Eli ..

You’re correct in how the shutter speed and aperture and ISO settings interlock. But this isn’t quite what is meant by ‘dragging the shutter’.

Flash exposure is not affected by shutter speed (while you remain below max sync speed.) This implies that if you have correct flash exposure (whether manual flash or TTL flash), then you can use pretty much any shutter speed, and your flash exposure will remain the same. Ambient exposure though, will change and at some point become more dominant. Or even add so much to the overall exposure, that you have over-exposure.

Now, with most cameras, when you set it to one of the auto exposure modes, and switch your flash on, the camera will default to a specific shutter speed. (Usually 1/60th or 1/125th, or thereabouts.) Similarly with film cameras, many photographers set the camera to the suggested sync speed (which was also 1/60th or 1/90th or 1/125th or 1/250th, depending on the camera). Which meant that in low-light conditions, the ambient light would be way under. But the overall exposure would be correct because the flash exposure would be corret. However, in this case, the background would be black, and there would be very little trace of the available light to give some of the mood of the place, or some kind of context to the photo.

So the technique then was to ‘drag the shutter’. To use a shutter speed lower than the suggested sync speed, and in this way allow the ambient light to register.

This method was particularly the way how film shooters would do it when they used manual flash. Since the ISO was determined by the film speed used, and the aperture was pre-determined by the manual flash’s output … the easiest way to allow more ambient light in, was to use a slower shutter speed.

Now, what the gist of this article above is all about, is that as digital photographers, we don’t need to be locked into the ‘old school’ way of doing it and only change our shutter speed to bring in more available light when using TTL flash. We can just as easily change our aperture or ISO … and our camera will follow our settings and let the (TTL controlled) flash give more light, or less light as we change our aperture and/or ISO settings.

Neil vN

Aha! I think I finally got it

In the past, the sweet spot for my D200 in a dimly lit hall is ISO 400 - f2.8 - 1/30th. I always “drag the shutter” to catch some ambient light. Now if I need more speed, let’s say @ 1/60th I have to bump my ISO to 800. And if I need more speed 1/125th I have to bump my ISO to 1600. All these three settings should give me approximately the same results without overloading my flash.

I will definitely try this one out. If it works, I’m no longer limited to 1/30th. Thank you, thank you, and thank you!!!

Eli

HI there Raphael …

To work in manual exposure mode, you can use (and probably need to use) your camera’s built-in meter. As much as it is very useful to be able to guess the exposure for the ambient light correctly, it isn’t necessary for that, for you to be able to shoot in manual exposure mode.

I don’t quite agree that working in shutter priority will help you LEARN how this works.

About the second part of your comment - it would appear you’re confusing the basic controls of your camera - shutter speed and aperture.

The flash fires at a much faster speed than 1/500th. (or 1/60th).

The way you’re assuming there that shutter priority will work doesn’t take into account that you / I / most people have no idea how the exposure algorithms work in a camera’s metering system. So your camera might very well default to a specific aperture when it detects a flash when you are in shutter priority mode.

In other words, you’re back to guessing what your camera is doing, and having to ‘fight’ it for control.

Your best option is to shoot in manual exposure mode on your camera and learn from that how to control the light, whether you’re using manual flash or TTL flash.

Neil vN

What you are basically saying is that the flash is going to fire at 1/500th (or is it 1/60th) of a second regardless as to what shutter speed I put on my camera. So when I’m firing my flash at the subject, it will take into account the sync speed of my flash and my aperture (and I guess my ISO), but my camera will still leave my aperture open for a longer time allowing my background to be illuminated more?

Raphael .. not quite.

With flash photography where you use the flash as the main source of light, ie, where you will have correct exposure from the flash regardless of the ambient light … the idea is then to ‘drag the shutter’ so that you allow more ambient light it.

Exposure would still be correct, but you have more of the mood of the scene. You retain more of the sense of place than if you only use flash.

By using shutter priority and forcing a slow shutter speed, you’d get the same effect. But personally I would still prefer controlling every setting.

Re your white balance question … here is how I approach it.

Neil vN

(the term “dragging” not to be taken too literally, of course…)

and let me join everybody else in saying “thank you.” even though i’ve only actually used it once so far, i’m nevertheless quite fond of and impressed with this technique (whatever you want to call it), and i appreciate your helping me to understand it better. that’s a valuable insight, that it’s not all about the shutter. that realization opens up all kinds of interesting possibilities.

I can’t get enough of this website and article. I am a newbee [do they call it?] on wedding photography and yet to cover a full-day wedding photography soon. And I can assure you that I would definitely dare try these techniques there, of course, after practicing it at home and somewhere else first.

I have been reading postings at Photo.net for the past 2 or 3 months now and pretty much everyone would mention your name when it comes to such issues. You are indeed a great asset to photography and photographers, so please keep up the good work! Thank you very very much!

This update just reconfirms to me that I gotta get me that 5D this year

It didn’t really register with me that I can actually maintain higher shutter speeds by keeping my ISO up and controlling the flash output manually. Duh! I know that now ISO 1600 won’t be a limitation on my future shutter-dragging escapades.

Incidentally, what fast wide prime would you recommend for Canon SLR?