Digital Capture Colour Temperature Question

[elderly]

Can digital capture accutately reproduce colours under mixed lighting conditions?

Crudely speaking films 'sees' daylight as blue,
tungsten as red
& flourescent as green.

So by choosing either daylight or tungsten balanced film
and/or by the use of CC filters one can produce a transparency that is accurate.
You can't do it without getting a 'wrong' colour cast somewhere if there is more than one
different light source; such as photographing a large office space lit with both flourescent
and tungsten lighting from the ceiling and say to complicate matters,
maybe some daylight.

Does the white balance of digital capture just give a compromise,
where probably no colour is accurate,
or does digital not 'see' the colour temperature of light sources
the same way as film, so giving 'as the eye sees' colours ????

>> Edited by elderly on Friday 11th November 15:47

>> Edited by elderly on Friday 11th November 15:48

[GetCarter]

Can only speak for mine (D2X) but it can set to any number of temps, or Auto, which is pretty bloody clever I have to say, and it's only sometimes that I override.

[beano500]

Plus get a known white, or preferably grey, and you preset the colour balance for the particular lighting conditions - even better!

[beano500]

elderly said:

You can't do it without getting a 'wrong' colour cast somewhere if there is more than one different light source; such as photographing a large office space lit with both flourescent and tungsten lighting from the ceiling and say to complicate matters, maybe some daylight.

But even this scenario is controllable with digital.

Either:

Take several shots, each balanced for one of the parts.

Or:

When you convert from RAW files, convert several images with correct WB for the parts.


Then blend the results together.

[simpo two]

Well, you could say that film has two colour temps, daylight and tungsten, whilst digital has infinite colour temps (and you can change them afterwards during RAW processing).

Personally I quite like mixed colour temps.

[elderly]

Thanks for the answers so far.
Let me be more specific:

If I'm photographing an office interior with only it's own lighting
with say flourescent being the predominant light source from the ceiling
and a little daylight leaking in through white blinds on the windows.

With film if I correct daylight film for the flourescent lit (horizontal)desktops
then the (vertical) walls will have a Magenta cast.

Or if I correct for the daylight then the desk tops would have a green cast;
it's just the nature of old fashioned film.

I understand the fact that digital, using a white balance method (known white
or grey card) will correct for any colour temperature,
but my question is - is digital capture much better at coping accuratley with mixed sources
than film - without going into complicated post capture work??

>> Edited by elderly on Friday 11th November 17:32

[bacchus180]

i shoot interiors and have found these problems.. and I shoot with digital or film. its the same problem when using mixed light whatever you use.. I balance the predominant source I'm using and use gels to bring up the temperature or reduce it accordingly... to get the correct balance as you would using film. either balancing the ambient light or balancing the flash heads..

with digital you don't have a fix all.. its the same as film. you tend to balance for one light source.

however as I'm writing this I'm thinking you could additionally balance in post prod and blend composite images.. but I'm not sure with out very complex masking you would get the same results due to the way light falls..

but then thats what makes this job sooo much fun...lol

[simpo two]

elderly said:

my question is - is digital capture much better at coping accuratley with mixed sources than film - without going into complicated post capture work??

By 'post-capture work' I take it you mean processing RAW files? This is standard practice for any discerning digital photgrapher wishing to get the best in terms of results and flexibility from his work. A RAW file is effectively a digital negative. I use Adobe Camera Raw (ACR) which allows me to adjust colour temp in steps of 50 degrees Kelvin between 2,000K and 50,000K - enough for anyone you'll agree!

The simpler alternative, but not really, is to shoot JPG. You can still adjust colour balance in PhotoShop or similar, but it's not as scientific. However, in the time you take to twiddle with this, you could be twiddling a RAW file.

You can still only optimise a shot for one colour temperature of light source. Are you trying to render accurately each colour temperature, or make them all appear the same?

elderly said:

Does the white balance of digital capture just give a compromise, where probably no colour is accurate, or does digital not 'see' the colour temperature of light sources the same way as film, so giving 'as the eye sees' colours ????

You can set the camera to Auto WB, in which case it will try to guess the correct value, or you can set WB manually, either to presets such as 'tungsten', 'fluorescent', daylight' etc, or in degrees Kelvin depending on the camera. However for reasons stated above, if you shoot RAW, it's largely unimportant as you can change it later - and because you're working with the 'raw' data from the chip, changes are *as if they were done at the time of shooting*.

>> Edited by simpo two on Friday 11th November 19:13

[elderly]

simpo two said:

[quote=elderly] You can still only optimise a shot for one colour temperature of light source. >> Edited by simpo two on Friday 11th November 19:13

Thanks ....
that's the answer ..... but not the one I was hoping to hear!
I had hoped that maybe digital 'saw' colour more in a way like our eyes
than film does.

I like your analogy between RAW files and a negative.
As soon as I can get a DSLR ( D200!!!) I shall start on the digital learning curve.

[simpo two]

elderly said:

Thanks ....that's the answer .....

Phew :mopsbrow:

elderly said:

I had hoped that maybe digital 'saw' colour more in a way like our eyes than film does.

Nothing quite matches the Mk I Eyeball. At least, not yet. As you move your eyes round a scene, they adapt in a second or two. But a camera is fixed.

elderly said:

As soon as I can get a DSLR ( D200!!!) I shall start on the digital learning curve.

Attaboy! I have one of those beasties on order. Moving from film to digital is interesting, to say the least. The physics is the same, the camera is basically the same, but the possibilities suddenly become not only endless but within reach. There's a lot to learn. As when buying a TVR, the limiting factor is usually yourself