polariser problem

ruffdog64 · 24 Jul 2012

I went out yesterday to use my polariser filter for the first time and when i tried to focus it wouldn`t lock onto anything; predominatly on landscape shots but not all the time and the focus point was in the distance can i assume it was just because of the range invovled? Harvey

gad-westy · 24 Jul 2012

Was it a circular polariser or a linear polariser? Modern DSLR auto focus systems don't like linear polarisers.

ruffdog64 · 24 Jul 2012

Circular

gad-westy · 24 Jul 2012

ruffdog64 said:
Circular

Hmmm, well the only other thing that springs to mind is that the CPL is cutting enough light to the camera that the auto focus is struggling. How much light was there?

HoppyUK · 24 Jul 2012

What filter exactly, lens and focal length, camera?

If it's a long lens and a low grade filter you'll praps get focus issues.

Nguss · 24 Jul 2012

Maybe focus without and then put the polariser on?

Bristolian · 24 Jul 2012

HoppyUK said:
If it's a long lens and a low grade filter you'll praps get focus issues.

I get the problem with a high grade filter on my 70-300mm. It's so bad you can actually see it's out of focus in the viewfinder :bang:

Take the filter off and it's bang on

ruffdog64 · 24 Jul 2012

The poloriser filter is a "camlink" on a canon 70-300 is usm lens and a 1d mk2 the conditions were bright sunshine and clear blue skies

HoppyUK · 24 Jul 2012

ruffdog64 said:
The poloriser filter is a "camlink" on a canon 70-300 is usm lens and a 1d mk2 the conditions were bright sunshine and clear blue skies

It's probably the filter, and worse at the 300mm end where that lens is already getting a bit soft. It's common.

At longer focal lengths, the lens only 'looks through' a small section in the centre of the filter, so any imperfections become greatly magnified. You'll probably not notice anything with a wide angle.

redhed17 · 24 Jul 2012

I had this problem when I bought a cheap Jacobs Polariser, it seemed to work fine on my 16-85mm, but when I put it on my 70-300mm, and was between 200-300mm, the camera couldn't focus, and the image was visibly distorted at 300mm. The chap in the shop tried to blame my lens, but when I showed it worked fine without the filter, he said, 'Oh, I've never seen that before'. He tried a Hoya filter on it, not that much more expensive, I think £15-25 more, and that was fine. He even said he'd let me have a couple of pounds off, but at the time I didn't have the extra cash.

Because I have the same filter size for both of my lenses, I've gone for a Hoya Pro Polariser, and I'me vey happy with it.

But I think a mid priced Hoya should be good enough. Certainly better than the Camlink filter.

hollis_f · 26 Jul 2012

ruffdog64 said:
The poloriser filter is a "camlink"

Ah, that's probably the problem. 'Camlink' is Korean for 'steaming pile of wombat poo'. I'll bet your problem is another example of how to waste money by saving money.

ruffdog64 · 26 Jul 2012

hollis_f said:
Ah, that's probably the problem. 'Camlink' is Korean for 'steaming pile of wombat poo'. I'll bet your problem is another example of how to waste money by saving money.

Lol can you recomend one?

HoppyUK · 26 Jul 2012

ruffdog64 said:
Lol can you recomend one?

Hoya HD is best IMHO. And especially for longer lenses where you need to keep shutter speeds up, and with your lens in particular that will benefit from stopping down a bit. Hoya HD only reduces the overall exposure by 1.2 stops, rather than the 1.7-1.9 of most others.