Flash too powerful
 

I've butchered an old flashgun for a specific task, but I've found that it's just too powerful for the job in hand. Even at ISO 200 and f22 I can't get the flash far enough away and am overexposing by about 2 stops.
I can't turn the power down because, as I said, it's an OLD flash. I can't get any further back (constraints of my studio).
I'm contemplating sticking a ND8 filter over the tube, but I'm concerned it might damage the filter.
Anyone got any other ideas?

piece of white paper or greasproof paper or white tissue over the flash head?

[QUOTE=Cathus;74229]piece of white paper or greasproof paper or white tissue over the flash head?[/QUOTE]

Good idea, but it's not likely to do more than 1 stop. The other snag is that it will diffuse the flash and I want to get the highlight. The subject is glass (I didn't mention that did I?). Part of the 'butchering' was to remove the diffuser to get a point light source.

You could use a ND lens filter.

make a snoot out of paper or card and stick a hanky or paper over the end, so you have a small point of light?

[QUOTE=jet_kit;74234]Good idea, but it's not likely to do more than 1 stop. The other snag is that it will diffuse the flash and I want to get the highlight. The subject is glass (I didn't mention that did I?). Part of the 'butchering' was to remove the diffuser to get a point light source.[/QUOTE]

hi jet_kit
I would sujest takeing test shots folding the paper as you go to get the right opasity or thickness. the greese prof paper is an old trick for flash defusetion if you did not have a defuser your self

[QUOTE=Cathus;74239]make a snoot out of paper or card and stick a hanky or paper over the end, so you have a small point of light?[/QUOTE]

Good plan, Garry. I'll try that because the snoot will cut down the output pretty seriously, and i could always hang a ND in front of that. I'll let you know how I get on, probably at the weekend.

I'm with Cathus on this one, I often use kitchen roll paper to achieve a reduction in flash power, sometimes several thicknesses. Just be a little careful and leave a small airgap between the flash and paper towel as you could burn the fresnel screen on the flash.

Harry

[QUOTE=hssutton;74260]I'm with Cathus on this one, I often use kitchen roll paper to achieve a reduction in flash power, sometimes several thicknesses. Just be a little careful and leave a small airgap between the flash and paper towel as you could burn the fresnel screen on the flash.

Harry[/QUOTE]

Thanks Harry, but there is no fresnel screen. It was one of the things I removed because I don't want any diffusion at all. That's why hankercheifs, tissues, toilet rolls etc. are not the solution because they would introduce the very thing I'm trying to get rid of and why I was querying the use of a ND filter directly in front of the tube. My concern was that it might burn the filter.
However, Garry's idea of a snoot could well solve the problem and I'll work on that. There is a possibility that this is not the solution and I might have to return to the drawing board. We shall see.

Hi Chris I used an homemade snoot to use on a flash where I've removed the flash tube from the flash head and extended the wires so that I can position the flash tube inside a flower. I made the snoot out of black card.

I made this initially for an experiment in backlighting a daffodil, the snoot was approx 18 in length with a narrow opening where I inserted the head of a daffodil. I adjusted the exposure by moving the flash tube inside the snoot/cone. Probably a little difficult to do with a complete flashgun though.

Harry

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