HX-754 / GLD are nice lamps, how do you like them? Dependable,
shock resistant, refined
filament sufficient to project a
pattern? The Philips #6981P is about the same lamp but 1,500 Lumens more in output and 100 hours more life. I would recommend switching to it.
For every 1% change in
voltage less than the lamp's stamped operating
voltage,
color temperature will be reduced by 0.4%.
This figure is only useful when you
meter the
voltage at the
fixture when the
dimmer is set to full. Than do the math in accounting for the difference between that voltalge asl no doubt different than that of what's stamped on the lamp. Than deduct that from your 74% to get the true
color temperature the lamp is operating at.
I expect that in a rough guess it would be about 78% which gives you roughly 3071 K in
color temperature. Very roughly as it's been many years since I have had math class.
Given 3.5% less output per percentage in output, why are you normally running this
fixture at 74%? Wouldn't something like a HPR 575/115 lamp work better in the
fixture for output when left at full? Or some mixture of lamps at partial where punch is needed and most at full? This no longer having to fight "Amber
Shift" than would bring the lamp up to it's rated
color temperature and above it by way of operation over stamped
voltage of the lamp no doubt when at full - normally over 115v. Your actual
color temperature might be something around 3.3K when at full which is why most 115v lamps look hotter/blue in
color temperature than the older styles of
Leko using 120v lamps. Granted your
fixture lamp life would be also reduced by 12% per volt percentage
drop.
So let's see, moving light arc source lamps. Hmm, my follow spot is too bright, whell that's why it's called a follow spot is it not? Same story with using arc source intels with conventionals. Way different beams of light.
If you specify what
fixture you are using, dependant upon what that arc source
fixture is, there might be a 3,200K arc source lamp available for it. High End even at one
point had a lamp on the market called the INdy 575. It was made by Amglo and was a
filament lamp for use in a studio spot. I have something like two of them left and Light Parts.com might have more available. Othewise the 250w versions have the new ST-250HR lamp from Philips available by now which is at 3,200K. This lamp should - not tested or looked into yet, but should work in most 250w moving light fixtures.
You can or should be able to thus in a 575w or 250w moving light
fixture, bring it down to 3.2K in
color temperature. Otherwise with all such lamps there is a range from 5.6K to 7.8K in
color temperature available. Given say you lower the
color temperature of your lamps some, and color correct the
color temperature of your
conventional fixtures, you should be able to get into the 5.0K range for both without a problem given
gel used.
In the end, you have amber
shift from dimming, two different
color temperature fixtures in use and the oh' by the way amber
gel in use. Before you do anything, start by using a lighter amber
gel in the
fixture. This should start to correct the problem by way of transmission
level of the
gel each step less dark you get.