Suggestion about linear or circular polarizer

[versanteest]

Hi!

I'd like to buy a polarizer filter for my contax lens (distagon 25) with 55m size filter.
I'll use It only in MF way.
I know that if I buy circular, I'll can use it with or without AF lenses/camera....Someone told me that linear polarirzer work fine only with MF and linear polarizer is superior.
Anyone has experience about linear and circular polarizer ?
What do you suggest me ?

both have same performances ?

I'm thinking to get one of this used:

B+W 55E TOP-POL



Regards

Pasquale

[Attila]

I have B+W 55mm polarizer honestly no idea circular or linear I used a few times only, -0.7EV + PP makes me same or almost same result so I rarely use it.

[philslizzy]

The filter in the pic is a linear

Linear polariser is best, circular is a compromise. I use the linear one to reduce reflections in water and glass, far more useful than the circular type. To increase colour depth in skies, the linear again is great, it has a rotating mount so the best effect can be achieved. The circular is so much a compromise.

I think that circular ones were designed not to interfere with autofocus or auto exposure sensors which rely on some sort of linear polarity.

A second hand linear one isn't much on ebay. Get one, at the very least it will service as a neutral density filter

Two linear polarisers screwed together make an incredibly useful variable neutral density filter, when one is turned it goes from about -4 to almost complete black. Cheaper than the Lee Big Stopper and more flexible (and no light leaks which is a big problem with the Lees).

To identify which is which, a linear polariser is named 'PL' a circular one is usually 'CPL' or 'PL-CIR' a brand new one will almost certainly be a circular. I buy 1970's or 1980's Hoya filters as the quality of the glass is superb and they are easily available. Yeah, there's B&W too which is fantastic quality and every camera manufacturer had one in their range but nowadays they're much more expensive.

[philslizzy]

You can make a linear polarizer by buying a variable nd filter, one that fades all the way to black. Take out the front element carefully, they're usually held in with a screw ring. Then smash out the rear one. Making sure the glass is completely cleaned up. Screw the front one back in. Instant linear polarizer

[RSalles]

philslizzy

One think more i learned today!
I don't understand fully how can a linear filter rotate, i didn't know abou that, i suposed only the CPL has a rotation ring, nice to know it, as i never had a linear PL, only CPL. Stacking 2 of them i had a var neutral starting from -4 f-stops or 4 X -1/3?

Thanks,

Renato

[philslizzy]

you've seen the effect a circular polarizer has, yes? Well with a linear polarizer the effect is WAYY stronger. Fantastic for eliminating water reflections. circular is a big compromise.

The linear polarizers come in a rotating mount. I didn't know circular ones rotated until i tried one for the first time a few days ago.

I think I'm going to have to do a test...

[RSalles]

I'm going to rewrite my question nº 2:

Q: With 2 LP filter stacked i can have a variable neutral density filter starting from "-4 f-stops" or "4 X -1/3" f-stops?

Thanks,



Renato