UV flash question

[axle01]

Hey guys and gals I have this water balloon setup I made and as you can see I have large diffusers in front of the flashes to protect the flashes from splashing water when the balloons burst.
I am in the process of converting 2 flashes to UV
My question is if I continue to use the flash diffusers to protect the flashes from water will it affect the UV light.

https://hosting.photobucket.com/images/ss174/axle01/IMG_0411.jpeg (https://hosting.photobucket.com/images/ss174/axle01/IMG_0411.jpeg)

Al

[ameerat42]

Hey guys and gals I have this water balloon setup I made and as you can see I have large diffusers in front of the flashes to protect the flashes from splashing water when the balloons burst.
I am in the process of converting 2 flashes to UV
My question is if I continue to use the flash diffusers to protect the flashes from water will it affect the UV light.

Al

It depends on what you want from the "UV light". I understand you want to use the UV to illuminate the subject.
The answer to your question lies in the properties of the diffusers re UV radiation - ie, whether they pass it, or block it.

You could look for some tech specs of the material in this regard, or you could devise some experiment. It would be simple
enough: use your converted flash to record un-diffused subjects illuminated with your UV-enabled flash, then try with the
diffusers interposed. If you get the old black-cat-on-a-dark-night result, then you have a/n (potentially unwanted) answer.
Or, it may just reduce it a little due to scattering, or... - I suppose you'll let us know :D

[axle01]

It depends on what you want from the "UV light". I understand you want to use the UV to illuminate the subject.
The answer to your question lies in the properties of the diffusers re UV radiation - ie, whether they pass it, or block it.

You could look for some tech specs of the material in this regard, or you could devise some experiment. It would be simple
enough: use your converted flash to record un-diffused subjects illuminated with your UV-enabled flash, then try with the
diffusers interposed. If you get the old black-cat-on-a-dark-night result, then you have a/n (potentially unwanted) answer.
Or, it may just reduce it a little due to scattering, or... - I suppose you'll let us know :D
Thanks mate for your feedback and I think it will be a shoot and see, just don’t want the flash units flooded with water.

Al

[axle01]

Finally the filters have arrived, I had removed the lenses in the 2 flash units waiting for the uv filters to arrived and I’ve just glued them with 24hr glue to the front of the flash units.
Hopefully in a few days when I finish sealing the filters to the flash units I will test them out.
Fingers crossed they will give me the results I’m hoping for.

https://live.staticflickr.com/65535/52957125193_f02c92bbe9_k.jpg (https://flic.kr/p/2oFD7jD)IMG_3371 (https://flic.kr/p/2oFD7jD) by alan_lorraine (https://www.flickr.com/photos/35116047@N06/), on Flickr

Al

[ameerat42]

Al. At some stage, fit the diffusers temporarily over the new UV filters.
They might help to focus the UV radiation, otherwise, you might end up
with an uneven illumination pattern. A few tests, I suppose.

[axle01]

Al. At some stage, fit the diffusers temporarily over the new UV filters.
They might help to focus the UV radiation, otherwise, you might end up
with an uneven illumination pattern. A few tests, I suppose.
Yeah I intend to do that, first to see if the diffuser has any affect on the UV flash and if it works with the diffuser to see if (as you say) the illumination pattern is even across the subject.
I'm hoping to shoot water balloons and water drops so the subject is not that big.
Testing tomorrow hopefully,,,,,,,stay tuned.

Al

[axle01]

https://live.staticflickr.com/65535/52959258191_235c01bfbb_b.jpg (https://flic.kr/p/2oFQ3ot)fullsizeoutput_4ac3 (https://flic.kr/p/2oFQ3ot) by alan_lorraine (https://www.flickr.com/photos/35116047@N06/), on Flickr

Al

[ameerat42]

Do U know Y yet?

[axle01]

Do U know Y yet?
Nup,,,,,,,it doesn’t look like the flash has enough power to get through the 2 filters.
I can look directly at the flash with uv glasses on without blinking.
More investigation tomorrow.

Al

[ameerat42]

What mods have you got/done on your camera sensor? I think some "hot-mirrors"
actually cut out UV as well as IR transmission. Put the filter directly over a lens and
take a pic of something sun-lit. More from there...

- - - Updated - - -

OK, more now...
1) check the transmission wavelengths of those filters, AND the
sensitivity of your sensor across all wavelengths.
2) If it "looks like"you should be getting something, then I'd
suspect the "hot-mirror".
3) I would not go looking directly at the sun though those filters
because they eye is still sensitive to UV that it CAN'T "see".
4) Test other known sources of UV with the filters over a lens.

[axle01]

What mods have you got/done on your camera sensor? I think some "hot-mirrors"
actually cut out UV as well as IR transmission. Put the filter directly over a lens and
take a pic of something sun-lit. More from there...

- - - Updated - - -

OK, more now...
1) check the transmission wavelengths of those filters, AND the
sensitivity of your sensor across all wavelengths.
2) If it "looks like"you should be getting something, then I'd
suspect the "hot-mirror".
3) I would not go looking directly at the sun though those filters
because they eye is still sensitive to UV that it CAN'T "see".
4) Test other known sources of UV with the filters over a lens.
Really appreciate your support I will look into your suggestions tomorrow,,,,,stay tuned.

Al