How reliable is flash slave mode?

[achee]

Hi!

I recently got a Nissin Di622 (my first speedlight) and I've been been using the flash off-camera in slave mode (wireless optical triggering). However it doesn't always work, so I've been trying to figure out how to get it to work more reliably. I haven't done a lot of testing yet.

What factors affect performance? The sensor is the big red transparent panel on the front, right? I guess that points at the subject... Should I expect it to perform reliably as long as the distances between the speedlight and the camera flash and the subject are all within, say, 10m, and we're not in direct sunlight?

I saw this product:
http://cgi.ebay.com.au/Fotogen-Lite-Trigger-Wireless-Optical-Flash-Hot-Shoe-/120575427361?cmd=ViewItem&pt=AU_Cameras_Photographic_Accessories&hash=item1c12db0321
What does this do that the speedlight doesn't already do? Is it more sensitive?

Thanks! :)

[OzzieTraveller]

G'day achee

The device you link to is similar to those I use as well

http://i35.tinypic.com/107mn8k.jpg
Link to google site = "http://www.thefind.com/search?query=optical+slave+flash+trigger#page=2"

I have a handful of these devices for the various flash guns I use in workshops
Some always operate perfectly, others are a bit temperamental

These devices ONLY work with a flash gun that fires a single-flash ... ie not a TTL flash that gives 2 flashes ... the 1st metering flash & the 2nd main exposure flash
I use them attached to old film-camera flash guns picked up for $25 from sunday markets, and then they are used as slave units for various workshop exercises - where they are triggered by a dSLR flash on 'single-flash-manual' settings

For P&S cameras AND dSLR cameras using pTTL (ie: the double-flash mentioned above) you will need a "digital optical slave trigger". These are hard to find and are about $A100 each ... waste of money compared with a certified digital slave flash gun

There are many of these around, Yongno (spelling?), mecablitz, sunpak, etc that sell from $A60 which have enough flash power for 'average' situations ... if you want a guide number >100/ISO-100, you will have to pay much more

Hope this helps a bit - come back with more Qs as they arise
Regards, Phil

[achee]

Cool, thanks for that. I'll probably look out for another old flash unit as you suggest. When shooting with flash I'm usually in M mode anyway, so the on-camera flash would only fire once.

What functionality do those optical triggers add, since most flash units AFAIK already have optical slave triggering? Do they improve sensitivity / reliability? Have you tried using them at large distances or in bright ambient lighting?

[ricktas]

Cool, thanks for that. I'll probably look out for another old flash unit as you suggest. When shooting with flash I'm usually in M mode anyway, so the on-camera flash would only fire once.

What functionality do those optical triggers add, since most flash units AFAIK already have optical slave triggering? Do they improve sensitivity / reliability? Have you tried using them at large distances or in bright ambient lighting?

These are often radio triggers, rather than infra-red triggers, meaning you can place your flahs heads more creatively, as infra-red needs 'line of sight' to activate.

[maccaroneski]

Another limitation for optical vs radio can be that optical don't work so well in bright light.

I have a set of Cactus V4's (from memory about $60 for a transmitter/receiver set, and then additional receivers at about $30) and I have used them in bright daylight at about 10 metres, but haven't pushed them any further than that.

One tip using optical systems can be to "bounce" the signal - for example point your optical trigger at the subject rather than toward the camera (as the camera will be pointing toward the subject too) or using bounce flash style bouncing off nearby walls, ceilings etc.