What Dave said. I was sorry to lose this capability when i sold the last of my *ist ds
Paul > On Jul 18, 2023, at 1:14 PM, David J Brooks <pentko...@gmail.com> wrote: > > 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. -- %(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.
