# Advice on light source, color balance
**URL:** https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196
**Category:** Digital Camera Scanning
**Created:** [July 27, 2020, 9:13pm UTC](https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196 "2020-07-27T21:13:10Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@livebeechocolatecake](https://forums.negativelabpro.com/u/livebeechocolatecake)
#### Post date: [July 27, 2020, 9:13pm UTC](https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196/1 "2020-07-27T21:13:10Z")
So I’ve gotten to digital camera scanning some 6x7 b&w negs by pointing my Nikon D600 up into the negative carrier of my 4x5 enlarger, and I’m using a solux 4700k light bulb as a light source (as suggested [here](https://forums.negativelabpro.com/t/suggested-backlight-sources-for-scanning-film-with-dslr/130/2)), with a little piece of frosted plexiglass from an old diffusion head as an diffuser. Here’s What it looks like:
   
Now, here’s my question: Because at some point I’d like to turn to scanning color negatives, What kind of white balance settings or setup adjustments would i need to make to give me the best files out of the digital? I have noticed that the color that the camera records is more than slightly warm;
like so:
)
such that when I invert the tone curve, I get a very blue image: 
Now this is all fine and dandy for b&w because I can simply use the black and white setting for color to get what I want, but am I correct in thinking that this might cause some trouble down the road for color negs or positives?
P.S: a few notes: currently i’m using manual white balance within the camera and setting it to 4760k, the closest i can get so I might expect it to turn out a tad warm, but seemingly not this warm. Also, I checked that the light source was even, this negative simply has some kind of development streak down the middle in the sky there.
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### Author:  [@Digitizer](https://forums.negativelabpro.com/u/Digitizer)
#### Post date: [July 28, 2020, 6:17am UTC](https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196/2 "2020-07-28T06:17:37Z")
Supposing that you shoot raw, you can always white balance in Lightroom. The WB you set in your camera does not change raw data but is used for the jpeg preview or the out of camera jpeg files. Press V in Lr to turn b&w on or off.
I set my camera to UniWB in order to see how I can set exposure for ETTR without saturating any of the r, g or b channels and mostly for getting the blue channel out of the noise. Previews look terrible, but _NLP will still turn the raw files into well balanced colour images_, some better than others depending on many qualities of the original negative.
Search this forum (or the Internet) for _ettr_ and _uniwb_ as seems fit.
Btw, you’ve got yourself quite a rig. If you could clamp your camera to the two vertical rods instead of the tripod, you’d get a setup that is less fussy regarding the position of the tripod, unless you use it for centering each shot. 👍
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### Author:  [@livebeechocolatecake](https://forums.negativelabpro.com/u/livebeechocolatecake)
#### Post date: [August 5, 2020, 11:58pm UTC](https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196/3 "2020-08-05T23:58:00Z")
> [@Digitizer](#):
>
> _ettr_ and _uniwb_
Digitizer,
Thanks for all your help, sorry for this late reply! I’ve finally gotten some time to get around to scanning some new negatives & researching what you have mentioned here. So for my UniWB, since I’ve got a Nikon D600 I used a file from [here](http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm) to set it. Now, a few questions: what kind of post-processing steps should I be taking after ETTR & setting uni-WB? The out of the camera raw is _very_ green, as shown here:
Just by messing around I have figured this process out: Set the tint back to 0, tune down the exposure to compensate for ETTR, marry the curves of the histogram on the right (by changing the color temperature), and finally invert the tone curve as I would for a normal negative. That results in something like this:
Close, but not quite there. I’d like more contrast, and this is seemingly still not _black and white_, it has some kind of color, evidenced by actually setting the contrast higher. Here’s a crop of this scan next to one where I set the color profile to adobe monochrome and shift the temperature all the way down, which seems to give me nice contrast:
 
So in the end, here’s my question: what should I be doing to get to a base image like that which would come out on my photo/darkroom paper? What slider should be controlling my contrast if it’s not actually my contrast slider? Should I be converting colorspace to b&w for b&w negatives? This whole process has me learning a lot and asking a lot of questions (aka being very confused ahaha).
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### Author:  [@Digitizer](https://forums.negativelabpro.com/u/Digitizer)
#### Post date: [August 6, 2020, 10:50am UTC](https://forums.negativelabpro.com/t/advice-on-light-source-color-balance/2196/4 "2020-08-06T10:50:59Z")
UniWB shots look very green indeed. Use the white balance pickup and select a bright area of a b/w negative or an unexposed part of colour negative film as is mentioned in [Nate’s guide to NLP](https://www.negativelabpro.com/guide/#tips-for-better-negative-scans).
Converting with NLP can produce tinted conversions. Set the conversion to b/w, set “film” to “none” and reset all other settings. If you convert using the tone curve, change the image to b/w using Lightroom’s menu or the “V” key.
Because of the inverted tone curve, many sliders work differently. You can always use the tone curve to change the contrast. Simply drag the corners horizontally towards the centre in order to set the black- and white points…