Mirror wall in a tight space...

I have a shoot coming up for a kids' dance studio that's a long rectangle (maybe ~16' x ~60') where one of the long walls is made entirely of mirrors (as dance studios often are.) I'll be setting up a 10' wide white backdrop with 2 strobes for the background, and 2 more strobes with shoot through umbrellas to light the dancers.

The only other time I've done a shoot like this I put the backdrop against the mirror to avoid reflections. I shifted it to a very slight angle to get a few more feet of space to work with, but was still limited in how much depth I had to work with since I could only use the narrow dimension of the room. The pics came out great, but I would love to change the setup so I could use the longer dimension of the room and be a bit further back from the talent for greater flexibility.

Only problem is the mirror wall, with no curtains available to block them off. I have no idea what the reflections will do, and I don't really have time to re-do the setup if that turns out to be a bust. I'm trying to see if I can do a test the day before, but waiting on studio availability.

What kind of lighting effects will those mirrors cause? Would any of you more experienced photographers have any suggestions or wisdom to share on ow to compensate? Thank you!

You could use gaffers tape and tape up black cloth or paper on a length of mirror to block reflections…

Good idea. I've been able to get a short window of time to test in the dance studio in a couple days, so maybe I can rustle something up and give it a try.

I thought about this situation and created a drawing to help in the analysis

Thank you, Wilt!!! Wow, you are basically spot on with the diagram and that analysis is amazing. So helpful. This is basically where my mind has been ending up for a best case scenario, hoping it might be as simple as adjusting the B light power down a bit to compensate for the extra fill.

The lights for the backdrop will be off to either side a bit, but I have some folding black posterboard flags for those to help minimize their reflection. As far as the reflection of the backdrop itself goes, I'm curious as to whether it will function similar to an additional backlight from the mirror reflection... hopefully not too powerful.

A little time to test this weekend will help make sure there aren't any other adverse reflections I need to consider. I'll come prepared with something to cover the mirrors a bit in case my angles are off a bit or I need to control the effect of the big white backdrop.

The backdrop will provide -1EV as bright simply because of the reflectivity of white surface (vs. a mirror), further intensity reduction will occur because of distance between it and the subject...which is why you do NOT want to position your subject just 2-3' from the white backdrop ordinarily. In the photo the shoulders of the subject should not be visibly brighter because of reflected light from the background. It you use a flashmeter, its intensity at subject position while aimed at the back wall should be less than the intensity facing the frontal sources.

Thank you so much for your help!

The shoot went pretty well. Reflections weren't an issue, for the most part. There was barely 15 min (!!!) to set up before the dancers were ready, so lighting was quick and simple. Due to the varying height of dancers and floor poses, moving poses, singles, and group shots... I had to kind of keep a simple "one-size fits all" approach and only do quick and simple lighting adjustments. On top of that, the rental house gave me 600RT's instead of the 600RT II's that I was using them with, so recycle time was a bit slower and individual lights dropped out of radio contact and needed to be power cycled a few times.

Lots to learn with lighting (only my second time doing this, really) so I would've loved a bit more time to play around and dial in the lights for each dancer a bit more. That being said, the dancers were happy, the studio was happy, hopefully the parents will be happy... so it's a success for me.

Nice photo. Glad to hear that what you encountered for reflections was a non-issue, as I had analyzed...reality matched theory!
Was the mirror wall on subject's right or left...obviously Main was on subject left. What was power setting that you used for Fill (vs. Main setting)?

Setup was a mirror image (hehe) of your diagram. So, mirror wall to subject's right.

If I remember correctly the key light was usually full power through a 40" umbrella, and the fill was a 46" photek soft lighter umbrella ranging 1/2 to full power depending on if I had to pull it back to fill more space. The two strobes lighting the background were between 1/4 and 1/2 power.

I'd bring the lights closer and wind the power down for solo dancers when I had the time. Most of the kids were pretty young and nervous, so I was focusing more on making it fun for them and often had to keep things moving to just to get through the whole group in the time we had. At some point early on I relented and moved the lights back at higher power to cast a wide pool of light. Key was probably a little hot, fill strobe was constantly losing radio connection and not firing at all.

Not sure what other lighting gear would be a better fit for next time, would definitely be open to suggestions.

Nicely executed shot! Wilt's lighting analysis provides me with additional insight into some table top stuff that a mirror can be used. Thank you for posting that question!