Re: Developing Konica IR

[George L Smyth <GLSmyth@xxxxxxx>]

Eduardo Ayrosa wrote:
> 
> Does anyone know the developing times for the Konica 35mm IR film? I
> exposed at 100 ASA and have T-Max, Rodinal, HC-110 and Perceptol
> developers.

>From the IR FAQ:

Konica Infrared 750 Black & White 

          This is available in 35mm (24 exposures) and 120 formats. It
is not so grainy as the Kodak film, though still grainy. It is less
sensitive to IR so the effects are less exaggerated (its sensitivity has
its peak at 750 nm, and extends to 820 nm). However it is also less
prone to fogging from stray-light whilst loading not only because it has
an anti-halation layer but also because of a better light trap. Kodak's
felt trap is considerably more transparent to infrared. It is also less
likely to fog due to heat < why? >. Its latency is greater thus get
better results if it is not possible to develop immediately. 

          I had the information that it is a much slower film, 3-4 stops
lower than the Kodak (ISO 12 ?). But Aaron Flin uses it at ISO 32
without filter. 

          On the other hand, George L Smyth uses it at EI 10 (with a 25
red filter). "I should mention that this speed (which is partially a
result of the developer) is employed in the late spring though early
autumn. Early to mid spring and mid to late autumn my speed drops." 

          Process using ordinary black and white developers. 
               examples 
               Rodinal 1:50 6.5 minutes 20 Celsius when shooting EI 10
with a 25 red filter (George L Smyth). 

I have a pointer to the FAQ on my Web page.  It's good reading!

george

-- 
 Handmade Photographic Images     
  http://www2.ari.net/glsmyth

------------------------------

Topic No. 9