EXPO DISC For White Balance

Seneca

Ok today I went to the camera store to go and buy a lint-free cloth for my camera lenses...and left there buying an EXPO DISC for White Balance control.

Without Expo Disc.




WITH EXPO DISC.





Anyone out there have one of these...and if so...do you use it often?

wxwax

I'm on a dark monitor, but i think the "without" looks better, myself. Less red, more natural.

Ted Szukalski

With is better exposure wise (compare highlight on his head). However, both are in need of white balance correction. Exposure and white ballance are different aspects of the photo.

Seneca

Thanks for your imput. I suspect I have a lot to learn with it. I'll keep trying to see how I can adjust the white balance. White balance has always been just a little hard for me to understand - hopefully I can play with this disc and adjust as needed.

Ted Szukalski

I find myself using temperature adjustment in DPP more often these days.

Seneca wrote:

Thanks for your imput. I suspect I have a lot to learn with it. I'll keep trying to see how I can adjust the white balance. White balance has always been just a little hard for me to understand - hopefully I can play with this disc and adjust as needed.

Scott_Quier

I have one and almost never use it any more. The directions read that you should use it to cover your lens, the point the camera at the most significant light source and take an exposure. Use that for your CWB or save it off for your post processing.

What I find works better is a WhiBal card as I have a hard time finding "the most significant light source". By default, he WhiBal card takes all your light into consideration. Have your subject hold it for a shot or expose it to your lighting and take a shot and use that as your source of neutral gray during PP.

wxwax

WhiBal works well... when I remember to pull it out. :uhoh

Seneca

Thanks Scott...white balance card huh? Yeah I got a CD of instructions with it and you're right about the CWB. Confused me a bit, but after several shots with it...I think I understand it a bit more.

Thanks for your advice on the white balance card.

Seneca

wxwax wrote:

WhiBal works well... when I remember to pull it out. :uhoh

colourbox

The thing about a card or diffusion disc is that they are averaging. Looking at the photo I am wondering if the room is lit incandescent (warm) but he is facing a candle on the table (even warmer). When two different color temperatures are in the same photo, it gets hard. An average will not match either temperature. I end up choosing the most important part, the face in this case, and using that to set the white balance slider in the Raw converter. I might use the whites of his eyes as a place to click the white balance tool and get a starting point.

The average in this picture looks closer to the overall room light, if that feather in the back is supposed to be neutral. The candle would then make the face appear warmer than the average.

My final theory is that the warmish white balance is not the fault of the ExpoDisc but of the camera. I don't know what camera was used but my Canon XT does not do very well with auto white balance in tungsten.

colourbox

Decided to take my own medicine and see if it worked. Here's what I got with the "click eyedropper on white of eye" suggestion:



It looked too neutral after the eyedropper so I nudged it back to the warm side a little to keep some of the warm room ambiance. Also brought up the black point and dropped the saturation a little. The background and the light on the chair seem too blue now - that's what I mean by saying the light on his face is probably warmer than the majority of the light in the room that was influencing the ExpoDisc.

pathfinder

Colourbox demonstrated what I felt was a serious problem in both of the first two images - Under exposure with no white and no specular highlights. The contrast range has bees significantly compressed.

When I measure the catchlights in his right eye, I cannot find a channel higher than maybe 175, and that is only in the red channel. Green and Blue are under 120. That is waaaaay too dark for a specular highlight, let alone white.

Colourboxe's image shows how far the imges has to shift to get just a white in the catchlights of the eye.

Which is more important for an image, color balance or proper exposure??

DavidTO

pathfinder wrote:

Which is more important for an image, color balance or proper exposure??

9 times out of 10 it's color. How many times have you adjusted the color, and then all of a sudden not minded the exposure problems as much? Sure, you still fix the exposure problem, but bad color is bad color, no matter the exposure.

DavidTO

colourbox wrote:

Decided to take my own medicine and see if it worked. Here's what I got with the "click eyedropper on white of eye" suggestion:



It looked too neutral after the eyedropper so I nudged it back to the warm side a little to keep some of the warm room ambiance. Also brought up the black point and dropped the saturation a little. The background and the light on the chair seem too blue now - that's what I mean by saying the light on his face is probably warmer than the majority of the light in the room that was influencing the ExpoDisc.

