What is my best bet for two background lights?

I'm currently in the process of building a studio in my home, and I've hit a problem.

I have a 9x9' space, which will be filled at one end with a 9' wide white Colorama, and then about 8' of flective flooring coming forwards.

I need two flash heads to light the background from either side, but I don't want my pants pulled down over the price, is there any budget lighting I can use, since I will never use them for anything other than blowing out my white background?

They have to be flashes, and I guess they have to be reasonably powerful.

Any advice would be appreciated, thanks.

What are you using for your main lights?

gonzogolf wrote in post #9686031
What are you using for your main lights?

This is pretty important, as whatever you use for your key light, your background lights need to be 2 stops brighter to completely blow out a white background.

9x9 space I am hoping you not planning to shoot adult people? If only 1 subject, I will put one light in the middle coming in from the ceiling. You don't have space to put two lights on the sides, IMHO.

In addition to power, there are recycle time considerations.

9 feet by 9 feet is more than adequate to shoot people, what do you mean? That's just the standing space, I'm in another 6x6 portion of the room with my camera.

Thanks for the replies, guys. The main lights are both 300w.

I don't need it to be too technical to be honest, just want to know the cheapest option in terms of old lights. They never have to move, they just have to blow the background. I was hoping there was an older alternative I could go for.

Edit: It's very important I have two lights on the background though. I want to lights to light the subject, if need be, and two to use on the background. I have two Venus 300w interfit lights already, which will probably be upgraded in the feature and moved to the background, but in the meantime, I want something cheap.

You could probably get away with some of the JTL monolights, although if you shoot at the full 300ws then they wont keep up. I hope you meant 300ws and not 300watts. But seriously though 9x9 is small for a studio space.

Well, it's just mainly portraits and product shots. That's all my business is really.

There will be the occasional full length portrait.

I'm surprised it's apparently not small enough, though. I tested it myself at 50mm from my shooting distance, assuming about 4 feet of distance from the background for separation, and it seems perfectly adequate. I was using a lot less before.

Also, the background is going to be blown, so I think I'm going to be a bit better off, since separation won't really be a problem, right?

God I hope I'm right, I'm spent a small fortune buying all my equipment!

Thanks for the tip on the mono lights. I doubt highly that I'll ever need to go full power, since the space is so small. I'll look into it.

Thanks Gonzogolf.

You may end up with issues blowing the white drop if the subject is too close as the light reflected off the drop will wrap and cause edge softness and glow that you may not want. And it's a problem if you want to use any other color drop, but if you do mostly headshots and product work I'm sure you can make it work.

Thanks for the tip. I was concerned about light spill myself, which is why I opted to have two large folding doors built to hide the lights behind so that I can be sure the light only hits the background. Of course, the reflected light hitting the back fo the subject is an issue, but do you think blocking the lights from the front is a good idea?

The full dimensions of the room are 21 feet in length, by 10 feet in width.

It cant hurt to screen the lights so you dont have an spill back toward the camera. I think the 21ft dimension is important. That ought to allow you do get your subject say 4 feet in front of the drop and still have enough room to work with a decent length portrait lens.

Ah Gonzogolf, that is the post I wanted to hear. I don't mind it being tricky, as long as I'm not told it's going to be completely impossible lol.

Essentially, I have about 6x8 for the subject to stand in, including background, which will be flush against the wall, and I have another 8x13 to move around with my camera.

I'm hoping all this will be achievable with a 50mm lens, and perhaps a 24mm lens for full body shots.

I think the problem is the way you are describing the space. Think of it all as studio space rather than designating subject space vs camera space. Are you using a ff or crop camera ? I wouldnt use a 24 for full body shots, even on a crop thats not a flattering focal length for humans in my opinion. As for the headshots 50 is okay on a crop, but I'd prefer an 85, more flattering.

I'm using a FF camera, what lens would you recommend given my studio dimensions?

It's a juggling act. You have a desired aperture you want to shoot. You have the distance of the subject from the background. You have the level the background lights must be at in order to achieve pure white, and that is based on the taking aperture.

If the subject is 6 feet from a white background and you want to shoot at f/8 then then means you're looking for a reflective value of f/32 from the background. This requires that the background lights be powerful enough to produce an even f/32 on your background. Assuming you're reading f/32 across the background, you now have to look at the incident reading at the back of your subject. Keep in mind that standing in front of a giant white reflector will return quite a bit of light back to the subject area. If it's more than about 1 stop under the incident taking aperture then you're going to start to see wrap, halo's, ghosting and potential flare.

So now, assuming you can't increase the distance from subject to background, this means you must decrease the power of the background lights. Lets say you pull back by 2 stops to eliminate all signs of wrap. That means that the reflective reading from the background will now be f/16 and this also means that your taking aperture now becomes f/4.

So what if f/4 is too shallow? What if there is a group and f/4 just wont give you a sharp image from front to back and left to right?

You see there are limitations and there is a bit of juggling involved to make it all work. If you've got a large space then 200 Watt seconds is not going to be enough, especially when you're shooting at f/11.

As a point of reference, I have a fairly small studio and when I shoot on pure white my background lights (left and right) are about 4 feet from the background and the subject is about 6 to 8 feet from the background.

If I shoot at f/11 that means my background lights are going to read f/45 reflective. Using a 600 Watt second strobe, I'm still at or under 1/4 power, which translates to 150 Watt seconds.

So, in a small to mid sized studio, a pair of 200 Watt second lights will work. Once the size of the room increases and the distances change, 200 Watt seconds becomes questionable.