White balance - RGB values (colour blind help)

-markie-

-markie-

Suspended / Banned
Messages
653
Name
MG
Edit My Images
No
Quick question.

I'm colour blind (on some shades of colours - mainly white -> light pinks), so looking at technical way to ensure i get my white balance correct.

I've been looking online and found info that says i should use the white balance colour dropper (which i've always done and click something that should be white (although not always possible in every image)).

I understand this should be a neutral colour and RGB values should be equal (or close enough).

Am i right in thinking if i select and an area of the image (regardless of the colour) as long as the RGB values match (or pretty close) it will calculate a true white balance?
 
markgodley said:
Quick question.

I'm colour blind (on some shades of colours - mainly white -> light pinks), so looking at technical way to ensure i get my white balance correct.

I've been looking online and found info that says i should use the white balance colour dropper (which i've always done and click something that should be white (although not always possible in every image)).

I understand this should be a neutral colour and RGB values should be equal (or close enough).

Am i right in thinking if i select and an area of the image (regardless of the colour) as long as the RGB values match (or pretty close) it will calculate a true white balance?
Click to expand...

If you have difficulty discerning a pure white then just using the colour dropper 'white point' selection I think could lead to WB issues.

Now, though not perfect because there will situations where using a "grey card" will be impractical but I have found it usefull and I keep a WhiBal card in my bag. It is used by taking a picture of it under the lighting conditions that you wish to correct and using it correct the white point.

This is the one, though and earlier model, that I have http://michaeltapesdesign.com/whibal.html there are user guide and video guide at the bottom of the page.

HTH and that you resolve the WB control :)

PS for some reason the videos are 'not there' but the pdf guide is viewable.
 
Last edited:
markgodley said:
Am i right in thinking if i select and an area of the image (regardless of the colour) as long as the RGB values match (or pretty close) it will calculate a true white balance?
Click to expand...


To put it bluntly, MG, no, you're not right.

I had to think about your very problem and I came up
with this solution… not clever enough to find others for
you!

The ONLY way to be absolutely sure is to use a WB card;
a grey one possibly.

Sooting in a given light situation, put your WB card in the
full light source and take a picture; this picture maybe read
with the WB picker in your software and copied. Then you
can apply the picked value to all the shots taken in the same
light condition.

PS.: set the camera on Auto WB!
 
Last edited:
Box Brownie said:
If you have difficulty discerning a pure white then just using the colour dropper 'white point' selection I think could lead to WB issues.

Now, though not perfect because there will situations where using a "grey card" will be impractical but I have found it usefull and I keep a WhiBal card in my bag. It is used by taking a picture of it under the lighting conditions that you wish to correct and using it correct the white point.

This is the one, though and earlier model, that I have http://michaeltapesdesign.com/whibal.html there are user guide and video guide at the bottom of the page.

HTH and that you resolve the WB control :)

PS for some reason the videos are 'not there' but the pdf guide is viewable.
Click to expand...
Great stuff, looks perfect.

Any UK sellers or anything similiar in the UK for a reasonable price?
 
markgodley said:
Great stuff, looks perfect.

Any UK sellers or anything similiar in the UK for a reasonable price?
Click to expand...

I think at the time I bought mine directly from the USA???

The instructions will apply to any grey card usage.....................it is just that I wanted a small camera bag 'friendly' size and robust enough to take some bag bashing.

FWIW I used it during a public tunnel walk before it was opened and the lighting was dire for photography but using the WhiBal and the correction this is what can be done even IMO with the worst lighting
5728248072_400d5d0a59_o.jpg


We did it this way HindheadTunnel-6256 by Imagin8, on Flickr

A few others from the same walk on my flickr
 
Last edited:
I use an X-Rite ColorChecker Passport that I keep in my bag for when I need to be accurate with my colour - at its most basic it does the same as the WhiBal card.

http://xritephoto.com/colorchecker-passport-photo

The software that comes with it allows you to profile the colour input of your camera's sensor rather than using a canned profile in your RAW converter, which is handy, particularly with tricky reds IME.

About £84 from reputable retailers.
 
Last edited:
I also use the X-Rite ColorChecker Passport,brilliant to keep in the bag.:)
 
Specialise in. black and white photography.
But the grey card method is the best you can hope for.
Of course you do not need to do it before each shot. You an take it after any shot, where you think colour balance will be important.
 
gerry s said:
Not on mine they aren't...
Click to expand...

I get DNS not found on both PC and smartphone.......common factor is the router & ISP ~ hmm?

Will the phone via 3G and see if it works?

Edit ~ 3G fails with same error.

NB chrome on the phone and on the pc , so will have to try IE and or Edge on PC later?
 
Last edited:
markgodley said:
I've been looking online and found info that says i should use the white balance colour dropper (which i've always done and click something that should be white (although not always possible in every image)).

I understand this should be a neutral colour and RGB values should be equal (or close enough).

