TTL phenomenon

If you have ever shot with TTL off-camera flash, you will have ensured that the on-camera flash is “off”. It still fires its “Morse Code” commands at group A, B or C flashes in the room, but when the actual image is taken a fraction of a second later, it is off.

Except that you may have noticed noticed the following phenomenon: Especially on Nikon cameras, but on Canons as well, it is not totally, 100%, off.

There is a tiny bit of afterglow, which causes an extra little catch light in the very centre of the eye. You can see it in this image by my student, photographer Laura Wichman:

You only see this if you view the image at full size. It is not really very annoying, but if you are determined to get rid of it, simply “Lightroom it out”.

Anyway – learn to recognize this. This is how I know we shot this image in remote TTL mode.

One more of Laura’s shots from this Creative Light session. Here’s we thought a gelled direct light might add some kick. And I love colour – this bright egg yolk yellow Honl gel is great.  Easiest gel to get saturated colour with:

Don’t you love those shadows? Today’s tip: hard shadows can be good. If intended and if created by an off-camera light.

 

A little known fact

When you shoot Nikon and use the CLS/iTTL systen, you can fire remote flashes and set them to manual instead of TTL. This is well known since you set the options through the on camera menu.

In the Canon world, this is not possible: remote flashes operated by light control must use TTL. Right?

Wrong. Canon too supports this functionality.

Here’s a TTL flash set to slave mode (a 430 EX in this case). The display looks like this: (And note that the “M” here refers to the flash’s zoom setting – nothing to do with flash mode):

So it’s a TTL flash set to slave mode.

Now press and hold the MODE button. After a few seconds, you see this:

Now your cannon flash is still in slave mode, but it is now in manual power mode – TTL will not meter: the flash will just fire at whatever level you set it to (1/8th power, in this case). Note that the “M” to the left of the “1/8” now flashes, to remind you. One press and it goes back to TTL mode.

I bet there are some here who did not know this! Yes, you can use light-operated remote slaves that you set to manual, even in the Canon world.

PS: what’s that on the front of the flash? A Honl Photo speed strap plus a Honl 1/4″ grid.

 

My Flash is too bright!

Help! My flash is too bright! Michael, I am doing what you say; and I am using TTL; and yet I get shots like this from my on-camera flash – way over-exposed:

What am I doing wrong?

A-ha. Look at the back of your flash, if it is a high-end unit like my 580 EX flash. And you will see something like this (and an SB-900, for example, would do the same):

That flash says “with the current settings, and the flash aimed ahead, you can take pictures roughly from 2 meters to 18 meters distance”. You see, there is a minimum power setting. And hence a minimum distance.

Which in this example means you cannot take pictures of an object (or a person) 1 meter away. The picture will be overexposed if you try!

Solutions?

  1. Pay attention to this warning!
  2. And when needed to get closer, use a lower ISO!
  3. Or use a smaller aperture (larger F-number).

Simple, once you know. Just like brain surgery.

(Bonus point if you know how much overexposed the image will be at 1m. Answer: Twice the distance is 4x the light, hence 2 stops over).

 

Let there be light.

When you shoot a studio portrait, you can use big studio lights – or small speedlights.

Because they are smaller and lighter, I tend to use small speedlights whenever I can.

And that does not mean compromising quality. Take this example. I took this shot of a very nice model and student during a course the other day, using TTL speedlights:

How is this done?

  • One flash on a light stand into an umbrella (the “A”-flash), on our left. High enough to give us nice catch lights in the eyes, but no reflections in the glasses.
  • The hairlight is one snooted speedlight (the “B”-flash) on the right (using a Honl photo snoot). I made sure this hairlight only lit of the hair, not the cheeks. That is what the snoot is for.
  • I used a Canon 7D with a 50mm lens.
  • I set the camera to manual, f/8, 1/200th second, 200 ISO. Normal settings for studio light. I made sure auto ISO was disabled.
  • The flash was set to its normal TTL mode.
  • I used flash compensation of, if I recall right, +1/3 stop.
  • The “A:B ratio” was set to 3:1, meaning A was three times stronger than B.

