Ad
Ad
Ad
Pages: [1]   Bottom of Page
Print
Author Topic: Click White Balance  (Read 5649 times)
lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« on: November 14, 2005, 02:32:02 AM »
ReplyReply

Click white balance is so useful for RAW conversions. But there does not seem to be an equivalent in photoshop itself (unless I have just not noticed it).

I sometimes scan in some of my old film stuff and want to click white balance but there does not seem to be an abvious way of doing this.
Logged
DiaAzul
Sr. Member
****
Offline Offline

Posts: 777



WWW
« Reply #1 on: November 14, 2005, 02:58:37 AM »
ReplyReply

Quote
Click white balance is so useful for RAW conversions. But there does not seem to be an equivalent in photoshop itself (unless I have just not noticed it).

I sometimes scan in some of my old film stuff and want to click white balance but there does not seem to be an abvious way of doing this.
[a href=\"index.php?act=findpost&pid=51234\"][{POST_SNAPBACK}][/a]

If you are refering to ACR then up by the hand and zoom tools there is an eye dropper tool which enables you to click on the image to sample for colour temperature. Click to select the button(eye dropper) then click where you want on the image.
Logged

David Plummer    http://photo.tanzo.org/
lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #2 on: November 14, 2005, 06:00:31 AM »
ReplyReply

Quote
If you are refering to ACR then up by the hand and zoom tools there is an eye dropper tool which enables you to click on the image to sample for colour temperature. Click to select the button(eye dropper) then click where you want on the image.
[a href=\"index.php?act=findpost&pid=51236\"][{POST_SNAPBACK}][/a]

No I am talking about PS not ACR, I thought I made that clear.
Logged
DiaAzul
Sr. Member
****
Offline Offline

Posts: 777



WWW
« Reply #3 on: November 14, 2005, 06:49:41 AM »
ReplyReply

Quote
No I am talking about PS not ACR, I thought I made that clear.
[a href=\"index.php?act=findpost&pid=51246\"][{POST_SNAPBACK}][/a]

In that case you want to add a Colour Balance layer and adjust the colour balance of the image. If you open the 'Colours' palatte at the same time then, with the Colour Balance dialogue open click on the neutral tone in the image with the colour sampler and adjust the sliders in the dialogue to get the markers in the colours palatte vertically aligned. You can adjust the colour balance of the image separately for shadows, mid tones and highlights. There is no 'auto' mode as per a RAW converter though.

Another alternative would be to add a Curves layer then click on options... . Within the options dialogue you have the opportunity to set the target colours. If you only wish to adjust the midtone colour the click on midtones swatch and then with the colour picker select the grey patch in the image. When you click OK then the curves will be set to colour correct your image. Again you have a range of options in this dialogue box for setting shadow and highlight colour cast and clipping percentages. Just be careful with this dialogue when you close it not to set a default otherwise all Auto corrections will use the new defaults that you set.

As to adjusting white balance in Photoshop I am unaware of any specific tools which work with that particular terminology within the main photoshop application (other than ACR). The closest is to use Colour Balance as described above, or to work on the individual channels directly either using levels or curves.
Logged

David Plummer    http://photo.tanzo.org/
lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #4 on: November 14, 2005, 07:15:59 AM »
ReplyReply

Yes that's what I thought, seems odd not to provide a specific tool to do this simple thing rather than having to trial and error adjust until your nutral reference tone is nutral - Oh well.
Logged
Lisa Nikodym
Sr. Member
****
Offline Offline

Posts: 1702



WWW
« Reply #5 on: November 14, 2005, 10:10:02 AM »
ReplyReply

There's a simple click white balance under the "Levels" command in PS.  Just go to Levels, click the button with the gray eye dropper, click somewhere that should be neutral in the image, and PS will adjust the image using Levels to make that point neutral.  Does this do what you're looking for?

Lisa
Logged

lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #6 on: November 14, 2005, 10:16:21 AM »
ReplyReply

Quote
There's a simple click white balance under the "Levels" command in PS.  Just go to Levels, click the button with the gray eye dropper, click somewhere that should be neutral in the image, and PS will adjust the image using Levels to make that point neutral.  Does this do what you're looking for?

Lisa
[a href=\"index.php?act=findpost&pid=51267\"][{POST_SNAPBACK}][/a]

Hi Lisa

It might be, will this just make that tone nutral and not set it to mid grey etc?
Logged
DiaAzul
Sr. Member
****
Offline Offline

Posts: 777



WWW
« Reply #7 on: November 14, 2005, 11:48:09 AM »
ReplyReply

Quote
Hi Lisa

It might be, will this just make that tone nutral and not set it to mid grey etc?
[a href=\"index.php?act=findpost&pid=51269\"][{POST_SNAPBACK}][/a]

This will set it to mid grey, pretty much in the same way that the curves option outlined in the previous post would do. The only way to get a neutral tone without adjusting the luminosity of the image is to use Colour Balance. Though perhaps you could use the Curves/Levels method and then set the adjustment layer to colour - this may change the colour tone without changing the luminosity values to much. As with everything in PS there is more than one way to skin a cat and twice as many ways to stick the fur back on.
Logged

David Plummer    http://photo.tanzo.org/
PeterLange
Guest
« Reply #8 on: November 14, 2005, 02:01:30 PM »
ReplyReply

Quote
Yes that's what I thought, seems odd not to provide a specific tool to do this simple thing rather than having to trial and error adjust until your nutral reference tone is nutral - Oh well.
[a href=\"index.php?act=findpost&pid=51252\"][{POST_SNAPBACK}][/a]
It’s more complicate than we would like to have it.

