so, what are your settings?

March 27, 2008 @ 3:03 am · Filed under exposure metering, flash, flash photography, lighting, technique

What are your settings?  -  a question that I am often asked about various images. 
And quite often, the answer is surprising  -  it doesn’t really matter.   
Sometimes the specific settings are of importance, but usually much less so than the method of getting to correct exposure of the ambient light and the flash.

This is the photographic equivalent of teaching someone to fish, versus just slapping a fish down on a dinner plate.  Just telling my settings will reveal very little about the how.  And yet, the how is far more important than just a listing of seemingly random figures.

Let’s look at this recent image from one of my workshops on flash photography - especially since it is exactly the kind of thing which I teach during the course of the day.

In this instance, I used manual flash - a speedlight in a softbox. Since the flash was manual flash, there were then 4 factors controlling the flash exposure.  This topic was covered in two recent posts: manual vs TTL flash // juggling shutter speed, aperture, ISO.   (And if anyone is interested in the specific equipment, such as the softboxes used, or radio transmitters, here is the page with the list of equipment I use.)

Now, those 4 factors that control  our manual flash exposure are:
- power setting on the flash.
(I kept this to 1/2 of full power, so the recycling would be fast enough for everyone at the workshop, even though each Speedlite was powered by a Quantum 2×2 battery.)

- distance to the subject.
(Since the flash was in a softbox held aloft on a monopod by someone else, the other person could help control the exposure by bringing the softbox closer or further away on instruction of the photographer. This is our one variable at this point with which we can control flash exposure independently from ambient light.)

- ISO.

- aperture.

.
But first we had to start with the ambient exposure:

The sky was still fairly bright, therefore 100 ISO made most sense.
The actual ISO could’ve been higher, if I needed more depth of field.
Since ISO affects both ambient and flash exposure, any ISO would’ve been okay as long as we didn’t run out of apertures.

Whenever we shoot a subject in shade against a bright background, we get most efficiency from our flash at max sync speed.  For many cameras this is 1/250th.  Check for your specific camera.

Now an appropriate aperture was chosen to expose correctly for the sky.  Or we could, as in this case, create a dramatic sky by underexposing slightly.  We’ve now established correct ambient exposure.

And then the softbox was held close enough - or far enough - for proper flash exposure. (ie, we controlled the distance between flash and subject.)

For that image, there were two speedlights, each with a softbox, that were triggered simultaneously - and pointing at each model.  But the same thought process holds as in the explanation.

.

.

Now, about the decision to go to maximum sync speed:

As noted in the previous postings, shutter speed controls the ambient light, and has no effect (directly) on flash exposure.

But when you work in bright conditions, the maximum flash sync speed is hugely important.

Think about it this way:
You want more range on your flashgun, since you rarely want to work riiiight up close to your subject. Or at least, not be forced to work right up close.

So you need more distance / range on your flash.  This implies that you need a wider aperture.

Since your ambient light is constant, you have a whole range of shutter speed / aperture combinations to work at.

Let’s look at an example of bright sunlight outside. (Sunny 16 rule)
These are all the same ambient exposure:

1/60 @ f22
1/125 @ f16
1/250 @ f11
1/500 @ f8
1/1000 @ f5.6
etc.

Your flash is going to have a hard time at f22 to dump enough light to match the sun.
It is going to have an easier time at f16 .. but even better at f11.

But then you hit the ceiling at max sync speed … over that, you go into high-speed sync mode, and your flash’s output drops considerably.

So you have a sweet spot at max sync speed.

Therefore, when you work in bright conditions,
you might as well just go to max sync speed immediately, since this is where you will have
- your widest aperture (and hence the most range / distance from your flashgun),
- for the most juice from your flashgun.

This is crucial in understanding how to balance flash with daylight.

It becomes an easy shortcut then:

Bright conditions? yup .. immediately go to max sync speed.
You might as well then go to 100 ISO.
Find your aperture for correct ambient exposure for these other two settings.
Now find your correct (manual) flash exposure.

You’re done.  And it was easy because you immediately went to max flash sync speed.

Simple.

For those of you who have delved in off-camera lighting via Strobist’s website, this will sound very familiar.  These are fundamentals of lighting techniques. You can’t escape them.

12 Comments »

  1. Matt Said,

    April 1, 2008 @ 10:29 am

    Thanks Neil,

    I know you’re a big proponent of the max-sync speed “sweet spot”, but I’m wondering about high speed sync. I know flash output drops considerably in HSS mode, and I’d expect 1/320th to be the worst, but in your experience, does the ability to go to 1/2000 @ f4 on a sunny day compensate a bit for the lowered flash output? I generally like to underexpose the ambient a bit, and I have this illogical fear (or guilt) about shooting at f16 or above with flash. Maybe I just need to get over it?

  2. Neil Said,

    April 1, 2008 @ 5:30 pm

    Matt,

    You do lose more than half your range if you go in to HSS mode.
    For most purposes where we are looking at fill-flash, this isn’t a huge concern.

    But as soon as you need to get a lot of power from your flashgun, then max sync speed is indeed a sweet spot.

    You could in this scenario possibly go to high-speed sync mode, but then you’d have to move your softbox much closer - nearly half the distance. This makes it tougher to work around the softbox and the person holding the light-stick.

