Is the 18% gray card still relevant today?

Mack

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I see a lot of people posting photos on DPR where the exposure shows a +0.7 EV (over-exposure). My own findings with RawDigger show there is still a lot of highlight detail still available in some of my photos with digital so I can push ETTR more than if I were to take the meter's average off a gray card. Maybe dynamic range increases in newer cameras allow for more over-exposure, or using ETTR over that of the (film era's) 18% gray card recommendation?

The gray card that is on the back of the Sekonic Exposure Profile Target II Card (No longer available.) is an exact RGB-118 or or Lab=50. My communication with Sekonic Japan said they are going to something different as to the reason that card is discontinued.

Could it be time to retire the 18% Gray Card and maybe use a darker card to allow for more over-exposure? Maybe a Lab=40 instead which is a RGB=90 value card in Photoshop?


Fwiw, my own exposure preference is to set the exposure using a large white Styrofoam ball and exposing until I see a hint of OE blinkies on its specular highlights on the EVF/LCD of the camera. That pushes the ETTR about as far as I can go with the JPEG preview, but there still can be some detail according to RawDigger based on the RAW histogram data.
 

wimg

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A middle grey card is only relevant to the final image, as in, the way you want to process it.
All it does is indicate a general exposure value at a certain iso, to get the exposure in the middle of the tonal curve.

Basically, you'd likely be better off with a multi-tonal card these days, in the digital era, to see the effect when processing.

Funnily enough I still expose a photograph based on what I know I will need later on when processing an image, IOW, I deliberately under- or overexpose, taking into account what the effect with digital is, namely loss of data at the overexposed end, but still being able to extract more at the underexposed end, basically the opposite of analog.

From that POV, you don't need an 18% grey card anymore, especially as live view, whether that is with a dslr or with a mirrorless camera, generally shows well enough what the end result without further individual corrections may look like.

Also, with film, you could extract 9 or 10 stops with b&w, and 6 or 7 stops with colour, which still had to be compressed to 6 stops for a print, and with digital youi generally have 12+ stops of wiggle room anyway, which generally still need to be compressed to 8 stops for viewing on a monitor, and 6 tot 6.5 stops for printing.

If you really would like to see what you are doing or can do, I'd personally suggest you invest in Nik software, specifically Silver Efex, to see what the different tonal levels do and how they react when manipulated, and take it from there. That will lekly help you more than an 18% grey card, IMO.

HTH, kind regards, Wim
 

RichardC

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I find that an 18% grey card (or colour wedge) is useful when photographing batches of products. Placing one alongside the product after any change in lighting gives me a reference neutral for colour correction later.

For general photography that's not colour critical, if I have a predominantly light or dark subject, I just bracket accordingly.
 

ralf-11

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I keep losing mine. I have LOTS of manila file folders tho - does anybody what % reflectance those are?
 

PakkyT

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Placing one alongside the product after any change in lighting gives me a reference neutral for colour correction later.
Just keep in mind that true 18% grey cards (like made by Kodak) are meant to set exposure, not color, and the actual color of the card may not be totally neutral in color. But they can work in a pinch since I bet if you bought a dozen different white balance cards you will likely get nearly a dozen different shades of grey cards, although most reasonably close to each other. The important thing is if you want to get the same color tone across a number of photos, especially if you might be tearing down a setup and setting up back up later to continue, that you use the same card for setting your white balance each time.
 

oldracer

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.... Could it be time to retire the 18% Gray Card and maybe use a darker card to allow for more over-exposure? ...
When I have used gray cards they have never restricted my exposure choices.
 

Mack

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Just keep in mind that true 18% grey cards (like made by Kodak) are meant to set exposure, not color, and the actual color of the card may not be totally neutral in color. But they can work in a pinch since I bet if you bought a dozen different white balance cards you will likely get nearly a dozen different shades of grey cards, although most reasonably close to each other. The important thing is if you want to get the same color tone across a number of photos, especially if you might be tearing down a setup and setting up back up later to continue, that you use the same card for setting your white balance each time.
Fwiw, I bought a pair of gray cards off Amazon (Neewer was the brand.) and they appeared more of a darker blue than a gray. The spectrometer measured them out as RGB: Red=102, Green=107, and Blue=111 when all should have been equal to that of a Munsell (Sekonic and Kodak) gray card which was a perfect RGB=118 for all. I did complain to Neewer and they apologized and sent me another set of cards, but they were the same values as first set I bought. :frown: They'd be rough to use to set a white balance from. I also bought a Delta brand card at a camera shop and it was a little better with a lot of info n the back (Zone System. lighting ratios,, etc.), but colorwise it was not as close as pricey Munsell gray card. Seems truly neutral gray cards come with a big price

I did find some info from Kodak on using their (i.e. Munsell branded.) gray card - which also gave me headache: Instructions for using the Kodak Gray Card
I believe Ansel Adams recommended tilting the card so the end effect was it became a (darker) 12% gray card.
 

ac12

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Fwiw, I bought a pair of gray cards off Amazon (Neewer was the brand.) and they appeared more of a darker blue than a gray. The spectrometer measured them out as RGB: Red=102, Green=107, and Blue=111 when all should have been equal to that of a Munsell (Sekonic and Kodak) gray card which was a perfect RGB=118 for all. I did complain to Neewer and they apologized and sent me another set of cards, but they were the same values as first set I bought. :frown: They'd be rough to use to set a white balance from. I also bought a Delta brand card at a camera shop and it was a little better with a lot of info n the back (Zone System. lighting ratios,, etc.), but colorwise it was not as close as pricey Munsell gray card. Seems truly neutral gray cards come with a big price

I did find some info from Kodak on using their (i.e. Munsell branded.) gray card - which also gave me headache: Instructions for using the Kodak Gray Card
I believe Ansel Adams recommended tilting the card so the end effect was it became a (darker) 12% gray card.

I dunno, it seemed pretty easy to understand. But then I've used an incident meter for YEARS.
And that is why using an incident meter for exposure is a LOT easier, than a grey card for exposure.
 

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