White balance fever

Hi guys,

I have a situation here. Take a look at the link

http://www.apogeephoto.com/july2004/jaltengarten7_2004.shtml

that shows a neat chart of color temperatures for digital photography.

 

On the other hand, let us consider the color correction done by 80/81/82/85

filters . For example, lets see the temperatures as given in the link:

http://www.bhphotovideo.com/c/product/54822-REG/Tiffen_13881EF_138mm_81EF_Color_Conversion.html

and if you go to "features", it shows a color correction table.

 

We know that 81A is supposed to correct cloudy white balance and so on. How do

the numbers in Kelvin correlate? For instance, if I want a correction of 9000K

to daylight (digital convention) which 81/85 filter will I choose for me to do

so? 81D can be an intuitive option but looking at b&h site, we see that it

correct 3700 - 3200K which is way off from what I want to do (9000-5500K). Has

anyone calibrated the filters to correlate with the digital camera convention?

 

Thanks a lot and sorry for the long question.

Why bother. I use raw and set the camera to 3200, 5400, or cloudy, or fluorescent and they come out with minimal work.

 

I use a pola filter and sometimes a protection UV.

How to select the PrE white balance measurement method:

 

1.

Press and hold the WB button.

2.

Rotate the rear command-dial until PrE shows in the lower right of the Control Panel LCD. You?ll also see d-0 in the top left corner next to the Mode letter (A, S, M, P)

3.

Release the WB Button.

4.

Press and hold the WB button again until the PrE starts flashing.

5.

Point the camera at a white or neutral gray card in the light source in which you will be taking pictures. It does not have to focus on the card, just be pointed at it so that it fills the frame.

6.

Press the shutter release fully as if you were photographing the white card. It will fire the shutter, but nothing will appear on the main image viewing LCD.

7.

Check the control panel LCD on top and see if GOOD is flashing.

If you see ?No Gd? flashing, instead of ?GOOD,? then the operation was NOT successful.

 

The PrE measurement is very sensitive, since it is using the light coming through the lens to set the white balance. Unless you are measuring in very low light it will virtually always be successful.

 

Please remember that the flashing GOOD means a successful white balance reading was taken, and your camera is now color balanced for that light source. If you do NOT see a flashing ?GOOD,? but instead see a flashing ?No Gd? then the operation was unsuccessful and the light may not be bright enough to take an accurate white balance reading.

 

That's the best way or otherway use software.

Shooting digitally, the filters you mention are an impediment to optimal exposure. Depending on the camera, AWB works well, for absolutely best results using a gray card and shooting in RAW is the best solution.

"81D can be an intuitive option but looking at b&h site, we see that it correct 3700 - 3200K "

 

 

Mean s that an 81D lowers the color temperature of the light coming through the lens by 500 K. So another way to state it is 5500K to 5000K

 

On the other hand an 85B lowers color temperature from 5500 Kelvin to 3200K, a drop of 2300 Kelvin. So in your case it drop the color temperature of the light from 9000K (What is your light source?) to 6700 Kelvin.

 

As Ronald suggests, the best thing to do with digital is to shoot raw with a known neutral in the scene or in a test frame as a point of reference for correcting the white balance in the raw processor.

Because some sensors don't have a neutral response to IR, UV or other wavelengths, I suppose a filter in conjunction with custom WB could be useful in some situations.

Ok guys. I think I gave the wrong impression. I know exactly what to do with my RAW (no offense) but what I wanted to do is have a filter for my film. If you increase color temperature in digital, (eg: 5000K to 9000K) the yellow saturation is increased and it looks warmer. On the other hand if you look at the filter ratings, the warming filters get the temperature from 3700K to 3200K for example. However, they both do the same thing to the pictures in digital and film respectively. Has anyone come up with a chart to correlate the two?

 

Thanks a lot for your opinion.

5500K is 5500K regardless of what the media is.

 

How different films interpret the relationships between colors this is one of the things that differentiate one film from another.

 

Processing variations can play a significant role in determining overall color balance especially with regard to E-6 films and with Kodachrome --C-41 is more consistent in this regard in my experience.

 

But back to your question: you have a daylight balanced E6 or Kodachrome film with either sunlight, electronic flash, daylight balanced fluorescent, or HMI and you want a really warm color interpretation recorded by the film. Generally the way this was done was to start with an 85B filter and if that wasn't warm it up add a second filter --an 81 series or an 85 series. If you wanted to add just yellow the second filter could be some strength of CC yellow filter CC05Y, 10Y, 20Y, or 30Y. Basically you'd make the mix of film, light and filters(s) to taste. If you want to be very semi-scientific about it get a good color temperature meter so you can look atthe numbers and start making educated guesses ast owha tthe outcome will be.

 

If using artificial light (Strobes, HMI etc.) you could gel the light instead. Start wit ha Full CTO and add either different strengths of CTO or Straw gel to your liking. Or just start with 3200K lights to start with.

 

You could of course give yourself a lot more flexibility by shooting without filters and changing the colro interpretation , after scanning, in Adobe photoshop CS3, etc.

With my D 200, I shoot in RAW 100%. I use cloudy white balance for almost all outdoor shots. My lenses all have B+W KR 1.5 filters on them, a skylight or a 81A coloration, even my long Nikon telephotos. Sometimes I adjust the white balance in Capture NX and use a Kelvin setting of around 5700. Most of the time I do not change anything. I really do not know what white balance my settings/filters produces except that I like the effect. When I don't like it, I change it, usually by reducing the amount of warmth. Joe Smith

This link will take you to the site for info on B+W filters made by Schneider Optical. On the top menu bar, go to the right and tab on Info and then on Literature and then on Filters for Still Photography, and then on Handbook, and then on Conversion filters. You can read about the KR series, 81 series, etc. There is a lot of info at this site:

http://www.schneideroptics.com/info/stillphotography.htm

 

Joe Smith

"If you increase color temperature in digital, (eg: 5000K to 9000K) the yellow saturation is increased and it looks warmer" I think you meant the opposite - if you increase the color temperature, it looks more blue. Is that your confusion?

 

Regarding your question, K is not a very good way to think about color temperature - the difference between 3200 and 3700 is much larger than the difference between 9200 and 9700.

 

What you want is the Mired value: http://en.wikipedia.org/wiki/Mired

So your filter changes the color by 42 mired, and you want to correct by 71 mired. Two of the filter you indicate, or a stronger filter, should be fine.

Thanks Ellis, Joseph and Brian. That information was helpful. This leads to another question. When you stack these filters up, does the Mired get merely added?

In the D300 and D3, you can now customize your AUTO White Balance via a nifty color grid

and save the setting.

 

I'm loving this feature. The grid's 4 directional axis really helps compared to the D200's +/-

two directional system. Now i can start somewhere between neutral and incandescent for my

interior shoots and have greater control of color. Spending less time in pp and more time

unwinding and destressing in Halo 3!