Mike Adams Loc: Connecticut

Members

I am using a YONGNUO YN685 N GN60 2.4G on my Nikon 7100 and would like the flash to deliver a series of 0.25 sec flashes. On the flash unit I have it set to show MULTI 4 1Hz 1/4Sec duration. If I read this right it should deliver four 0.25 sec flashes, 1 second apart. In fact it delivers a very short, single, flash. If anyone is familiar with this flash, I would really appreciate help with getting the settings to provide what I need.

Many thanks

PixelStan77 Loc: Vermont/Chicago

Mike, The issue I believe is recycle time of three seconds at full power is the spec of the unit

BebuLamar

It's very difficult (and because of that I think the flash can't do) to produce 0.25 sec duration pulse.

Mike Adams Loc: Connecticut

I guess I misunderstood what the 1Hz setting means: I took it to be that it would fire at 1 second intervals. As is common with flash manuals, they are not always easy to interpret.

rwilson1942 Loc: Houston, TX

Not sure, but I think the 1/4 sec duration means that the it will do the requested flashes FOR 1/4 of a second.
Except when using 'High Speed Sync' you will not get a flash duration longer than the duration of a full power flash.
That is 1/200 of a second for that flash according to the specs.

BebuLamar

Many flashes can do 1Hz or 1 second interval multiple flashes but not with 0.25 sec duration. Not too many flashes can do 0.25 duration and those that do it's at maximum power and thus there is no way to do it at 1Hz.

BebuLamar

I must correct my own mistake. When I said 0.25 sec I was thinking of 1/250 sec which is really 0.004 sec. So there is no flash that can do 0.25 sec duration.

Thomas902 Loc: Washington DC

A colleague of mine recently ask me why I bought a Nikon speed-light since knockoff clones were so much cheaper. Well guess what... The documentation you get with a YONGNUO flash isn't stellar (I'm being politically correct here). I have links to excellent YouTube videos for the SB910 plus a 2 hour 34 minutes DVD (SKU #11484) put out by The Nikon School and Joe McNally that covers the SB910. There are many other YouTube Videos by Joe McNally on the Stroboscopic (Repeating Flash) Effect. Blue Crane Digital also has and excellent DVD on the SB-910

Mike Adams you might consider a Nikon SB910 which can easily accomplish this task...
See pages C-18; 19; 20; and 21 in the User Manual

Here's the link to the Manual: https://cdn-10.nikon-cdn.com/pdf/manuals/Speedlights/SB-910_EN.pdf
Fantastic Unit: It's paid for itself many times over shooting events...

All the best on your journey Mike Adams

E.L.. Shapiro Loc: Ottawa, Ontario Canada

What are you shooting and what result are you trying y to acheive? You may need a flash unit whit High Speed Synchronization capabilities. You may require an actual stroboscopic light source with variable frequencies.

GregWCIL Loc: Illinois

Mike, a 1/4 second flash would be veey very long. I believe you are confusing seconds with percent flash power. Flashes can be set to full power, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64 or 1/128th of full power. They do decrease the power of the flash by reducing the length of time, but it is way less than 1 second.
Watch some YouTube vids on manual flash setting. You will usually be better off using the auto ttl feature.
It wont trigger at intervals, o nly in sync with your shutter. You might get two or three flashes only if it is using much less than full power. Most flashes take from one to several seconds to recharge.

Dikdik Loc: Winnipeg, Canada

A 1/4 second flash duration seems a tad long since most flash durations are in the millisecond range.

Dik

Mike Adams Loc: Connecticut

Good point.
I shoot virtually 100% macro, using continuous LED lighting, and with no experience using flash (hence my ignorance and misinterpretation of the manual).
I am starting to work with UV fluorescence macro. The standard UV lights have two drawbacks: they have a limited UV range and all bleed heavily into the visible spectrum. So, I have bought a cheap flash, removed the filters that block UV and inserted UV bandpass filters, so now only wavelengths below 400 nm are emitted. The downside is that the final UV light flux is quite low, so the total fluorescence is also low. My hope was to force multiple, longer, flashes on every shutter release so increase the output.
Another option was to leave the shutter open and manually fire the flash: the problem with that is that the system has to be light-tight, since any extraneous light overpowers the fluorescence and so reaching in destroys the shot. My third choice is to set up for multiple exposures and merging them, and hope nothing moves!
Thanks for the input: I will keep working on it.

ecurb1105

If you can encase your set in a light tight box, a simple tome exposure and multiple flash pops using a switch extended out of the enclosure should do the job. Perhaps with the camera teathered to a computer.