Paul C. Buff, Inc. Technical Forum

Dear PCB Technical team and forum readers,

I am very excited to be a new member of the PCB forum and brand. I just bought, Dec 2013, 3 Einsteins with their respective CyberSync Transceivers and a Cyber Commander.

My problem/issue?
I have been trying to shoot with my Canon 5D Mk III a portrait and a few water shots that require my camera and 85mm 1.2f lens to be set at f2.8 and 1/1000 of a sec with ISO 100. I need high bokeh as well as high stop motion.

Observations: What do I get:
The black frame of frustration! Yes, that famous blurred black line, that in my case covers the entire frame.

Questions: Why? Is there a fix? Is it possible with the current setup?
I realize that my camera has a sync limit of 1/200sec, but I also know that my Speedlites can handle HSS. I bought, maybe mistakenly, the Einstein(s) with the Cyber Commander thinking that I would be able to transmit or use High-speed Synch with my Canon 5D, but I am wondering if that is not possible at all. Is it? Can I make the Cyber Commander, Einstein(s) and 5D Mk III play together and allowed me to shoot at HSS, settings, configurations?

Please, if anyone know of how to solve, fix, hack this issue. I'll appreciate your help.

Thank you very much,

Ludvik

Ludvik,

Above your post you will find a thread that describes the limitation of high speed sync and studio strobes. Assuming that you understand that at f/1.2 with an 85 mm lens, your depth of field (the area in focus) will be very shallow and leave your water drops difficult to focus upon, try this:
Set your 5DMIII to a shutter speed of 1 second and your Einstein to 1/32 power and use the spike of light to freeze the scene. You might have to increase the Einstein to 1/16 power and the shutter speed to 1.5 sec., and you might have to reduce ambient light that washes the scene, but you'll get the idea.

Ken Richmond

No, the Einstein is not HSS capable regardless of remotes used. CyberSync (incl. Cyber Commander) is not HSS capable. In fact, no studio strobe is HSS compatible to my knowlege.

Cyber Commander™ offers 16 light channels and 16 user-selectable frequencies within the 2.4GHz band for complete freedom from interference or misfiring and from other photographers with radio systems. Extreme signal integrity is assured via 256 bit state-of-the-art encoding, and its extremely low delay of 1/4000 second allows sync speeds as short as 1/2500 second on compatible cameras.It will not, however, support High Speed Sync (HSS/FP).-Cyber Commander features tab

Even still, HSS would not be the best choice in this case, as you would still be susceptible to what ever blur may happen at 1/1000s. HSS is also very power inefficient in that it uses a lower power intensity, spread over a longer period of time. So you use all of your energy, and get maybe 1/8 of the exposure (this will vary based on several parameters). This then will reduce your recycle times.

On the other hand, in studio and at normal studio settings (ISO 50, 1/200s, and even relatively wide apertures), you will get a dark frame without the studio lights firing. This means if you add the studio lights, they will be the only source of light.

When Einstein is dialed down to -1f in color mode, the flash duration is 1/1300s in color mode, or 1/2000 in action mode. This is t.1 times, and will closely resemble action stopping similar to shutter speeds of the same duration. As you dial power down, flash durations get shorter, and action freezing gets better, and you get more efficient energy consumption.

At minimum power in action mode, flash durations are shorter than 1/13,000s, or faster than most any DSLR can actuate its shutter. However, in action mode at this low of power, you will have a significant color shift to blue than would need correcting in post. Minimum constant color will get you to about 1/8000s duration, similar to most high end DSLR's, and maintains a constant color.

The other thing to consider is this low of power is starting to approach interior lighting. This means you will need to reduce the ambient lighting to avoid it polluting the image.


Below are links to discussions regarding HSS, sync speed, and HSS alternatives.


viewtopic.php?f=8&t=66
viewtopic.php?f=8&t=67

Thank you very much for posting the detailed information. Details, at a very technical level is what I was seeking, as it does help me comprehend and learn more about strobes, flash and light.

I very much appreciate your reply.

Ludvik Herrera

Thank you Ken. I do understand DOF, and I do appreciate your instructions.

Thank you,

Ludvik

They do a hack called Hypersync which will let you mostly do what you want.

But it's best if you can control all your ambient lighting and let the strobe duration control the actual "shutter speed" for freezing motion...

Hi, Ludvik

Here is an example of freezing motion using the short flash duration (about 1/5000th for this shot) capability of Einstein's action mode:

http://www.flickr.com/photos/92211832@N04/9643911655/

As described above, you need to set up so that your flash duration in effect BECOMES your shutter speed.

So, as long as:

1. You kill off any or enough natural light (via low ISO, stopping down your aperture, using and ND filter, turning off interior lights, or any combination of these)

and . . . . .

2. Your shutter is open longer than your flash duration (most shooter will choose max sync shutter speed just for the sake of camera shake)

. . . you will be able to stop motion without a high shutter speed and without suffering the dreaded black shadow of the shutter curtain.

Another way to put it is if your exposure (without any strobe) is dark enough but your flash is bright enough and short-lived enough, you will be able to light your subject *and* freeze motion.

Now, I was at F/9 for the photo of the soccer player above, but you could combine an ND filter in situations where you also need to limit depth of field with a wide aperture but you have a good amount of ambient light you cannot control. As also mentioned, though, shallow depth of field can become a challenge. Manually pre-focusing is one possible approach.

I don't remember the shutter speed or flash duration on this one below because I was not stopping motion, but I was using my Einsteins in combination with an ND here to shoot right into and overpower the afternoon sun, and at about F/2.8:

http://www.flickr.com/photos/92211832@N ... 2576126665

Here is an extremely good article by David Hobby which covers all the best techniques for working with difficult combinations of wide aperture, bright ambient, and flash:

http://strobist.blogspot.com/2010/06/us ... field.html

And last, here is a great article by Rob Galbraith about stopping motion using Einsteins:

http://www.robgalbraith.com/multi_pageb ... 0053-10715



Craíg

http://www.craigwasselphotoart.com

Craig,

Thank you very much for the examples and the instructions. It helps me understand how to proceed.
I very much appreciate your message.

Ludvik