Ilford Film Reciprocity Failure - New(ish) Info.
 

The inclusion of the same reciprocity failure chart in all of Ilford's film data sheets has always made no sense as the films clearly have different characteristics, along with Ilford/Harman’s insistence that they stand by the charts when challenged on them has finally changed!

Not sure if others have already seen this but a new(ish) document (dated Aug 2017, but I have only just tripped over it) on Reciprocity Failure has appeared on the IlfordPhoto site that gives a calculation for each film:

https://www.ilfordphoto.com/wp/wp-co...mpensation.pdf

I still have no idea how accurate it is, but at least they have finally admitted there are differences and I can try it for myself next time I am out shooting at slow shutter speeds.

Cheers, Bob.

I have used this new data with FP4+ and it worked for me. Just need as calculator with you.

Thank you, Bob. I've downloaded the pdf for later use.

Thank you Bob. Very helpful. I have downloaded to phone and PC. That will be easier to use than trying to decipher a squinty chart in the dark :confused:

Regards,
Svend

Well I never.
My phone calculator turns scientific if I use it landscape.
And, the calculator on my PC does tricks I didn't know about.
Thanks Ilford.

I'd actually like little graphs for PanF and HP5. I have one for Fomapan 100, and the generic Ilford one, printed and laminated in my bag.

Will have to join 21st century and give the calculator trick a try. When out and about I do carry a phone, so I have a timer available for long exposures. It's also got a sunrise/sunset app which is handy, but my 'phone is so elderly I can't get The Photographers Ephemeris to run on it.
That is actually really good for planning things like where and when the moon will rise, or at what time of year the sun will set in a given direction.

As for the increased contrast with longer exposures I have run into that with Fomapan, as it has seems to show a precipitous drop off in sensitivity as exposure times stretch. The trick is to be aware, and use it to your advantage. Dim light can be very flat, and choosing a longer exposure can give an apparent boost to contrast.

Neat - and really easy to use if you have a smart phone.

I have always thought the reciprocity compensation tables people have banded about were over generous.

Martin

Here's the Ilford reciprocity chart with the new data added.

http://lostlabours.co.uk/Uploads/reciprocity.jpg

Ian

Ian, thanks. I can identify all the colours against each film except the black line. What film is this? Thanks

Mike

Ian, nice work on the graph!! It'll be going in my bag(s) once laminated up.
Is the solid black line the original 'generic' one Ilford offered?

Svend, you may want to check out this tiny LED flashlight (torch) to ease the ability to see in very dim conditions. It only weighs about 1 oz. and has more than enough output for setting shutter/aperture etc. I also find it useful in the darkroom. Here is the store's website and user manual for the E05 model:
http://www.fenix-store.com/ (search E05)
http://www.fenix-store.com/content/E...UserManual.pdf

Jerry