I could have metered and used Pocketwizards and the flashes set to manual, and if I had done many portraits, I would have. But for a quick shot like this, I think TTL is a better way, since it is very quick. Indoors, wireless TTL is a no brainer, and it works:  the on-camera flash, which is only used to direct the slave flashes, can be seen by any flash in the room. On a Nikon, or a Canon 7D or 60D, I need only the camera and its pop-up flash. On any other Canon, I would also need a 580EX flash on the camera, to direct the slaves.

But the portrait above is missing something, no? The background is a bit, well, bland.

So we add one more light, using a grid. And a gel. For the gel, I choose a complimentary colour: complimentary to the hair colour. So for brownish-reddish hair I use a beautiful blue-ish gel.

Now we get:

Better, no? Nice portrait, and it took only one light stand, one umbrella, three flashes, one grid, one gel, one 5″ snoot.  All this is affordable, small, light.Professional portraits are now within reach of everyone.

“One step at a time” lighting technique

You have heard me say it many times: “bright pixels are sharp pixels”.

Let’s say you want a picture of a lady. Just let’s say that.

So then you put a lady by the counter. Because there’s a bright background behind her, and you know your camera, you use Exposure Compensation to avoid her turning into a silhouette. I used a Canon 7D with a 35mm prime lens. And hey presto, here’s the snap – and that is all it is, a snap:

The background is now too bright, and the person is “dark pixels”, meaning the picture misses that crisp sharpness you were after.

So now let’s take it in steps.

First, decrease the exposure to get the background right. Use manual, or use exposure compensation (minus!). In my case, it was manual exposure mode, 200 ISO, and 1/200th second at f/8, which gave me this (and that should not be a surprise to those of you who know the “sunny sixteen rule”):

Better – for the background. Now we have a nice dark background, and we can see the trees, and so on.

Now the next step: to light up the foreground!

Flash is evidently called for. So I used a light stand with a flash-and-umbrella mount on top, with a simple 430EX flash on it, shooting through an umbrella:

Now I do the following:

  1. I set the flash to “slave” mode (“remote” on Nikon”)
  2. If I have a 7D, or a 60D, or a Nikon, I use the popup flash to fire that remote flash in TTL mode. If I have another Canon, I use a 580EX on my camera to fire the remote flash.
  3. In both cases, I ensure that the on-camera flash (popup or 580) is disabled, other than sending commands.
  4. Since the background is white, and I am using TTL rather than manual flash, I use flash compensation, +2/3 stops.
  5. I set my White Balance to “flash”.

And now when I fire, the umbrella lights up:

Which, finally, once we ask the lady to stand by the counter again, leads to this shot:

(Thanks for being the patient model, Lita!)

I have now achieved what I wanted: Lita is “bright pixels”, and the background is nice and colourful. Other than explaining, this all took just a few seconds, of course.

The technique above is just one of the many things students learn on my Flash courses. The last Mono, Ontario course ever is “Creative Lighting” with Joseph Marranca, on April 23rd – and there are only a few places left. Just saying!

Wireless flash tip

In keeping with the “flash” tips, in anticipation of Saturday’s Advanced Flash course in Toronto, with Guest Star David Honl, for those of you who are trying wireless flash for the first time: here’s a beginner’s problem to avoid.

A picture of one of my favourite items (not) lit with an off-camera flash on my left using a Honl Photo Traveller 8 softbox; and a reflector on my left:

Can you see the problem? If you have eyes, you can: that horrible shadow.

You see, even though I used the off-camera flash with the Honl softbox, I failed (for the purposes of this demo, of course!) to disable the on-camera flash.

The on-camera flash (which can be the popup, on a Nikon or on a Canon 60D or 7D, or else an on-camera 580 EX or SB-900) is there to direct the off-camera flashes with “Morse code” pulses that happen before the shutter opens. So you need to make sure that when the actual flash happens, that on-camera flash is silent.

