Filter Question

[mike001]

The shop i work in uses sodium phosphate vapor lights which give off a extreme yellowish-orange cast.
If i wanted to get the lighting on the products we build, more"natural" for lack of a better word, would i use a 80A or 80B filter?

thanks,
m. allen

[highbarger]

Those lights are hard to work with! If you're using digital capture it would be easier to set a custom white balance than try to compensate with filters. If you're shooting film and have to resort to filters my GUESS is that you'd need the extra compensation from the 80b. It would be a good idea to shoot a roll of E6 (slide film) to test before the actual shoot. Craig

[Tom Swaman]

Mike,

I do not like answering a question with a question, but have you tried to compensate for the yellow-orange light by adjusting your white balance? This just might solve the majority of your problem.

I do not remember the exact filter number to compensate for sodium vapor lighting and I am not where I can look this up, but you might look up Lee Filters or contact any good stage lighting organization and they will most probably be able to tell you the best filter from their published chartd. just a thought.

Tom

[mike001]

Hi,
thanks for the replys,
I'm using a 20D, but haven't used the WB that much & thought a filter might be the easy way out.
I'll try the custom settings and see what happens.


regards,
mike a.

[cyclohexane]

Custom WB works pretty much just as well as a filter, and with less degradation to your image too.

[dougsmit]

I doubt there is a good answer but would give RAW a chance. Vapor lamps are not continuous spectrum and will never be 'natural' looking. The question is whether you can tweak it to a point that it looks 'good' even though it is not exactly natural looking. White balance assumes there is a continuous spectrum available and gaps in that spectrum make ledges that you have to fight. At least shooting RAW allows you to see the adjustments before you drop the quality to JPG level and also allow combining conversions if you decide you need to make one area a different color than another. Another trick might be to reduce the saturation a bit leaving some color but playing down the fact that it is not the right color.