Quite possibly the strangest lighting mystery ever

[patrick_f]

<p>Hello everyone, once again I am back to attempt to find a solution. The last time I posted, it was this question:<br>

http://www.photo.net/photography-lighting-equipment-techniques-forum/00XndN<br>

I was stumped about the lights, and what was going wrong with them. This week I discovered what is really happening. I will give you a nickel (to any of you!) who can shed some light on quite possibly the strangest thing I have experienced to date. In my previous post, I had stated that the lights sometimes would not fire, regardless. Here is what I have finally discovered - The lights, when in sunlight, will not fire (the two EL500c's purchased as a kit in 1998). Basically they work fine all the time in darker areas. But what I discovered this week is that if they are out in a bright area (outside, middle day) they will not fire at all - even if I hit the test button, the pocket wizard, or with a direct sync cable. If the light is out in the sun, it will not fire - period! Not the slave, or a slaved light. I mean that both lights, if in bright light will not fire whatsoever when the test button his hit, or for any other reason. If I take a black cloth, and place it over the entire light they work fine. PLEASE someone explain that one....<br>

Thanks in advance!</p>

[lornesunley]

<p>Well I have to say that I have never heard of a strobe that was smart enough to know when it was too bright out for the strobe to be useful for lighting the subject :-)</p>

[mark_loofburrow]

<p>So with the entire light covered it will fire..... how about different parts of the light? Or it will only work if you cover the entire thing?<br>

My EWAG is that if you cover the photo sensor it will fire with the test button/PC port.</p>

[patrick_f]

<p>Lorne, <br>

love your witty reply, but the subjects (BMW Cars) were in the shade. When I put the light out where direct sunlight was hitting the strobe, it would not fire. If I moved it back in the cove, or covered it with a black cloth it fired every time. Maybe Elinchrom is that smart though, to design such a strobe ;)</p>

 

[mark_sirota1]

<p>The EL-500C has a built-in infrared slave on the back, right? I would bet that if you cover it with a piece of gaffer's tape, it will fire. (There's a switch for it too, ensure that the slave is disabled. I think it has to be in the recessed position to disable the slave, but that's from memory so check the manual to be sure.)</p>

[leighb]

<p>It's probably the thermal safety circuit. This disables the strobe if the internal temperature is too high.</p>

<p>When you shade it the internal temperature drops and it works normally.</p>

<p>To test the theory, put it out in the sun for a while, then let a large fan blow on it for a few minutes and see if it works.</p>

<p>- Leigh</p>

[patrick_f]

<p>Thank all of you for your replies. Leigh, your suggestion sounds most likely but I have not yet tested it. Still, it has only recently started happening, so do you think that it might be something going bad?</p>

 

[leighb]

<p>Hi Patrick,</p>

<p>Quite probably the electrolytic capacitors have developed excessive internal leakage.</p>

<p>All capacitors have some leakage, but usually not enough to cause a problem. It increases with age and temperature.</p>

<p>Leaky capacitors can explode if left to their own devices. This is a common problem in all electronic products. It has nothing to do with photography.</p>

<p>The strobes should probably be checked by a repair shop that specializes in such equipment.</p>

<p>- Leigh</p>

[patrick_f]

<p>Thank all of you for your replies. Leigh, your suggestion sounds most likely but I have not yet tested it. Still, it has only recently started happening, so do you think that it might be something going bad?</p>

 

[ellis_vener_photography]

I've owned Elinchrom EL1000 monolights -quite similar to your lights just more powerful. You need to cover the slave

eye. They also required very regular repairs. I replaced them with older Balcar Monobloc II and III monolights which

were more recently replaced with Paul C Buff Einstein 640 monolights.

[joseph_wisniewski]

<p>Mark and Ellis are correct. It has nothing to do with temperature. The Elinchrom slave eye is notoriously vulnerable to both high intensity light (direct sunlight) and modulated light (fluorescent or other gas discharge light, pulsing 120 times a second).</p>

<p>That is why they failed on you in the four places you mentioned in the December thread (Food manufacturing plant, Baseball Stadium (pro team), Jet Aircraft FBO Hanger, and a manufacturing plant).</p>

<p>My Elinchrom experience is similar to Ellis's, We had a flock of maybe 8 Elinchrom style S and RX back at MPW, and those things were constantly rotating into repair. And MPW is "low utilization".</p>

[patrick_f]

<p>Thank you everyone for your insightful responses! The strangest thing to me is that it is only doing it with two of the lights (el 500c's). My older EL 500's seem to work fine. I orginally purchased the two lights in 1998, and they have been used professionally for the last 6 years or so. Thing is, this only started to happen about a year ago and it does not happen with the other two lights, or the EL 250. And the strangest thing is why when I hit the square green test button they will NOT fire, at all. Even if it is a slave issue, I do not understand why the test button would not fire. After years of photo assisting, and encountering hundreds of different systems I have never seen that happen. Ever, with any brand!! I am wondering if it is something more than the slave, because after all, it should still fire if I hit the test button, right? As for the comments on the constant repairs...I am going to knock on wood here - I have been pretty lucky I guess. Although two need to be repaired for the adjustment knob (the bottom, where you put it on the stand) they have held up very well and have never needed repair. If I do, does anyone have any suggestions? I was told flash clinic in NY is good.....<br>

Thanks everyone, I appreciate your help.</p>

[mark_loofburrow]

<p>It can't trigger while its already being triggered.<br>

To test get a bright light and shine it at the photo cell. Try the test button and PC jack/port. Turn off the unit, hold the test button down and power the unit on and while holding the button down attempt to trigger the light with the PC port or photo detector.<br>

A "flash" is a off-ON-off condition. OFF = trigger UNasserted (low), ON = trigger Asserted(high). If when you power on the flash the trigger is "stuck" asserted(high), it may still light the Green ready light (showing the caps are charged) but without a low-to-high signal, it won't trigger.</p>