Diffusing a Macro Twin Flash

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Dalantech
Posts: 694
Joined: Sun Aug 03, 2008 6:57 am

Re: Diffusing a Macro Twin Flash

Post by Dalantech »

aveslux wrote:
Thu Sep 17, 2020 11:09 am
If your diffusers are bigger now are you still using the Gary Fong puffer plus as the final layer?
They're wider, but still the same length. For the compact set I reduced the width (height).

aveslux
Posts: 83
Joined: Tue May 28, 2019 6:13 am

Re: Diffusing a Macro Twin Flash

Post by aveslux »

I've been playing around with configurations based on your recent blog post, seems moving the diffusion layers away from the flash bulb makes the biggest difference to the actual diffusion

Dalantech
Posts: 694
Joined: Sun Aug 03, 2008 6:57 am

Re: Diffusing a Macro Twin Flash

Post by Dalantech »

aveslux wrote:
Sat Sep 19, 2020 3:57 pm
I've been playing around with configurations based on your recent blog post, seems moving the diffusion layers away from the flash bulb makes the biggest difference to the actual diffusion
Yup. gotta separate them with an air gap.

This is my current worse case lighting cause the mag is just 1x:

ImageViolet Darter IV by John Kimbler, on Flickr

aveslux
Posts: 83
Joined: Tue May 28, 2019 6:13 am

Re: Diffusing a Macro Twin Flash

Post by aveslux »

It seems Canon publish durations for the MT-26ex I don't remember seeing this before

https://www.usa.canon.com/internet/port ... mt-26ex-rt

Code: Select all

Flash Output	Firing Duration (Approx., sec.)
1/1  (Full)	1/1300
1/2	1/1900
1/4	1/3700
1/8	1/8700
1/16	1/13000
1/32	1/23000
1/64	1/34000
1/128	1/42000
1/256	1/58000
1/512	1/67000

aveslux
Posts: 83
Joined: Tue May 28, 2019 6:13 am

Re: Diffusing a Macro Twin Flash

Post by aveslux »

Dalantech, have you ever looked at this material?

https://www.edmundoptics.eu/f/holograph ... ers/12652/

"Holographic Diffusers are used to control the diffuse area of illumination and increase transmission efficiency to greater than 90% from filament lamps, LEDs, arc lamps, and other sources. Standard ground glass and opal glass will produce diffuse illumination, but the diffuse light area will often exceed the requirements of the system. This over-illumination, associated with traditional diffusers, reduces efficiency and can often lead to added costs by requiring higher power illumination sources, lenses, and possibly filters. It is important to note that diffusing angles are given for a collimated input beam and angular divergence will vary for different incidence angles."

Seems high transmissive diffusion, expensive as hell though, 350 euros for 200mm x 200mm.

Dalantech
Posts: 694
Joined: Sun Aug 03, 2008 6:57 am

Re: Diffusing a Macro Twin Flash

Post by Dalantech »

aveslux wrote:
Sun Jan 03, 2021 10:05 am
Dalantech, have you ever looked at this material?

https://www.edmundoptics.eu/f/holograph ... ers/12652/
Sorry for the late reply -had to move to a new city during a pandemic and life got busy for a while.

Most of the continuous light diffusion material that I've tried hasn't worked -a flash is so bright it just blows right through most of it. Not sure I'd want to invest the money to test it ;)

Dalantech
Posts: 694
Joined: Sun Aug 03, 2008 6:57 am

Re: Diffusing a Macro Twin Flash

Post by Dalantech »

aveslux wrote:
Thu Dec 17, 2020 3:39 am
It seems Canon publish durations for the MT-26ex I don't remember seeing this before

https://www.usa.canon.com/internet/port ... mt-26ex-rt

Code: Select all

Flash Output	Firing Duration (Approx., sec.)
1/1  (Full)	1/1300
1/2	1/1900
1/4	1/3700
1/8	1/8700
1/16	1/13000
1/32	1/23000
1/64	1/34000
1/128	1/42000
1/256	1/58000
1/512	1/67000
Good to know -thanks!

Looking at the 1/32 and lower range motion can still be a problem. The effect won't look like traditional motion blur -no "trails". You'll just lose detail and blame diffraction. I'm convinced that motion amplified diffraction, or what I call Macro Motion Blur, is one of the main reasons why a lot of macro shooters resort to focus stacking. Drop the Fstop down a few notches and the flash fires faster to compensate for the larger aperture -but then the "virtual shutter speed" goes up and motion becomes less of a problem...

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