Maybe this area isn't of interest anyone except Carlos and me... but we try to be tolerant of each other's pet subjects, right? I'll try to include some educational content that might be useful to other artificial-light shooters. I'll also bloviate a bit about why I made the choices I made... although certainly there would be other ways to handle these problems, and I'd be interested in hearing alternative approaches!
Anyway, we've just finished Omaha Theater Ballet's spring repertory performance, and it presented an interesting set of technical problems -- mostly because the artistic director had asked the lighting designer to use "follow-spots" (spotlights that are guided by an operator to follow performers around the stage.)
There are three issues in photographing spotlighted productions:
-- The spotlight is much brighter than normal stage lighting -- often a two-to-three-stop spread. This means that if you expose for the spotlight subject, the background will be underexposed, and if you expose for the background, the spotlit subject will be bleached out.
-- A high-power spotlight uses arc illumination (nowadays typically a sealed "mini-arc" lamp instead of big scary carbon electrodes) which emits light at a roughly daylight-balanced 5500K. Meanwhile, the rest of the stage is lit with tungsten 3200K theater lamps. The result is that if you set your white balance for the spotlight, the rest of the stage will look orange, and if you set white balance for the rest of the stage, the spotlit subject will look bluish. (Of course this isn't a problem if you can shoot in black-and-white, but that wasn't an option for this colorful production.)
-- The spotlight emits hard-edged, highly collimated light that casts very distinct shadows -- particularly a problem when the performers get close enough to the backdrop for the shadows to fall right behind them.
There's no perfect answer for this -- but in this show I followed the same strategies I usually use when confronted with follow-spots:
-- Choose camera positions on the diagonal to the stage rather than the center, so shadows won't be right behind the subjects.
-- Shoot in raw format (which I always do anyway) so I can tinker with white balance and exposure after the fact to get the best compromise for each picture.
-- Try to pick moments when the necessary compromises don't hurt the effect of the image.
Because the non-spotlit scenes were so relatively dim, I had to forgo my 70-200 f/2.8 G lens, and shot the whole thing with the 50mm f/1.4 G and 85mm f/1.8. Fortunately these were dress rehearsals, so I was free to move around the theater to make up for the reduced flexibility of shooting with fixed focal length lenses.
Some results (all with a D300 at EI 1600):
This ballet to the music of George Gershwin was deliberately lit and costumed with a "cool" color palette, so I simply eyeballed this to reproduce my perception of the effect. The lighting here was so dim that I needed an exposure of 1/60 at f/1.4, so I had to choose a moment when there wasn't much action:
By this point the lighting had brightened enough to let me use 1/500 @ f/1.4:
For the second piece, a little romantic duet about a boy and girl who meet while flying a kite, the lighting was soft, warm and (usually) bright. I was able to use the 85/1.8 lens here to get a slightly tighter crop. The stage was mostly front-lit... but by shooting along a diagonal axis, I got nicer modeling of the lighting along the dancers' bodies.
Now we get to The Firebird, and into spotlight territory. In the first picture you can see how the spotlights tend to spill onto the backdrop -- but by keeping off to the side, I was able to keep most of the spill out of the shot; this trick also brings the dancers closer together visually:
When the villains (an evil sorcerer named Kastchei and his pet snake) came on, the stage got dark and eerie except for the spotlit performers. There wasn't much I could do about it except pick compositions where harsh, cold lighting was appropriate:
When the Firebird swoops in to rescue the hero and heroine, the lights go bright and the color goes orange. Again, I stayed off the center axis so any spill onto the background would be out of the frame.
The finale was a perfect example of what happens when you've got spotlit and tungsten-lit performers close together in the same scene -- there was no way to get perfect color balance on both the wedding couple and their attendants, and since all the girls were wearing white, any color casts were painfully obvious. Since this was a happy-ending ballet, I decided I couldn't very well let the principal couple turn blue -- so set a compromise color balance that kept them looking fairly natural, while accepting the yellowish cast in their surroundings.
Incidentally, during the rehearsal I used my WT-4 transmitter to send the images back to my laptop computer, where they were auto-imported into Lightroom. After the rehearsal, the artistic director and I picked these plus a few more, and I uploaded them onto a server so they'd be available for download by the news media in case the reviewers wanted photos. I don't think any media actually did use them, but I wanted them to be seen somewhere... thanks for indulging my vanity in posting them here!