Slow Sync

[ksmattfish]

One of the things that I think makes photos look snapshotty is harsh, frontal lighting. Basically the kind of lighting that you get if you use the on camera flash of any point-n-shoot or SLR on auto exposure. It's like we are all wandering around in a world where everyone is lit by the miners' helmet of the viewer.

Slow sync is combining flash with a slow shutter speed in order to pick up a little of the ambient light in the area.

SLRs have a focal plane shutter, and therefore have a "flash sync speed". This is the fastest shutter speed that can be used with the flash. For most entry level SLRs it's between 1/60th and 1/125th sec, depending on the model. If you use a faster shutter speed than the sync speed you will find that portions of you pic did not get flashed. On the other hand, it's okay to set a slower shutter speed. The slower the shutter speed, the more ambient light will be evident on the photo. The flash tends to "lock" the image onto the film fairly sharply, but you still need to hold the camera still or use a tripod to avoid too much camera shake.

Point-n-shoots usually have a "night mode" or something with a little star or moon. On my wife's camera it is designated by the flash symbol with an "S" next to it. Watch out when using point-n-shoots, you'll have no control over how long the shutter stays open, and on some models it can be up to four seconds after the flash goes off, so hold very still until you are sure the camera is done exposing.

Here's some pics from a wedding reception. I was using my Pentax ZX-5 with an 50mm f/1.7 lens and a Pentax dedicated flash. The film was Kodak Gold 200. For all the shots the aperture is set at f/2, and the flash is auto TTL (I'm almost positive it was firing at full blast anyway).

This is the first shot at shutter speed 1/100th, which is the ZX-5s flash sync speed.

Besides being too darn far away for the power of the flash (I was up in a balcony), the lighting in this picture is boring and sucks. What a lame reception!


Here's the same shot at shutter speed 1/15th.

Much better. Now these people are having a good time!


A few more from the same reception.

Obviously the dance floor lights add a lot of color, but even regualr household lighting provides nice background warmth when used with slow sync.

 

[wwjoeld]

those look pretty cool, but do the people who you shot those for like those?

 

[ksmattfish]

The people I shot these for loved them. But they were definately open-minded creative types.

Sometimes I do run into folks who think that the slow sync pics are a little crazy, but after they look at them a few times they usually end up liking them. I always take "normal" flash pics too, so that they have both.

Using slow sync flash with subjects that are closer usually produces a more normal looking photo without so much blur.

Anyway, my portfolio that I show when getting hired demonstrates that I don't always take straight forward photography. I assume that if they don't like a photographer who experiments then they won't hire me.

 

[Jeff Canes]

Then did the flash fire in the exposure? I ask this because I saw on some photo show. Something similar I think called a slow or late firing flash. The flash fire at the end of the exposure, this caused the background to be burred but the motion stopped and sharp.

Just Curious

 

[ksmattfish]

Then did the flash fire in the exposure? I ask this because I saw on some photo show. Something similar I think called a slow or late firing flash. The flash fire at the end of the exposure, this caused the background to be burred but the motion stopped and sharp.

Just Curious

Yes. The flash fires usually (with closer subjects than in my examples) capturing the subject sharply, while the slow shutter speed keeps exposing available light.

Most of the time the flash will fire at the beginning of the exposure, but some flashes allow "rear curtain sync". This fires the flash at the end of the exposure.

Think of a car with it's lights on driving by at night. If the flash fires, and then the exposure continues you will get a photo of a car, and the lights will seem to be shooting out from the front of the car. With rear curtain sync you would get the car with the lights trailing along behind.