I found a DIY gray card for those interested in this kind of thing. https://shuttertux.wordpress.com/2012/01/18/do-it-yourself-18-grey-card/
On Wed, Feb 22, 2017 at 5:26 PM, Michael <bmi...@gmail.com> wrote: > So with raw and dt it is okay to zoom in on the spot? What I mean is when > you take the picture do you take one (with the white spot in it) or two > (one with and one without). I'm thinking two but just to be sure..... > > You know..... I actually like this idea. I'm going to tape a couple of > pieces of white printer paper together and then tape that to a folder and > use that to white balance off of. > > On Wed, Feb 22, 2017 at 5:14 PM, Michael <bmi...@gmail.com> wrote: > >> so with raw and dt it is okay to zoom in on the spot? What I mean is >> when you take the picture do you take one (with the white spot in it) or >> twon (one with and one without). I'm thinking two but just to be sure..... >> >> On Wed, Feb 22, 2017 at 4:07 PM, Martin Burri <i...@burrima.ch> wrote: >> >>> If you shoot in raw then it only needs to give a big enough patch to use >>> the dt white balance tool on it. >>> >>> If tuning the in-camera white-balance setting, then i think you must >>> refer to the camera manual, since there is probably no universal answer. >>> >>> Best regards, >>> Martin >>> Am 22.02.2017 21:50 schrieb Michael <bmi...@gmail.com>: >>> >>> sounds good.... but shouldn't it be bigger? Or else.... how close can >>> you be when taking the white balance picture? An exposure picture off of a >>> gray card? So it does NOT need to cover most of the field of view? >>> >>> On Wed, Feb 22, 2017 at 3:27 PM, Martin Burri <i...@burrima.ch> wrote: >>> >>> There is a way more reliable DIY way than printing: >>> https://photographylife.com/diy-reliable-and-cheap-universal >>> -white-balance-reference-device >>> >>> I tried it and compared the result with a real gray card. I was unable >>> to see a difference between both methods. So, teflon comes close enough at >>> least for my visual perception :-) >>> >>> Best regards, >>> Martin >>> >>> On 22.02.2017 05:21, Michael wrote: >>> >>> Well, I guess I can try to print a gray card! >>> Anyone know what the code is for 18% gray? If 18% is right in the middle >>> of the shades of gray I found one page (http://www.computerhope.com/c >>> gi-bin/htmlcolor.pl?c=808080) that says the code is: >>> 808080 >>> and according to the same page it is made up of equal part RGB >>> *W3C Color Name:* Grey >>> *RGB:* 128, 128, 128 >>> *HSL:* 0.00, 0.00, 0.50 >>> so what is the authoritative answer? >>> >>> On Tue, Feb 21, 2017 at 7:53 PM, Marcus Sundman <sund...@iki.fi> wrote: >>> >>> On 21/02/17 23:16, Michael wrote: >>> >>> is there something where we can take a picture of a gray card and then >>> we click on it and then dt will adjust all of the colors so that the gray >>> card is >>> 33-33-33%? >>> >>> Usually you use "18% gray" meaning a card that reflects 18% of the light >>> in the visible spectrum and equal amounts of red, green and blue. >>> >>> It might actually be nice if the whitebalance module would support >>> exposure adjustment as well, to make a selected area a specific brightness, >>> or what do others think? >>> >>> by the way: what is the color of the remaining 1% >>> >>> That "33-33-33%" is your invention, so nobody but you can know what >>> "remaining 1%" you are talking about. If you were talking about the >>> reflected % of the individual color channels then there is no "remaining >>> 1%", but the "remaining" (absorbed) amounts of light are 67%, 67% and 67%, >>> respectively. >>> >>> >>> - Marcus >>> >>> >>> >>> >>> -- >>> :-)~MIKE~(-: >>> >>> ____________________________________________________________________________ >>> darktable user mailing list to unsubscribe send a mail to >>> darktable-user+unsubscr...@lists.darktable.org >>> >>> >>> >>> ____________________________________________________________________________ >>> darktable user mailing list to unsubscribe send a mail to >>> darktable-user+unsubscr...@lists.darktable.org >>> >>> >>> >>> >>> -- >>> :-)~MIKE~(-: >>> >>> >> >> >> -- >> :-)~MIKE~(-: >> > > > > -- > :-)~MIKE~(-: > -- :-)~MIKE~(-: ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
