Archived posting to the Leica Users Group, 2011/06/08

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Subject: [Leica] What film did HCB use?
From: john at mcmaster.co.nz (John McMaster)
Date: Thu, 9 Jun 2011 03:47:24 +0000
References: <BANLkTi=J1ypG1YeJdYm1EFj3t+LnEd1nig@mail.gmail.com>, <CA15B87D.FF77%mark@rabinergroup.com>, <80F9701439F20347874CE5E4E03C22E91318D397@WhizzMAIL01.whizz.org>

And from the 1943 HP3 entry "(post 1960 the 200ASA emulsion was revised to 
400ASA but there was no actual speed increase, it was in recognition that 
with better exposure determination methods at that time, there was no longer 
need for all film manufacturers to include an exposure safety margin. This 
2x speed increase applied to all black&white films of all makes)."

john - with a quiet day at work
________________________________________

I would guess 1960, in the 1938 (HP2) entry on 
http://www.photomemorabilia.co.uk/Ilford/Chronology.html it mentions "the 
film was rated at 125ASA (equivalent to a 250ASA emulsion after the 1960 
'universal' speed rating revision"

john
________________________________________

Both sites cite the change of HP3 and or HP4 from 200 to 400 without citing
the exact date this happens.




Mark
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Replies: Reply from mark at rabinergroup.com (Mark Rabiner) ([Leica] What film did HCB use?)
In reply to: Message from benedenia at gmail.com (Marty Deveney) ([Leica] What film did HCB use?)
Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] What film did HCB use?)
Message from john at mcmaster.co.nz (John McMaster) ([Leica] What film did HCB use?)