Why I REALLY care about WB in RAW - buying an Expodisc

pbleic said:

PS - invitation still valid.

RATPhoto said:

Sorry about that Paul. I in no way was trying to imply that your
photography was subpar. I realized the test shot was just that, a
test shot. I do the same kind of thing.

I was just saying that all of us can improve our photography and
that in your case, I think you have the white balance down to the
point where I would move on to other things for a while and come
back to it later on.

That is not to say that I think your buying a disc would be a bad
thing.

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See my profile for my equipment

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Paul

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Paul

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Photographs at: http://www.pbase.com/pbleic
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Copyright 2003, 2004 All rights reserved.

Paul,

Hope you had a fun trip. Prauge must have been interesting!

I'm wondering if you're completely wrong -- and I'm not saying that in a nasty way or trying to be a PITA.

Here's what I mean: if the camera captures a RAW image, puts it in a buffer, and then applies the WB to the captured RAW image and creates a file, how is that different than shooting RAW and applying the WB afterwards?

I can see the issue if you're using jpeg files or RAW files when the application doesn't support Kelvin. Certainly changing the WB in Photoshop is challenging. The Kelvin scales on the RAW programs are another story.

Basically I can't see a conceptual difference between capturing RAW and changing the WB later and capturing RAW and using Expodisk to tell the camera what WB to use when creating the file. But I'm probably missing an important bit. Maybe you or someone else can help me out.

As to what's right, to my thinking "right" is what you want it to be. Sometimes warming things up a bit works, sometimes cooling things off is better, and somtimes it's just right as is.

DSC

pbleic said:

I just got back from a trip to Prague. Took lots of photos and
will be working on them. As usual, took them all in RAW. The most
frustrating thing is that the photos have little true white/true
gray. I have played with WB, but I just can't be sure what is
right.

Click to expand...

Forrest,

I like the road trick. Very nifty. But it sort of takes you briefly into and then out of the pic!

DSC

I feel the same way as you. But I'm using the pringles lid solution because I'm saving money for other gear. Not as exact as the ExpoDisc, but close enough for me.

Nothing different technically.

The question is, how do you get it right? After the fact, you have no reference to "get it right."

Paul

Donald Cooper said:

Hope you had a fun trip. Prauge must have been interesting!

I'm wondering if you're completely wrong -- and I'm not saying that
in a nasty way or trying to be a PITA.

Here's what I mean: if the camera captures a RAW image, puts it in
a buffer, and then applies the WB to the captured RAW image and
creates a file, how is that different than shooting RAW and
applying the WB afterwards?

I can see the issue if you're using jpeg files or RAW files when
the application doesn't support Kelvin. Certainly changing the WB
in Photoshop is challenging. The Kelvin scales on the RAW programs
are another story.

Basically I can't see a conceptual difference between capturing RAW
and changing the WB later and capturing RAW and using Expodisk to
tell the camera what WB to use when creating the file. But I'm
probably missing an important bit. Maybe you or someone else can
help me out.

As to what's right, to my thinking "right" is what you want it to
be. Sometimes warming things up a bit works, sometimes cooling
things off is better, and somtimes it's just right as is.

DSC

pbleic said:

I just got back from a trip to Prague. Took lots of photos and
will be working on them. As usual, took them all in RAW. The most
frustrating thing is that the photos have little true white/true
gray. I have played with WB, but I just can't be sure what is
right.

Click to expand...

Click to expand...

--
Paul

------------------------------------------------
Pbase supporter
Photographs at: http://www.pbase.com/pbleic
--------------------------------------------------
Copyright 2003, 2004 All rights reserved.

Forrest41926 said:

With an Expodisc, do you point the lens at the open sky, or at the
clouds? Or using a grey card, do you hold it in the shade, or in
the open sun?

Click to expand...

You can do either. You can point at the sun, the primary source....or you can just shoot the landscape shot, which is what I would do.

Shooting at the sun allows you to use the ExpoDisc as an incidenct meter as well as for WB.

But, you can simply shoot the same shot you will do without the ED...and you will get an 18% grey shot of the reflective light of your scene.

Which makes getting mixed lighting balance a much easier task than before.

Lee

Would love to see some of your before and after shots.

