Thursday, October 25, 2012

Q&A: Server Room—With Speedlights?

In the comments of last week's server room portrait, reader MeruWarrior (along with several others) asks:

I love the blow-by-blow account. Could this be achieved with just hotshoe flashes?

Short answer: Yes, sort of. But you're gonna have to be willing to "go with the flow" a little with regard to the ambient room light...
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Power = Versatility

First off, I went with big lights here because I wanted to be able to dominate the ambient and create my own color palette. This EDA project has come with a lot of restrictions, so the last thing I want to do is impose more of my own. Plus, I knew we'd be working quickly here. So I wanted to be loaded for bear.

Certainly, we could have done it with speedlights. But it would have been a little different. There would be no nuking of the ambient. Instead, in our hypothetical speedlight version, we will be … cooperating with the ambient.

So let's look at it:



You'll remember this daylight WB auto exposure shot from last week. It is where I always start. Get the lay of the land. Look at the ambient. Learn it's shape, light level and color. Here I'm on ISO 200 and daylight WB. Lens is at f/5.6. The camera gives a shutter speed of ¼ second on "A" mode.

As a big light shooter, I am fine with this. It means I can easily walk the shutter speed up to kill ambient. As a speedlight shooter, this would have been my first problem to solve. Because I
will need that ambient light for my photo.

But first, let's look at the light quality. I have mystery meat industrial lighting in the back, and a wall of diffuse (daylight balanced) light coming from behind me. This is something we can work with as a base.

We're looking at a full exposure, with a ¼ second shutter. Not good for shooting people. So let's go to ISO 400, which still looks just fine on my D3. Now, we are up to ⅛ second as a full exposure.

But that's for a full exposure. Instead, I will want to use this ambient light as my fill. So we can underexpose that by, let's say two stops and still be just fine. Bingo, we're up to 1/30th of a sec. That's doable, given our flash will be carrying the key light duties.

And, as we have happily discovered before, "mystery meat" lights can end up looking pretty cool when you play with the exposure. I can't go back and tweak the exposure onsite, so let's crank it down a coupla stops in Photoshop:



This would have been the second photo I would have shot in hypothetical speedlight mode. And this looks pretty cool. I won't have the ability to own the color palette, but this would work fine as a "base" exposure.

Next thing would be to put a couple of ungelled speedlights in the back, just where we put the big lights in the original shoot. The speedlights would define the fronts of the servers in those aisles, and also create a normalized color to them. At ISO 400 and f/5.6, I am guessing ¼ power would have handled it.

The shadow (i.e., ambient-filled) areas would retain the orange look you see above. Fine. Different, but fine. And the daylight color of the strobe backlights would anchor the color a little. Logic to the light.


Now, Light the Guy

Okay, look at the facade of the server that will serve as the background for our hypothetical speedlight-lit guy. It is a specular reflection from the wall of light behind me.

As I dropped my ambient exposure, I would have been watching that tonal level. I would want the dark gray to still separate from black (for nice depth) so I would not drop the ambient exposure past that point.

So now, the wall-o-light becomes our fill light and the specular on the cabinet gives the photo a similar (if not blue) look to what we did with big lights.

So really, all we need here is an umbrella key light floating out over the guy up top in front. I'd use a stand and a volunteer (remember, hypothetically working lean here) to hold it out there. So, no need for a boom.

I'd warm that key up a little—maybe ¼ CTO—to tie him to the warm undertones we have in the ambient in back.

It's a similar photo (if more light balanced and less sledge-hammered) than the big lights version. But totally doable.
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Long story short, don't fall into the trap of thinking that having different gear means you automatically can't do something. You just might have to think about it a little differently, and/or maybe finesse it a bit.

But there's almost always a way to do it.


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11 Comments:

Blogger Trebuchet said...

Hi David,

I'm guessing the reason you can't "nuke the ambient" with your speedlights because of the large difference in power output?

According to your original post, the large lights were set -2 stops to ~160 Watt-seconds Searching the internets and your blog, the SB-800/900/910 seems to have a power roughly equal to 60-80 Watt-seconds, or about 1/3 of you big lights. However, your large lights are also covered with CTB gels.

