Background colors inconsistent

[aribabybug]

I'm really new to studio lighting, and am figuring things out as I go along. (I've got a huge stack of books at my feet as we speak, and I'm hoping they help!)

I learned on a blog that I can point a strobe with a gel at the background and get a colored background. I've been working on this, but I'm running across a problem. Sometimes when I shoot, the background has the color I expect and everything is fine. Other times, the background strobe seems to not be flashing or else my camera is not capturing the color. In these shots, the background is just dark gray. As far as I can tell, I'm not changing anything between shots, or if I am it's really minor.

I've got two Square Perfect strobes (they were gifts from my father. I'm hoping to upgrade soon), the closer one with a softbox and the further with gel and barn door. I'm triggering the strobes wirelessly with my on-camera flash at it's lowest setting. I've also tried using the on-camera flash at a higher setting and deflecting it so that the light triggers the strobes but doesn't hit my subject. As long as the closer strobe is firing, I see no reason that the further strobe shouldn't, even if it isn't registering the light from the on-camera flash.

Are there any suggestions anyone can make? At this point I'm not sure that I know enough to even know what my problem is, but I'm hoping someone can steer me in the right direction. Thanks!

[sk66]

I would guess that sometimes the background strobe isn't going off with the camera flash...it may be firing from the front strobe, but behind the shutter...A slower sync speed might help.

[aribabybug]

I wondered if that might be a problem, but assumed that if one strobe fired, the other would fire at the same time and the camera would capture it all. Like I said, I don't know much about this yet. I've got my flash sync speed at 250 right now, as that's the highest it will go on my camera. I can try lowering it and testing things out.

Do you know of any good books or websites relating to lighting? I've tried a number of the ones that people have suggested (Strobist, Light: Science and Magic, etc), but they always seem to focus on how to create specific lighting effects, and don't explain things like sync speeds and lighting ratio, or else they get so scientific and technical that I get lost.

[klam]

Are you letting the enough time to past so the strobes can recycle? Maybe the background strob isn't seeing the flashes it needs to fire. If the ambient room in the light is too bright it can affect the strobe from seeing the flash.

When I use lights that are triggered by flashes the room i'm in is has a very dim ambient lighting. That helps my lights register the flash fire.

Strobist is the a very good site. Did you read the "Lighting 101" articles on strobist? If not I would start there.

[OsmosisStudios]

Examples, with EXIF please.

[imatt.au]

A sync speed of 250 is pretty high, and would be on the limit of a lot of equipment; especially if you are operating wirelessly or the rear strobes are acting as wireless slaves. I would reduce the shutter speed down to around the 125-160 mark. You will also need to re-adjust your aperture due to the increase in light coming in.

I'm assuming you are not trying to capture any high speed action.

The only other thing I would recommend when working with strobes, is a light meter. It will save you ALOT of time, as well as help you with metering your lighting contrast.

I got a Sekonic 308S for an extremely good price of ebay. Although many will recommend the 358 for a slightly higher purchase price

[aprillove20]

Well, I agree with imatt,au ideas that need to re-adjust your aperture due to the increase in light coming in.