Quantcast

Question Which white balance values would you use for these photos?

Johnmcl7

Distinguished Member
I can't the white balance right in some night time shots in artificial lighting, the photos either have too much of a yellow cast or if I get rid of that the colours don't like right with a dark green looking more like a navy blue. I've uploaded two sample raw files here:


To show what colour the body of the locomotives should look like these are a couple of photos taken during the day in similar positions:




I've assumed I'm at the mercy of the platform lighting but thought I'd see if it's possible to get them looking better if anyone fancies having a go or can suggest some WB values.
 

shotokan101

Distinguished Member
You've got LR right? - Just use the WB eyedropper to set the WB by sampling the white headlight area or any other part you know should be white....
 

Johnmcl7

Distinguished Member
You've got LR right? - Just use the WB eyedropper to set the WB by sampling the white headlight area or any other part you know should be white....
You can't use the headlight area as it's too bright (Lightroom gives an error saying as much) and it's also the wrong colour since it's not source of lighting in the scene. If I choose the platform edge which is painted white the platform looks ok but the whole scene looks far too blue, I can move the WB slider up a bit which looks better but the body of the locomotive is a dark navy blue which looks wrong.

I realise with four light sources in the scene (the locomotive's external lights, its internal cabin light, the platform lighting and the bright flood light behind it) I'm not going to be able to get them all looking correct but I'd like to get the loco looking better.
 

Faldrax

Well-known Member
Looking at the daylight photos, there appears to be a hazard sticker on the front of the loco with a white background - that might give a decent starting point.
 

Snake79

Active Member
I had a quick go in Lightroom. I used auto white balance, then switched to Tungsten which gave identical results, reducing the yellow cast to a more natural amount. I am assuming they are tungsten lights so they are going to give a slight yellow cast which is how they should look.

I also went into HSL and changed the hue of the yellow and orange a bit to reduce it further still but too much will affect other areas of the images, unless you use a local adjustment.
 

shotokan101

Distinguished Member
If I can ever get my pc to boot from its recently upgraded SSD I will have a look in LR
 

snerkler

Distinguished Member
I can’t access my computer at the mo but the only way to get correct colour accuracy in scenarios like this imo is to use grey cards, those colour passport thingies or setting a custom WB in camera before shooting. In situations like this trying to fix WB and colours in post is a PITA :(
 

newbie1

Distinguished Member
Did you try the "match color" option in photoshop?
 

newbie1

Distinguished Member
Tricky puzzle. I've had a play with the example pictures and I'm getting reasonable results with Kelvin adjusted to approx 1500 and a small tint adjustment. This is lower than the 2000K limit in LR so you will likely need Photoshop or something else. This main adjustment corrects for the dominant light source, the lights above the platforms. After that I tried fine tuning with radial masks from the moon and other lights to correct for those too.
 

Johnmcl7

Distinguished Member
Tricky puzzle. I've had a play with the example pictures and I'm getting reasonable results with Kelvin adjusted to approx 1500 and a small tint adjustment. This is lower than the 2000K limit in LR so you will likely need Photoshop or something else. This main adjustment corrects for the dominant light source, the lights above the platforms. After that I tried fine tuning with radial masks from the moon and other lights to correct for those too.
I'm a bit puzzled by that, are the WB values equivalent? Even at 2000 with some tint adjustment it looks far too blue, this is the result of using the WB dropper on the white platform paint which sets the WB to minimum in LR:



Using the overhead wire warning symbol on the locmotive body is a bit higher at around 2250:



And this is something in between those two and still too blue:



Originally I thought the second photo was too yellow but now I'm looking at it (which I've spent too much time doing now!) I think it is probably the best of the three even though the colours on the locomotive body aren't right.

Actually the more I look into this it seems specifically an issue with blue, this locomotive is in Arriva blue and should look like this:



At night however it's a very different shade of blue but the rest of the platform looks about right:



Similarly the loco on the right is in BR blue which should be a much duller colour rather than vivid blue whereas the one in the main part of the picture in BR green looks correct:



John
 

snerkler

Distinguished Member
I'm a bit puzzled by that, are the WB values equivalent? Even at 2000 with some tint adjustment it looks far too blue, this is the result of using the WB dropper on the white platform paint which sets the WB to minimum in LR:



Using the overhead wire warning symbol on the locmotive body is a bit higher at around 2250:



And this is something in between those two and still too blue:



Originally I thought the second photo was too yellow but now I'm looking at it (which I've spent too much time doing now!) I think it is probably the best of the three even though the colours on the locomotive body aren't right.

Actually the more I look into this it seems specifically an issue with blue, this locomotive is in Arriva blue and should look like this:



At night however it's a very different shade of blue but the rest of the platform looks about right:



Similarly the loco on the right is in BR blue which should be a much duller colour rather than vivid blue whereas the one in the main part of the picture in BR green looks correct:



John
Ok so now seeing the photos that’s really tricky. With an extreme light source like that I doubt the blue will ever look exact as the reflection of light will be different.
One thing I’d try along with WB is to reduce the yellow/orange saturation (preferably using the colour picker) and then brush back the saturation of the yellow fronts of the train. Unfortunately I’m not going to be able to get to my computer until next week.
 

newbie1

Distinguished Member
This really is a puzzle. Capture One has a normalize function where you can pick a color from one image and select where the color should be the same in a second image. It then adjusts white balance to achieve the match. This tool gives a huge range of results for the images depending on the color selected and I'm struggling to think of a reason why.

For example, taking the two images of 67003 the WB adjustments to move from daytime to nightime images are:

railway blue 5000K, -60 tint
grey roof 1060K, -10 tint
67003 number 970K, -10 tint
yellow 5850K, 0 tint
platform 800K 10 tint

This would mean creating masks for the different colors and adjusting each separately.

Does anyone know why this is happening?
 

snerkler

Distinguished Member
This really is a puzzle. Capture One has a normalize function where you can pick a color from one image and select where the color should be the same in a second image. It then adjusts white balance to achieve the match. This tool gives a huge range of results for the images depending on the color selected and I'm struggling to think of a reason why.

For example, taking the two images of 67003 the WB adjustments to move from daytime to nightime images are:

railway blue 5000K, -60 tint
grey roof 1060K, -10 tint
67003 number 970K, -10 tint
yellow 5850K, 0 tint
platform 800K 10 tint

This would mean creating masks for the different colors and adjusting each separately.

Does anyone know why this is happening?
I’ve never looked into it but I would imagine WB can only ‘correct’ things so far. At the end of the day we’re talking a completely different light source/spectrum reflecting off various surfaces and colours and I would guess that cameras, software, and WB simply can’t adjust for every colour reflected off the various surfaces. Also in extreme situations like this you’re asking a camera/software to produce a colour that isn’t there. Take the blue for example, we know what colour the blue is but the reflected ‘blue’ is different under tungsten and the correct tones of the blue might not be reflected for the camera to capture.

Now this is just me thinking out loud and it could be nonsense, but it’s also why I don’t believe the widely regarded rule that you don’t need to worry about WB settings when shooting raw as you can correct in post. Yes you can most of the time, but in extreme situations I’m not sure you can fully. You can’t get colours that weren’t there/were being ‘masked’ at the time of the shot without some serious photoshop skills.
 

Similar threads

Top Bottom