Plus X reciprocity

[Craig]

I'm going to be doing a shoot of building interiors, natural light only, and its pretty dark inside. Typical exposures are in the 30 second F8 range. I was planning to use up a box of Plus X in 4x5 that I have, but don't have the reciprocity data sheet.

Will I need to lengthen the exposure time and/or increase the development at these light levels? Artifical light isn't an option, so I'm stuck with these long exposures.
I've also got some HP5 if that will work better.

Craig

 

[titrisol]

Kodak PDF here:
http://www.kodak.com/global/en/professional/support/techPubs/f8/f8.pdf

If Indicated
Exposure
Time Is
(Seconds)
Use This
Lens-
Aperture
Adjustment
OR
This
Adjusted
Exposure
Time
(Seconds)
AND
Use This
Development
Adjustment

Indicated exp Adjust by or expose by and develop adjust:
1/100,000 +1 stop Adjust aperture +20%
1/10,000 +1⁄2 stop Adjust aperture +15%
1/1,000 None None +10%
1/100 None None None
1/10 None None None
1 +1 stop 2 –10%
10 +2 stops 50 –20%
100 +3 stops 1200 –30%

 

[Craig]

Exactly what I need, thanks!

 

[Deckled Edge]

... and/or increase the development at these light levels?
Craig

Craig,
Notice that for increasing exposure times over 1 sec. you will decrease, not increase, the development. Contrast inherently increases with the exposure time, so you counteract that with minus development.