Konica 750 and development.

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Some Dude - 05 Dec 2004 15:49 GMT

Hi-

I've been developing Konica 750 for a few years now and have been
rating it whatever I want and I remember reading somewhere thats its a
very slow film; I believe an EI of 32. So I'm wondering if anyone
has shot this at 32 and if so what sort of times and developers
they've used. I've shot a roll at 32 and am sorta interested in not
destroying it (its 120) so..

On another thought- if you look at the wavelength curves of the film
it seems that it its really a "red" film more than an infrared film.
Seems heavily responsive to 800-900nm where it drops off fast...What
defines an IR film anyway?

Thanks!

p.s. don't try develping it for 11 hours :) (on the other hand..maybe
12!)

Cheers,
-sd
http://www.zoom.sh

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Michael A. Covington - 05 Dec 2004 17:19 GMT

> Hi-
>
[quoted text clipped - 9 lines]
> Seems heavily responsive to 800-900nm where it drops off fast...What
> defines an IR film anyway?

I presume it's called Konica 750 because it goes to 750 nm. The limit of
human vision is about 670 to 700 nm, and anything beyond that is, by
definition, infrared. Obviously we don't want to go *far* beyond that, or
our camera lenses won't work. Most films cut off at about 620 nm. Elite
Chrome goes to 670 nm (hurrah! I use it to photograph hydrogen nebulae,
which other films can't see). Film with an extended red response is not
wanted for portraiture because reddish patches on skin show up too
prominently, particularly if it's color film.

Signature

Clear skies,

Michael A. Covington
Author, Astrophotography for the Amateur
www.covingtoninnovations.com/astromenu.html

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mr. chip - 05 Dec 2004 18:19 GMT

Hello there.

I've developed this film in both 35mm and 120 sizes, and I shoot it at 32
(sometimes 25 or 20, depending on the scene and how much IR film I guess is
present).

I have developed it with ID11 (1+1) for about 8.5 minutes and Xtol (1+1) for
7.5 minutes and obtained good results with both.

I used an Ilford SFX filter (equivalent to a Hoya R72) and a polariser and
with these two in place it's definately an IR film. Without these it does
respond much like a normal film.

The 'Light Falls' series of images here
http://www.photosig.com/go/users/viewportfolio?id=101892 were taken with
Konica IR film and developed with Xtol.. The other IR images were taken with
Maco 820c.

Simon.

> Hi-
>
[quoted text clipped - 18 lines]
> -sd
> http://www.zoom.sh

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Some Dude - 07 Dec 2004 01:20 GMT

As I use neither i'll try rod 1:25 for 8 say at about 22c!...sounds
about right ...its all fun n games :) (i'm sure some of you disagree)

thanks for the numbers chip

>Hello there.
>
[quoted text clipped - 38 lines]
>> -sd
>> http://www.zoom.sh

Cheers,
-sd
http://www.zoom.sh

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Some Dude - 08 Dec 2004 23:05 GMT

FYI I developed the roll like this:

k750 (87d) at ~32ei
rod 1:50
20c, 8m
1/4tsp sodium ascorbate

muy excellente'! Maybe a *little* too dark but thats probably for not
compensating for the 87d and shooting auto exposure.

I've begun only agitating rodinal about 5 seconds per minute and love
the results. Plus saves the wrists when doing 20 minute developments

sharp as a tack!

>As I use neither i'll try rod 1:25 for 8 say at about 22c!...sounds
>about right ...its all fun n games :) (i'm sure some of you disagree)
[quoted text clipped - 47 lines]
>-sd
>http://www.zoom.sh

Cheers,
-sd
http://www.zoom.sh

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