I found my istD made for a great ir camera with the Hoya r72 filter Dave
On Thu, Jul 13, 2023 at 10:10 PM <jco...@iinet.net.au> wrote: > That's a very fine image, Ralf - I might try that myself. My *ist-D has > been sitting on the shelf for most of the last seven years, it will be nice > to fire it up again. > > > John in Brisbane > > > > -----Original Message----- > From: Ralf R Radermacher <fotor...@gmx.de> > Sent: Thursday, July 13, 2023 6:13 PM > To: pdml@pdml.net > Subject: Re: IR Photography > > Am 13.07.23 um 01:59 schrieb Larry Colen: > > > You'll need to focus based on the live view, which is what the sensor > sees, either that or manually focus based ton the distance scale and the > little red dot that shows the IR focus point. > > Maybe even a little beyond the red dot which is calibrated for an IR > wavelength of around 750 nm corresponding to the usual near-infrared film > stock like Ilford SFX200 or Konica 750. The infrared sensitivity of a DSLR > sensor extends way beyond that, well into the 800's, shifting the focus > point even more. > > And don't try to step down beyond f8 to gain more DOF. Aperture > diffraction at IR sets in a lot sooner than with visible light. > > I've been using a #87 gelatine filter on my unmodified *istDS. This filter > is almost completely impervious to visible light. > > Here's an example: > > https://www.fotocommunity.com/photo/la-bistade-fotoralfbe/32223101 > > Ralf > > -- > Ralf R. Radermacher - Köln/Cologne, Germany Blog : > http://the-real-fotoralf.blogspot.com > Audio : http://aporee.org/maps/projects/fotoralf > Fotos : https://www.fotocommunity.de/user_photos/770012 > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from > the PDML, please visit the link directly above and follow the directions. > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-le...@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. -- Documenting Life in Rural Ontario. www.caughtinmotion.com http://brooksinthecountry.blogspot.com/ York Region, Ontario, Canada -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
