[StarDust]

I noticed something yesterday that made me worry a bit about my V4's. The weather is turning for the worse, rain and cold, and when I went for a walk and did a quick setup with the flash on my tripod for a portrait photo I couldn't get the trigger to work any fast that 1/15 s shutter speed (it wasn't raining just then).

When I came home I tried switching the batteries on one of my two receivers (I tried both outdoors) but it didn't help.
That made me a bit uneasy and upset, hoping that it might be a discharged battery in the transmitter, but it wouldn't make any sense since the receivers are supposed to take 10 000 shots and the transmitter 20 000 (I think it said in the manual) and these are brand new.

After an hour or two I was going to show the problem to someone else and you know what always happens when you want to show something to someone else. In this case I'm pretty glad I failed in proving my misfortune but I'm worried it might happen again.
Is this because of the high humidity? In that case, would transporting the triggers in a zip-loc help?
Or is it an entirely different problem?

[vizjerei]

what are your flash? I did get it sometime with my 540FGZ, but with other flash like AF280T it doesn't happen.

I can't explain why, but after I pull out the wide angle thing in 540 then put it back, the flash can go back to 1/180.. Either the battery in the flash is not as full as I think it is or it just take time to charge the flash up.. I have no idea.. but then i was testing it at 1/64 power...

[StarDust]

It's the 360. I tried different power setting because first I thought I didn't crank it up enough but when I had it at full power 15 cm away from the "object" I started doubting that the flashes power was the problem. When I had the flash on camera it worked like a charm so I don't think it's the flash.

[Class A]

... I couldn't get the trigger to work any fast that 1/15 s shutter speed (it wasn't raining just then).

Did you see the receiver LED light up?
Just wondering if it is a problem with the camera triggering the sender or a sender / receiver communication problem or a receiver problem.
Or did the flash fire but not in time for the shot?

Were the flash batteries low?

Some older receivers (V1?, CT-301) had trouble with the relatively low trigger voltage of Pentax flashes and but the V4 should be trouble free in that regard.

Never had a problem with my V4's and two (non-Pentax) flashes.

[StarDust]

The Cactus transmitter and (two) receivers are of the V4 version. They did fire (always), I saw it with my own eyes, and I took several shots with my camera with different shutter speeds to confirm that. That's why I could deduce that they did not transmit at a faster shutter speed than 1/15 s.

It's been a month since this thread was active and it's nice that's it's of interest. I've made a couple of tests since then but I cannot deduce whether it's the cold or the humidity that is causing it (or both). A couple of days ago I used them for a university paper (Techna if someone might be interested). I carried one receiver and the transmitter in a plastic bag in a pocket, so I would know that it would not be affected by humidity or cold, and used them outdoors with no problem at all.
After some previous similar experiences before this particular test I can assure you that the V4's are affected by either cold or humidity.

However, considering the price, carrying them in a plastic bag close to your body to achieve maximum performance is a small price to pay (no pun intended).

Oh yeah, and the batteries for the flash were properly charged. The batteries in the V4 are practically new. The pretty much always fire without any problems indoors.

[Class A]

They did fire (always), I saw it with my own eyes, and I took several shots with my camera with different shutter speeds to confirm that. That's why I could deduce that they did not transmit at a faster shutter speed than 1/15 s.

What do you mean by they always fired?

Did the receiver red confirmation light always come on and the flash didn't fire or did the flash fire but not in sync with the camera?

[StarDust]

When the V4's did not work properly, the flash fired but it was not in sync with the camera.
The reciever blinked red and it seemed instantaneous but my untrained eye can't tell the difference between 1/15 s and 1/500 s so well. My camera can though and I timed it, ergo the 1/15 shutter speed I'm talking about.

[Class A]

When the V4's did not work properly, the flash fired but it was not in sync with the camera.

Ah, thanks for clarifying.
A bit odd that temperature / humidity could cause this but from your description it seems to be the case.

I hope this won't ever happen to you, but if it does you could try to take a picture of the red confirmation light just to check whether that is in sync or not.

[marnold]

Hi. I have exactly the same problem.
I have 2 receivers, each on a 360 and my transmitter on a K20D. Sometimes they sync at 1/180, but quite often I need to go to 1/15.
If I test fire the flashes from the transmitter, I can sometimes hear the flashes popping at slightly different times.

I took a picture of the receivers and the red light is on at all speeds up to 1/180, but the flashes only fire at 1/15 or slower. It doesn't matter which receiver is attached to each flash.

[Class A]

I took a picture of the receivers and the red light is on at all speeds up to 1/180, but the flashes only fire at 1/15 or slower.

That sounds like the old problem of the trigger voltage of a Pentax flash being too low. But that shouldn't occur with V4 receivers. Do you use V4 receivers? Have you tried replacing the batteries?

[KOFT]

Hi. I have exactly the same problem.
I have 2 receivers, each on a 360 and my transmitter on a K20D. Sometimes they sync at 1/180, but quite often I need to go to 1/15.
If I test fire the flashes from the transmitter, I can sometimes hear the flashes popping at slightly different times.

I took a picture of the receivers and the red light is on at all speeds up to 1/180, but the flashes only fire at 1/15 or slower. It doesn't matter which receiver is attached to each flash.

I saw this thread before I decided to jump on the V4s as well. I received my triggers about two weeks ago and I have the exact same problem, I was hoping the OP had received a lemon. It sounds like alot of people are having this problem, maybe we should start a poll and see how many people really have it versus how many people are doing fine with them.

For me it seems that the triggers and receivers are very temperature sensitive. The manual claims a 14 degree F to 114 (IIRC) working range. This is incorrect. I bought one transmitter with 2 spare receivers (3 total), all the receivers and the transmitter need to be approximately 65 degrees F before they will function correctly (as in let me sync faster than 1/15). My guess that the "working temperature" they quote in the manual is the lowest working temperature and highest working temperature of the individual components they used in manufacturing the set. However, putting the components together created systematic temperature tolerance errors that severely limit the operating temperature range. My second guess is that since the company is based in Hong Kong (where its about 70 right now in the winter) they didn't see these errors in their testing--they probably didn't do a full clinical test with the units and just called them good.

Sending them back is a huge pain ($$$ plus time for what would amount to be a <$100 refund) and I don't know if any of their other units would perform better, so as of now I'm thinking about investing in Cybersyncs. In the meantime I am carrying around the V4s in my pockets...

[the swede]

So...They dont like cold temperatures?

[StarDust]

That's correct. I can't rule out humidity, but the cold will make them trigger slower.
I've also been carrying them around in my pocket so I can use them in the cold but they are a bit big for that and I'm trying to figure out a way to keep them warm in my camera bag.
If someone starts a poll, link it in the thread please.

the_swede: Good luck getting them to work on New Years Eve, here in Uppsala it's going to be -30 C so I'm bailing out of the country

[vizjerei]

Hi. I have exactly the same problem.
I have 2 receivers, each on a 360 and my transmitter on a K20D. Sometimes they sync at 1/180, but quite often I need to go to 1/15.
If I test fire the flashes from the transmitter, I can sometimes hear the flashes popping at slightly different times.

I took a picture of the receivers and the red light is on at all speeds up to 1/180, but the flashes only fire at 1/15 or slower. It doesn't matter which receiver is attached to each flash.

That's what happen to my 540. but with AF280T and AF200T they are all fine and sync at 1/180 every time. I don't think it is temperature issue, as it happens in my house.

[StarDust]

I assure you that they are temperature sensitive. They always work accordingly when not cooled down (or not at all i.e. misfire) but when under a certain temperature, about 8 degrees Celsius they go down to 1/15 s.