That's awesome.  Do you have any of them scanned?  I'd love to show
them to a MUA friend.

On Tue, Jun 14, 2011 at 4:40 PM, William Robb
<anotherdrunken...@gmail.com> wrote:
> On 14/06/2011 12:46 PM, Igor Roshchin wrote:
>>
>>
>> Tue Jun 14 13:48:28 EDT 2011
>> John Francis wrote:
>>
>>> On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote:
>>>>
>>>> Hi All!
>>>>
>>>> After taking photos at a party, I discovered an interesting effect.
>>>> It was indoors, with uneven and not very bright light, so, I used
>>>> a flash bounced from the ceiling, which made the light rather uniform.
>>>> [ .  .  . ]
>>>> I suspect, that this particular color (dye) fluoresces from the flush,
>>>> or something like that.
>>>
>>> Quite likely - dyes (or pigments) used to colour plastic items often
>>> have significant response to ultra-violet light.  Even if they don't
>>> fluoresce, the output from a flash can produce quite a bit of UV light,
>>> and sensors "see" further into the UV than does the human eye.
>>>
>>> You could try using a UV filter on either the camera or the flash.
>>
>> John,
>>
>> Even though purple might have an mixture of blue/violet with red,
>> I would expect that purple would be farther on the spectrum and closer to
>> the violet part than blue.
>>
>> That would mean that hitting the violet (or UV) part of the spectrum
>> should shift the color toward violet, not toward blue.
>>
>>
> Igor, filters aren't all that spectrum specific, and tend to be cut filters,
> in that they don't pass any spectrum below a particular wavelength (which
> will vary from filter to filter).
> UV florescence has been a problem since the dawn of electronic flash. A lot
> of things reflect a disproportionate amount of UV light.
> This is especially true of man made fabric materials (nylon, rayon, satin,
> and the like and make up.
> My wife has a lovely emerald green gown that photographs blue with flash,
> and bluey green under daylight, for example.
> A wedding I shot many years ago ended up being an epic fail because the
> bride and bridesmaids ended up pooling their make up resources, and probably
> used half a dozen different brands of product.
> They looked gorgeous, but the flash pictures showed all sorts of blotches
> and zebra stripes where make up brands met each other.
>
> --
>
> William Robb
>
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