Diffusing the Canon MT-24EX Macro Twin Lite...

[motleypixel]

Just thought I would share how I've come about to diffuse and increase the surface area of the light coming from each strobe of the Canon Macro Twin Lite MT-24EX...seems to work pretty well for me:

VIDEO LINK (http://www.youtube.com/watch?v=ZpMHbKCXzUc)

[LordV]

Good one Roy
Brian v.

[pturton]

Thanks for the video Roy. I can see that this will be a big improvement to the MT-24 EX when used with the 100 or 180 macro lenses.

But with the MP-E 65, I've already run into problems of physical interference of the flash heads and the enviroment surrounding my subjects especially when using the lens at 2x or greater. With open surroundings your design should work reasonably well the MP-E 65.

Your solution is a lot cheaper than the Stoffen diffusers that still need a lot more diffusion. Now if Stoffen threw in a free oil change with their product....

[motleypixel]

Thanks Brian and pturton!

pturton, ah, man that's a bit of a bummer...the whole reason for the mpe is to get a bit more mag...but if this is the case with the MT-24EX then I'll have to re-engineer or even more drastic move to a different flash setup. I've always took a heavy liking to Brian's light in his shots, so maybe a bracket and off-camera sync cord?

The Kaiser hot-shoe raisers help a lot for these diffusers, perhaps using the raisers with the diffused stofen diffusers might help?

[pturton]

Thanks Brian and pturton!

pturton, ah, man that's a bit of a bummer...the whole reason for the mpe is to get a bit more mag...but if this is the case with the MT-24EX then I'll have to re-engineer or even more drastic move to a different flash setup. I've always took a heavy liking to Brian's light in his shots, so maybe a bracket and off-camera sync cord?

The Kaiser hot-shoe raisers help a lot for these diffusers, perhaps using the raisers with the diffused stofen diffusers might help?

Roy,

I envy the lighting that Brian, Remus (FM macro forum) and others get with their flash configurations. What I found for my purposes is that the MT-24 with proper diffusion and with slaves if possible, fits most of my needs. There are times when only the MR-14 will work; example, shooting into a hole.


The Stoffen diffuser makes a good holder for additional diffusion. I used the wide angle diffusion plates from a couple of flash units I purchased at a pawn shop. The plates are similar to the wide angle plate that is attached to the 550 EX flash. After cutting the diffuser plates to fit inside the Stoffens, I glued one piece to the inside face of the Stoffen and one piece at the surface of the MT-24 flash head. I placed a layer of kitchen paper towel between the assembly and the MT-24 face. The inside surfaces of my Stoffen are covered with aluminium tape.

I use one Kaiser raiser but try to keep the light as close as possible to the subject to make the light size vs distance as large as possible and to also reduce the flash duration. For most images, I can use manual flash at; A 1/8: B 1/16: C 1/8 to 1/16 for a flash duration of 1/5600 second. C flash is a 550 EX for manual or a 420 EX if ETTL is used. The flash duration of the MT-24, MR-14, 420 EX and 550 EX is 1.4 ms or shorter which resolves to ~1/700 second.

Do not disgard your design. It has some good benifits when used with the MP-E 65 at 1X to 2X under many subject situations. With the Stoffen + internal diffuser approach, the heads must be as close as possible to the subject to get a soft light and short flash duration.

[MichelleL]

Just thought I would share how I've come about to diffuse and increase the surface area of the light coming from each strobe of the Canon Macro Twin Lite MT-24EX...seems to work pretty well for me:

VIDEO LINK (http://www.youtube.com/watch?v=ZpMHbKCXzUc)

Thanks for that - very informative. When are you going to go into production and will you post to Australia? :D

edit - have you thought about using tracing paper as your diffuser material over the top of the oil bottles?

[motleypixel]

@ pturton: Thanks for the very informative reply...boy you sound a lot like someone else I know ;-) So much of what I've learned in photography just in the past 3 years (my photog career) has been watch/see and try/learn. I have this instinct to believe that light diffusion-size is king, but when you start talking flash duration it get me thinking. I only understand these concepts only about half-way. I take it that the flash fires sometime between the beginning of the shutter opening or not until the shutter is fully open. If say the MT-24EX has a flash duration of 1/700 sec and the shutter is 1/200th sec., then there's plenty of time for the flash to illuminate the subject. The part I think I may know about duration is like viewing it as a secondary shutter...at these shutter speeds and apertures the only thing that will expose on the subject is that which is illuminated by the flash and the longer it's illuminated the higher the probability for "flash blurr"? Right now I get the feeling that my diffusers are good for 1:1 with the 100mm macro lens, but I'm sure I will break out the stofens if and when I get the MP-E.

I know exactly what the wide-angle diffuser material is that you put on your MT-24EX. I would love to try your approach...I wonder if they sell this material? I'm curious, that seems like an awful lot of material between your flash heads and the subject...is the diffusing directly proportional to flash duration? I assume there's some sort of trade-off. Also, what about heat and possible damage to the flash heads? I take it that it's okay so long as you don't fire them rapidly. I think I've seen a thread somewhere of a bare flash head melting just from overuse.

@ MichelleL: Thanks for the comment. The design is pretty simple and I hope the video will help others if they desire to make a set. I haven't tried tracing paper, but I went to a fabric shop this past weekend and I have several samples of white fabric that I will try out. The paper is a good thought, but I want to try to marry durability with functionality.

Thanks,

[pturton]

Roy,

1. "light diffusion-size is king" To some degree I agree with this but with macro photography, the effect of light size relative to the subject size becomes more apparent. A flash head with a 6 x 2 cm diffuser area at 6 cm from the subject should give similar light relative to the subject, as a light source twice as large at twice the distance. Since light falls off dramatically with distance travelled, the closer the light to the subject, the shorter the flash duration required.

The power output of the MT-24 is much less than that of single flash units often used with a diffuser for macro work. These more powerful flashes can be used at longer working distance with a diffuser because of this increased power.


2. "flash duration" Considering normal flash operation: The shutter is pressed, a pre-flash to determine flash exposure is fired, the shutter opens fully, flash is fired for the duration required to make the pre-flash calculated exposure. The duration of the flash determines how much light is produced while the shutter is open. With the flash set to manual mode, there is no pre-flash and the user must determine the anount of power the flash requires for proper exposure.

You are correct in realizing that the flash duration acts as a 'shutter' when using the maximum flash sync speed and small apertures.


3. "wide-angle diffuser material" To give me some comparative values of light loss, I placed different materials over my Gossen Digipro F and metered a flash. The wide angle diffuser taken from an old flash unit seemed to have the lowest light loss of the various materials I tested. One layer was not enough and I was tempted to rip the diffuser off my 550 EX but instead found another piece on included with an old Vivitar unit. The material used to make the wide angle diffuser plates appears to me to be a clear acrylic plastic with a pyramid pattern embossed into it.

By adding the single layer of paper towelling between the assembly and the flash head face, I lost another 1.5 stop of light which of course, increases flash duration but the diffusion effect was more pleasing to me. So for now I'll use ISO 200 for most of my macro images.

4. "heat and possible damage to the flash heads" For normal usage of the flash the diffusers pose no heat threat.

Paul