Lee

Locster said:

I feel the same way as you. But I'm using the pringles lid solution
because I'm saving money for other gear. Not as exact as the
ExpoDisc, but close enough for me.

Click to expand...

And from what I understand it "integrates" a 180 degree scene, through the prisms.

Paul

LeeBase said:

LeeBase said:

With an Expodisc, do you point the lens at the open sky, or at the
clouds? Or using a grey card, do you hold it in the shade, or in
the open sun?

Click to expand...

You can do either. You can point at the sun, the primary
source....or you can just shoot the landscape shot, which is what I
would do.

Shooting at the sun allows you to use the ExpoDisc as an incidenct
meter as well as for WB.

But, you can simply shoot the same shot you will do without the
ED...and you will get an 18% grey shot of the reflective light of
your scene.

Which makes getting mixed lighting balance a much easier task than
before.

Lee

Click to expand...

--
Paul

------------------------------------------------
Pbase supporter
Photographs at: http://www.pbase.com/pbleic
--------------------------------------------------
Copyright 2003, 2004 All rights reserved.

...what you want from the expodisc (or Pringles lid.) It seems to me (and I just know someone will correct me if I'm mistaken!) that all you are doing with one of these strap-on devices is sampling the light in the area in front of the camera, in a general, diffuse kind of way. Isn't that what the camera records when it does an AWB reading without any additional devices? And isn't that what image editing software does when it carries out an auto-correction (I don't mean C1, BB or FVU, I'm talking about PWPro etc.)?

--
DB

The first (AWB) looks closest to me - closest to what I would think the scene looked like when the shot was taken, but I'll repeat I was not there. That correction about driveway and fence actually reenforced this. The others do not look like asphalt to me and the other fences do not look like they have a greenish or greyish moss. What saturation did you use in C1?

I do agree the others look nicer as images, but after lunch and being outdoors and coming in and seeing the first one I just keep coming back to it as being the most right (not the best, but the most right). I do agree it looks bluer than the others, but is it too blue because of side by side comparision or is it really to blue?

I think in the end as others have said, WB is not just to make an image perfectl WB (and most images can not be - that is what part of the image is perfect WB?), but to make it look how the photographer wants it to.

Al

pbleic said:

No, I checked this on a copy of C1 I have here.

Click to expand...

wow - either C1 has different WB values or I am loosing my mind. I would not be surprised if it is the later.

pbleic said:

pbleic said:

pbleic said:

pbleic said:

I think the auto WB may be closest for a cloudy day - grey
driveway, a bit blue cast to garage door. What if you boost
saturation a bit on that one - I'd be interested to see that?

Click to expand...

Actually looking at the scene it was not accurate. Too blue.

Click to expand...

It is a bit blue, but it looks most like what I imagine the scene
to look like on cloudy day - an accurate representation vs. a
corrected one. I keep looking at the driveway and the fence in the
background - I always think of these type of fences to be more grey
after the wood ages. And the other versions of the driveway have a
color which looks like resddish dyed cement vs. the bluish cast
cement ususal has. But you are right - I have never seen this
before.

Click to expand...

The wood is aged and has a bit of a greenish mossy bit to it. The
driveway is ASPHALT.

Click to expand...

pbleic said:

--
Paul

------------------------------------------------
Pbase supporter
Photographs at: http://www.pbase.com/pbleic
--------------------------------------------------
Copyright 2003, 2004 All rights reserved.

Click to expand...

That's an interesting observation, but I think it's a little bit off. For example, one way that software can auto-WB an image (like Photoshop can...although it may use more sophisticated techniques) is to look at the brightest highlight in the image, which is commonly created by some specular highlight for example, and see how far it's off from equal amounts of R, G, and B and by applying the necessary scaling to each of those channels you get a properly white-balanced photo much of the time. This sort of algorithm is reined in by detecting extreme devations from neutral, though, so that a shot of a red wall isn't converted to a picture of a grey wall.

With the Pringles lid or the Styrofoam coffee cup methods, the light on the inside surface of those objects will include light outside the field of view of the lens by scattering in the plastic and thus get a better average of ambient light than just a numeric averaging of the scene would give you. A coffee cup, for example, may be capturing upto about 300 degrees of light rather than just the few degrees in the lens's field of view.

