light hitting the card is the about the same as the light the subject, it would come from the same direction, the same intensity as mentioned by Jo Avela

You don't need incident meter if you have a 18% gray card both of them measured the light that illuminates the subject, why ? when you take an incident meter reading, the white plastic cap on the meter admits 18% of this light. This is exactly the same as taking a reflected light from the grey card. The gray card reflects 18% of the light that hit it.
:)