Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
02-01-2009, 08:46 AM   #1
Veteran Member
Syb's Avatar

Join Date: Aug 2007
Location: Near Utrecht, Netherlands
Photos: Gallery
Posts: 1,224
Pentax A*300/2.8 and CPL drop-in-filters


This thread may look a little bit like the one about the FA*300/2.8, but this question is about the manual focus A*300/2.8.

The SMC A*300/2.8 lens has a rear filter slide with size 49mm. "Cool!" That is the same size as ther front of my FA50/1.4, I thought, so all my filters for that lens can be used in there, too.

True. But the CPL is too thick. Just cannot slide it in. That really is a pity, I'ld like to see how this lens performs with a polarizer.

Is this inconvenience dependent on the filter brand? Or will all polarizer filters be too thick? (Will a Linear polarizer do the trick? Or be too thick, too?)

Can anybody help me out?

02-01-2009, 01:55 PM   #2
Veteran Member
Ben_Edict's Avatar

Join Date: Jul 2007
Location: SouthWest "Regio"
Photos: Albums
Posts: 3,303
A linear polarizer won't do anything for your problem. You must search for a slim filter, used for wide angle lenses. There are some polarizers available with around 3mm thickness (Hoya/Kenko and, if I remember rightly, also B+W) - these might fit. I had the same problem, when I needed a drop-in filter for my old Tamron 300/2.8 and searched quite a while...

02-01-2009, 04:19 PM   #3
Site Supporter
Site Supporter

Join Date: Feb 2008
Location: MT
Posts: 1,082
If cost is no object, there are 112mm circular polarizers available, including the famous Kasemann Circular Polarizer. As I recall, they are about $400 from B&H. I used one with the A*300/2.8 and it worked very well. Already sold it to another forum member. I've never seen reference to a drop-in circ. polarizer for the A*49mm drop-ins--with the external wheel for rotating the polarizer. They exist for FA*43mm drop-ins--in silver color, and for M*67mm lenses for 6x7 format in cream color, but I've never seen the cream colored 49mm polarizing drop--ins.

Using slim circ. pol. in the drop-in will probably work fine, but it is a pain to have no simple way to rotate it from the outside. If trying to use it while following wildlife it will be difficult as the angle to the sun will change frequently requiring you to pull it out and reregister it (you may want to spring for a polarizer with the degree numbers around the ring--if they still exist and exist in slim configuration).

  • 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!
a*300/2.8, cpl, filter, filters, k-mount, lens, pentax lens, polarizer, size, slide, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: 7 Filters (UV + CPL) Okami Sold Items 1 11-03-2008 11:16 PM
CPL and UV Filters... Hannican Pentax Camera and Field Accessories 3 07-22-2008 06:21 PM
CPL filters axl Pentax Camera and Field Accessories 1 05-16-2008 06:23 AM

All times are GMT -7. The time now is 02:43 AM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]