Saturday, September 6, 2008

Something about Sony's Alpha WL flash...

All we know that Sony Alpha's WL flash uses the pop-up flash as the commander to trigger one or many Sony flashes off camera. Technically speaking, the pop-up flash communicate with our off camera flash using minute burst so short that we can only see the final burst with our naked eyes. Actually the pop-up flash flashes about 5 times sending information to the off camera flash. Hence, we have our very own off camera strobist style photography.

Our alpha system does not use optical slave flash system, or infra-red communication system, but near infra-red system. Hence, sight of view is needed when ever we wish to trigger the Sony off camera flash.

So, ideally, under WL system, the communicating bursts should not contribute onto the final exposure of our photo. However, this is not true at all. The burst do capture onto our photos if the shutter speed is under the high syn speed of the camera body. The highest scyn speed for Sony A100 is 1/160s, and my current A700 is 1/250s.


Exif attached: 1/60s, F4.0, ISO100

The above picture was capture some while ago. Yes, that is my singlet. One F42 was placed on a flash stand at camera right. This shot was shot at shutter speed of 1/60s. The ambient was not possible to be captured at f/4 and ISO 100 combine with the this shutter speed. Hence, I was expecting my pic would be more strobist one flash style. But I was wrong. With the same setting, I covered my pop up flash with my hand, and I got this pic:

Exif attached: 1/60s, F4.0, ISO100

See the big different between these two photos ? The pop-up burst do contribute to the exposure when on WL mode. However, this does not apply IF the shutter speed is at and more 1/250s.

Why not set the shutter speed to 1/250s then ? I would not have such problem. Yeah, correct, I could just set my shutter speed to 1/250s and problem solved. However, if you read through the flash manual book, the GN of the flash will drop when the shutter speed touches 1/250th and faster. I do not what that to be happened. Hence, I'll tried not to turn my shutter speed to 1/250th, but to 1/160th under room condition to save up my flash power.

So, what should I do? Cover the pop-up flash with an exposed film. This film will cut out the burst, but still allow the communication ray out to get in touch with the flash.


See the flash from the pop-up commander ? It bursts ! I shot this with a mirror. Look at the shadow of the flash on the wall. The flash reflect from the mirror comes from the pop-up flash itself! So, by covering the pop-up with a film, I get this :


The flash from the pop-up had reduced in big amount, but still it could let go the command ray to talk to the flash, and the shadow is gone. This is how the film attached to the pop-up :


Pretty un-secure the film is. I just tie the film with a wire. It is so troublesome to do the tying, hence, with the help from my wife, and some Velcro from the DIY shop in Mid Valley, I made myself the WL-pop-up-film-cover.

Very easy to put on, and very secure on the pop-up flash. It does not falls off, and no light leak as well.





The Velcro is neat and hold the film on place without worrying it will displace. Do I worry about the film will be burned ? Well, so far, I've brought it out for many shots, and the film is as good as it was originally. Of course, cosmetic wise, this Velcro-made-film-pop-up-flash-cover does not look good with my camera, but who cares? As long as I got my photos the way that I figured in my mind, and as long as it doesn't burned, I am happy with it. :D

Learn how to flash off-camera, visit www.strobist.com.

5 comments:

oren | gelap said...

Wat else can I say other than Thamks siffooo...

Templar Tan said...

oren gelap

You welcome. I not sifoo lar. We sama sama belajar lar. :D

albert said...

Wow, the film strip is real neat! Somemore still got the sprockets, looks classy!

Templar Tan said...

Albert
Thanks.
At least I have no worry it from falling down. :D

Ezani said...

Thank Templar, you give me idea how to diffuse the pop-up flash!