The expodisc seems to try to be extra careful to use prisms to get a broad area of light values and then color adjust them with filtration within the disc. I don't have an expodisc, but get decent results from the coffee cup trick...though I only get picky about WB for the technical shots (documentation) that I take and usually don't bother for artistic shots. (I'm just an amateur).

David Barker said:

...what you want from the expodisc (or Pringles lid.) It seems to
me (and I just know someone will correct me if I'm mistaken!) that
all you are doing with one of these strap-on devices is sampling
the light in the area in front of the camera, in a general, diffuse
kind of way. Isn't that what the camera records when it does an AWB
reading without any additional devices? And isn't that what image
editing software does when it carries out an auto-correction (I
don't mean C1, BB or FVU, I'm talking about PWPro etc.)?

--
DB

Click to expand...

pbleic said:

And from what I understand it "integrates" a 180 degree scene,
through the prisms.

Click to expand...

Which sounds awesome ... but my question remains. Would you use the Expodisc to measure the WB from the open sky / direct sunlight, or through a cloud? Because both of these light sources ( obviously ) have different color balances, and impact large areas of the picture.

David Barker91965 said:

all you are doing with one of these strap-on devices is sampling
the light in the area in front of the camera, in a general, diffuse
kind of way.

Click to expand...

Well, with the ExpoDisc it's a very specific kind of way -- designed to work with how the cameras work.

If all your pictures come out of the camera with accurate colors, then you have no need of a pringles lid or an ExpoDisc.

If, on the other hand, you frequently get these horribly cast colors (shoot indoors without flash if you nee examples) -- then you'll look for a solution.

Take a look on the http://www.expodisk.com site for a good explaination of how it works.

Maybe you are just one of those who gets good color in the situations you shoot.

Me....I like to shoot indoors without flash and I am sick and tired of the incorrect color and difficulty and time it takes to correct the colors in post processing.

I got the expodisc, and right away I'm able to shoot in my church's light with not color problems. Before, I got so frustrated I just changed my pictures to black and white to not have to deal with the color issue.

Lee

You would compose your picture as if you were going to take the shot. Then set the focus to manual, wb to AWB, put the expodisc in front of the lens, shoot, set the custom wb, and turn the custom wb on, then take your pict.

Take a bunch of pictures -- until the light changes.

Since you are pointing at the scene you want to capture, you'll get all the different light sources averaged to 18% grey.

That's the beauty of the expodisc with mixed lighting. You just point at your subject and you'll adjust for the reflected light from all of the sources in proportion to how they affect the subject from your pov.

Lee

Forrest said:

Forrest41926 said:

And from what I understand it "integrates" a 180 degree scene,
through the prisms.

Click to expand...

Which sounds awesome ... but my question remains. Would you use
the Expodisc to measure the WB from the open sky / direct sunlight,
or through a cloud? Because both of these light sources (
obviously ) have different color balances, and impact large areas
of the picture.

Click to expand...

Thanks Lee - I'll look up the expodisk link when I've a little more time.

I know what you mean about the indoor WB (without flash). I find the camera handles outdoor situations usually very well, but less so indoors. I think a lot of this is because most indoor lighting gives off light across a narrow frequency range, and despite the camera's best efforts there just isn't any light within large parts of the visible spectrum. Good though the 300D is it cannot invent what isn't there!

However, you sound as though you have had good results in exactly these circumstances, so I remain interested and willing to be persuaded of the merits of expodisk (and, potentially, food-related white objects.)

DB

LeeBase said:

LeeBase said:

all you are doing with one of these strap-on devices is sampling
the light in the area in front of the camera, in a general, diffuse
kind of way.

Click to expand...

Well, with the ExpoDisc it's a very specific kind of way --
designed to work with how the cameras work.

If all your pictures come out of the camera with accurate colors,
then you have no need of a pringles lid or an ExpoDisc.

If, on the other hand, you frequently get these horribly cast
colors (shoot indoors without flash if you nee examples) -- then
you'll look for a solution.

Take a look on the http://www.expodisk.com site for a good explaination of
how it works.

Maybe you are just one of those who gets good color in the
situations you shoot.

Me....I like to shoot indoors without flash and I am sick and tired
of the incorrect color and difficulty and time it takes to correct
the colors in post processing.

