Any photog dopers own/use a ring/macro flash?

I want to own one but they’re ex-bloody-ensive.

I found one that’s just within my price range (Sigma EM 140 DG Macro Flash), but I am curious about something.

I bought a very cheap one once and the hole was tiny. Too small for my only small lens (a sigma lens with a 72mm end on it) so I sent it back.

I then bought a thing that is supposed to attach to an ordinary flash and channel the light down to a ring. It gives good light but it’s heavy and doesn’t attach well to the flash so you kind of have to hold it on while you take a photo.

I would really like to own a ‘proper’ macro flash.

When using a flash like the sigma em 140 on a 72mm lens is the hole smaller than the end of the lens, such that resulting photos will have their edges obscured by the body of the flash?

Can this ‘DG’ flash be used on a lens that isn’t DG? (sigma 17-70 mm DC)

Well, here’s the customer reviews for it on B & H: http://www.bhphotovideo.com/c/product/352442-REG/Sigma_F309101_EM_140_DG_Macro_Ringlight.html#reviews

Looks like it’ll work for up to 77mm lenses. Opinion is divided about the overall usefulness of the lighting it provides.

Thanks for the link. As can be expected the mixed reviews give me mixed feelings about getting this flash.

Anyone else got any input? Why do these things have to be so expensive for something that ticks the main boxes? (Gives a ring of light, no shadows, uses real light and not ‘channelled’ light from an ordinary flash, fits a big lens, is bright etc…)