Également disponible en : French


The diffuser aim is to smooth hard shadows generaly caused by the direct firing flash. Thanks to a wide light surface, it gives a great light homogeneity, more natural, efficiently limiting high contrasts. As John Hallmén, I’ve chosen to base my diffuser on the Beauty dish method which consist on generating almost one light bounce before the light goes out, to enhance the light surface and limit the directionality.
Numerous pro manufacturers offer solutions, more or less efficient, more or less dedicated and more or less expensive; it’s why at the moment, I’ve tried to make my own.
Materials and overall costs
- Lampshade (Ø 25 cm): ≈ 5 € on sale (otherwise 13 €);
- The half sphere from the make-up box I’m using. (Hopefully, the make-up is not lost ^^): ≈ 12 € in promotion (otherwise 24 €);
- Saucer: ≈ 0,7 €;
- Half rigid plastic sheet to diffuse: ≈ 5 €;
- Chrome painting: ≈ 10 €;
- Glue: ≈ 15 €;
- Scotch: ≈ ?;
- Polystyrene: ≈ ?
Total amount: ≈ 47 €, knowing that glue, painting, sctoch, etc. will allow to make multiple other diffusers :)
Simple working figure


What you need


Basic principle


The main reflector


Cutting the flash support


Mounting the flash support


Mounting the flash support


Flash support: inside view


Gluing the reflector on his base


Watch out with the painting!


When the lamshade becomes a reflector


When half sphere becomes reflector


Reflector in reflector


Diffuse the diffuser


Top view


On place diffuser


A great thing: thanks to the simple assembly system of the “diffusion discs”, it’s easy to add colored ones (i.e.: a whole monochrome, muliple colors, half blue, half red, etc.).
Does it work? Here’s a little test with and without diffuser. Clearly fastly and badly realized
How it behaves?
Comparison with / wihout diffuse



Diffuser and flash firing


Test conditions
Gear:
- Body: Canon 5D Mark II;
- Lens: Canon EF 180mm ƒ/3.5L Macro USM;
- Flash: Canon Speedlite 580EX II;
- Diffuser: homemade.
Lighting:
- An almost enterely dark room (flash will more likely give his higher power ouput);
- A simple white surface, almost opposed to the flash position, to get a bounce light.
Pictures:
- All taken in RAW;
- Exposures with bare flash at ƒ16,
and flash + diffuser at ƒ16 and ƒ32; - Shutter speed willingly leave at 1/60e for all shots;
- Shots have not been post-processed (color, luminosity, levels, etc.);
- Only some sharpen applied after resizing for uploading here;
- Pictos on pictures are Apple property.
Toothbrush case
Toothbrush 3/4



Toothbrush front



Toothbrush profile



The thing we can immediately note is the diffuser role. Light is way softer, the result is less contrasted. I like the fact that no area is over-exposed, burned out, when taken with flash + diffuser. Even if without post-processing, this pictures are a little under-exposed (with those settings) compared to bare flash shots, they offer an higher flexibility in many aspects for post-processing. For such a subject, flash + diffuser has no problem exposing picture, even at ƒ32.
After post-processing comparison



Paintbrush case
Paintbrush



Here, with a dark subject + metal, firing bare flash (without particular settings) cause over-exposed result. Flash + diffuser at ƒ16 works great but the flash shows his own power output limits at ƒ32. However, bare flash at ƒ32 works.
Cow case
Cows



For this last example, I choose to take some distance from “macro” stuffs and try with a bigger object (7 or 8 cm long). Diffuser efficiency is as clear as the toothbrush essay. Shadow cast of the head on the body is really attenuated but still present (great to give volume feeling). About the flash + diffuser result, it’s still efficient at ƒ32. Same remark as previously about the little under-exposed result, easily recoverable. Please note (once again) the tests was occuring inside a very dark room.
I hope I’ll have some more time to continue my tests, anyway, I found results satisfying and it was a fun diffuser to build.
This symbolic coffee or your comment would be a true encouragement to offer you more contents. Thanks…