    It is just simpler staying with the proven method here.

    Also, you’d only hit f16 if you shoot in bright sunlight, and possibly only then if you were using a camera which has a base ISO of 200.
    (Sunny 16 rule here dictates that you’d be using settings like 1/250th @ f11 @ 100 ISO, when you shoot in bright sunlight.)

    In this example however, the aperture was much wider than that, since we were shooting in the late afternoon, close to sundown.

    And now I just know, you’re going to ask me what aperture I had used … and I will have to tell you … it doesn’t matter. ;)
    HOW we got there is of much greater importance. :)

    Neil vN.

  3. Stephen in NJ Said,

    April 1, 2008 @ 6:29 pm

    Neil,
    You have a bad link in your blog entry. The link that is in the sentence, “Let’s look at this recent image from one of my workshops on flash photography - especially since it is exactly the kind of thing which I teach during the course of the day,” goes to a non-existent page.

    Otherwise, great post as usual.

    –Stephen

  4. Neil Said,

    April 1, 2008 @ 11:37 pm

    Stephen, thank you for the heads-up. I fixed the link now.

    Neil.

  5. Matt Said,

    April 2, 2008 @ 10:51 am

    “It is just simpler staying with the proven method here.”

    Very true. Thanks for the response, Neil. And, I really wasn’t going to ask what aperture you used… honest! :)

    -Matt

  6. Phil Said,

    April 4, 2008 @ 12:03 am

    Neil,

    Your techniques are almost textbook for me, and I have learned so much from reading about how you do things and combined with my practicing of them, i’ve already gotten better results.

    However, I do have a question on one item. Given that you are shooting with flash outdoors, have the max flash sync speed, lowest ISO, would the only expense be to adjust the aperture accordingly to achieve a correct exposure?

    My reason for asking is that when I started shooting outdoors, I noticed that I have to “give-up” the ability for a shallow depth of field to keep from simply overexposing. I needed some flash to keep some shadows off of the model’s face, and, of course, using a smaller aperture the flash is less effective.

    What would be some tips for these particular instances? Am I doing right by keeping ISO 100, shutter maxed at 250, and only changing F stop?

    Thanks!

  7. Neil Said,

    April 4, 2008 @ 12:54 am

    Phil,

    In this kind of scenario where we have bright available light, the only real way of controlling the exposure is via the choice of aperture. So you’re stuck with fairly small apertures in bright light … unless you can go to the option of high-speed-sync.

    Then you can choose wider apertures, and higher shutter speeds.
    And I think this is what you’re looking for, and need to play around with.

    best of luck

    Neil vN.

  8. Robert Said,

    April 5, 2008 @ 4:44 pm

    Bright conditions? yup .. immediately go to max sync speed.
    You might as well then go to 100 ISO.
    Find your aperture for correct ambient exposure for these other two settings.
    Now find your correct (manual) flash exposure.

    Neil,
    You say “Now find your correct (manual) flash exposure”. Can you use TTL in this situation as well?

    Rob

  9. Neil Said,

    April 5, 2008 @ 10:33 pm

    Robert,

    Sure you could use TTL, as long as you remain within the range of what the speedlight is capable of. The main drawback with using wireless TTL in the scenario above, is to keep line-of-sight and make sure the speedlight triggers.

    To that end, a radio slave is just easier. It works. Every time.

    Neil vN.

  10. Romo Said,

    April 6, 2008 @ 12:10 am

    Thanks, Neil! All of these tutorials and ground-up tips are very helpful, considering I just bought a new speedlite and am trying to learn the ins and outs of flash photography.

    There was something that I don’t quite grasp yet (or maybe I do)? I’ve read that the key for balancing ambient light and flash for outdoor shooting is to meter the ambient with the shutter speed and the aperture for the impact of the flash lighting in the final picture. So if this is true, that means when I adjust the shutter speed the flash impact is unaffected, but doesn’t that mean when i adjust the aperture it changes both flash and ambient light?

    Today, for example, I was in a tricky situation that I wasn’t sure of. This is one of the results of my shot:

    http://img509.imageshack.us/img509/9288/img8306mb9.jpg

    Basically, my technical info was as follows:

    60mm
    1/250
    f2.8
    FEC was dialed to about -1
    bounced off of the wall to my right

    The background still seems to be blown out despite me being at 1/250 and 100 ISO, my trouble came with my aperture. Do I change my aperture to meter correctly for the background ambience (as to match my 1/250, which seems to not be enough) and simply use more FEC to get the foreground, since the aperture change will affect the model’s ability to be lit by flash? Do I keep the F stop and go into high sync mode? This just seems like a balance that I have a fundamental misunderstanding about.

    Thanks, Neil!

  11. planet neil - tangents » travelling light in Vegas Said,

    April 24, 2008 @ 11:58 pm

    [...] whole time.  (Anyone who is interested in my specific settings, the thought process is similar to the explanation here.)  I had the Wide-Angle Diffuser over the Q-flash, to spread the light more [...]

  12. gray Said,

    May 6, 2008 @ 2:15 am

    this was informative. so much so that i have to bookmark it and return to read again.

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