Overpowering the sun

Okay so now that i have strobes + Singh-Ray Vari-ND filter to achieve this application (of overpowering the sun with shallow DOF).. I would actually like a few tips on the easiest / best way to achieve this.

From my common sense.. this is how i'd go about it:

- Set the aperture I want (lets say f/2.8), the max sync speed of my strobe (1/250) and ISO of 100.
- Now using these settings in the cyber commander, fire my flash at the subject and take a meter reading and try to get lets say f/16.
- Now f/16 is 5 stops above where I want to shoot at (f/2.8)
- Basically plug the ND filter on the lens and adjust it to 5 stops of neutral density.

Is this how you guys do it? or am i doing something wrong?

Here is how I do it. I get the exposure ratio I want without concern over DOF. Then, I open up the lense to the desired aperture giving me the DOF I desire. Screw on ND filter and adjust accordingly to get the correct exposure on the subject. I think this will be easier for you because the dots on the ND filer dont really line up with actual stops. Of course, any way that works for you is the best.

Your common sense approach would be fine -- if it were a really cloudy day...1/ISO shutter speed and f/5.6; but under those circumstances you don't need a fill flash, as there are no shadows to fill in with fill flash!
Under Sunny 16 conditions, where you need fill flash, you have 1/ISO f/16 light from the sun. While the -5EV ND allows f/2.8 on the lens, it is reducing the max range of the flash at the same time! Assuming you were using a 'powerful' 580EX, its GN for normal lens coverage angle is GN130...at f/16 it will reach only 8' away to EQUAL the power of the sun! Use f/2.8 and a -5EV filter, the same flash will still only reach 8' away and EQUAL the power of the sun...only 5.6' away to overpower the sun by 1EV!

5.6 feet is reasonable unless its a full length shot. And, My guess is that, using HSS, the speedlite would also deliver at that distance and one can do away with the ND filter.

Sounds like you're going to be using strobes, not canon flashes. Set your shutter speed to 1/200 or 1/160 since you're using 5D3s, then just use equivalent exposure formulas to reach your desired exposure. If your subject is properly exposed, but the background is too bright, then drop it down to ISO50, and turn up the power a stop, or move the light closer.

Oh, reread it, you have a variable ND filter. Forget the ISO50, and just add a stop on your filter haha.

Guys read his post. Cyber Commander doesn't work with hot shoe flashes. So no need for GN math. He is using Einstein's.

OP what you said is OK but f16 won't over power the sun depending on what time of the day you talking about. Unless you using BD close by it is hard to over power mid day sun with Einstein at full power. I know some folks will show some pictures in Nevada sun but I just couldn't do full length shots with softbox and using 5d which gives me barely 1/200.

Get a Maxilite. AKA: Fireball

bobbyz wrote in post #15201944
Guys read his post. Cyber Commander doesn't work with hot shoe flashes. So no need for GN math. He is using Einstein's.

OP what you said is OK but f16 won't over power the sun depending on what time of the day you talking about. Unless you using BD close by it is hard to over power mid day sun with Einstein at full power. I know some folks will show some pictures in Nevada sun but I just couldn't do full length shots with softbox and using 5d which gives me barely 1/200.

Einsteins aren't really powerful enough unless you are getting it close with no modifiers.

You probably want to invest in a scrim to create shade and light it that way. I prefer to use Lasolite's scrims.

Thomas Campbell wrote in post #15202058
Einsteins aren't really powerful enough unless you are getting it close with no modifiers.

You probably want to invest in a scrim to create shade and light it that way. I prefer to use Lasolite's scrims.

I'l have 2 x einstein lights.. what if i use 2 einsteins (1280ws) into a 51'' silver parabolic umbrella?

dmward wrote in post #15200852
5.6 feet is reasonable unless its a full length shot. And, My guess is that, using HSS, the speedlite would also deliver at that distance and one can do away with the ND filter.

The typical HSS flash loses -2EV or even -3EV of power when it is actively in HSS...dropping the distance from 5.6' to a mere 2.8' or even 2'

As for doing away with the ND filter, the OP's idea is to reduce the intensity of the ambient in order to permit f/2.8 with a shutter speed within X-sync speed range.

Thomas Campbell wrote in post #15202058
Einsteins aren't really powerful enough unless you are getting it close with no modifiers.

You probably want to invest in a scrim to create shade and light it that way. I prefer to use Lasolite's scrims.

I already said that Einstein not powerful enough.

5W0L3 wrote in post #15202080
I'l have 2 x einstein lights.. what if i use 2 einsteins (1280ws) into a 51'' silver parabolic umbrella?

how you going to mount two strobes on that PLM?

bobbyz wrote in post #15202449
how you going to mount two strobes on that PLM?

well its possible to put two einsteins next to each other on two diff light stands (literally next to each other) and mount the umbrella on one of them.. since the umbrella is quite large the light from the second einstein would hit almost the middle of the umbrella as well?

bobbyz wrote in post #15201944
Guys read his post. Cyber Commander doesn't work with hot shoe flashes. So no need for GN math. He is using Einstein's.

OP what you said is OK but f16 won't over power the sun depending on what time of the day you talking about. Unless you using BD close by it is hard to over power mid day sun with Einstein at full power. I know some folks will show some pictures in Nevada sun but I just couldn't do full length shots with softbox and using 5d which gives me barely 1/200.

Guide Number arithmetic works with manual power flash units even more necessarily than hot shoe flashes, which make GN arithmetic usually unnecessary with automation!

The Einstein has GN155 with standard reflector, so the arithmetic is the same and the result is different from the 580EX arithmetic I did earlier...except f/16 is good for 9.6' and not 8' to equal the power of the sun.

5W0L3 wrote in post #15203236
well its possible to put two einsteins next to each other on two diff light stands (literally next to each other) and mount the umbrella on one of them.. since the umbrella is quite large the light from the second einstein would hit almost the middle of the umbrella as well?

Yes, and with two units into the same umbrella, you will reach 1.4x as far.