Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > Monochrome Work > Monochrome Film

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 1st September 2017, 06:00 AM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default Ilford Reciprocity Calculation

Ilford have released a new recommendation for reciprocity calculation. It is in the form of a pdf and has factors for each film so that you can calculate the corrected time instead of trying to read it from a graph. Instructions are included on the sheet.
It can be found at https://www.ilfordphoto.com/wp/wp-co...mpensation.pdf

Bill
Reply With Quote
  #2  
Old 1st September 2017, 07:34 AM
MartyNL's Avatar
MartyNL MartyNL is offline
Friend
 
Join Date: Sep 2010
Location: based in The Netherlands
Posts: 3,341
Default

Unfortunately the link doesn't work for me, neither does the Google search link. So perhaps something is going on with that document at Ilfords end?
__________________
MartyNL

“Reaching a creative state of mind thru positive action
is considered preferable to waiting for inspiration.”
- Minor White, 1950
Reply With Quote
  #3  
Old 1st September 2017, 07:56 AM
Paulographic Paulographic is offline
Friend
 
Join Date: Jun 2010
Location: Mid Pennines
Posts: 835
Default

Worked for me and I saved it as an image in pictures.
Reply With Quote
  #4  
Old 1st September 2017, 07:57 AM
Michael Michael is offline
Friend
 
Join Date: Dec 2008
Location: Ballinderry Lower, Co. Antrim
Posts: 1,345
Default

Try again, Marty. It just worked for me there.
Reply With Quote
  #5  
Old 1st September 2017, 08:26 AM
mpirie mpirie is offline
Friend
 
Join Date: Jul 2009
Location: Highlands of Scotland
Posts: 430
Default

I've attached the document from Ilford.

Mike
Attached Files
File Type: pdf Reciprocity-Failure-Compensation.pdf (35.9 KB, 1569 views)
Reply With Quote
  #6  
Old 1st September 2017, 08:45 AM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

Just checked and it is working for me.

Bill
Reply With Quote
  #7  
Old 1st September 2017, 10:04 AM
MartyNL's Avatar
MartyNL MartyNL is offline
Friend
 
Join Date: Sep 2010
Location: based in The Netherlands
Posts: 3,341
Default

Yes working fine now. Thank you.
__________________
MartyNL

“Reaching a creative state of mind thru positive action
is considered preferable to waiting for inspiration.”
- Minor White, 1950
Reply With Quote
  #8  
Old 1st September 2017, 05:17 PM
Jerry Bodine Jerry Bodine is offline
Friend
 
Join Date: May 2015
Location: Seattle area, Washington state
Posts: 169
Default

Here's a statement (slightly edited by me) from Ilford about this release:

The charts currently in all our individual film fact sheets are calculated with the same method using a factor of 1.48. The people who came up with this factor left the company many years ago so I have no idea how it was derived. It was because of our customers questioning this factor that we did the work.

I was curious to see how this new pdf compares with the factor given for my two favorite films, HP5+ and FP4+, so I used MS Excel to plot the readings from the curve shown in the many film data sheets and find a best-fit curve through those readings, then plotted the results yielded by the new pdf for the comparison. I was able to confirm the factor 1.48 very closely. The attached final plot shows all my results. I think the pdf is the best way for Ilford to present their results, as it allows one to either plot curves to put in a field notebook OR tabulate the corrections for preferred films to place on a light meter. Obviously, the reciprocity corrections required now are much less vigorous than Ilford's previous recommendations.
Attached Thumbnails
Click image for larger version

Name:	2017-09-01.png
Views:	519
Size:	118.7 KB
ID:	2789  

Last edited by Jerry Bodine; 1st September 2017 at 05:28 PM.
Reply With Quote
  #9  
Old 1st September 2017, 05:24 PM
PanFrank's Avatar
PanFrank PanFrank is offline
Friend
 
Join Date: Jul 2017
Posts: 681
Default

Thank you for posting this, Bill. I made up a table with exposure corrections for my three mostly used films, which will find a place in my bag.
Frank
Reply With Quote
  #10  
Old 1st September 2017, 06:03 PM
Tony Marlow Tony Marlow is offline
Friend
 
Join Date: Sep 2008
Posts: 1,282
Default

For some years I have been using a table produced by Les McLean which he found to work for him and I have found to work for me. However Les's values start off similar to Ilfords new values at two seconds but Ilford's values become less than Les's upto two minutes exposure by less than half for FP4 and HP5. It would be interesting to hear how anyone finds how Ilford's new values work.

Tony
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Reciprocity for Pinhole? PavelDerka Photography in general 7 3rd February 2012 10:07 PM
Reliable reciprocity data for Ilford FP4+ PaulG Monochrome Film 10 25th April 2011 11:36 AM
Reciprocity and Fuji Acros Mike O'Pray Monochrome Film 2 30th July 2010 05:29 PM
HP5 Reciprocity Failure Victor Krag Photography in general 0 15th February 2009 08:34 PM
Reciprocity? Mike Meal Monochrome Film 8 8th January 2009 05:30 PM


All times are GMT. The time now is 12:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.