Linear vs circular polarisers

In this article it discusses the reason linear polarisers don't work with many modern cameras that use TTL metering and autofocus:

• https://luminous-landscape.com/polarizers/

In the article, the author Michael Reichmann states:
"The reason for this is that both of these systems use semi-silvered mirrors to siphon off some of the light coming through the lens. If that light is linearly polarised it renders either the metering or the autofocus ineffective. This means that you're going to have to buy circular polarisers unless you're shooting with a pre-1970s camera, or a view camera."

Can anyone here confirm that this applies to mirrorless cameras? I'm assuming it does, but not knowing the technical aspects of how the metering works in my GH4, I just want to make sure. Since I am using mostly manual focus lenses, as long as the metering works a linear filter would be a good choice for me.

Thanks.

All my CPL filters are priced $4.99 to $5.99, some people think

price must be $80 to $160 (or higher)  .... hahaha 

Tom Board wrote:

Can anyone here confirm that this applies to mirrorless cameras? I'm assuming it does, but not knowing the technical aspects of how the metering works in my GH4, I just want to make sure.

According to Panasonic UK, you should use a circular polarizer, but I admit I don’t understand why:

https://www.lumixgexperience.panasonic.co.uk/lumix-academy/using-lens-filters-and-converters/#.XBrtIqROmEc

New linear polarizers are fairly scarce — there are only a couple of odd corner cases where a linear polarizer is preferred.  With a more expensive polarizer, what you are paying for is the name, coatings, sometimes high transmission polarizering film, sometimes “encasing” (Kaesemann), sometimes brass hardware, and general fit and finish.

A multicoated filter will transmit about 7-8% more light than an uncoated filter.  Uncoated filters are also more likely to cause flare.  I own polarizers in a lot of sizes, and most are multicoated.

Mirrorless cameras can use both types

Importance of polarisers is grossly exaggerated - today software does better job in eliminating haze and improving contrast.

no

s_grins wrote:

Mirrorless cameras can use both types

Importance of polarisers is grossly exaggerated - today software does better job in eliminating haze and improving contrast.

Can't do it in software if the data isn't in the file. You can do a lot of great, basic haze removal and contrast improvement in post, but a skilled photographer taking the time to use a filter will still produce some photos that are beyond what can be done in software.

Same goes for gradual NDs. You can do a regional post processing job, but you will never get the same total dynamic range in the photo as using a grad. I guess multi-shot HDR can get you there, but then you really want a tripod for the best results, so more gear is more gear.

And you can't replicate the polarizer's effect on reflections.

From what I'd heard (and which seems to be confirmed by the other messages in the thread), Linear vs circular isn't relevant for cameras using contrast-detect autofocus.

The question I haven't seen answered is whether it works with mirrorless cameras that have phase-detect systems as well? The E-M1 I and II are the only ones I currently know of on the M4/3 roster, so it's more of an academic issue for me now - but if there is a Pen-F successor that includes phase-detect...