White balance will be the death of me...

[ORourkeK]

With my new setup I am doing everything I can to learn and do new jobs. I have taken on a pro bono product photography job and for the life of me I cannot achieve a proper white balance. It doesn't help that a lot of the items I am taking pictures of are off white. I have started using a grey card and I change my white balance in camera to fluorescent since I am using two soft boxes with fluorescent bulbs. This causes the pictures to have a blue hue pre post, and when I use the grey card in post it changes to a slight orange hue. I was having much better success using auto white balance in camera. This is really just a rant to get my frustration out. Time to go read up more on white balance.

1. This is using fluorescent white balance and a grey card. Besides the underexposure, I was pretty happy with it, until I couldn't shake the blue tone.

IMG_0357 by KC ORourke, on Flickr


2. This is with auto white balance.

IMG_0316 by KC ORourke, on Flickr

 

[tirediron]

The best way is to shoot in raw, include a WB reference in the first image (and every image thereafter that exposure changes) and correct in post.

 

[ORourkeK]

"I Shoot RAW". I think I should have changed the in camera white balance to custom. I believe that is where I went wrong.

 

[Ysarex]

"I Shoot RAW". I think I should have changed the in camera white balance to custom. I believe that is where I went wrong.

If you shoot raw the in-camera WB setting is meaningless. Raw data has no WB set. Raw converters will try and read the in-camera WB setting and set something similar typically called "as shot" but that's completely changeable.

Joe

Couple thoughts: In what way is your display calibrated?
The two softbox lamps; are they the same color?

 

[ORourkeK]

If you shoot raw the in-camera WB setting is meaningless. Raw data has no WB set. Raw converters will try and read the in-camera WB setting and set something similar typically called "as shot" but that's completely changeable.

Wow. Not sure how I never learned that. Thanks for the info.

Couple thoughts: In what way is your display calibrated? The two softbox lamps; are they the same color?

I have not used anything to calibrate my screens. I just use the default settings. Both of the softboxes are the same with identical bulbs.

 

[ORourkeK]

I am a bit confused though. If shooting in RAW makes in camera WB settings meaningless, how come changing the WB in camera messes with the hue of the image?

 

[ORourkeK]

Never mind. I just read that it changes the preview of the image but since it can be changed in post, it doesn't really matter.

 

[Ysarex]

If you shoot raw the in-camera WB setting is meaningless. Raw data has no WB set. Raw converters will try and read the in-camera WB setting and set something similar typically called "as shot" but that's completely changeable.

Wow. Not sure how I never learned that. Thanks for the info.

Couple thoughts: In what way is your display calibrated? The two softbox lamps; are they the same color?

I have not used anything to calibrate my screens. I just use the default settings. Both of the softboxes are the same with identical bulbs.

Without a calibrated display you're out of control. How can you assess the color of your images when the odds that the display is showing you the wrong color is nearly 100%?

The two bulbs in the softboxes -- they're the same make/model -- have you tested them to see if they are the same color. Unless they are manufactured for photo use odds are they're at least subtly different.

Do you have Photoshop? I assume you do if you have LR. Load one of your finished photos into PS. Open the ColorPicker. Right click the mouse and set the sample size to at least 5x5 pixels. Click on what you expect is white in your photo. In the ColorPicker look at the RGB values displayed. If they are the same or nearly the same you clicked on a white area.

Create a new blank image in PS and fill the screen with it. Open the ColorPicker and set the RGB values to 220 each making that color (white) the foreground color. Get the paint bucket tool and dump in that color over the entire image. Does your screen look white?

Joe

 

[Jeff15]

Shoot raw, sort the problem later........

 

[ORourkeK]

I went back for a quick test tonight after work. The first of each set is the WB straight out of the camera and the second I edited using the grey card. All I learned tonight is that I really have no clue what I am doing. These are worse than the first two I posted.

IMG_0481 by KC ORourke, on Flickr


IMG_0481-2 by KC ORourke, on Flickr


IMG_0483 by KC ORourke, on Flickr


IMG_0483-2 by KC ORourke, on Flickr

 

[480sparky]

How, exactly, are you using the gray card?

 

[ORourkeK]

I put the item I want in my display, find the exposure I want to use, place the grey card in the frame where the item would be, and take a picture. Then in post I use the eye dropper to change the WB, copy the WB settings, and paste it to the other photos.

 

[480sparky]

Your color issues might be related to shutter speed and the alternating current cycle of your electrical system. As the voltage peaks, reverses, peaks, reverses..... the lights will flicker. Too fast for the eye to detect, but with a fast enough shutter speed it can catch minor changes in color temperature.

 

[Ysarex]

I put the item I want in my display, find the exposure I want to use, place the grey card in the frame where the item would be, and take a picture. Then in post I use the eye dropper to change the WB, copy the WB settings, and paste it to the other photos.

Most grey cards are made as exposure aids and not specifically WB targets. Instead of a grey card a piece of white Styrofoam (coffee cup) can work well.

