Benefits of RADIO modules?

EdinburghGary

EdinburghGary

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Gary
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Guys,

I have my lights with me, 3 x Gemini Pro R 1000 watt. I also have TWO pocket wizards (which I have been told is enough to fire all lights if I use "photocell" mode)...

Now, whilst I am currently struggling to get my head round how only ONE pocketwizard receiver can trigger my three flash heads, I am looking forward to testing...

Also wondering if there is any advantage to ALL flashheads being triggered by Pocket Wizards (modules are only £100 for my lights)....

In short...

3 lights. Pocket Wizard and Photocell triggering vs Full Pocket Wizard setup...

Anyone? :D

Gary.
 
Camera PW triggers PW on main light - the flash burst triggers the other two - all in sync - you only need the two PWs. :) No advantage in more PWs in a small studio situation.
 
Only reason would be if there were other lights in the area- or other togs, as using the method AWP mentions- his/her lights would trigger yours.
 
The light detects other light being fired, and fires itself- no idea about exactly when- but definitely within your flash sync time.
 
They detect it at the flash, cos the light is moving at the speed of, well, light, you don't notice that they are marginally slower, and we are talking marginally.
 
The only time I have had trouble with an optical slave not firing is when it's been washed out by the modelling light from another unit very close nearby. Very rare, and easily fixed, but it can happen. You might get the same thing in a domestic envirionment and there was a shaft of sunlight or something shining directly on the slave. The other advantage of radio is of course range, but I've never had a problem with that indoors.

Optical slaves are effectively instantaneous, it's the Pocket Wizards that are the slow-coaches but they are also extremely fast. I can use full x-sync speed with mine whereas with the RF-602 I have to slow from 1/250sec to 1/200sec, or 1/160sec to maybe allow for non-fresh batteries. The cheap ebay radio triggers seem to need at least 1/125sec.

Hundreds of pounds worth of Pocket Wizards seem to me to be a bit of a waste in a (normal) studio environment. Just stick a £30 IR trigger in the hot-shoe and it's sorted. Not long ago I somehow used to manage with just the free sync lead plugged into the camera :eek: :D
 
Why do you think Pocket Wizards are slow coaches? They use radio waves - optical triggers use light - both members of the electro-magnetic spectrum and both travelling at 186,000 miles per second! A dead heat I'd say! :)
 
awp said:
Why do you think Pocket Wizards are slow coaches? They use radio waves - optical triggers use light - both members of the electro-magnetic spectrum and both travelling at 186,000 miles per second! A dead heat I'd say! :)
Click to expand...

I used to think the same, but in practise it is not. Radio waves might move fast, but the signal processors that switch them do not.

As I say, I have never had a problem with Pocket Wizards and I believe the high cost of them is at least partly attributable to their more sophisticated design and expensive components.

The truth of the matter is evident if you try a set of cheaper radio triggers. As I said, my 40D with RF-602s will not quite sync at the normal 1/250sec (just visible shadowing) but is clear perfectly at 1/200sec. However, many people say go much slower still to be safe with the really cheap jobbies like 1/125sec and the evidence is also that low batteries can make even this marginal (I haven't got any duff batteries to try).

As an aside, the new E-TTL Pocket Wizards can even exceed the normal sync operating speed and increase it by almost a stop in some cases, eg 1/250sec raised to 1/400sec, but that's actually a bit of a cheat in that they pick up the firing signal early via E-TTL contacts (not the regular sync port) and time its release according to custom settings for each camera model. They do this by exploiting the duration tolerance in time window that the shutter is actually fully open for and fire the flash the very instant the frame is fully clear, which gains that extra fraction of a second. I imagine that the timing is then so tight that they run the danger of clipping the flash if the pulse of light has a longer flash duration as some studio units do. Come to think of it, my Canon 580EX is quite a lengthy 1/833sec duration at full power but I don't have access to the new PWs to see what effect this has.
 
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