Am i right in thinking if i select and an area of the image (regardless of the colour) as long as the RGB values match (or pretty close) it will calculate a true white balance?
Click to expand...
Just to clarify, what you read online was correct, but you interpretation of it wasn't.

The advice was to use the colour dropper on an area that *should be* white or neutral, not on an area that *already is* white or neutral.

Thought experiment: photograph taken under sodium street lighting. Your grey car appears very orange in the photo. You click on it with the colour dropper because you want it to be grey. It doesn't matter whether the RGB values are close together or not; the only thing that matters is that you want this to be grey.

The reason you'll see people advising for and against this technique is that it works OK to get the white balance in the right general area, but not necessarily *exactly* right. The latter depends on you knowing that the target you're clicking on should be *exactly* grey or white (equal RGB values), but in the real world you can't be sure. For example my wife's white car isn't the same colour as my neighbour's white van. That's why an accurately coloured target such as a grey card is recommended. Having said that, the white balance which is technically correct isn't necessarily the same as the white balance which is artistically correct.
 
StewartR said:
Having said that, the white balance which is technically correct isn't necessarily the same as the white balance which is artistically correct.
Click to expand...

Totes :agree:

A couple of my Wedding shooter pals have also found that couples usually prefer images a little warmer than strictly correct, which is why I only really use the Grey Card as a starting point rather than an end result

Dave
 
DG Phototraining said:
Totes :agree:

A couple of my Wedding shooter pals have also found that couples usually prefer images a little warmer than strictly correct, which is why I only really use the Grey Card as a starting point rather than an end result

Dave
Click to expand...

The ColorChecker Passport has already been mentioned - just to add it also has a set of patches that give 'neutral' together with a couple of warmer and a couple of cooler tones - so you have both a neutral reference and the warmer and cooler ones if you prefer a particular look.
 
DG Phototraining said:
Totes :agree:

A couple of my Wedding shooter pals have also found that couples usually prefer images a little warmer than strictly correct, which is why I only really use the Grey Card as a starting point rather than an end result

Dave
Click to expand...


It's usually a 2 stage process:

1) get all images to technically correct (especially important if more than one camera is in use)
2) apply artistic "look"

Also, it must be noted that you can only judge if it's correct if viewed under the right lighting conditions.
 
You can also take a white balance dropper reading from black as well. So Ryan Brenizer says anyway (y)
 
DG Phototraining said:
Totes :agree:

A couple of my Wedding shooter pals have also found that couples usually prefer images a little warmer than strictly correct, which is why I only really use the Grey Card as a starting point rather than an end result

Dave
Click to expand...

Interesting comment Dave. I'm not a wedding shooter, but I thought the rule was to get the bride's dress as accurate as possible, pretty much at all costs. They're not all a neutral white, and often quite a long way from it with cream and ivory and whatnot, or other different colours very carefully chosen and coordinated. And in that case, wouldn't it dictate colour balance for the whole album?
 
wibbly said:
You can also take a white balance dropper reading from black as well. So Ryan Brenizer says anyway (y)
Click to expand...

Not from black you can't. True black is a total absence of light, so there's no white balance to measure. You can get a pretty good reading off very dark grey but it's less reliable than lighter tones as more likely to be polluted with noise.
 
HoppyUK said:
Interesting comment Dave. I'm not a wedding shooter, but I thought the rule was to get the bride's dress as accurate as possible, pretty much at all costs. They're not all a neutral white, and often quite a long way from it with cream and ivory and whatnot, or other different colours very carefully chosen and coordinated. And in that case, wouldn't it dictate colour balance for the whole album?
Click to expand...

st599 got it spot on with his 2 stage comment

Dave
 
HoppyUK said:
Cheers. Something to bear in mind for the next wedding I'm never going to shoot :)
Click to expand...

lol

I'm just finishing one now where the WB of the dress varies hugely between the top and bottom in many instances due to multiple light sources and carpet colours, I tend to use the middle of the chest as the 'correct' area and the rest can do what it likes :)

Dave
 
HoppyUK said:
Not from black you can't. True black is a total absence of light, so there's no white balance to measure. You can get a pretty good reading off very dark grey but it's less reliable than lighter tones as more likely to be polluted with noise.
Click to expand...
You can take a reading/sample from anything that *should have* equal RGB values... depending on the method used (LR W/P dropper vs PS Levels) the behavior may be different. In LR, if what is sampled has no RGB variability (I.e. clipped white or black) it just won't do anything and returns an error message.
 
sk66 said:
You can take a reading/sample from anything that *should have* equal RGB values... depending on the method used (LR W/P dropper vs PS Levels) the behavior may be different. In LR, if what is sampled has no RGB variability (I.e. clipped white or black) it just won't do anything and returns an error message.
Click to expand...

I've seen people using a sheet of A4, but that is usually bleached and can flouresce. I have some nice credit card sized colour patch cards which can be used to generate a camera profile for a specific lighting condition - they were less than £15 on eBay. (And quite close to a proper Colour Checker when measured properly)
 
You must log in or register to reply here.
Back
Top