Indoor Lighting / Strobes / Settings

[leomaris]

Hi everyone, first post so apologies if my etiquette isn't right yet. :|

I was hoping to get pointed in the right direction on a lighting question. Pretty new to photography, so I have a lot to learn.

I was playing around with a Canon Rebel XSi and a couple of strobes doing some portrait shots, so indoor shots in a medium-sized room. Strobes were positioned maybe 5 feet away from the subject, and were triggered by the pop-up flash. I had the camera in manual mode.

My problem is that at 1/60 or even 1/50 shutter speed, I had to set the ISO to 800, and the f-stop as low as I could get it (sometimes wouldn't all below F5.6, no natural light in the room since it was evening), and still couldn't get the exposure I wanted. With Photoshop, I can brighten them up enough to where they look nice... but at ISO 800, the shots are way too grainy for my liking. The low shutter speed also meant the shots aren't as crisp as I'd like.

So other than adding strobes or upgrading strobes (which I am considering) what else might I look into?

Thanks in advance for any thoughts.

 

[leomaris]

I should add, I was using umbrellas to bounce the light.

 

[Dao]

Changing the shutter speed only affect the ambient light. It has little or no effect on the strobe light.


What kind of light are you using? Can the strobe power be adjusted? Can the light move closer to the subject?

 

[Derrel]

My guess, based on experience, is that the pop-up flash was the only flash actually firing DURING the actual SHUTTER exposure...

Your disappointing results have been experienced by many people over the years; unless the on-camera or pop-up flash AND the satellite strobes are all synchronizing, the images will be very DARK.

With multiple flash units from five feet away, needing ISO 800 and a low f/stop number means...the satellite flashes are NOT contributing to the exposure. If they were, you'd be firing at a SMALL aperture, like f/11, with multiple flashes at 5 feet distant!

WHat happens is that the on-camera pop-up flash fires a very rapid, ultra-brief series of PRE-FLASH emissions; the sensor in the camera reads the incoming data on return flash, and then determines how much flash is needed. The problem is typically that the satellite (or slave) strobes see the PRE-flash emissions, and all fire; the camera's shutter however, opens a few milliseconds later, AFTER the satellites have all gone off.

This happens at such a speed that the human eye can not see the process.

Try setting the pop-up flash to MANUAL mode, which cancels the pre-flash emission, and will allow the satellites to all synchronize with the actual shutter opening. It's also possible that you have the wrong settings programmed into the satellites, or the camera...but one thing is for sure: if the images are dark at ISO 800 and at low f/numbers like f/2.8 or f/3.5--then the satellite flashes are NOT firing during the shutter's exposure!

 

[Dao]

Derrel,

I think you are right on the pre-flash issue. I have 2 optical slaves that I used in the past, one of them has a switch for pre-flash and the other one do not. And the one do not have the pre-flash switch will fire before the actual flash. So OP, make sure you turn off any pre-flash and red eye flash stuff.

 

[Designer]

Yes, leomaris, what the two posters above said.

When you get this setup working properly, you will probably find that you have too much light, rather than not enough.

I have used that feature to fire remote flashes myself, and the way to check this is to simply take a picture of your strobes. If they are firing when the shutter is open, they will be brightly lit in the photo. Either back up far enough that both umbrellas are in the frame, or move one close to the other, and get the brollies in the picture. If they are bright white, then you're good to go.

Keep your shutter speed up to the sync speed (especially for portraiture, etc.) unless you are adjusting for ambient light or something. Such a long shutter opening should not be necessary nor even advisable in the average situation.

 

[leomaris]

Thanks for the replies guys.

The strobes are indeed firing, and they're at full strength. They're also contributing to the light, because shadows are all eliminated... a couple shots where I forgot to position them right, you could see the shadows created behind the subject.

They aren't the BEST strobes, I bought them for a modest price about 15 years ago. But hadn't really started to play with them much until now.

Even though they're not top quality, it seems like I should be able to get better than 800 ISO, no?

The strobes are Rokunar Studio Pro Model 150 ... some stats written on the unit include Flash 135WS (modeling lamp 40/60W).

As for the camera, I was shooting in manual mode, so I don't think anything is adjusting based on the pre-flash, or do I have that wrong?

The light was... sufficient, once I used PS to bump up the exposure by anywhere from +.5 to +1 in some cases. But I want to shoot really crisp portrait style shots, not excessively soft grainy ones.

 

[j-digg]

Time for some examples.

Post some with the strobes on/off if you could. The on-board flash could be taking care of the shadows. Maybe there is indeed a preflash and it is just catching the modeling lamp during the actual exposure? I'm pretty sure that's a good amount stronger than the bigger speedlights so it should be able to crush 5.6 @ 800 ISO.

 

[Derrel]

Well, the FLASH is what must be in the manual output mode. I just looked up the strobes...Rokunar Studio Pro Model 150 ...you ought to get a decent f/stop out of these...

Again, if the images look "grainy/noisy" at ISO 800, something is amiss; could the shadows seen be from the modeling lights? Do you have the flash units set to FULL power? Could you post a photo?

 

[hirejn]

Shutter speed has little effect on motion blur when using flash. The flash will freeze the motion, but there might be a slight trail on the subject if it's moving fast. Rear-curtain sync is the best way to correct that; then the subject will be sharp at the end of the exposure vs. the beginning.

It's not clear what your problem is other than not understanding flash. That's difficult to explain in a forum. Not getting the exposure you wanted is too vague. There's no reason a Speedlight can't do a reasonably good job, so you'll have to be more specific. If ambient light is a significant element in the exposure and there isn't enough of it, the only options are to raise the ambient light or raise the ISO. You could drop the shutter speed but eventually, if you're not on a tripod or objects are moving, there will be trails. If flash is the only light, then it will freeze any motion, but if enough ambient light is blended, the ambient light will leave a motion trail.

 

[Gavjenks]

ISO 800, wide open aperture, strobes 5 feet away is ridiculous.

Your strobes are broken or you are not using them correctly or something like that. That's not normal or expected for that many watt seconds of light.


The fact that you changed your shutter speed and actually got different results leads me to believe that Derrel is correct in his guess that the shadows were from your modeling lights, and that the actual flashes are not being properly triggered or recorded.