CB,

I believe that the skin tones in your correction are too magenta and not yellow enough.

colourbox

DavidTO wrote:

CB,
I believe that the skin tones in your correction are too magenta and not yellow enough.

That is entirely possible. I only spent a few seconds on it, in the Lightroom beta, where things like are almost fun compared to the layer gymnastics in Photoshop. I knew there was still something wrong but couldn't put my finger on it. You may be right. I always have trouble color-balancing tungsten. Adding yellow like you say could also remove some of the background blue.

Re Exposure vs. color balance...I would think that with the right exposure you can have almost any color balance you want, but if you have the right color balance but the wrong exposure, the image could have a fatal flaw like highlight clipping or shadow noise. If a shot is fast moving and I have to hit the shutter now, I will try to check exposure but let color balance slide until later.

DavidTO

colourbox wrote:

Re Exposure vs. color balance...I would think that with the right exposure you can have almost any color balance you want, but if you have the right color balance but the wrong exposure, the image could have a fatal flaw like highlight clipping or shadow noise. If a shot is fast moving and I have to hit the shutter now, I will try to check exposure but let color balance slide until later.

poe-tay-toe

Nikolai

Seneca,
While we can spend days talking about color balance, the simplest thing to do IMHO is to shoot RAW and do not worry about the expo discs and other stuff that tends to get lost or make your camera bag to weight more than a metric ton.

I'm not talking about fully controlled studio session, where a large number of pictures is taken under identical lighting situation. In this case a shot or two with a gray card in frame in the beginning of the shoot will simply help to quickly adjust the whole series and forget about it.

However, in all other cases light tends to change unpredictably, and, again from my standpoint, all those white-balance gizmos are only useful if you're shooting jpegs. Shooting RAW cures WBAS (White Balance Anxiety Syndrome) once and forever:-)

colourbox

Nikolai's post shows that I should have been more precise in my earlier statement, so let me restate it:

If you shoot in Raw, and expose correctly, you can set any color balance you want with no quality loss, in the raw converter after the shot.

A gray card helps determine what was neutral in the shot when you go to adjust it later.

Even as a raw shooter, I could see a use for an ExpoDisc because it's good to get it right in the original raw file's metadata. I don't like opening up and seeing a whole card of orange images knowing I'll have to work out the right white balance; it's nicer when they're close right off the bat.

If I had an ExpoDisc and was shooting JPEG in changing light, I would use the ExpoDisc at intervals to catch up to whatever the white balance is that minute. But it can still be fooled, if the subject's local light source is not the same as the overall average, as in the example above. As long as you watch out for that it could be a useful tool.

But even then...What has changed very dramatically in the last year is that tools like the Lightroom beta and the Adobe Camera Raw 4 beta let you make decent, fast white balance changes even to well-shot JPEGs! It is just shocking how well and how easily it works.

Scott_Quier

What Nik and colorbox are say is right on. I always shoot RAW ('cause I'm not good enough yet to get it right the first time, every time:D) and from time to time rely on RAW to pull my chestnuts out of the fire.

I use the WhiBal card when I can so that I don't have to guess about the WB. Where you have mixed light, it does average the light but it also gives you a decent starting point from which to make final corrections.

And, like Seneca said, it works well when you remember to pull it out! I've forgotten to use it a number of times but have been lucky in that there was, in these cases, an identifiable neutral in the frame of at least one shot to work with.

Cason

Has anybody tried a coffee filter? I guess you would do they same as if it were a Expodisc.

wxwax

pathfinder wrote:

Which is more important for an image, color balance or proper exposure??

Interesting. Both, of course.

But contrary to what David posted, I find that when I fix the exposure, my color problems suddenly become a lot less serious.

Seneca

Well the only lighting I used in this picture was natural lighting from the window that is behind my subject or to the side since I shot at an angel.

