Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-18-2010, 07:49 AM   #31
Veteran Member
Eruditass's Avatar

Join Date: Jul 2009
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 2,206
sample photos taken of foliage need to be shown, this is one of the most important effects

04-18-2010, 10:50 AM   #32
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,397
QuoteOriginally posted by Wheatfield Quote
Pentax cameras, with only one exception, meter off the focusing screen, if I am not mistaken.
With this in mind, a linear polarizer isn't going to affect metering at all, since there is no beam splitter involved.
If you are like me and use mostly manual focus lenses, there is not much reason to spend the bucks on a circular polarizer, and you are better off buying a good quality coated linear than an uncoated circular.
quite true

all the way back to my PZ-1 the justification for circular polorizers was to insure the AF worked, not the metering.

If anyone wants really good proof that pentax cameras meter off the focusing screen, just look at the impact changing the focusing screen makes on K10D metering, or for that matter why split image view finders mess up the metering. If it was a beam splitter at the mirror for metering, the focusing screen would have no impact.

04-18-2010, 03:51 PM   #33
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 9,403
QuoteOriginally posted by Lowell Goudge Quote
quite true

all the way back to my PZ-1 the justification for circular polorizers was to insure the AF worked, not the metering.

If anyone wants really good proof that pentax cameras meter off the focusing screen, just look at the impact changing the focusing screen makes on K10D metering, or for that matter why split image view finders mess up the metering. If it was a beam splitter at the mirror for metering, the focusing screen would have no impact.
Thanks for the chart, Lowell. Matches the effect I got with the K10 and the *ist screen.

Even the LX was fine with linear polarizers, except for manual exposure, because the LX continued to meter from the film after the mirror lifted in auto exposure modes.

I am of the opinion that only occasionally do the circular polarizers have an effect on anything. It depends entirely on the differing angles of the polarized light trying to pass through the half silvered mirror. There is an angle at which there is no effect at all. There is another, 90 degrees off, where things would really go south. The half silvered mirror is a form of polarized light filter. Knowing my luck, the one and only time I would have an opportunity of photographing a grizzly bear doing a headstand on the ten meter diving board would be the one time that the CPL filter would ruin the shot. I therefor purchased the circular polarizer. I guess I am a suspenders and belt kind of person.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
auto-focus, camera, comparison, dslr, effect, files, filter, k20d, photography, polarizer, shots
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Choosing a Linear Polarizer Eruditass Pentax Camera and Field Accessories 33 11-28-2010 08:06 AM
linear polarizer repair pdophoto Pentax Camera and Field Accessories 8 04-26-2009 12:29 PM
Circular vs. Linear Polarizer on a K100d? lokerd Pentax SLR Lens Discussion 7 04-03-2009 09:41 PM
Linear Polarizer & Manual Lenses konraDarnok Pentax Camera and Field Accessories 1 10-10-2007 12:34 PM



All times are GMT -7. The time now is 07:50 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top