[kevingun]

Any suggestions for a polarizing filter for a sigma zoom telephoto 70-300 f-4-5.6 apo dg macro lense

Thanks

[stevbike]

Use a polarizer that circulator in design. The older style design does not work well with the newer digital cameras systems. Here is a link that explains the differences with two types of polarizing filters.

Polarizers

[Docrwm]

I asked a similar question recently and this thread is the result:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/149950-nice-co...ml#post1559048

[kevingun]

Thanks guys

[SOldBear]

Use a polarizer that circulator in design. The older style design does not work well with the newer digital cameras systems.

All the times I've been hearing that one should not use linear polarizing filters. But from what I can tell, my K10Ds and K7 don't seem to know the difference between linear and circular polarizing filters. Can someone please confirm or deny my observation. Thanks.

How do you tell if a polarizing filter is circular or linear?

1. If the label says "circular," then it is circular.
2. If the label doesn't say "circular," there is a good chance it is linear.
3. Stand in front of a mirror, put the filter to cover one of your eye, then flip it (so the face of the filter that used to face your eye now faces the mirror). If in both cases, you can see the eye behind the filter, the filter is linear. If you see your eye in one case but can't in another, the filter is circular.