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Ians Tata
26th January 2010, 02:39 AM
May seem like a stupid question but... I am still and will forever be learning. All the "books" say that to precisely set the white balance to use a standard "gray card" but in my e-510 manual it says to use a white sheet of paper. Why the difference and what's the recommendation of the experts here?:confused:
Jeff

Byll
26th January 2010, 05:16 AM
I use anything white that is in the light that I want to set for Ian. It has worked so far for me. Must admit I haven't tried a grey card though it seems to me it may work, just giving a difference balance maybe. I have on the odd occasion pointed the camera at a difficult scene and set WB with pleasing, maybe not accurate, results.

Bill

Wijtze
26th January 2010, 10:02 AM
May seem like a stupid question but... I am still and will forever be learning. All the "books" say that to precisely set the white balance to use a standard "gray card" but in my e-510 manual it says to use a white sheet of paper. Why the difference and what's the recommendation of the experts here?:confused:
Jeff

I use the collapsible gizmo by Lastolite (EzyBalance). It has a white and an 18% gray side. On my EP1, pre-shot, whitebalancing on the white side gives better results then on the gray side.
B.t.w. my good old gray card had a white back also.

With aftershot (in Photoshop, Olympus Studio, Lightroom) I've no experience, but I think gray should work better since you're sure it isn't clipped.

Wijtze

photo_owl
26th January 2010, 01:41 PM
I believe that there is more danger that you will pick up a reflected light source from a white sheet than grey

additionally, many white sheets of paper have coloured elements - as do most normal sheets. dedicated grey/gray cards are supposed to be excatly that.

finally dedicated grey cards can also be used as exposure aids too.

Ians Tata
26th January 2010, 02:20 PM
I believe that there is more danger that you will pick up a reflected light source from a white sheet than grey

That was one of my thoughts too, it was just puzzling that Olympus would say to use a white sheet of paper.

Jeff

Wijtze
26th January 2010, 02:38 PM
That was one of my thoughts too, it was just puzzling that Olympus would say to use a white sheet of paper.

Jeff

A white sheet reflects about twice as much light as the gray-card. Maybe that's a difference. A higher reflection makes it surer small differences disappear.
Also Olympus will never say "... a gray surface ..." since natural gray isn't clear for most people. White is clearer. How many people carry a gray-card around?

Wijtze

photo_owl
26th January 2010, 05:45 PM
as has been suggested I think it's Olympus giving advice to those who won't know better!

addieleman
26th January 2010, 06:09 PM
How many people carry a gray-card around?

I do, it's always in my bag and I mostly forget to use it:(

Ian
26th January 2010, 06:22 PM
I believe that there is more danger that you will pick up a reflected light source from a white sheet than grey

additionally, many white sheets of paper have coloured elements - as do most normal sheets. dedicated grey/gray cards are supposed to be excatly that.

finally dedicated grey cards can also be used as exposure aids too.

This is very sound advice, but if you don't have a grey card on you, a neutral white sheet of paper is usually a very effective alternative.

It's worth adding that if you shoot raw, it's easy to correct in post processing without worrying about WB at the time of shooting. It can be very difficult to get good WB conversions this way from a JPEG though.

Ian

Kiwi Paul
26th January 2010, 06:38 PM
I used a sheet of A4 printer paper to calibrate my E3's white balance under incandescent light, when I select the white balance I have calibrated the colour balance is spot on in that room. I think Olympus have calibrated the cameras for using a white card which is why a white card is specified.

Paul

pewidane
26th January 2010, 07:02 PM
I never use it if I`m in doubt i take the picture as a RAW file.

click-click
26th January 2010, 07:17 PM
May seem like a stupid question but... I am still and will forever be learning. All the "books" say that to precisely set the white balance to use a standard "gray card" but in my e-510 manual it says to use a white sheet of paper. Why the difference and what's the recommendation of the experts here?:confused:
Jeff

White card for white balance, gray card for exposure. But which "gray" ? There is an interesting writeup here:
http://www.bythom.com/graycards.htm

Ians Tata
26th January 2010, 09:39 PM
This is very sound advice, but if you don't have a grey card on you, a neutral white sheet of paper is usually a very effective alternative.

It's worth adding that if you shoot raw, it's easy to correct in post processing without worrying about WB at the time of shooting. It can be very difficult to get good WB conversions this way from a JPEG though.

Ian

My wife had given me a portable collapsable light box for Christmas, mostly for photos of e-bay sales. With the auto-wb the pure white background was very amber. I ajusted that in RAW but could only get it to a shade of gray, then ajusted the exposure to bring it up to almost white. If I took it all the way to white then the object was overexposed. Using a white sheet of papper in the light box to set WB produced better results but sill had to be adjusted. That's why I was curious, and as usual here I got plenty of good advice.
Thanks,
Jeff

photo_owl
26th January 2010, 09:49 PM
My wife had given me a portable collapsable light box for Christmas, mostly for photos of e-bay sales. With the auto-wb the pure white background was very amber. I ajusted that in RAW but could only get it to a shade of gray, then ajusted the exposure to bring it up to almost white. If I took it all the way to white then the object was overexposed. Using a white sheet of papper in the light box to set WB produced better results but sill had to be adjusted. That's why I was curious, and as usual here I got plenty of good advice.
Thanks,
Jeff

this is absolutely normal - colour temperature has an impact on exposure

this is another reason why people shooting a low light test using a lght bulb and the wrong WB are adding underexposure to the noise issues!

olynut
28th January 2010, 12:17 PM
I always carry around a Whibal with me... love it!

dougdanter
28th January 2010, 01:09 PM
Here is some more information regarding gray cards for digital photography. Go to rmimaging.com and read the material in the Information tab. Interesting reading.

Doug