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Message: <blockquote data-quote="WayneF" data-source="post: 475932" data-attributes="member: 12496">We can only aim a camera in one direction.And of course, if you instead aim the Expodisk at the scene, it is falsely affected by colors in the scene, green trees or blue sky, etc.  Have you thought that out?  The design is that its diffusion averages (blurs) all the color it sees into one color (like the Photoshop Average filter). Then this one color can be processed by Custom WB (which is just AWB) to serve as white balance.  That can work if you aim it at the one light source, away from the subject.I experimented a few years back, and with several things, but I have not used the 2.0 Expodisk.  I can think about it though, and frankly, I see it as a marketing opportunity,  just something to sell.Your version is not even what the Expodisk instructions say about using it:<a href="http://www.expoimaging.com/MediaFiles/instructions/EN_62.pdf" target="_blank">http://www.expoimaging.com/MediaFiles/instructions/EN_62.pdf</a><a href="http://www.expoimaging.com/MediaFiles/instructions/EN_62.pdf" target="_blank"></a><a href="http://www.expoimaging.com/MediaFiles/instructions/EN_62.pdf" target="_blank"></a>5. Aim the Camera (Measure Incident Light).   Aim the camera towards the dominant light source (just like an incident light meter).  Note:  The light illuminating your subject must pass through the ExpoDisc, which may require you to stand at your subject’s position Incident meters at least have the full hemispherical dome on them, but they measure total intensity, NOT concerned with the color of multiple light sources.  The incident meter plan is to aim it at the camera, AWAY from the subject, to not be affected by the subjects color reflectance, which mess up our reflected meters. Should affect the Exposdisk too.  Instruction says aim it at the light.White cards are not aimed, they sit in the subjects lighting and reflect what's there, the non-white color cast they pick up.  And it is called White Balance. <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" />What the camera manual says about how to use preset white balance is:D800 manual page 154 and 155: Direct measurement: Neutral gray or white object is placed under lighting that will be used in final photograph and white balance is measured by camera. All of the camera manuals say the same.  The idea is to eliminate the influence of the subject (like incident light meters too).   And that instruction ought to work as well as any white card method, for JPG, except that we do still have to get it into Adobe Raw.   WB is not in raw files. It is in JPG.Direct sunshine can be consistent since we only have one sun, if no shade or reflections or other light is involved. But if using two lights, each can be very different color.  Even if two of the same flash model and assumed equal, one may be at high power and one at low power.  The high power one is dominant, but it is not alone.  Window light and interior light are extremely different, etc.  Mixing is not a good plan, but it often happens.Sorry, I am not a believer.    Seems fiddly to mess with all the time anyway, probably better than nothing, but certainly questionable as the best way.  Especially since a major part of the problem is that we still have to get it into Adobe  raw (camera WB is not in raw images, previously mentioned).  But the white card placed in the subject's same scene lighting reflects what light  gets there, and it is already automatically in Adobe. Then it only takes a click.   <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" />  Raw can do all the session images in the same one click.  And sorry, it was not my plan to knock anything.  I am only answering because of your direct messages to me bringing it up. I use a different method.  Because the raw WB tool is of course designed for the white card system.  So is the camera Preset WB method.In truth, I don't shoot JPG, so I only mess with the white card for any critical or important work, certainly for flash sessions, or sometimes obvious difficult cases, or where there will be many pictures in same lighting. But for the many walk-around vacation snapshots, I skip the white card, and totally ignore WB in the camera, and enjoy the vacation.  I do set camera AWB, only something fast just for the camera rear LCD and histogram, but I never intend to use the AWB. Then later on, when and if Adobe standard Daylight or Flash WB fails, I usually rely on finding other white things in the subjects area of the picture. Maybe not easy on our first try, but we can get pretty good at this pretty quick. Now and then I might take an extra picture of a good white target at the location, if it seems difficult.  Or might pull out the white card sometimes.  I might even check Adobe AWB for really tough cases.  Or I may just tweak by eye if necessary (using the good raw tools).   All this admittedly is a poor second, and maybe a little experience helps, but convenient, and still better than Auto WB, which is not in raw files anyway.  But when I will want it right, I use the white card.  In worst case, the wife just holds it near subject (in the same light), and I click an extra test frame for later comparison and correction.  Easy, it's just a shutter click to take it, and a mouse click to fix it.  And it is correct.No one is arguing for Auto WB.   I readily agree that some attempt at correcting WB is a good thing, to be commended.</blockquote>

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