There's a section in Digitaltruth (if you click on the link 'site map' at top right)Does anyone know of reliable, proven charts.
I'm getting mind boggled with googling.
Particularly interested in Tri-X, Delta 400 and Fomapan 100 and 400.
Thanks
There's a section in Digitaltruth (if you click on the link 'site map' at top right)
http://www.digitaltruth.com/data/reciprocity.php
http://www.digitaltruth.com/devchart.php?Film=&Developer=ID-11&mdc=Search&TempUnits=C for ID11
There's a recent document from Ilford on this regarding their own films. https://www.ilfordphoto.com/wp/wp-content/uploads/2017/06/Reciprocity-Failure-Compensation.pdf
Ian Barber is a good man to know, find him on Google.
Right, I've done a litlle spread sheet of info gained so far, but I can't figure out how to post it here.
Can anyone help please?
Oh, I've used Open Office rather than Microsoft Office.
Thanks Chris.
There does seem to be some significant differences between the two sets of numbers which is a bit of a puzzle.
The data sheets and testing? Yeah They're pretty mad. I think Illford got a bit lazy with the their T grain stuff and just used the same formula, it does work and gives a good exposure but its far too much when you're standing in a cold street covering the lens everytime a car comes past.
I guess the time has come for me to just do it and see what happens.
Chris, I think the times in your table for FP4+ are the OLD times given by Ilford - you might want to use their NEW times. So for example a 30s metered time would give an actual exposure time of 73s instead of 155sThis is one I made earlier, the numbers probably need an update s I put the date in to distinguish...
General idea is: green, as metered. Amber, up to one stop extra (in time); might get away with metered. Red, more than one stop extra.
I use exposure compensation on the Pentax LX so I don't have to count elephants; it will meter down to EV 1 or less, and keep the shutter open (in aperture priority) until it's got enough light in. So +1 or +2 compensation works for most cases!
EDIT: thanks ti @steveo_mcg and @Kevin Allan for providing some basic data.
Chris, I think the times in your table for FP4+ are the OLD times given by Ilford - you might want to use their NEW times. So for example a 30s metered time would give an actual exposure time of 73s instead of 155s
Kevin
I shall try 1 or 2 per roll until I get confident in the numbers.