[alt-photo] Re: cyanotype

[francis schanberger]

Chris,

I always viewed the lavender as a nice surprise in botanical photograms done
in cyanotype. The moisture trapped in the leaves often gives a surprise
purple kick in the light midtones that I suspect is fugitive.

After moving from the relatively dry climate of Southern California to Ohio,
I viewed the 60% relative humidity as a bonus for working alt. What is the
relative humidity at Penland and how are you dealing with, despite the high
humidity, working in a "dry" county?

-francis

On Wed, Jun 2, 2010 at 11:58 AM, Loris Medici <mail at loris.medici.name>wrote:

> As for the "why?" I would suggest that you try to add a drop of 40%
> citric acid into 10ml sensitizer and see if it gets better. If yes,
> then it's probably chemical fogging (always more noticeable in the
> highlights) due combination of increased sensitivity and paper
> impurity (or sensitizer contamination?)...
>
> Regards,
> Loris.
>
> P.S. Sorry for the "stuttering" postings...
>
>
> 2010/6/2 Loris Medici <mail at loris.medici.name>:
> > BTW, remember FAC is incredibly hygroscopic and deliquescent,
> > therefore it's pretty normal that the paper doesn't want to get dry in
> > very humid environment.
> >
> > Regards,
> > Loris.
> >
> >
> > 2010/6/2 Loris Medici <mail at loris.medici.name>:
> >> Christina that's my standard practice with cyanotype. I always expose
> >> hot air force dried paper (after paper absorbed the sensitizer
> >> completely that is - usually takes not more than 4-5 minutes...) for
> >> sake of consistency. That way my exposure times and contrast remain
> >> constant in all seasons / environmental conditions...
> >>
> >> Humidity increases sensitivity a lot and maybe that is causing the
> >> chemical fogging (my interpretation) which doesn't kick in when you're
> >> under a specific sensitivity threshold (with thoroughly force dried
> >> paper)... ???
> >>
> >> Regards,
> >> Loris.
> >>
> >>
> >> 2010/6/2 Christina Anderson <zphoto at montana.net>:
> >>> ...
> >>> We've taken to blow drying the paper with blow dryers til "snappy" to
> alleviate it.
> >>> ...
> >>
> >
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>



-- 
francis schanberger

www.frangst.com