Saturday, April 16, 2011

Flash 101 with LP 160

test shot with lp 160:can't say I know how to use it yet. at least the flash provided illumination in this windowless bathroom.  f/6.3, iso 160, 1/160, my subject was very enthusiastic about posing.

I got an off camera flash about a week ago. Holy cow, I didn't realize flash photography is a whole new animal. The flash I got is the Lumo Pro 160 recommended by the Storbist blog. For those who aren't familiar, Stobist is an online community devoted to learning lighting with small off camera flashes. I got this flash because it was much cheaper than Canon and because it was recommended by the Strobist himself. I got my unit assembled yesterday per instructions on the Stobist blog and not surprisingly ran into some obstacles.  To start, I didn't realize that the LP 160 is a manual flash that works somewhat differently from the high-end flashes made by Canon or Nikon. I'm writing out these hiccups for myself and for others who are having similar confusions.

Obstacle 1: Jargons.
While reading my manuals and books, I kept encountering words like slave, ttl, first and second curtain. It began to drive me crazy so I'm outlining short definitions here. Note that I am no flash expert and these are my own definitions in my own words so that I could grasp the idea easily. Probably not worth quoting if you are writing a paper or some other publication.

Flash is also called a Speedlite and also called a strobe.

What is a slave flash?
A slave flash is a external flash unit that is dependent on a master flash unit. Usually, the master flash unit is the camera's built in flash.  The master and slave flash unit communicate information through sensors. There are several different ways (and tools to use) for sensors to communicate, but I won't get into that because that information is pretty easy to find.

What is a TTL system?
TTL is for Through The Lens flash technology and it is a method that enables the camera to automatically calculate exposure when using flash. It was developed by Nikon in the '80s.
I found a really good explanation of this system here:

and here

What is 2nd Curtain Sync:
(still investigating)

Obstacle 2: Lumo Pro 160 is manual flash.
I didn't realize this at the moment of purchasing. I'm not 100% sure what this means, but I do know that LP 160 does not have a TTL system.  So now my question is how to measure exposure when using this flash.  This article had some solutions 
I posted a question about this issue on a flickr discussion board and it looks like I just adjust exposure by shooting and adjusting and winging.
Here's the flickr thread, people wrote some good advice: