Adjusting Light Intensity on Speedlites without variable power

[lennon33x]

Sooooooooo....new guy to off-camera flash/strobes/monolights...whatever you might call it.

Here's my setup:
Canon Rebel T3
Two 33" White Shoot-through Umbrellas or Brollyboxes
Canon Speedlite 155a
Sunpak Digiflash 3000

Flashes on 7 foot stands.

My issue is that I can't turn down the power (1/2, 1/4, 1/8...) on the flashes because they aren't equipped to do so. The 155a has a auto/man/auto switch, but doesn't adjust power significantly. The Sunpak only has On/Off, therefore I cannot adjust power. It does have a zoom, but I'm not looking to diffuse light. I'm looking to reduce power. So what are my options for reducing the power so that I have control? My friend suggested an ND filter, but I would either have to use an ND Variable filter or have a bag full, then compensate for underexposure. Are there gels/diffusers that I can use to reduce power?

Thanks!!

 

[Derrel]

Move the flashes farther away from the subject. Light will fall off at pretty much one EV value at the following sequence of distances from flash-to-subject:

1.0, 1.4 ,2.0, 2.8, 4, 5.6 ,8 ,11, 16, 22 ,32 feet.

Seriously. Not kidding you. Each "space" between any two of those distances represents pretty much a one f/stop difference, either more, or less, depending on which way you move across that distance line.

 

[Flyhigh]

If you haven't already, take a look at the Strobist tutorials. A wealth of knowledge about strobe lighting.

 

[lennon33x]

Move the flashes farther away from the subject. Light will fall off at pretty much one EV value at the following sequence of distances from flash-to-subject:

1.0, 1.4 ,2.0, 2.8, 4, 5.6 ,8 ,11, 16, 22 ,32 feet.

Seriously. Not kidding you. Each "space" between any two of those distances represents pretty much a one f/stop difference, either more, or less, depending on which way you move across that distance line.

And what if I want to control my light more (direction)? And what if I am limited in the distance I can move my umbrella/brolly?

 

[Derrel]

Move the flashes farther away from the subject. Light will fall off at pretty much one EV value at the following sequence of distances from flash-to-subject:

1.0, 1.4 ,2.0, 2.8, 4, 5.6 ,8 ,11, 16, 22 ,32 feet.

Seriously. Not kidding you. Each "space" between any two of those distances represents pretty much a one f/stop difference, either more, or less, depending on which way you move across that distance line.

And what if I want to control my light more (direction)? And what if I am limited in the distance I can move my umbrella/brolly?

Well, there is an seven-stop difference between 1 foot and 11 feet. I think that'll be enough variation.

 

[lennon33x]

Move the flashes farther away from the subject. Light will fall off at pretty much one EV value at the following sequence of distances from flash-to-subject:

1.0, 1.4 ,2.0, 2.8, 4, 5.6 ,8 ,11, 16, 22 ,32 feet.

Seriously. Not kidding you. Each "space" between any two of those distances represents pretty much a one f/stop difference, either more, or less, depending on which way you move across that distance line.

And what if I want to control my light more (direction)? And what if I am limited in the distance I can move my umbrella/brolly?

Well, there is an seven-stop difference between 1 foot and 11 feet. I think that'll be enough variation.

Here's an example: I was taking pictures of my twins in their nursery. I had two brollys set up, one from the left/behind as an accent and then another to provide more ambient. Because the light was too intense, I backed them up as far as I could go. But if I wanted to soften one of the lights, I would have loved to have turned down the power. But I couldn't. So other than a diffuser on the flash, inside the brolly, I am unsure of what to do. I am considering some low cost strobes to start out with that have variable power since I forsee myself using the speedlites more outside and use the strobe inside.

 

[Mike_E]

What Darrel said.

You can get neutral density filters that will do the same thing but by the time you pay for those you'll be well on your way to a new one that adjusts.

99% of the time spending the money to get what you want in the first place will save you about twice whatever it costs.

Sucks, but it's true.

 

[Helen B]

Moving a light away does tend to make it less soft, but it doesn't matter much for short distance moves. Feathering (aiming off) can also be used for intensity reduction, but that can also change the character of the light. ND gels for lights aren't expensive, they do not have to be the same optical quality as camera filters and you don't have to baby them. You only need small pieces. Don't 'stack' them unless you leave an air gap between for cooling. You can also use black mesh, but ND gels are usually easier. As already mentioned, these solutions are not nearly as good as getting a variable power flash.

 

[andrewkurcan]

What Darrel said.

You can get neutral density filters that will do the same thing but by the time you pay for those you'll be well on your way to a new one that adjusts.

99% of the time spending the money to get what you want in the first place will save you about twice whatever it costs.

Sucks, but it's true.

I don't necessarily agree with this. You can also buy ND gel - it's pretty cheap. Alternatively make some lighting scrims with metal screen - one layer is called a "single scrim", two layers set 45 degrees off of each other is called a "double scrim". There is also diffusion gel that you can drop in front of the strobe head that will help in your situation. I came into photo via television/film lighting - while an expensive flexible light source is amazing - cheap ones work, you are truly only limited by your ingenuity.

 

[andrewkurcan]

Also - go buy a roll of "cinefoil/blackwrap". And when attaching this stuff to hot surfaces (gel included) - go get some "blacktack".

Have fun!

 

[Mike_E]

What Darrel said.

You can get neutral density filters that will do the same thing but by the time you pay for those you'll be well on your way to a new one that adjusts.

99% of the time spending the money to get what you want in the first place will save you about twice whatever it costs.

Sucks, but it's true.

I don't necessarily agree with this. You can also buy ND gel - it's pretty cheap. Alternatively make some lighting scrims with metal screen - one layer is called a "single scrim", two layers set 45 degrees off of each other is called a "double scrim". There is also diffusion gel that you can drop in front of the strobe head that will help in your situation. I came into photo via television/film lighting - while an expensive flexible light source is amazing - cheap ones work, you are truly only limited by your ingenuity.

The last time I checked they were about $15 a sheet. Two sheets, 1/4 and 1/2, would run you around $30 plus shipping, or gas in my case, and that's about half of a new Yongnuo.

Just sayin

 

[Helen B]

The Rosco Strobist collection includes two each of three densities and costs $11. 20 different colors, 55 pieces of filter. Even cheaper if you use the free swatch books.

 

[amolitor]

Tape a single layer of tissue over the business end of the strobe for roughly a 1 stop reduction (1 layer only, most tissues are two layers, so you have to split it). This will probably alter the color subtly, but it should be close enough for government work. It will tend to soften then light a trifle, depending on how snug the tissue is to the strobe.

 

[Mike_E]

True but coming from a recovering DIY nut it really is cheaper, better and easier over the long run to just go ahead and save up for the right equipment.

Sure you can improvise -I brought up ND gels too, remember?- and in a pinch sometimes it's all you can do but spending on the gels (even free ones) and the tape and the this and the that and then keeping up with all of it along with keeping up with the amount you have on hand to make sure you can do a shot... in the end after answering the OP's immediate question don't you feel that we should also point out the Best Workable solution?

Telling someone that they need to just go spend money isn't always the answer and sometimes their spending any extra just isn't doable (been there, done that) but pointing out something as affordable as a third party flash is, in this case I think, called for.

Sorry to sound argumentative here, I do understand how much you can learn from cobbling things together for yourself but to go on about more complex options to someone who has just begun their experience is being cart-first.

 

[Derrel]

Years ago, a rather dickish photographer asked me if my studio strobes had one-tenth f/stop power control. I said "Yeah...I grab the light stand and I move the light back or forward and inch and a half."