Could the following trick work? Instead of blue gels on the flashes in the back of the isle, could you fake the white balance like your Gary Fong post?
Use a red card to fake the white balance and make the camera think everything is blue, and then use a red gel on the on the subject light?

This way you can use all available light of your speedlights in the distance rather than blocking them with gels.

I don't know what the shutter speed was in your original post, but if there were some headroom, you could increase the shutter speed and open up the aperture getting a little more out of the speedlights?

Thanks - I found this blog not too long ago, and I find it incredibly informative and fun.

-Tom

October 25, 2012 1:28 PM  
Blogger Oscar said...

Great post! reading though your thinking process helps me (the n00b) gain valuable insight that I can take with me. Now when I look at other photographs that use "big lights", I will use this as a reference and will attempt to replicate them with the gear I own to better understand lighting. Thanks!

October 25, 2012 1:43 PM  
Blogger David Hobby said...

@Trebuchet-

It would take a lot more than just a WB swap and tungsten gel on the flashes to get those oranger-than-tungsten ambient lights all the way to to blue. So no, I don't think the original version would be something I could have done w/speedlights.

October 25, 2012 3:12 PM  
Blogger Mike Levad said...

Hey, Here is a shot I did in a library instead of a server room with just speed lights. In order to nuke the ambient I over-clocked my sync speed to 1/320. Sure it left a bit of a black bar on the left side of my frame. So I cropped it out. No big deal! There is a CTO gel on the main light in an umbrella and I shot in tungsten white balance to turn the bare flash in the back blue.

https://www.facebook.com/photo.php?fbid=539227122770413&set=a.539226936103765.140844.167276289965500&type=1&theater

October 25, 2012 3:35 PM  
Blogger -RL said...

You rock like a hurricane David! Your thought process is invaluable. This is one of your best posts to date!

October 25, 2012 4:06 PM  
Blogger Blonde Woman Stamping said...

I had exactly the same thought when I read your original post (how could you do this with speedlights?) Thank you so much for the explanation.

October 25, 2012 10:01 PM  
Blogger michael anthony murphy said...

just playing the devil's advocate here. Couldn't the original be pulled off doubling up on the back speedlights, opening to f/2.8 or so, cranking the shutter to 1/250, and if need be, bringing it up in post a bit? Or, will certain elements get lost?

October 26, 2012 8:03 AM  
OpenID markonestudios said...

David,

Many thanks for responding to my query with an entire blog post :)

Once again, your explanations and simulated show-and-tell are superb. Lately I've been struggling a bit with inspiration (I work a full-time job elsewhere), so I am glad I saw this. It's given me a great idea for a shoot...

Best regards,
Mark (aka MeruWarrior)

October 26, 2012 8:41 AM  
OpenID markonestudios said...

David,

Many thanks for responding to mny query with an entire blog post :)

As most will agree, the extra effort you take in explaining your thought process is invaluable.

Lately I've been somewhat lacking in inspiration but I'm happy to say this has rekindled a thirst, if that were possible.

Many thanks,
Mark aka Meruwarrior

October 26, 2012 8:45 AM  
Blogger Jonh Hernández said...

Hi David, thanks for this follow up article.

Still i don't get why you couldnt have done it with speedlights more than the slower refresh etc..

if you were on 5'6 at 1/4 sec... at 1/250 would been already 6 stops darker, wich i guess was your final image settings ...

With a full power speedlight you can't get enough light at 5'6?

in the worse case putting a 2nd speedlight wouldnt do the trick?

i still havent found any situation indoor where i couldnt kill the ambient and use speedlights...

im missing something?

i totally understand that having to choose obviusly the big lights work better as they refresh faster etc..

but beside that...

thanks for clarifying.

October 26, 2012 2:50 PM  
Blogger Keith said...

Am I missing something, or would the easy money answer for speedlights be to turn the lights off? Perhaps you couldn't though.

This is one of the things I really like about McNally's one light two light job, he shows how to get similar looks from both options.

Well done, Mr. Hobby! Great info.

October 27, 2012 1:49 AM  

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