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Sea: Linear polarizer with S-M-C 120/2,8
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PostPosted: Wed Apr 15, 2009 1:51 pm    Post subject: Sea: Linear polarizer with S-M-C 120/2,8 Reply with quote

This is crop. Everything the same but polarizer turned.



Ok, it is not actually a wildlife lens ..


PostPosted: Wed Apr 15, 2009 2:10 pm    Post subject: Reply with quote

So the polarizer actually makes the picture worse... As can be seen in the right photo where the swan exhibits a lot of CA (there's none in the left photo).

OK, now I remember why I never use filters Wink


PostPosted: Wed Apr 15, 2009 2:21 pm    Post subject: Reply with quote

How could plain glass cause CA? Wink

Slight misfocus and different exposure are more likely the reason of that axial color.

I used a lot of filters in past - cheap, expensive, different brands, various versions and none of them affected CA. Pure flat glass can affect contrast, sharpness, colours, but it can't create CA.


PostPosted: Wed Apr 15, 2009 2:34 pm    Post subject: Reply with quote

You are right... I usually never see this type of "defects" as I always make sure that the exposure is right (no blown highlights or crushed blacks) and I shoot in RAW too. So I'm less likely to be affected.


PostPosted: Wed Apr 15, 2009 2:45 pm    Post subject: Reply with quote

Are you using a linear polarizer with a DSLR or is this film.
You should use a circular with a dslr. The Linear can cause Color transmition problems and Moire to a bayer type sensor.


PostPosted: Wed Apr 15, 2009 5:55 pm    Post subject: Reply with quote

Didn't notice the CA .. Embarassed
Just thought that colors are better on the right.
Remember this is 100% crop not 100% crap. Wink


PostPosted: Wed Apr 15, 2009 8:41 pm    Post subject: Reply with quote

Perhaps polarizer not so good, my first cheap polarizer dropped out from my hands when I saw result on camera back it was too crap.


PostPosted: Wed Apr 15, 2009 10:21 pm    Post subject: Reply with quote

Polarizers are very useful don't give up on them.

We must think of any filter as we do a lens.
A sheet filter is going to give sheet results.

Best to stick with B+W or Heliopan.
If you are a landscape shooter buy the best Circular polarizer for your largest diameter lens.
You may buy cheap step down rings for the smaller lenses to adapt this one.

Do not use old linear Polarizers with a DSLR you will get Moire and other strange results.

There is a reason that Circular polarizers were invented. AF sensors and Bayer array are that reason.


PostPosted: Thu Apr 16, 2009 3:03 am    Post subject: Reply with quote

Buy two of them and stack them. You now have a variable neutral density filter. But don't tell THAT company that charges $300USD+ for theirs, it might hurt their feelings..................

Wink


PostPosted: Thu Apr 16, 2009 7:10 am    Post subject: Reply with quote

F16SUNSHINE wrote:
Polarizers are very useful don't give up on them.

We must think of any filter as we do a lens.
A sheet filter is going to give sheet results.

Best to stick with B+W or Heliopan.
If you are a landscape shooter buy the best Circular polarizer for your largest diameter lens.
You may buy cheap step down rings for the smaller lenses to adapt this one.

Do not use old linear Polarizers with a DSLR you will get Moire and other strange results.

There is a reason that Circular polarizers were invented. AF sensors and Bayer array are that reason.


Thank you for the advice.

I planned to use the linear polarize just to shoot sky, sea and vegetables. In Finland they always have pretty low contrast so CA is not very serious problem. The swan was very extraordinary sight visually, old people wrote them in mythologies and Sibelius wrote some dramatic music about it.

http://en.wikipedia.org/wiki/The_Swan_of_Tuonela

The nice thing of linear polarizer is to control the reflections. With the circular polarizer it is just on / off?

How often you get moire or other weird things (this is really a question): A) one in every two frames, B) one in ten frames, C) one in a hundred or less. And does the direction of the polarizer have any effect?


PostPosted: Thu Apr 16, 2009 7:15 am    Post subject: Reply with quote

Spotmatic wrote:
So the polarizer actually makes the picture worse... As can be seen in the right photo where the swan exhibits a lot of CA (there's none in the left photo).


The filter is on both shots, it is just different direction.