And you do that by setting the on-board flash to off. “–” on a Nikon, in the CLS menu, and just “disable” on a Canon. On the Canon, look, there are no rays coming from the flash head:

So then it still looks to you like it is working, but in fact it only fires its “Morse code” instructions, bu nothing else.

Now we have:

That’s better!

—–

One more recommendation, if I may (you will forgive me): there are spots open for the all-day “The Art of Photographing Nudes, 2 April 2011, Mono, Ontario. We use the same lighting techniques you are learning from me here, and more. Same model as last time, same two pros teaching! Click here to book.


Metering Gotcha

A photographer I know well (who shall remain nameless) called me in despair a few days ago.

She was doing some creative flash shots and had set her Nikon remote flash to manual. She was driving it with her pop-up flash. And because the remote flash was on manual, she had to meter. No problem. (Yes, you can set the remote flashes on “manual” while still using wireless flash to drive them!)

A Photographer using remote flashes

A Photographer using remote flashes

Oh. But however she set the flash, using the menus on the LCD control panel on the camera, the Sekonic light meter always indicated the same!

Huh? Was the flash not in fact varying its power in response to her settings?

Looking at the images, it seemed to be – but the meter kept indicating the same. She checked: the on-camera flash was disabled, meaning its light would not contribute to the shot.  So that wasn’t it. Now what?

After trying for an hour and a half, she called me in desperation. What was going on?

Do you know?

Okay, read on. It’s simple – as all these things are, once you know.

  • When you are using wireless flash, the on-camera flash tells the remote flashes what to do.
  • It tells them this using special flashes – binary signals in the form of short light pulses sent out before the mirror is lifted and the shutter opens. A sort of “Morse code instructions to the other flashes”.
  • But this “Morse code” is generated using short pulses of light!
  • The light meter sees these pulses of light, these instructions, and thinks they are the actual flash. So it reads them!
  • And since these pulses are always the same brightness, the meter always indicates the same.

D’oh!

So the solution is equally “simple once you know”:

  1. For a minute, set the remote flashes to manual (rather than “remote” or “slave” mode) using the switch at the back, and fire them using the test button at the back. Vary their power as needed.
  2. When you are happy with the thus achieved light, note down the power value (e.g. “1/16th of full power”).
  3. Then set that power on your camera’s remote menu
  4. ..and now finally, set the flash back to wireless slave mode.

Now you can go ahead and shoot, and every shot is well exposed.

As I said – when you know, it seems simple. But if you did not know the workings of TTL, it would take you forever.

You see, there is method behind the madness: this is exactly why I teach “TTL insides” in my one-time “Advanced Flash” workshop with Special Guest Star David Honl from L.A.- Toronto, 19 March, as you all know by now – a few places left only.

Portrait weekend

One setup at yesterday’s music school shoot was this one:

We did four setups:

  • One traditional “three strobes” setup.
  • One setup with one strobe and a reflector, in a small piano room.
  • One drum room with just an on-camera bounced flash.
  • The above “overflow” three speedlight setup: main light through an umbrella, fill into an umbrella, and a background light.

The first three setups are pretty straightforward. For the last, the question was: TTL or manual?

Yes, you can use the flashes on manual and still use wireless “commander mode” to drive them.

But when you are only going to use a setup for a few shots, it is often just as easy to leave the flashes in TTL mode. Works fine.

But there is one very important thing to keep in mind. TTL measures reflected light. And with a black background, keep in mind that the more background you get onto the image, or the darker your subject is, the higher the exposure will be (the camera’s metering system is dumb: it does not know what your subject is: it sees a darker picture). And vice versa. So you need to compensate for this with flash compensation. When using TTL, be ready to use flash compensation for many shots. If I had set the flashes to manual, and metered, each shot would then have been perfect, independent of the subject or composition.

