copying white balance from existing photo accurate ?

[topcat07]

This is on a Nikon d40 (not sure if all cameras do this)

There is the option to copy the white balance from photo of your choice. Is this just copying the white balance mode you had selected at the time of the photo was taken? Or is it looking at the photo to determine the best white balance to use? If the second option wouldn't this just be the same as auto wb?

Got myself slightly confused and book isn't very clear

 

[Terrywoodenpic]

If you take a number of shot in AWB during a session they will all have slightly different white balances depending on the contents of each shot even if the light is the same..
This is a way to match them all up incamera.

A far easier and better way would be to do it during raw processing.

But what ever floats your boat.

 

[topcat07]

If you take a number of shot in AWB during a session they will all have slightly different white balances depending on the contents of each shot even if the light is the same..
This is a way to match them all up incamera.

A far easier and better way would be to do it during raw processing.

But what ever floats your boat.

Ah okay thank you.

Was just trying to get it right during the capture stage so I don't have to guess what looks right in post processing

 

[topcat07]

Think your advice of pp may be easier after reading the below

' White balance during post-processing (on the computer)
Another way to set the white balance is to do it in the post-processing phase. This is the way I do it! Shooting in RAW for best possibilities to edit the images after a session is a must. *When shooting in RAW, the image is separated into two pieces. One with the image and one with all Data like white balance, B&W conversions etc. When you import RAW images into Lightroom these two pieces are put together virtually so that you can manipulate the image without any loss of quality. When you’re done editing you finally export your image to the format you like (JPEG, TIF etc) and the two pieces is put together and merged into one, the image. Since you’ve shoot in RAW, you have the original file intact and can continue to make changes to it over and over again without any loss of quality. I never edit a JPEG-file twice if it’s an important photo. Everytime a JPEG is opened and saved it’s being compressed. Every compression of it will reduce its quality.

This is how I set the white balance in Lightroom.
On the first photo I take in a photo session, I place a gray card, or tell the person in front to hold it for me. This photo will be my reference photo that I will use when I start the post-processing in Lightroom. I only need one reference shoot with this gray card for each location I shoot (or if the light sources changes).

When I have imported all of my photos from my session, I start by setting the white balance for my reference image. To do this I simply use the White balance selector (shortcut = W )*and click on the gray card (there shouldn’t be any reflections on the card!). This will make sure that the image has the right white balance and since all of my other photos have been shoot in the same set-up (environment) I just have to synchronize them with my reference image. Voila, now all of my image are set with the correct white balance.'

 

[Terrywoodenpic]

Ah okay thank you.

Was just trying to get it right during the capture stage so I don't have to guess what looks right in post processing

Unless you measure the white balance using a card (as in the post above)
Or you have an accurate colour meter to measure the colour of the ambient light. the white balance that a camera sets is little more than an informed guess.

The light illuminating a scene can be made up of many sources... The main light may be the sun but there are always secondary sources such as skylight or reflected light. the auto white balance of a camera has no way of measuring this, so it uses an algorithm that assumes for instance that all the colour elements in a picture if averaged out are equal to grey. It then uses this to set the balance.

suppose you are taking a portrait of a blond girl in the sunshine against the back drop of a road and large sandstone building you take a shot.... Before you take another a large red London buss picks ups passengers right behind her, it looks great so you take another shot.
In each case the white balance will have clicked in and come to a different conclusion and the skin colour will have changed in the resultant shot.
The real skin has of course not changed at all nor has the light, what has changed is the error made by the camera because it was influenced by the background.

The only way to get it right in camera is to shoot in raw and Use a grey card.
in at least one picture.

Of course in many circumstances life is too short and it is sufficient to do much the same thing only in raw processing.
The eye/brain sets its own white balance and sees a white card as white both in sunshine and in tungsten light though they are very different. What it does notice very easily is changes between photographs if the white balance changes. The importance of synchronising sets is for them all to look the same. the eye neither knows nor cares if this is entirely accurate to a measured white balance. it will accept what it sees as white as white.

No two models of camera give the same white balance result.....

 

[topcat07]

Unless you measure the white balance using a card (as in the post above)
Or you have an accurate colour meter to measure the colour of the ambient light. the white balance that a camera sets is little more than an informed guess.

The light illuminating a scene can be made up of many sources... The main light may be the sun but there are always secondary sources such as skylight or reflected light. the auto white balance of a camera has no way of measuring this, so it uses an algorithm that assumes for instance that all the colour elements in a picture if averaged out are equal to grey. It then uses this to set the balance.

suppose you are taking a portrait of a blond girl in the sunshine against the back drop of a road and large sandstone building you take a shot.... Before you take another a large red London buss picks ups passengers right behind her, it looks great so you take another shot.
In each case the white balance will have clicked in and come to a different conclusion and the skin colour will have changed in the resultant shot.
The real skin has of course not changed at all nor has the light, what has changed is the error made by the camera because it was influenced by the background.

The only way to get it right in camera is to shoot in raw and Use a grey card.
in at least one picture.

Of course in many circumstances life is too short and it is sufficient to do much the same thing only in raw processing.
The eye/brain sets its own white balance and sees a white card as white both in sunshine and in tungsten light though they are very different. What it does notice very easily is changes between photographs if the white balance changes. The importance of synchronising sets is for them all to look the same. the eye neither knows nor cares if this is entirely accurate to a measured white balance. it will accept what it sees as white as white.

No two models of camera give the same white balance result.....

Thank you for this very detailed information very useful and helpful I notice there is a option to measure the white balance by getting a measurement of the grey card at first shot then setting that as the pre white balance for reset of the shoot. Is this a good method?

Would this give same result as the above method just a matter of preference?

Sorry if I'm going round the houses here a bit just want to make sure I'm not missing anything

 

[Phil V]

Thank you for this very detailed information very useful and helpful I notice there is a option to measure the white balance by getting a measurement of the grey card at first shot then setting that as the pre white balance for reset of the shoot. Is this a good method?

Would this give same result as the above method just a matter of preference?

Sorry if I'm going round the houses here a bit just want to make sure I'm not missing anything

Not in any way meant to sound harsh, but go out and shoot some stuff, you can learn everything about photography from asking questions on the internet, but seriously it'll not improve your understanding, the quickest way of learning is to try it yourself.

 

[Terrywoodenpic]

Thank you for this very detailed information very useful and helpful I notice there is a option to measure the white balance by getting a measurement of the grey card at first shot then setting that as the pre white balance for reset of the shoot. Is this a good method?

Would this give same result as the above method just a matter of preference?

Sorry if I'm going round the houses here a bit just want to make sure I'm not missing anything

The problem with all methods is that you may not like the result. It takes no account of taste. It seems that we in the UK prefer our photographs to be a little warmer than might be technically accurate.
That is why I prefer to do it at the raw processing stage. This takes into account your own preference and you only need to set it in one shot of the series then "Synchronise" the others.

But setting a custom white balance works fine. And is the best way if you only shoot Jpegs.

 

[Bristolian]

Thank you for this very detailed information very useful and helpful I notice there is a option to measure the white balance by getting a measurement of the grey card at first shot then setting that as the pre white balance for reset of the shoot. Is this a good method?

Would this give same result as the above method just a matter of preference?

Sorry if I'm going round the houses here a bit just want to make sure I'm not missing anything

Using the custom wb option works very well BUT you need to remember to switch out of cwb at the end of the shoot or it'll be applied to everything you do afterwards ... ask me how I know