White balance in ACR acts on linear, non-tone-curve-treated data. At this stage, it is just a question of linear scaling (multiplication) of the single R/G/B channels.  One single neutral bright gray is enough to set the eyedropper.  Otherwise, while Raw conversion, RGB data and "color temperature“ get distorted and inhomogeneous along the grayscale because of application of a brightening S-shaped tone curve.

Therefore, in Photoshop it requires at least two gray patches for reference to achieve neutral white/gray. With the brighter one, the top channel should just reach 255, so that you can set this patch to R=G=B by means of the single R/G/B Levels’-highlights sliders.  Next, you need a mid gray to adjust R,B to the of level of G by means of the single Levels’-midtone sliders.

In short, Photoshop can not offer a (proper) white balance tool, whereas Camera Raw can.

Peter

--
Logged
lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #9 on: November 15, 2005, 06:41:20 AM »
ReplyReply

Peter,

Thanks for the explanation. I guess what you saying is because the data is semilog via a tone curve the colour correction has (at least?) two degrees of freedom and thus needs two values at either end of the dynamic range.

My memory is the colour adjust tab lets you set shaddows, midtone and highlights.

So I guess from you explanation I should set at least shaddows and highlights. What should I do with the midetones, some tutorials on the wed suggest leaving it?


Lester
Logged
PeterLange
Guest
« Reply #10 on: November 15, 2005, 02:31:55 PM »
ReplyReply

Lester,

Once a cold or warm grayscale has passed through a typical tone curve (brightening, slightly S-shaped, such as applied by ACR or in-camera conversions), you will find that HSB color saturation decreases from the shadows to the highlights.

Acceptable white balance can be achieved by combining (1.) highlights and (2.) midtone settings – referring to the single R/G/B sliders. So it’s helpful to have a very bright gray and a mid gray for numerical reference (e.g. same truly neutral target patch, differently exposed).  Like always, there are many ways in PS to do basically the same: Levels, Curves or the Color Balance tool.

This effort of a two-point white-balance approach (at least) is needed because RGB-based tone curves (e.g. such as applied while Raw conversion for a pleasing look) as a matter of principle have a side effect on the ratios of R:G:B = HSB hue and saturation [(same but less pronounced with Lab or Luminosity mode)]. Whereas consistent Color Temperature requires constant data all along the grayscale.

Accurate white balance – which does not necessarily mean neutral white / gray – is one of the solid reasons to shoot Raw.

Peter

--
Logged
lester_wareham
Full Member
***
Offline Offline

Posts: 116


WWW
« Reply #11 on: November 16, 2005, 06:25:44 AM »
ReplyReply

Quote
Acceptable white balance can be achieved by combining (1.) highlights and (2.) midtone settings – referring to the single R/G/B sliders. So it’s helpful to have a very bright gray and a mid gray for numerical reference (e.g. same truly neutral target patch, differently exposed). 
[a href=\"index.php?act=findpost&pid=51368\"][{POST_SNAPBACK}][/a]

Right thanks Peter.

So if I can find a mid tone and a highlight reference what do I do with the setting for shadows, leave it at zero or set it to the mid tone, or set for nutral shadow.
Logged
PeterLange
Guest
« Reply #12 on: November 16, 2005, 03:31:01 PM »
ReplyReply

Well - Lester,

That's a quite hard question (at least for me). If you really heave a very dark gray as close as possible to black clipping at RGB zero, and if you're sure that it should be neutral, then it can make sense to adjust it to R=G=B on the level of green "luminance" channel G by means of R, B shadows sliders. If such ideal conditions are not given, I see a certain risk that R/G/B shadows settings do more damage than good. That said, anything that leads to a more pleasing look has of course its justification beyond all numbers.

I'd prefer to stay with a two-point approach via highlights & midtone settings as suggested above. Luckily, my personal taste and my photo math tell me the same.

Regarding such white balance after Raw or in-camera-conversion, there's a certain metaphor for comparison which probably only makes sense in my mother-tongue; direct translation would be: "Try to nail a pudding at the wall".

Peter

--
Logged
Concorde-SST
Full Member
***
Offline Offline

Posts: 102


« Reply #13 on: November 17, 2005, 09:47:58 AM »
ReplyReply

Hello,

on the Radiant Vista website is a very nice
tutorial - you can download it as PDF.

www.radiantvista.com

best,

Andreas.
Logged
Jonathan Wienke
Sr. Member
****
Offline Offline

Posts: 5759



WWW
« Reply #14 on: November 17, 2005, 04:12:08 PM »
ReplyReply

Quote
Regarding such white balance after Raw or in-camera-conversion, there's a certain metaphor for comparison which probably only makes sense in my mother-tongue; direct translation would be: "Try to nail a pudding at the wall".

I've heard it expressed here in the States as "nailing jelly to a tree" which is close enough for most purposes.
Logged

Pages: [1]   Top of Page
Print
Jump to:  

Ad
Ad
Ad