So why did I use TTL instead of metering? Ease of use. Only a few shots at this setup, so why make it difficult? Sometimes the easy way out is the best way out.

Simple Means.

Today, I taught a flash workshop that concentrated on the use of just small flashes. (Of course as you know I am doing an in-depth version of that workshop on March 19, with special Guest Star David Honl, yes? See www.cameratraining.ca/Flash-Honl.html – not to be missed!)

Anyway, simple portrait lighting with speedlites. You normally use wireless TTL for that – multiple flashes that the camera talks to using its wireless TTL technology. All major brands support this.

So here we have a simple shot of one of tonight’s students, using:

  1. a 580EX flash on our right…
  2. …shot through an umbrella, and
  3. a 430EX flash on our left…
  4. …using a Honl 1/4″ grid and a blue gel.

All this fired from a 580EX on a Canon Camera (if you have a Canon 7D or a 60D, or a Nikon, you can use your popup flash for this).

If you set the two flashes to different “groups”, i.e. A and B, you can set the ratio to what you like (e.g. A:B set to 4:1 means A is 4 times, or two stops, brighter than B). On Nikon, the system is the same although the way you set it is different (stops with respect to zero).

One important thing to remember: a key difference between strobes (you meter by measuring incident light, and it’s always good whatever the subject) and speedlites (TTL meters reflected light). So when using TTL instead of a studio, your subject makes a difference.

A subject with dark hair, a dark top, and against a dark background, will be overexposed so you need to use Flash Compensation of minus 1 to minus 2 stops. In the shot above, I used minus 1.3 stops.

Go try this if you haven’t. It’s fun. As a minimum, you need a camera with an on-camera flash (or use the pop-up on a 7D or 60D or a Nikon); one additional flash; a light stand; an umbrella; a bracket to mount them together; and a reflector (see yesterday’s post).

About that home studio

One more about the simple TTL home studio. I can give you some pointers to do your own.

Here’s how.

You need:

  1. A modern SLR camera.
  2. A lens – anything over 50mm will do. A 50mm f/1.8 might be a great choice: sharp and affordable (and if you need it, fast).
  3. If you have a Nikon, or a Canon 60D or 7D, just one flash (a 430EX/580EX for Canon or an SB600/SB900 for Nikon).
  4. If you have a different Canon camera, an additional 580EX to command the other flash.
  5. An umbrella (shoot through).
  6. A stand for the flash, with a mount for flash plus umbrella.
  7. A reflector (silver or gold or white, or a multi-purpose one).
  8. A stand for that reflector.

As an option, another flash with a small stand to light up backgrounds, but this is not a must have. You can just move the umbrella and subject closer to the wall if you want the wall to be lighter.

Now that you have the equipment:

  1. Set your flash to “slave” (Canon) or “remote” (Nikon) mode. Use the manual to find out how. On a modern Canon with a modern flash you can use the camera to set the flash.
  2. Set up your on-camera flash to be the “master” (“Commander”, on Nikon).
  3. Ensure that the on-camera flash is not going to fire (it will only  send commands to the remote flash, but it will not actually fire – else you get a shadow).
  4. Move the umbrella close to your subject. For a “standard” portrait, the best position is 45 degrees up, off to the side 45 degrees.
  5. Move the reflector close on the opposite side.
  6. Set your camera to manual exposure mode, f/8, 1/125th second, 100 ISO (or 200 on a Nikon).
  7. Take a test shot.
  8. Check the histogram. If you are shooting a dark subject against a dark wall, you may need negative (perhaps -1 stop) Flash Exposure Compensation; if you are shooting a light subject against a white wall, you may need positive (perhaps +1 stop) Flash Exposure Compensation.
  9. Make sure there is a catch light in the subject’s eyes. Ensure that any glasses do not reflect (move subject or umbrella if they do).

It is as simple as that. You will have studio quality shots, for very little investment. Shots like this (which I made with the exact setup above):

With a modern camera and flash and a little knowledge, it really can be that easy.