MT24 diffuser.

[BasAndrews]

In an attempt to get the best from the MT24 flash, I tried to get the diffused light area as large as possible, and preferably close to the subject. I also wanted a cost effective solution, if I could.

I already had Sto-fen diffusers for the flash, they helped, but did not address the size of the light source. The Gary Fong puffer seemed a good idea, but I was not sure it would be worth the money, so I went for a cheap alternative. It was bigger than the original, and didn't seem to work that well, the light source was still too close to the puffer-type diffuser, and therefor was still a small source.

The simplest solution was to place a piece of clear plastic between the puffer and the Sto-Fen. That allowed the light to disperse before it hit the diffuser. It worked pretty well, apart from on shots like honey where the pattern on the puffer-type diffuser could clearly be seen.

Again the simplest solution, put some kitchen paper over the puffer, and since then I seem to have had little problem with blown highlights, or patterned reflections.

I use a couple of flash mount adapters to get the flashes at the right height. The beauty is that the curved surface of the front diffusers are convex, so they spread the light, while the angle of the two flashes when mounted on the lens (MP-E) make a tent, so also wrap around the subject. The reflection on things like hoverfly backs looks a continuous light source, rather than two, but they do have a unique shape in the reflection.

The main downside is the distance in front of the lens can be enough to stop the rig getting close enough to the subject if there is an obstruction above it (or behind if taking a shot from above). So a fly on a top leaf is fine, but lower down and the rig may hit other leaves or the stem.

I will (one day) get rid of the copious amounts of sticky-backed Velcro and simply glue the rig to the Sto-fen diffusers, but it has served well as a Heath-Robinson setup.

[calypsob]

Hmm interesting, got any resulting images? I enjoy orion mysteries method of using deodorant caps on his mt24 rig, his exposures always seem to cup the contours of the insects, if thats physically possible. This method looks very similar to the deodorant caps so I'm interested to see the results.

[BasAndrews]

Pretty well all my images titled EOS_600D.... on Flickr use this flash. Of course one recent batch I shot had a little problem in that the paper snagged on a plant, and there was a strange pattern on some reflections.

The ant shot shows the reflection of the light in the honey. No processing except sharpness. One thing I still need to fine tune is that shots at 5x on may need different lighting, and I want to try to use the angles on one of the flash heads to put more light on the camera side of the subject subject.

The soldier fly may have had an issue with the paper on the flash, but shows the sort of shape of the reflection

EOS 600D3401 by BasAndrews, on Flickr

[calypsob]

Wow that looks really good. The light is evenly distributed across the body and everything is well lit and exposed. Id say that is a winning configuration as far as diffusion goes. I take it that the 5x shots are a lot darker?

[BasAndrews]

I use flash exposere compensation, and on the ant shot the flash is set to +1. On the soldier fly it is set to -1, but it could have been safely shot with no FEC. (I looked and I had adjusted the brighness in DPP by +2/3)

The ant shot is about 4x BTW.

[Lester Wareham]

What sort of light loss do you get with that setup Bas?
I worry about the number of shots I can burst for focus stacking.

[BasAndrews]

I don't usually use continuous shots, but I will give it a try. There is not much in the way, the sto-fen the puffer and a bit of paper. Most shots are taken with the FEC set between -2 and 0.

[BasAndrews]

I have tried with the batteries in whatever state they were in. Shot some dark flowers on continuous and pulled 4 shots before it needed a charge period.

What FEC setting would you expect and how many shots would you expect? I can try the settings.

I can pretty safely use only one layer of the kitchen paper if more light is needed, but I suspect the difference would be minimal. Again apart from very reflective subjects the paper is not essential, I just don't like the reflected pattern of the puffer-type diffuser on it's own. Attached is a shot before I added paper (and as can be seen, when I used elastic bands to hold it together)

[Lester Wareham]

4 shots sounds reasonable, what magnification was that with?

Fec I just set by trial and error for the subject checking the histogram.

If the background is very light or dark (= far away) I will pre-dial in + or - respectively. Also depends how much natural light one is trying to blend in.

[Lester Wareham]

4 shots sounds reasonable, what magnification was that with?

Fec I just set by trial and error for the subject checking the histogram.

If the background is very light or dark (= far away) I will pre-dial in + or - respectively. Also depends how much natural light one is trying to blend in.

[BasAndrews]

I have tried today with 1:1 on some flowers and got good light levels with six shots in burst mode (I didn't leave it to fail I stopped at that point).


Tried some at higher mag and higher power, and got 4.

[Lester Wareham]

Thanks Bas, I must try and find some time to experiment.

[AntonLargiader]

Can you use a hood with that? It looks like you would get some light back into the lens which I've always assumed to be a bad thing even if the lens isn't flare-prone.

[Lester Wareham]

Originally Posted by AntonLargiader

Can you use a hood with that? It looks like you would get some light back into the lens which I've always assumed to be a bad thing even if the lens isn't flare-prone.

There is a little metal hood for the mt-24 and MP-E combo. Canon part CAN0028T225.

[calypsob]

Oh hey I wanted to suggest using some elmers glue to coat the diffuser and then applying a piece of paper towel to that. It would not be permanent but it would take some effort to get the glue back off if you didn't like it.