Recommendation: Field flashes

Hi all,

 

I'm running a project to do photogrammetry of tropical tree branches. This involves field work in tropical forests sometimes far from power. Hence, I'll need to run off motorcycle or small car batteries. I'll either have the branches in front of a green screen or inside a large (2m cube) photo box, mounted on an automated turntable. The flashes are necessary to speed up the process (long exposure times slow things down when I need to snap 300 pics of a branch). I'll need the flashes on their own stands with softboxes (the latter at least when the photobox isn't being used), and to be able to be trigged by a Nikon D810.

 

Wondering if folks here might be kind enough to offer some recommendations? Something under $1k would be ideal. Hope the above info is enough to go on.

 

Thanks very much!

 

Allie

If you use a shoe flash, you need to be very careful on rapid sequential shots with a shoe flash.

A shoe flash is a plastic box, and the heat generated inside the box will not dissipate very fast. Plastic is a heat insulator, so will trap the heat inside.

Too much heat will lead to thermal failure or melting of the flash.

 

A monolight that can be cranked DOWN in power (to reduce heat) and that can run off 12vdc or an inverter sounds like what you need.

I'm a pack guy so the monolight guys would have to step in here.

Sunpak 622 Super Pro has alot of power and runs on C size batteries. Power can be reduced by shooting in auto (non-dedicated, non-TTL) or manual modes. It can be triggered by a pair of PocketWizards (or other radio triggers), one on the D810 and one connected to the 622 using a cable available from PocketWizard.

That's great - thanks Wilmarco. Sounds like there are some ways to wire it to an external battery, though not super straightforward (https://www.photo.net/discuss/threads/diy-power-supply-for-sunpak-622.458333/)? Do you think it will have the heating issue that Gary raised? I may (try to) trigger them every few seconds for up to 60-100 photos at a time...

also, wondering if a yonguo trigger setup or similar might work? those pocketwizards seem pretty pricey...

The 622 or 610 will work fine, you just have to rig up an appropriate power supply.

The 610 and 622 are 6vdc.

 

Yes the 610/622 have the same heat issue, as the voltage step up circuit is inside the unit.

For 60-100 shots about 10 seconds apart, you better put the power down at least 1/4.

I would probably use the metal 610 for this, and even better TWO 610s and swap them for each set of pictures.

Looks like the Yongnuo 622 tranceiver set can handle the communication.

 

From the Yongnuo literature, looks like one trigger would mount to the D810 shoe. The slave unit would mount any way you like (velcro, tape, etc.) to a light stand. You would need a threaded PC to household cable to drive the Sunpak 622. You would need to search for the cable, something like this: http://www.paramountcords.com/product/5-1s-household-to-nikon-screwlock-1-ft-straight/

 

I don't know if the "Nikon screw lock PC" fits the Yongnuo trigger unit. I know nothing about Yongnuo equipment other than by reading what is available online.

 

I use the above configuration, with the exception of using PocketWizard triggers and analog cameras.

If you just want 'dumb' triggering (no TTL or remote power setting) then YongNuo's RF-602 or 603 transceivers will do the job. They can also be used as camera triggers via an adapter cable, and cost a fraction of the PW equivalent.

 

Been using my 603s for a couple of years with complete reliability and robustness. They take common AAA cells for power.

 

The issue with speedlights overheating is mainly when they're used on full power for over a dozen pops in succession. I'm ashamed to say that I'm guilty of (accidentally) overriding the thermal protection on one speedlight, with the result that the plastic fresnel lens softened and distorted! Apart from that it suffered no other damage. Still, it's not what you want to happen miles from anywhere.

 

Basically, the bigger the flash-head, the less problem you'll have with overheating. I would think a Sunpak 622 on 1/4 power should be immune to overheat issues. However, they don't look very well sealed against humidity and rain. I'd be quite wary of using any flash in rain-forest conditions without tropicalising it first. This might involve silicone sealing any joints in the casing and adding seals to battery compartments, etc.

 

PS.

"I don't know if the "Nikon screwlock PC" fits the Yongnuo trigger unit."

- Yes, it does. The screwlock isn't unique to Nikon BTW. It appears to be an industry standard thread.

Edited April 16, 2018 by rodeo_joe|1