Velocity Reviews (http://www.velocityreviews.com/forums/index.php)
-   Digital Photography (http://www.velocityreviews.com/forums/f37-digital-photography.html)
-   -   Re: Infrared photography (http://www.velocityreviews.com/forums/t636992-re-infrared-photography.html)

 Jürgen Exner 09-25-2008 03:25 PM

Re: Infrared photography

DaveC <me@bogusdomain.net> wrote:
>I'm looking for quantitative data (the existence of IR) not qualitative data
>(a pretty picture).

Isn't that the other way round?
Qualitative meaning just yes/no while quantitative in addition tells you
how much, e.g. darker or lighter on a b/w IR-image or
blue/green/yellow/red/white on a color IR-image?

jue

 Jürgen Exner 09-25-2008 05:23 PM

OT: qualitative/quantitative (WAS: Infrared photography)

DaveC <me@bogusdomain.net> wrote:
>> Isn't that the other way round?
>> Qualitative meaning just yes/no while quantitative in addition tells you
>> how much, e.g. darker or lighter on a b/w IR-image or
>> blue/green/yellow/red/white on a color IR-image?

>
>Quantitative: does it exist? do we have presence or absence? 0 or >0?
>Qualitative: what are its qualities?

That is opposite to what I learned in science, especially in chemistry.

There a qualitative analysis tells you _which_ components are present in
a sample (yes/no).
And a quantitative analysis tells you _how much_ (what quantity) of each
component can be found.

Wikipedia seems to support this view:
"A quantitative attribute is one that exists in a range of magnitudes,
and can therefore be measured. Measurements of any particular
quantitative property are expressed as a specific quantity, referred to
as a unit, multiplied by a number. Examples of physical quantities are
distance, mass, and time."

>Please let's not detour into this realm. Those who want to discuss

Ooops :-). "Subject" adjusted as requested.

jue

 me@mine.net 09-25-2008 06:04 PM

Re: Infrared photography

On Thu, 25 Sep 2008 08:58:06 -0700, in rec.photo.digital DaveC
<me@bogusdomain.net> wrote:

>But to define in other terms, I want images that show the existence of IR
>wavelengths. If it's not a pretty picture, that's OK.

What you will possibly do is show that your camera will be able to or
not detect IR, not whether it exists.

 All times are GMT. The time now is 03:20 AM.