Polarising filter

As I've mentioned before I'm off to Iceland in a couple of weeks and I want to take some polarising filters with me. I was looking at the Hoya Pro 1 Digital range but they look a bit pricey, I notice Kenko also do these filters as well. Has anyone used Kenko before and are they any good in comparison?

Thanks

Rob

Good polarising filters aren't cheep! Especialy if you want them to fit multipul lenses.
There are two ways around this -
either
buy a filter to fit your lens with the largest filter diameter then use step up rings to allow the large filter to be used on the lenses with a smaller filter diameter.
or
invest in the Cokin (or similar) filter system where by use of different diameter mounting rings the holder can be used on different lenses.

Basicaly buy a big filter which can be used on all lenses.

The Cokin A size will fit on the kit/basic lenses (18-55 and 50-200) OK but will cause vigineting on larger diameter lenses so if useing the Cokin system then go for the P size which can then be used should you invest in DA* lenses [DA* 16-50 needs the wide angle Cokin P mount which only holds 1 filter not 3]
7dayshop.com has competitive prices on Cokin filters

Also do get a CIRCULAR polariser not a linear polariser as I believe the latter interferes with the auto focusing

Good luck
Bob

Check out the prices on eBay before deciding that Hoya Pro filters are unaffordable.

A non Pro version should be alright too if you don't mind it being thicker.

I've used the Kood P-size polarising filter for a few years (£26-ish)
SRB Film supplied it.

Other users have said the Pentax AF system is not confused by the (cheaper) linear polarisers (about £18 in P-size Kood)... that's worth knowing (though I haven't personally tried it)

Matt

For Kood P filters, 7dayshop.com are very well priced. I use the Kood polariser too, and haven't had any problems with it.

Kood P Circular Polariser - £14.99

Kood P Series Filter Holder - £3.99

Adaptor Rings - £2.99 each

Dan

Be careful ... there are some ebay sellers who are passing off other variants and Pro1-D ploarisers.

Has anyone had a linear polarizer interfere with focusing or metering on modern cameras? I don't seem to have any problems and have heard other people report no issues on their cameras as well.

Is this an issue that just doesn't exist any more?
i.e. is this merely a myth perpetuated to sell higher priced circular polarizers?

How noticeable is the problem? Perhaps the issue is there but not perceivable by myself.

I use both and don't seem to have a problem, but have written about the myth many times. It was bad on film cameras like the Canon T90 and Olympus OM4 as it affected the metering, but I've used them on all the digital Pentax models without any problems. If the meter is fooled you can easily compensate anyway.

I haven't had any problems with auto focus at all using a linear PL, I picked up - on the usual place - a 49mm Pentax Circular PL filter, just the ticket for my 40mm DA Ltd. I was pleased since it was BNIB but of considerable vintage. The instruction sheet describes at some length that linear PLs will give erroneous exposure readings with the LX's metering system (pre auto focus of course).

Perhaps I should scan and post the instructions for someone (Peter Bargh, perhaps ) to perform scientific tests with the current meters.

Ken

I am using Marumi Circular Polarising Filters, they are anti-reflection coated and in slim mounts ie. the equivalent of Hoya Pro 1 filters. They are about half the price of the Hoya Pro 1. Camera World in London sell them.

Sorry if I've passed on bad information, but it's what I've been told.

May-be other Camera systems are effected but not Pentax, or its only if you happen to have the polariser exactly 90 degrees to a linear focus sensor but cross sensors will always cope?

Good luck
Bob

I didn't notice any AF or exposure problems when I tried a linear polariser with an *ist DS - but that doesn't mean there couldn't be any. Problems might arrise in certain circumstances.

Nothing to apologize for, but that is why I asked the question. I have also heard this mantra for so many years, I only discovered what appeared to be a lack of problems by accident. I also wondered if it is just certain circumstances that cause the problem to be more or less noticeable.

Anyway, that's why this forum is so great... the camera store is not likely going to tell me to buy a less profitable item.

I understand the physics of linear v.s circular polarizer to some degree (find plenty of sites explaining how those work), but if anyone knows why this affected some cameras but does not seem to affect others, I'd be interested to know.
i.e. is it simply due to cross sensors, or something else?

Just remember with systems such as the Cokin P system, you can't use your lens hood and lens flair might be a problem. Though Cokin do do hoods, I have not tried these.

Pentax Lens hoods have a small removable part that will allow you access to rotate the filter without removing the hood. Using a larger filter with a step up ring might mean that the hood won't fit.

Just a few thought worth bearing in mind.

The Cokin systems all have lens hoods