I downloaded the last photo above that you indicate was processed from a CR2 file and WB set from the grey card. The background is white/light grey. I loaded the file in PS and checked it:

RBG values are R = 238, G = 238, B = 236. That two point discrepancy is insignificant and that plate is on a white background. On the other side of the plate I got a slightly higher discrepancy (could be a difference in the softbox bubs). The exposure is rendering the background as light grey but that's adjustable. If you're seeing a color cast in the background that's more than imperceptibly slight you may want to consider display calibration.

Joe

 

[Tim Tucker 2]

All the above, and a couple of points to add.

Computers have to deal in absolute colour where a number is a specific colour, but we do not see colour as absolute. Colour is not a property of light but simply how we *see* wavelength. So move away from the assumption that your camera records accurate colour that can be corrected to *absolute* colour by the touch of a button. You camera does not know if the subject is lit by yellow or blue light so has no way of knowing how to *correct* this to the neutral or reference WB. All it does is correct it so it displays a neutral mix of primaries which it assumes is also close to how the colours would look if they were lit by such a light. This is where you use something of known colour such as @Ysarex suggests, if you include something of known white under a neutral or reference WB then it is logical to assume that any shift in colour it displays is also roughly equal to the shift in WB from the reference you are trying to achieve. So:

1. Calibrate your screen. It is vitally important that you screen is showing colour as close to reference as possible, that the *absolute* colour as described by the number in the computer is being displayed as close as possible to that actual colour.

2. Look carefully at the actual subject you are photographing rather than just glancing and assuming that the camera will capture accurate colour and somehow magically display this on your screen, (remember your eye corrects and tries to see a neutral WB as well and so will not always either see where WB is slightly off or sometimes will not recognise where it is correct.) It is often the case that the camera is producing accurate colour and it's you as a viewer who's not understanding quite what you see. For instance look carefully at the shadows *before* you photograph and see if there are indeed colour casts in them. Do the shadows look the same on both sides? Is the background actually neutral white or does it reflect a slight cast into those shadows? Are the shadows the same colour on both sides or is there a slight difference in WB between the two lights? Your camera my indeed be capturing the colour accurately and it may be you who's interpreting these slight and accurate representations of hue as colour casts.

3. Always remember that whatever your camera does the result is seen by the human eye. You cannot subtract this from the equation. There is NO *accurate* colour that is captured by the camera and displayed correctly on a computer screen, there is only colour that is perceived by the human eye. So no matter how accurately you capture and display colour it is always subject to human perception. With the grey that is in the background of the first image, you are trying to interpret that as white and so you are already trying to see and understand the colour as *absolute* whilst deliberately trying to see it as a colour it is not, (white in a computer is 255:255:255, 220:220:200 is grey so you must learn to see it as grey and not white if you are to judge colour accurately). Slight grey will also tend to show the colour shift on un-calibrated monitors more than pure white will and so will be more perceptually *unstable* and open to different interpretations of *correct* than white, (See below).

Move away from the idea that your vision is absolute and that you see *correct* colour straight out of the box, you don't. Looking at and evaluating colour on a computer monitor is something you learn, (screens or additive colour systems are the most perceptually ambiguous form of colour reproduction). By understanding that colour seen by the eye is perceptual you teach yourself to observe, understand and *see through* perceptual effects rather than glance and jump to the assumption that what you see is absolute and true. By doing this for a year or two with this understanding you will be surprised at just how much more accurate you vision becomes, you will begin to see colour casts that were invisible to you before and you will see casts in shadows and understand where they come from.

I'm trying to move you away from an understanding that correct colour is all about what the cameras sees and how you adjust parameters in the camera to create accurate colour. I'm trying to move you more towards an understanding that correct colour also includes how you see the original with how your eye corrects WB and how you see the finished image with how your eye corrects that WB. You can use a colour managed work flow to eliminate colour casts on the original, (a predominance of yellow light reflecting off the subject under fluorescent light), and in the reproduced image. This makes colour more stable and more perceptually accurate for reproduction. (EDIT: It works because your eye corrects colour. Your eye tries to remove casts by producing a neutral mix of primaries and this is where the reference WB comes from. If you walk from a room lit by yellow light into an outdoors lit by a very blue light you do not notice the shift in colour because your eye corrects. So the reference WB is not the one that produces *accurate* colour but the one that your eye tries to correct to and so is the one that your eye is least likely to correct from. Therefore the colours produced under this WB are considered to be more perceptually stable and thus is the WB from which reference colour is derived.)

But consider that you are photographing a subject under fluorescent light, what you see is how your eye is correcting for this, what you are trying to create is an image that corrects for this. What you're not doing is capturing that actual colour displayed under that WB or reproducing it. You're trying to produce an image that shows different colour to that your camera records, colour that is how the system thinks it should look under a different WB. Sorry for the essay but there is no short answer.