[rollei_list] Re: OT: B&W Filters in digital...Pola filters

  • From: CarlosMFreaza <cmfreaza@xxxxxxxxx>
  • To: rollei_list@xxxxxxxxxxxxx
  • Date: Mon, 12 Jul 2010 22:04:23 -0300

2010/7/12 Laurence Cuffe <cuffe@xxxxxxx>:
>
> What about a Pola-Screen? I can not find a
> reference to polarization in the IB for my camera.
>
> Marc
>
> Yes good point. Thats another glaring exception to the notion that it can
> all be done in Photoshop.

Regarding a polarizing filter for PS and others image edition
software, it's necessary to distinguish two main practical effects you
can obtain from a regular true polarizing filter used during the image
taking. The effect to obtain deeper and darker blues for the sky and
for the greens, etc. can be obtained using PS or similar software
judging the image after to take it, you don't need a Pola-Screen for
this case. It can be done working with the R-G-B channels in PS or it
can be easily done with simpler tools like the Sky graduated filter
from Picasa. This is a method for PS:
http://photoshoptutorials.ws/photoshop-tutorials/photo-effects/polarizing-filter.html

However there is another very useful effect you can obtain from a true
Pola filter (Rolleipol f.e.) that cannot be obtained from PS and
similars; this is the effect to eliminate reflections from bright and
transparent surfaces allowing to capture subjects beyond this surface,
f.e you wan to capture fishes and stones within clean and transparent
water but the reflections are avoiding to see them, turning the
Polafilter you'll find a point where the light is polarized and the
reflections are eliminated allowing to capture fishes and stones. If
you want to capture the _real_ image for this and similar cases, you
need to use the filter during the image taking, PS cannot invent the
real subject.

Carlos
---
Rollei List

- Post to rollei_list@xxxxxxxxxxxxx

- Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' 
in the subject field OR by logging into www.freelists.org

- Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 
'unsubscribe' in the subject field OR by logging into www.freelists.org

- Online, searchable archives are available at
//www.freelists.org/archives/rollei_list

Other related posts: