Need advice on backlit subjects

[Radiant]

I think I'm in a bit of trouble here.

My history is as a landscape and figurative photography, so I don't have any experience using a flash to speak of.

Tomorrow I'll be shooting a wedding. The space is a lighting nightmare. There are no lights. One wall is a gigantic curved window. And the stage is placed directly in front of the window.

I did some test shooting during the rehearsal today, and found myself very unhappy with the results. Without a flash, I get little more than silhouettes. With the flash, I'm not getting much better. Focus is a bit soft and blurry in a number of the images, a cloudy glow obscures some of the features, and I'm getting some odd artifacting (blue/purple lines along edges of backlit figures)

As a studio photographer I'm used to having complete control over every lightsource, and avoiding flashes like the plague. Anyone have some advice to help me rescue this?

Other miscellaneous problems:
-Holding the flash in my left hand while shooting in my right seems to get me somewhat more flattering results. But that means I don't have the ability to zoom or adjust focus while shooting. Any pros want to give advice on how they handle flashes during the ceremony? I have a stand for the flash, but it's too large to use in front of the audience.

-Shooting the wedding party as they exit-- the bridesmaids and best man are pausing before they processional out about five-ten feet further away from me than the immediate family members, who are pretty much standing on top of me (I've got the center aisle spot on the second row, immediate family is front row). With the flash at the same setting, either the wedding party gets almost no light, or the family gets a really really strong flash. Any suggestions on how to scale down the flash on the fly? I have it set to commander mode, and won't have enough time to jump into the camera menu to step the flash level down.

I can fudge things enough in lightroom/photoshop to salvage faces, but they aren't the kind of results I'm particularly proud of. Any suggestions on how to deal with this lighting nightmare?

Here's a completely unedited shot of the space:

And a detail shot of that weird blue line artifact.

Using:
Nikon D80 body
AF-S Nikkor 18-70 1:3.5-4.5G wide angle lens (also have a 55-200mm VR available)
SB-600 flash, gold diffuser (also have a white diffuser available)

Thanks!

 

[Plato]

For starters, you need something like this. In over twenty years, I've never taken a flash shot without it.

 

[Samanax]

Flash Photography Techniques

 

[Radiant]

Egad, that's exactly what I need. Will give me back my left hand and make things a lot easier!

Thanks Plato!

 

[musicaleCA]

That blue line is chromatic aberration. It's a function of the lens quality; poorer quality lenses are subject to more CA. You can remove this in post, but the loss of sharpness at high-contrast edges can't be reduced. So, best to reduce the contrast of those edges (BAM!!! FLASH!!! MRAWR!!!), and use a better lens too. Wide-angle lenses tend to suffer more from CA.

Flash brackets are great, but something like a Presslite Vertex can function sorta-kinda similarly. Not the best solution, of course, but it can work.

 

[Radiant]

Flash Photography Techniques

Thanks Samanax, that guide was a great reference. Most of the guides I've come across online have been rather useless("Never shoot a backlit subject"), but that was chock full of actually useful information, without ever descending into technobabble. Unfortunately the very high ceilings and extreme backlighting will rule out a lot of his tips, but still a very useful read for someone with my aversion to flashes. The quality of the work made the most convincing argument I've ever seen for flash photography!

 

[Radiant]

That blue line is chromatic aberration.

I was using a wide angle lens indeed-- this might be a sign that I need to add a mid range lens to my kit. I'll be a bit too close to capture the whole wedding party with my 200mm. Quality of the lens- well, I think this is one of the lenses that comes kitted with the D80, but it was very well reviewed.

Now that I think about it, I have seen similar artifacts once before- shooting a thorn bush silhouetted against a sunset a couple years ago, which was also pretty extreme backlighting.

As for the bracket, I think I'll be stuck with whatever I can find at the photography store downtown, as the ceremony is tomorrow!

 

[Derrel]

Some fill-flash would really,really help. Using the lowest ISO your camera has, and the top flash synch speed your camera has, you need to add some flash to fill-in the shadows. A speedlight on a bracket would be good. A speedlight in the shoe with a Sto-Fen diffuser and the flash angled upward at 60 degrees would work too. Even the pop-up flash would help.

A second thing you need to make absolutely sure of is that your lens is immaculately clean and free from all grease,oil, and environmental film, like the off-gassing that can occur from foam camera bag padding--whatever the source, you need to be positive that the front element and rear elements are both freshly cleaned before you shoot the real gig. That much glass behind the subjects looks like a major PITA with the dim indoor light. being that dark indoors, the darkness indoors will act like a dark field, making CA and flare and ghosting a major potential problem.

Holding the flash in your hand with a remote cord connecting the flash to the camera is a good way to get the shadows down and to the right, but a flash bracket can accomplish the same thing, and leave you with both hands to run the camera. I would be tempted to shoot this old-school, using Auto-Aperture flash control with the flash mounted on a bracket, and count on the flash giving me the right flash exposure for f/9.5 at 1/200 second at ISO 50.
If you shoot the event in RAW mode, you can use Nikon Capture software to eliminate/minimize some of that chromatic aberration.

 

[Radiant]

Thanks for the detailed advice, Derrel. If you don't mind me picking your brain a bit more...

Using the lowest ISO your camera has,

I actually shot this on 100, was planning to try switching to 400 tomorrow. I might be understating how bad the backlighting was-- to get anything other than a complete silhouette without the use of a flash, I took this to 3.5 aperture with a 1/60 exposure, which is just about all I could do without my tripod (that was the settings on the above shot). There is actually no lighting at all in the room. Given that, do you think adding in the flash will offer enough fill to get me back to a reasonable shutter speed at 100 ISO?

and the top flash synch speed your camera has

I use a 1000w softbox in my studio work, so this is all new to me. Did a bit of research, and enabled the auto FP. But I'm still a bit confused- will this maximize the synch speed, or only tie it the shutter speed? I'm looking through my manual, haven't found a way to manually set the sync speed yet.

A speedlight on a bracket would be good.

I'll be trying to lay hands on a bracket tomorrow before the ceremony-- sounds like a lifesaver!

make absolutely sure of is that your lens is immaculately clean

Great advice, I'll be doing that tonight.

I would be tempted to shoot this old-school, using Auto-Aperture flash control with the flash mounted on a bracket, and count on the flash giving me the right flash exposure for f/9.5 at 1/200 second at ISO 50.

I'll be trying to get in before the guests tomorrow to run a few more test shots. Thanks for the advice!

 

[KmH]

Actually, it's called Purple Fringing and it's not necessarily an effect of CA. (chromatic aberration)

 

[Derrel]

I was thinking low ISO simply to control the highlights in the window--the blue sky at the right hand side looks blown out to me, and I know you have an SB 600 flash. I was suggesting a 1/200 synch speed at a small f/stop and fill flash just based on "pegging" the outdoor,window light level with a 1/200 top synch speed and bringing up the shadows with full-power flash.

My personal preference is to "peg" the window lights, and use whatever combo of aperture and shutter speed and ISO and flash power needed to get a good balance between outdoor light and the flash-lighting indoors. Other people might prefer to let the background almost blow out, but then you do get that purple fringing effect showing up in a more pronounced way when you allow the backlight to be really strong.

If I shot this, I'd be using my rotating Stroboframe bracket and a flash that has Auto-Thyristor cicuitry,and using smaller apertures. BTW, I was married in front of a wall of windows, similar to this; it started off foggy outdoors, but as the event wore on, it came to be bright sunlight and blue skies. I was nervous as the photos,first formals, then the wedding were shot, but I had hired a seasoned pro,and after the ceremony he told me, "I bet you were nervous about that sun starting to peek out mid-way through the shoot, but I thought about that this morning,and decided I'd start off at 1/60 and then if the fog burned off I'd notch her up a little bit. Sure,enough, every 20 minutes I had to notch up a shutter speed. By the end, I was shooting at f/8 at 1/500!"

I told him that was exactly what I was thinking and worried about--that the outdoors would blow out and look awful. He did a great job though!He was using a Hassleblad 500 C/M and Norman 400 portable strobes and had 25 years' experience in wedding photography.