August 22, 2014, 09:48:56 PM

Author Topic: Shaping the Lite  (Read 4322 times)

neuroanatomist

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Shaping the Lite
« on: December 11, 2013, 01:33:07 PM »
I recently purchased a bundle of Honl modifiers for Speedlites (grids, snoots, and gels), to use on my 600EX-RT flashes.  I wanted to determine the optimal zoom setting for them (from the available 20-200mm zoom settings on the flash head), and took the opportunity to test them out, along with a couple of diffusers. 

The setup was a 600EX-RT on a light stand, 5 feet from a neutral-colored wall (measured distance between front of flash head and wall surface).  Images were captured with a 1D X and 24-70mm f/2.8L II at 35mm, 1/200 s, f/8, ISO 200.  Ambient light was nil, and the flash was triggered with an on-camera ST-E3-RT.  Flash power was set manually, 1/32 power in most cases, but higher power was used for the diffusers (1/8 power for the Sto-Fen OmniBounce, 1/16 power for the Honl Heavy Frost filter).   The dots on the wall are spaced 12" apart, so beam spread can be determined from the images.

First up is the bare flash.  The 14mm setting is the built-in pull-out diffusion panel.



The Sto-Fen provides a pretty even distribution of light, and is able to effectively diffuse even the 200mm zoom setting.



The Honl Heavy Frost diffuser (part of the Color Effects Gels kit) is weaker than the Sto-Fen, and has some fall-off at the higher head zoom settings.



The shape of light from the snoots is obviously quite dependent on how you connect the Velcro bits and how you shape the end of the tube.  With the 5" 'shorty' snoot, at 70mm and narrower zoom settings the pattern of the flash zoom head is apparent within the area projected by the snoot itself.



The 8" snoot gives a tight beam with no effect at long zoom settings, although light lost to the zoom mechanism is apparent wider than 70mm. 



Unlike the snoots, the honeycomb grids deliver a nice, circular beam (although the grid must be flush and tightly attached for the beam to porject straight).  With the 1/4" grid at zoom head settings wider than 70mm, there is a horizontal pattern evident in the beam.  One online comparison that I found shows a smooth beam with no pattern; I think this is because those shots were focused on the flash itself (shot from behind) and not the wall onto which the flash beam was projected.  At 80mm and narrower, the circular shape is affected by the shape of the light exiting from the zoomed head.



With the 1/8" grid, the horizontal pattern is evident at 35mm and wider, while at progressively longer zoom settings the falloff is faster and spill is reduced even further.



Get out there and shape the light!
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Click

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Re: Shaping the Lite
« Reply #1 on: December 11, 2013, 01:50:38 PM »
Very good information Neuro. Thanks for posting.

« Last Edit: December 11, 2013, 06:44:45 PM by Click »

Mr Bean

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Re: Shaping the Lite
« Reply #2 on: December 11, 2013, 05:35:47 PM »
Very good informations Neuro. Thanks for posting.
+1. Great info and examples. Thanks Neuro.
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Drizzt321

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Re: Shaping the Lite
« Reply #3 on: December 11, 2013, 06:18:31 PM »
Wow! That's just about as detailed as Roger Cicala's work :)  Thanks!
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sagittariansrock

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Re: Shaping the Lite
« Reply #4 on: December 11, 2013, 06:41:02 PM »
Thanks a lot for the information. This should be made a sticky or something.
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Quasimodo

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Re: Shaping the Lite
« Reply #5 on: December 11, 2013, 07:11:23 PM »
Interesting and informative
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RC

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Re: Shaping the Lite
« Reply #6 on: December 11, 2013, 07:43:53 PM »
Excellent tests and nice presentation, thanks for sharing!  I have a few Honl mods and have been debating over the regular or shorty snoot.  Your examples will be helpful.  Did you by chance do any bouncing tests with flash pointed straight up and snoots opened up?

neuroanatomist

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Re: Shaping the Lite
« Reply #7 on: December 11, 2013, 08:28:45 PM »
Did you by chance do any bouncing tests with flash pointed straight up and snoots opened up?

Sorry, no - I didn't try using the snoots as reflectors for the tests.
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cervantes

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Re: Shaping the Lite
« Reply #8 on: December 12, 2013, 04:14:44 AM »
Thanks for the comparison neuro! Is there a chance that you can do the same test with a better beamer attached? Would be interesting to see the beam spread then.

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Zv

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Re: Shaping the Lite
« Reply #9 on: December 12, 2013, 05:17:33 AM »
Nice. I used to use 24mm when using a mid sized shoot through umbrella but I find 35 or 50 a bit more efficient. Any thoughts on that?
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RC

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Re: Shaping the Lite
« Reply #10 on: December 12, 2013, 07:34:33 AM »
Nice. I used to use 24mm when using a mid sized shoot through umbrella but I find 35 or 50 a bit more efficient. Any thoughts on that?
Great question.  I'm interested in what zooms settings others are using when using shoot-thru umbrellas and softboxes. Typically I've been using about 24mm for a 45" umbrella and 24x24 (Lastolite) softbox.  I'm probably wasting light, especially on the umbrellas, but since I'm using manual flash, I can always adjust it. 

neuroanatomist

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Re: Shaping the Lite
« Reply #11 on: December 12, 2013, 08:30:35 AM »
Is there a chance that you can do the same test with a better beamer attached? Would be interesting to see the beam spread then.

I tested it at the time, the spread was barely beyond the flash head/Beamer combo, and was hard to see past the strong reflection from the back side of the Fresnel lens.  There were actually some secondary patterns a few feet above and below the beam, which I think resulted from light reflecting off the back of the Fresnel lens then off the flash head itself, bouncing toward the wall. 

Basically, the Better Beamer at 5' wasn't an informative test.  What I really need to do is test it with the 600 mm lens, from a greater distance, to determine which zoom setting fills the frame without wasting light.  I know the manufacturer recommends setting the flash head zoom to 50 mm, but I have read that that is not always best, depending on the focal length you are using.

Nice. I used to use 24mm when using a mid sized shoot through umbrella but I find 35 or 50 a bit more efficient. Any thoughts on that?

Sure.  Depending on how far the umbrella is from the subject, a tighter zoom setting on the flash head may make sense.  The snoot tests also suggest that there is some internal light loss within the flash head at the widest zoom settings – 35mm or 50 mm may be giving you more light output.
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pierlux

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Re: Shaping the Lite
« Reply #12 on: December 12, 2013, 12:10:24 PM »
Thanks a lot, neuro!

ishdakuteb

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Re: Shaping the Lite
« Reply #13 on: December 12, 2013, 12:49:21 PM »
love this kinda of information.  thanks very much neuro...

Pugshot

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Re: Shaping the Lite
« Reply #14 on: December 12, 2013, 01:10:07 PM »
Thanks, Neuro - this is very useful information!