Weird China RF triggers

[chanjyj]

The cheapo China RF triggers I have (bought one set and one extra receiver, then not happy with quality control, thus went to change for another brand new receiver) all exhibit WEIRD characters.

BAH. I am going to stick to the higher end ones from now on. Wasted my cash :mad2:

1. It takes 1/40s!* for the signal to be sent from trigger to receiver at 20m** distance! This is weird ain't it? I never knew know that RF signals (433MHz) move so slowly. Or am I missing something here?
   
2. The trigger is useless beyond 15m (Even at 15m missfire occurs roughly 20% of the time). At 20m it is pretty much a touch and go affair.

*(You ask me how I know - well, at 1/60s I fire the camera shutter. I can see the flash fire, but in the final photo the flash is not seen. I.e. shutter closes before the flash fires!)[/B]
**At closer ranges like 5m this is no longer a problem, and I can safely trigger up to 1/200s. But then, at 5m range I might as well use CLS i-TTL right? (Doesn't apply to studio strobes. For Canon E-TTL I am not too sure


Image for your reference. 15m

 

[catchlights]

一分钱，一分货。

 

[chanjyj]

一分钱，一分货。

Distance wise, if the thing cannot work beyond 15m I will still accept it. But...


It takes 1/40s!* for the signal to be sent from trigger to receiver at 20m** distance

what kind of stupid nonsense is this? And is it physically possible anyway?!

 

[catchlights]

is your trigger pass the handphone test??

 

[chanjyj]

is your trigger pass the handphone test??

This one, strangely, pass the test.

 

[chanjyj]

This one, strangely, pass the test.

Forgot to mention though, that they did not pass the test of close proximity. Keep at least 40cm apart.

 

[LittleWolf]

Distance wise, if the thing cannot work beyond 15m I will still accept it. But...


It takes 1/40s!* for the signal to be sent from trigger to receiver at 20m** distance

what kind of stupid nonsense is this? And is it physically possible anyway?!

It doesn't take 1/40 s from transmitter to receiver. It may take the receiver 1/40 s to react to the signal. By evaluating the signal for a relatively long time, the receiver gains immunity against electrical noise and interfering signals.

 

[chanjyj]

It doesn't take 1/40 s from transmitter to receiver. It may take the receiver 1/40 s to react to the signal. By evaluating the signal for a relatively long time, the receiver gains immunity against electrical noise and interfering signals.

What you say would make sense had the flash not fired at speeds of up to 1/200s at 10m. Why the sudden increase in reaction timing at 20m leaves me bemused.

 

[chanjyj]

Thinking back... I did alot of testing (alot means I blinded the whole neighbourhood).

the final part of my testing was at 20m. It may be possible that the 1/40s speed at 20m is due to a low battery. I'll get round to testing it sometime.

Have been thinking of zhnging it and adding an antenna too :think:

 

[chanjyj]

Used a coiled piece of wire (5.5cm, should be ideal for the 433mhz frequency, engineers pls correct me if I am wrong ;p)

Works ok now (I no more energy left to walk to 20m again and test at this time of the night) ;p

Strangely, straight piece of wire is useless, wire wrapped round transmitter also useless... only this shape seems to be able to trigger reciever. Really weird. REALY WEIRD JUJU :dunno:

 

[chanjyj]

 

[Youhong]

You use it to trigger SB-800? :think:

 

[chanjyj]

You use it to trigger SB-800? :think:

800, 600 also. Have not used on strobe yet.

 

[chanjyj]

Disappointed. After adding the extra antenna, (despite theoretical increased range of 30m), range remains the same and the furthur you go, the slower the flash responds. By the time I reach 11m, shutter speed has to be approx 1/60s (which means I cannot overpower the sun) and that is, if the stupid receiver fires the flash at all. (I would say failure rate of 50%).

Any engineer here who can advise me on the antenna? I really at a loss now. According to science, I have already done everything right.

(It is not the transmitter or receiver problem. I have already went to change for a new set. Problems are identical)

 

[longkangman]

search the strobist think there is a mod for it. I did it too does improve the signal but I switch to something which is never fail and longer distance. :dunno:

 

[chanjyj]

search the strobist think there is a mod for it. I did it too does improve the signal but I switch to something which is never fail and longer distance. :dunno:

I saw those mods. I use them as a basis for my own mod but realised that their antennas all don't work with mine although we all using the same chipboard.

I had to make a curly shape for the darn thing to work (and must circle around 2 times somemore).

 

[longkangman]

mine does improved a lot, but I switch another america brand but make in PRC. :dunno:

 

[chanjyj]

mine does improved a lot, but I switch another america brand but make in PRC. :dunno:

=.= Why my receiver like so suay one.

What is the shape of your antenna?

 

[longkangman]

=.= Why my receiver like so suay one.

What is the shape of your antenna?

I just let it come out of the casing, you can have mine to test it. After the mod wow it is shoik but still can't beat the real one. :dunno:

 

[chanjyj]

I just let it come out of the casing, you can have mine to test it. After the mod wow it is shoik but still can't beat the real one. :dunno:

I just modded another one. Fed up. This time I just took one antenna and stick on the stupid transmitter. (when I shoot I extend the transmitter antenna up by 3 times).

Look like some stupid alien :angry:

Your real one is what? Pocket Wizard, Bowens or Elinchrom?