Archived posting to the Leica Users Group, 2003/06/17

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Re: [Leica] Ortho-chromatic film
From: Martin Howard <mvhoward@mac.com>
Date: Tue, 17 Jun 2003 09:51:40 -0700

Slobodan Dimitrov wrote:

> Anyone know what adjustments in PS, or any other software, can be used
> to turn an image taken with ortho film into one that simulates the
> tonality of pan-chromatic emulsions?

If I understand correctly, orthochromatic film captures less spectral 
range than does panchromatic film.  Since PS can only work with what 
you give it, short of "inventing" new pixels, I don't see how ANY 
manipulations in PS could turn orthochromatic images into panchromatic 
images, because you don't know the reflective properties of the objects 
in the scene with regard to the range of frequencies that the ortho 
hasn't captured.  While you might be able to make some educated 
guesses, and locally adjust contrast accordlingly, I doubt you'd be 
able to results which are "the same".

M.

- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html

Replies: Reply from Jerry Lehrer <jerryleh@pacbell.net> (Re: [Leica] Ortho-chromatic film)