BRHSLIST
[Top] [All Lists]

Re: [CBQ] Black Boxcar Theory

To: CBQ@yahoogroups.com
Subject: Re: [CBQ] Black Boxcar Theory
From: "Randy Gordon-Gilmore randy@prototrains.com [CBQ]" <CBQ@yahoogroups.com>
Date: Wed, 03 Feb 2016 20:52:07 -0600
Authentication-results: mta1001.groups.mail.ne1.yahoo.com from=prototrains.com; domainkeys=neutral (no sig); from=prototrains.com; dkim=pass (ok)
Delivered-to: archives@nauer.org
Delivered-to: mailing list CBQ@yahoogroups.com
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoogroups.com; s=echoe; t=1454554275; bh=1FobygOOIOoYY9pXD+eaRKImWpW8+xsvJOwSrPq0Lls=; h=To:In-Reply-To:References:From:List-Id:List-Unsubscribe:Date:Subject:Reply-To:From:Subject; b=d3m0Ns3ZisLRfrnzEPKEY7IswRCs56+og2KxJhs6IDhfQhTC9Gnfj0tTNk0gUMk2OfzIkekK+m87kyyUt7ssL62xVSyqjuuGKbBOXEk5l4lICl4VIVNH/M6khTqyYjjvmfNqy0g1myPgMJ0/6SU0M62/FmP03oHCiCoB2RPC9Ro=
In-reply-to: <3B7DC710-7D36-4C07-A9F8-90F9E12B357C@mchsi.com>
List-id: <CBQ.yahoogroups.com>
List-unsubscribe: <mailto:CBQ-unsubscribe@yahoogroups.com>
Mailing-list: list CBQ@yahoogroups.com; contact CBQ-owner@yahoogroups.com
References: <3B7DC710-7D36-4C07-A9F8-90F9E12B357C@mchsi.com>
Reply-to: CBQ@yahoogroups.com
Sender: CBQ@yahoogroups.com
At 05:43 PM 2/1/2016, Randy wrote:

 >taking measurements of the individual RGB color channels,
 >Red, Green, Blue with the Eyedropper tool

Randy, an RGB scan of a B/W print contains no useful information 
relative to a grayscale scan.  The color separation was not there to 
begin with.  The negative or print contains pure density 
information.

If a scan of a B/W print results in differing R, G, and B values per 
pixel, that only reflects an imbalance between the color channels of 
the scanner.  Scanning something like a 21-step Stouffer density 
wedge would let you calibrate your scanner for grayscale scans.

It is possible to theorize about colors if the type of B/W film 
(orthochromatic vs. panchromatic, etc) used for the original negative 
is known, and thus their response to particular colors.  I used to 
belong to American Aviation Historical Society, and there were 
discussions on this exact subject on interpreting colors of pre-WWII 
military aircraft back in the 1980's or so.

Sorry if I'm preaching to the choir (not the first time I've done 
that...)

Best regards,

Randy
--
Randy Gordon-Gilmore
http://www.prototrains.com
randy@prototrains.com



------------------------------------
Posted by: Randy Gordon-Gilmore <randy@prototrains.com>
------------------------------------


------------------------------------

Yahoo Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/CBQ/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/CBQ/join
    (Yahoo! ID required)

<*> To change settings via email:
    CBQ-digest@yahoogroups.com 
    CBQ-fullfeatured@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
    CBQ-unsubscribe@yahoogroups.com

<*> Your use of Yahoo Groups is subject to:
    https://info.yahoo.com/legal/us/yahoo/utos/terms/


<Prev in Thread] Current Thread [Next in Thread>