Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: JeanPaulKelly on February 07, 2011, 04:12:22 pm

Title: Non-post digital equivalent to "non-repro blue"?
Post by: JeanPaulKelly on February 07, 2011, 04:12:22 pm

I am wondering if there is an equivalent to using "non-repro blue" ("non-photo blue") in digital optics or scanning? Is there any color that will not register to a digital camera sensor or to a scanner? I am not interested in a post-production solution, but rather a process that will work at the time of shooting. I'm am pretty sure there is no such process, but any information would really help.  Thanks.

Title: Re: Non-post digital equivalent to "non-repro blue"?
Post by: Schewe on February 07, 2011, 05:27:46 pm

Green screen (or blue screen) can be used to composite people or things in front of the green screen. Used in motion a lot. But you do need some pretty pure green in the capture and you'll need a post technique to take it out. Otherwise, not, sensors are active in pretty much the visible spectrum. So if you can see it, it'll be captured. It might be interesting to test out the far ultraviolet (UV) since sensors are more sensitive to infrared (hence the IR cutoff filters).

Title: Re: Non-post digital equivalent to "non-repro blue"?
Post by: Mike V on February 23, 2011, 05:08:29 am

Do you mean marking prints with something you can see but it won't scan?

If so you can use UV ink or paint with no colour and illuminate the print with a UV source.

e.g.

http://www.dealextreme.com/p/invisible-ink-pen-88 (http://www.dealextreme.com/p/invisible-ink-pen-88)


Or do you mean marking a set with something you can see but not photograph?