I got the expodisc, and right away I'm able to shoot in my church's
light with not color problems. Before, I got so frustrated I just
changed my pictures to black and white to not have to deal with the
color issue.

Lee

Click to expand...

--
DB

LeeBase said:

That's the beauty of the expodisc with mixed lighting. You just
point at your subject and you'll adjust for the reflected light
from all of the sources in proportion to how they affect the
subject from your pov.

Click to expand...

Okay, I think I understand. Thanks for taking the time to spell this out for me!!

David Barker91965 said:

However, you sound as though you have had good results in exactly
these circumstances, so I remain interested and willing to be
persuaded of the merits of expodisk (and, potentially, food-related
white objects.)

Click to expand...

Check for threads started by me. I've started about 4 on my ExpoDisc journey.

My gallery relating to expoDisc testing is: http://www.pbase.com/leebase/expodisc

Other threads with picts:
http://forums.dpreview.com/forums/read.asp?forum=1014&message=7984319

http://forums.dpreview.com/forums/read.asp?forum=1031&message=8000661

http://forums.dpreview.com/forums/read.asp?forum=1031&message=7984188

http://forums.dpreview.com/forums/read.asp?forum=1031&message=8010730

Lee

pbleic said:

I just got back from a trip to Prague. Took lots of photos and
will be working on them. As usual, took them all in RAW. The most
frustrating thing is that the photos have little true white/true
gray. I have played with WB, but I just can't be sure what is
right.

Click to expand...

Paul,

When it comes to WB, what do you consider to be "right"? The purpose of white balance correction is to recreate how the scene would have appeared if illuminated in a particular spectral mix of light rather than in the actual light that was present. Is it really so important to normalize perfectly to such a standard? The spectrum of daylight, the typical standard, varies with the position of the sun in the sky. In addition, the illumination of a scene consists not only of direct light, but of light reflecting off of other large objects in the scene. Finally, even though the brain white balances for you, allowing you to observe "white" even under light conditions drastically different from actual white light, this doesn't mean the process is perfect or that it's not easily fooled in situations where there are multiple lighting sources of different spectra. Standardization and calibration of equipment may require setting an exact definition for white light. But, this doesn't mean that this standard is absolute in an aesthetic sense. Thus, it seems hard to justify seeking one right answer, especially if it comes at considerable cost and inconvenience. As with other aesthetic aspects of photographer, you do have license to adjust the image so as to give you whatever pleasing result you wish. If a given street scene might have actually looked slightly different at the time you took the exposure, that doesn't mean that this was the "correct" look of the scene. A few hours earlier or later in the day, or with a few more clouds in the sky, things may have looked different.

If you can't tell if a given scene is "right" when postprocessing on your screen, than it's likely that nobody else can and that there's nothing unnatural or obviously wrong with your adjustments.

David

Isn't that an incorrect use of the Expodisc? I though you are suppose to sample the light at the subject's position. Take the camera to where the subject is, aim the camera toward the direction you are planning to take the shot and take a reference pic with the Expodisc at that position. Basically sampling and referencing the light hitting your subject.

David Barker said:

...what you want from the expodisc (or Pringles lid.) It seems to
me (and I just know someone will correct me if I'm mistaken!) that
all you are doing with one of these strap-on devices is sampling
the light in the area in front of the camera, in a general, diffuse
kind of way. Isn't that what the camera records when it does an AWB
reading without any additional devices? And isn't that what image
editing software does when it carries out an auto-correction (I
don't mean C1, BB or FVU, I'm talking about PWPro etc.)?

--
DB

Click to expand...

Like a distant mountain range, for instance? By the time you get back it'll be dark...

Homl said:

David Barker said:

...what you want from the expodisc (or Pringles lid.) It seems to
me (and I just know someone will correct me if I'm mistaken!) that
all you are doing with one of these strap-on devices is sampling
the light in the area in front of the camera, in a general, diffuse
kind of way. Isn't that what the camera records when it does an AWB
reading without any additional devices? And isn't that what image
editing software does when it carries out an auto-correction (I
don't mean C1, BB or FVU, I'm talking about PWPro etc.)?

--
DB

Click to expand...

Click to expand...

--
DB