Test Driving the Profoto Pro-B4 at 1/25,000 of a Second

Several weeks ago I wrote an article about Profoto's new-ish pack, the Pro-B4, which has a flash duration of 1/25,000th of a second. Well, last week I was finally able to take it for a test drive. And what better way to test an insane flash duration than with water?

I am a speedlite photographer. That's all I own, and for the most part, all I use. Speedlites are also great for freezing liquids because, when fired at a lower output, they have flash durations upwards of 1/30,000th of a second. The problem with using speedlites at low outputs is that you are either stuck with a lower aperture or forced to use a higher ISO to have a greater depth of field.

Power and speed is where the Pro-B4 excels. I do need to note that though the Pro-B4 is a 1,000 watt pack, when you are shooting in "freeze" mode, you using less than half of the 1,000 watts. Even with this wattage handicap, I was still sitting pretty at f/20 with an ISO of 400 during my test. Note that the light on the left side of the model is the sun.

nick fancher profoto pro-b4

nick fancher profoto pro-b4

As you can see in the photos, the water is captured in several different ways. To disperse the water, the only tool I had at my disposal was a watering can, which accounts for the longer streaks of water. The droplets in the image, as you can see, are perfectly frozen. Given another opportunity, I'd like to try a different method of getting water into the frame. In hindsight, simply tossing water from a cup may have been a better choice. Either way, I view the test drive as a success.

Unrelated question- do human kidneys fetch anywhere close to $8,000?

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42 Comments

Previous comments
アイザック (Isaac Medina)'s picture

Nice pic. Lose the unrelated question, it takes the focus away from your images.

What unrelated question?

I think it was a joke referring to the price of the Pro-B4. It made me smile at least.

Did you test supersync yet? You'll need a flash-head with very slow speed, but will be able to sync faster... Fully up to 1/8000s.
For those who understand german: I wrote a blogpost yesterday about this, explained almost from scratch: http://www.synczeit.de/2013/04/supersync-blitzen-jenseits-der-synchronzeit/

Roman Kazmierczak's picture

I don't understand German so I don't know what is in the article but
1/8000s in camera doesn't have as much effect at freezing motion as
short flash duration.
Short focal-plane shutter speed will decrease
exposure, and allow to use wide aperture but it still needs the time to
travel all the way across the sensor.
I didn't test it myself but here is an example of the idea of the concept:

http://people.rit.edu/andpph/photofile-b/lartigue-1.jpg

Fetching image

Sure, it doesn't get close to the 1/25000s of the profoto, but you if you can cut a 1/8000s slice of light out of your long flash-duration, motion will be fixed more than at 1/250s. Furthermore you also cut down your ambient... ;)

Spy Black's picture

Not for nuthin', but f/20? Why not just crap on your lens while you're at it?

Roman Kazmierczak's picture

I understand you are talking about diffraction. It is true that mathematically diffraction will decrease sharpness on a pixel level (for 5dmk3 from f/10). For a landscape photography where you care for smallest details on horizon, because you will plan to blow it up for gallery size it may be important. In case of portrait photography I don't believe it is important to see skin pores on microscopic level. If you remember, photographers use to use lenses with "soft focus" for portrait work.
So, I wouldn't use so strong words just because smaller aperture for grater DoF was used.

Spy Black's picture

"In case of portrait photography I don't believe it is important to see skin pores on microscopic level."

That's a judgement call, but besides the point. I doubt intentional diffraction was the objective.

"If you remember, photographers use to use lenses with "soft focus" for portrait work."

That would primarily be wide-aperture optics, used wide open. I suppose he just achieved the same thing with great depth-of-field.

Roman Kazmierczak's picture

Wide aperture lenses with adjustable levels of spherical aberration.
"That's a judgement call, but besides the point. I doubt intentional diffraction was the objective."
Was it or not I don't think you could tell the difference from displayed pictures or even printed in size 11x14.

Ed Stone's picture

it'd be good to see a comparison with a speedlight. I understand they have less wattage. but i've had great results and at 1/128 freezing water droplets etc

Tasos's picture

if you wanted to remove the streaking couldn't that have been accomplished with the use of and ND filter?