[Alt-photo] Re: Alt-photo-process-list Digest, Vol 807, Issue 1

Mon Feb 17 00:27:14 UTC 2014

Estuve mirnado el trabajo de
http://binhdanh.com/Projects/1Week/1Week.html me parecio muy
interesante, no conocia esta tecnica y me gusto mucho
Fernando Cruz
Teléfono 57 -1 -2494755
Movil 57 - 3108686025
Codigo postal 110311
twitter @fotocolombiana
skype fernandocruzflorez
www.facebook.com/fotografia.colombiana

http://fernandocruzf.wordpress.com/

CV Fernando Cruz

www.fotografiacolombiana.com


2014-02-14 13:04 GMT-05:00 Anne Chansonette <chansonette at gmail.com>:
> Thanks so much to everyone who answered my question about chlorophyll
> printing ---I should have remembered myself that chlorophyll sensitivity
> would not respond well to UV. However, I wonder if lamps specifically for
> plants, various kinds of grow bulbs might work? I am going to look into the
> various types and the light spectrum generated and do some experimenting. I
> am familiar with Binh Dahn's work and was excited that he had figured out a
> way of fixing the images using resin. Thanks again for your very helpful
> answers!
> Anne
>
>
> On Fri, Feb 14, 2014 at 11:46 AM, Francesco Fragomeni <fdfragomeni at gmail.com
>> wrote:
>
>> Hi Anne,
>>
>> I didn't see this question until now but Tomas touched on some important
>> points. Chlorophyll-a is the most active of the light absorbing pigments in
>> plants for the purpose of photosynthesis. Obviously plants photosynthesize
>> using sunlight but what's important to note is that sunlight contains many
>> spectrums of different types of light, each of which have their own
>> particular importance to the photosynthesis process. Sunlight actually
>> contains only about 4% UV radiation so realistically not much compared to
>> around 52% infrared radiation and 44% visible light radiation.
>> Chlorophyll-a absorbs light most readily within the 400-450nm and 650-700nm
>> wavelengths, Chlorophyl-b absorbs 450-500nm and 600-650nm. Those ranges are
>> are within the visible light spectrum and fairly far outside of the UV
>> spectrum. UV-a is around 315-400nm, UV-b is around 280-315nm, UV-c is
>> around 200-280nm, and Vacuum UV (which is blocked by air but can operate in
>> a vacuum) is around 100-200nm. Not much of those UV wavelength ranges are
>> absorbed readily by Chlorophyl for the process of photosynthesis.
>>
>> With that said, I'm sure something would happen but to what degree will be
>> for you to try out! I haven't tried working with chlorophyl prints in a uv
>> box so I can't tell you for sure one way or another what will happen but I
>> suspect some result will occur but probably not what you would expect when
>> using direct sunlight.
>>
>> Best,
>> Francesco
>> www.francescofragomeni.com
>>
>>
>> On Fri, Feb 14, 2014 at 10:56 AM, Tomas Sobota <tom at sobota.net> wrote:
>>
>> > Anne, I expected that someone more knowledgeable than me would answer
>> your
>> > question, but since nobody comes forward ...
>> >
>> > If by "chlorophyll prints" you mean something like the juxtaposing of a
>> > negative on a living plant leaf to get after a time a positive image, my
>> > answer to this would be an unambiguous "who knows", never having
>> attempted
>> > this technique.
>> >
>> > Looking at absorption spectra of chlorophyll a and chlorophyll b, for
>> > example here: http://www.biologie.uni-hamburg.de/b-online/e24/3.htm
>> > it is apparent that chlorophyll as a whole is mainly sensitive to the red
>> > and blue regions of the spectrum, with a strong cut-off towards the near
>> > UV. This, at least in theory, would preclude the use of UV light sources.
>> >
>> > Again, producing an image this way using strong sunlight needs many hours
>> > or even several days of exposure, do you really mean to have your UV bank
>> > on for such a long time?
>> >
>> > But if I were you I would try, who knows ...
>> >
>> > Tom
>> >
>> >
>> >
>> >
>> > On Thu, Feb 13, 2014 at 7:16 PM, Anne Chansonette <chansonette at gmail.com
>> > >wrote:
>> >
>> > > Does anyone know if it is possible to do chlorophyll prints using a UV
>> > box
>> > > instead of natural light? I am currently in the grey and unending New
>> > > England winterland and don't want to wait months before working on a
>> > > project!
>> > > Anne at lesleyU
>> > >
>> > > Sent from my iPad
>> > >
>> > > > On Feb 21, 2013, at 7:00 AM,
>> > > alt-photo-process-list-request at lists.altphotolist.org wrote:
>> > > >
>> > > > Send Alt-photo-process-list mailing list submissions to
>> > > >    alt-photo-process-list at lists.altphotolist.org
>> > > >
>> > > > To subscribe or unsubscribe via the World Wide Web, visit
>> > > >
>> > http://lists.altphotolist.org/mailman/listinfo/alt-photo-process-list
>> > > > or, via email, send a message with subject or body 'help' to
>> > > >    alt-photo-process-list-request at lists.altphotolist.org
>> > > >
>> > > > You can reach the person managing the list at
>> > > >    alt-photo-process-list-owner at lists.altphotolist.org
>> > > >
>> > > > When replying, please edit your Subject line so it is more specific
>> > > > than "Re: Contents of Alt-photo-process-list digest..."
>> > > >
>> > > >
>> > > > Today's Topics:
>> > > >
>> > > >   1. Re: Gelatin (Michel Debar)
>> > > >
>> > > >
>> > > >
>> ----------------------------------------------------------------------
>> > > >
>> > > > Message: 1
>> > > > Date: Wed, 20 Feb 2013 23:55:36 +0100
>> > > > From: Michel Debar <michel at debar.org>
>> > > > To: The alternative photographic processes mailing list
>> > > >    <alt-photo-process-list at lists.altphotolist.org>
>> > > > Subject: [alt-photo] Re: Gelatin
>> > > > Message-ID:
>> > > >    <CAOtyDPLifUi342p44Anj5k2orcXT=fZkg=
>> JtZfT3y_FqMRzLWw at mail.gmail.com
>> > >
>> > > > Content-Type: text/plain; charset=UTF-8
>> > > >
>> > > > An amazing quote from Douglas Cockerel 1910 book, Bookbinding and the
>> > > care
>> > > > of books :
>> > > >
>> > > > [...]
>> > > > The following is quoted from ?Chambers? Encyclop?dia? on Gelatine:?
>> > > >
>> > > > ?Gelatine should never be judged by the eye alone.
>> > > >
>> > > > ?Its purity may be very easily tested thus: Soak it in cold water,
>> then
>> > > > pour upon it a small quantity of boiling water. If pure, it will
>> form a
>> > > > thickish, clear straw-coloured solution, free from smell; but if made
>> > of
>> > > > impure materials, it will give off a very offensive odour, and have a
>> > > > yellow, gluey consistency.?
>> > > >
>> > > > [...]
>> > > >
>> > > >
>> > > > ------------------------------
>> > > >
>> > > > _______________________________________________
>> > > > Alt-photo-process-list | http://altphotolist.org/listinfo
>> > > >
>> > > > End of Alt-photo-process-list Digest, Vol 807, Issue 1
>> > > > ******************************************************
>> > > _______________________________________________
>> > > Alt-photo-process-list | altphotolist.org
>> > >
>> > _______________________________________________
>> > Alt-photo-process-list | altphotolist.org
>> >
>> _______________________________________________
>> Alt-photo-process-list | altphotolist.org
>>
> _______________________________________________
> Alt-photo-process-list | altphotolist.org