Why are polorising filters so expensive?
Posted 28/01/2010 - 19:19
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Bob, there is no point in having a decent lens if you put a couple of slabs of frosted glass in front of it. Modern filters from major suppliers apply coatings to them just as lens manufacturers do. Remember that a polarising filter is primarily two finely finished filter elements placed in a holder that permits the outer element to rotate and fulfil it`s function.
Cedric
Cedric
Enjoy life
Posted 28/01/2010 - 20:00
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doingthebobs wrote:
Following the thread on the 'classified' section on polorising filters, I was thinking why are filters so expensive for ones that work properly?
Dealers with high overheads add a big margin so they can make a living.Following the thread on the 'classified' section on polorising filters, I was thinking why are filters so expensive for ones that work properly?
Dealers with low overheads, like eBay small traders, charge more affordable prices.
~Pete
Posted 28/01/2010 - 20:15
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Some of the cheap polarisers aren't bad. I've got three of the "Green Filter" ones from Hong Kong (49mm, 52mm and 58mm) and I've had surprisingly decent results considering the price.
Matt
Shooting the Welsh Wilderness with K-m, KX, MX, ME Super and assorted lenses.
Shooting the Welsh Wilderness with K-m, KX, MX, ME Super and assorted lenses.
Posted 28/01/2010 - 20:41
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Here is a little tip, get a linear filter instead of a circular it save you some money and the linear also work better I believe.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 28/01/2010 - 20:44
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The circular type of polariser is supposed to be necessary for auto focus, but reports of actual problems with linear ones are rare.
~Pete
Posted 28/01/2010 - 20:55
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iceblinker wrote:
The circular type of polariser is supposed to be necessary for auto focus, but reports of actual problems with linear ones are rare.
Yep, I think it might be something of the early days of AF or the type of AF that they use.The circular type of polariser is supposed to be necessary for auto focus, but reports of actual problems with linear ones are rare.
I believe that you can look through a circular both ways but with a linear only in one way, the way the AF works in current DSLR this shouldn't be a problem.
I'm just speculating now though, do someone know the true reason?
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 28/01/2010 - 20:56
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I have a Hoya linear which I bought with a ME Super. Works fine on my DSLR`s
Cedric
Cedric
Enjoy life
Posted 28/01/2010 - 21:11
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Here we have it link
cedricd do you want to do the test on that page, I don't have a linear filter
cedricd do you want to do the test on that page, I don't have a linear filter
Quote:
there is an easy test which can often indicate whether or not a camera needs a circular polarizer. Attach a linear polarizer to the camera and take a TTL meter reading off a blank wall illuminated by indoor (tungsten) lighting. Don't use any kind of shiny (reflective) surface. A carpet might also make a good target. Rotate the polarizer and see if the indicated exposure changes. If it does, you need a circular polarizer.
there is an easy test which can often indicate whether or not a camera needs a circular polarizer. Attach a linear polarizer to the camera and take a TTL meter reading off a blank wall illuminated by indoor (tungsten) lighting. Don't use any kind of shiny (reflective) surface. A carpet might also make a good target. Rotate the polarizer and see if the indicated exposure changes. If it does, you need a circular polarizer.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 28/01/2010 - 23:11
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doingthebobs wrote:
Following the thread on the 'classified' section on polorising filters, I was thinking why are filters so expensive for ones that work properly?
Don't get me wrong, I agree with the idea that the cheap ones are usually not much cop and a waste of money but given that I can get a fairly good multicoated lens for around £100 how can it be justifyed to charge the same for a flat piece of glass?
well if it is for your point and shoot camera, you did get two free polarizers if you wet to see Avatar in 3d.... just take apart the glasses!Following the thread on the 'classified' section on polorising filters, I was thinking why are filters so expensive for ones that work properly?
Don't get me wrong, I agree with the idea that the cheap ones are usually not much cop and a waste of money but given that I can get a fairly good multicoated lens for around £100 how can it be justifyed to charge the same for a flat piece of glass?
they also tape right on to your 360ftz flash units if you orient them right they work.
Fired many shots. Didn't kill anything.
Posted 29/01/2010 - 19:58
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Stefan, I will try the experiment over the weekend. Probably Sunday as we have the twin grandsons on Saturday.
Cedric
Cedric
Enjoy life
Posted 29/01/2010 - 20:48
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Don wrote:
well if it is for your point and shoot camera, you did get two free polarizers if you wet to see Avatar in 3d.... just take apart the glasses!
they also tape right on to your 360ftz flash units if you orient them right they work.
Eh?well if it is for your point and shoot camera, you did get two free polarizers if you wet to see Avatar in 3d.... just take apart the glasses!
they also tape right on to your 360ftz flash units if you orient them right they work.
The construction of polarising filters involves drawing lines on the glass the less than the wavelength of light apart, and you ain't going to do that with a felt pen and rule. They are expensive to produce, especially properly.
Posted 29/01/2010 - 20:55
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Thank you Cedric, will await your result
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 31/01/2010 - 11:40
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Hi Stefan, I have tried the test by pointing at a blank non reflecting surface and the shutter speed alters from 60th. to 125th. I tried both K10 and K20 and the same result. This was in AV mode. In TV mode the F stop altered from 5.6 to 8. I would expect these sort of changes but how can we determine how this affects the auto focus?
Cedric
Cedric
Enjoy life
Posted 31/01/2010 - 15:25
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Thank you Cedric.
You just proved that it does effect the exposure metering with 1 stop. AF need to be tested as well since that's a separate system, it might quite easily work correctly without a problem though.
Although we can already say that Pentax DSLR is not suited for linear filters.
Of course this only effects auto-systems so manual modes can still be used without a problem.
You just proved that it does effect the exposure metering with 1 stop. AF need to be tested as well since that's a separate system, it might quite easily work correctly without a problem though.
Although we can already say that Pentax DSLR is not suited for linear filters.
Of course this only effects auto-systems so manual modes can still be used without a problem.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
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17 years
West Berks
Don't get me wrong, I agree with the idea that the cheap ones are usually not much cop and a waste of money but given that I can get a fairly good multicoated lens for around £100 how can it be justifyed to charge the same for a flat piece of glass?