I've read so many magazines that say LIGHTING IS EVERYTHING. I really need to try and master this. Colorbox you mentioned that you shoot RAW...can you explain that to me? So basically if I shoot RAW, I can correct WB in Photoshop 7.0? Feel free to drop me a PM if you'd like.

I am learning photography...and I knew that if I became a member here that I could probably get some really good feedback. You guys are a little above my head when it comes to WB knowledge...but I am willing to get any advice...I am extremely thicked skinned.

Thanks for all the comments...

ChrisRPhoto

Here is the Expo disc use in studio conditions.

First shot is using the modelling light from the Broncolor softbox which has given a natural tungsten look.

Second shot was taken using the Expo disc and applying the settings it suggested.

kygarden

Scott_Quier wrote:

What I find works better is a WhiBal card as I have a hard time finding "the most significant light source". By default, he WhiBal card takes all your light into consideration. Have your subject hold it for a shot or expose it to your lighting and take a shot and use that as your source of neutral gray during PP.

I bought one (WhiBal card) awhile back...but I seem to be too lazy to use it! However, it's nice to have around. If I ever DO need to take some important photos, I have it handy and can use it then. I just tend not to use it for everyday shots.

I posted some test shots with it back when I bought it - here...
http://www.dgrin.com/showthread.php?t=45592


.

Seneca

ChrisRPhoto wrote:

Here is the Expo disc use in studio conditions.

First shot is using the modelling light from the Broncolor softbox which has given a natural tungsten look.

Second shot was taken using the Expo disc and applying the settings it suggested.

Big difference in the color of her jacket. In one it's peachy and the other its pink.

ALSO...

KY...
That's for showing me what that WB card looks like

Scott_Quier

Seneca wrote:

you shoot RAW...can you explain that to me? So basically if I shoot RAW, I can correct WB in Photoshop 7.0? Feel free to drop me a PM if you'd like.
Thanks for all the comments...

Seneca,

Here's a link to a quick RAW tutorial (Thanks, Andy)

http://www.dgrin.com/showthread.php?t=2592

and you'll see my contribution to the thread starting at post #42. So, rather than repeat myself here, let me recommend you read that. If you have any questions after that, please feel free.

Does Adobe Raw Converter work with PS 7.0? I don't know but I'm sure someone here does. If not, and assuming your camera will shoot/record RAW (that's a plug for you to update your profile so those that are of a mind to answer questions have something to start with), there's bound to be a RAW converter that came with your camera.

Seneca

You're awesome Scott!!! Thanks so much...I'm printing this out now...thanks so much!

pathfinder

ChrisRPhoto wrote:

Here is the Expo disc use in studio conditions.

First shot is using the modelling light from the Broncolor softbox which has given a natural tungsten look.

Second shot was taken using the Expo disc and applying the settings it suggested.

Very nice - her blouse and the background were both almost the same shade of gray?

ChrisRPhoto

The shot on the right is very accurate in colour balance and tonal range,
the background is a white colorama roll, unlit, becomes an off grey colour.

This little gadget is really handy and more practical than sometimes fighting with bits of card/paper out on commercial jobs as I have found in the past

Chris

pathfinder wrote:

Very nice - her blouse and the background were both almost the same shade of gray?

Seneca

ChrisRPhoto wrote:

The shot on the right is very accurate in colour balance and tonal range,
the background is a white colorama roll, unlit, becomes an off grey colour.

This little gadget is really handy and more practical than sometimes fighting with bits of card/paper out on commercial jobs as I have found in the past

Chris

I like that it has a strap with the EXPO DISC...keeps it handy to take along when you want to use it. I will practice more with it. Not sure how I feel about it just yet.

White Balance scares the bejibbies out of me so I thought this could be a quick fix. I am extremely serious about learning how to shoot under bad lighting conditions.

Again, I'll have to play with it.

Thanks for your comment.

kygarden

If you have software to convert RAW files to JPG and your PC is fast enough, you could consider shooting raw. At least that would give you a few more chances to save a photo if the white balance is off. You can change the white balance after the photo was taken via the software on the PC. Other advantages to raw too....but so far I still use JPG mainly.