Does a cheap polorizer degrade image? examples

juno_first · 4 Jul 2011 at 00:02

I recently bought a filter kit from the rain forest as I also needed a UV filter to protect the lens.
For some strange reason the kit also has a purple filter for tube lights, well it comes in handy as a 2 stop neutral density filter as the Auto-WB compensates ok.

£16.30
Zeikos ZE-FLK67 67mm Professional MULTI-COATED Glass Filter Kit UV Polarizer Flourescent

Maybe the VR lens cant hack long exposures or something else, but shots with the polarizer set to cut out reflections seam a bit fuzzy.
I dont know if im going paranoid here and without doing a load of tests, does anyone with experience here know if a cheap polarizer is even worth putting on your lens, or even a cheap UV filter :confused:

Thanks

Polarizer set to accept reflections (not removed):

Polarizer set with no reflections:

Rest of the album here if you're interested, all with polarizer except 50mm.
Flickr 14pics

FreeStream · 5 Jul 2011 at 12:17

Yup, *any* additional glass interferes with the quality of a shot.

Even the expensive filters do but it's less obvious.

Since I tried even the Hoya Pro 1 filters i've never bothered with filters, 100k photos later and I still don't bother!

Tafkap · 5 Jul 2011 at 15:07

I was stung years ago at a camera shop on the Las Vegas strip - I was looking for a polarising filter and was talked into buying an unknown brand at the shop owner's recommendation. It absolutely destroyed detail and clarity. There's probably another point to be made about avoiding tourist traps...!

D.P. · 5 Jul 2011 at 15:10

As above really, cheap filters noticeable reduce image quality in various ways. Good filters such have minimal impact, my B+W MRC CircPol lives on my lenses.

juno_first · 5 Jul 2011 at 16:50

The colours are certainly more saturated with the polarizer & im wondering if the same could be achieved by shooting in the vivid shooting mode, or would that look a bit fake?
I knew the D90 gave softer/less punchy images before I bought it, which is no big deal & maybe better.

Oh, a bit off topic but Im trying get to grips with Lightroom & dont know how much sharpness to add or if theres a pre-set amount that should be added with a particular camera?
ta

Derek W · 5 Jul 2011 at 18:00

juno_first said:
Oh, a bit off topic but Im trying get to grips with Lightroom & dont know how much sharpness to add or if theres a pre-set amount that should be added with a particular camera?
ta

Sharpness is dependent on what you're shooting as well. With the likes of the footy shots that i do i can add anything up to 150% sharpness and the image is still acceptable. You can push the sharpness up so much before you start getting a white and black outline around the subject matter which is not what you want to see in the final image / print. You can experiment with different levels per picture to find a good balance to either your own personal tastes or to the level where its not noticable but the standard of your original image is improved upon because at the end of the day theres not point in taking a good shot and post processing it to look crap

rG-tom · 5 Jul 2011 at 19:23

massive image alert

This was taken with a Jessops own brand CP filter over my 24-70 F2.8L:

as was this:

and this

I'm happy with the quality of them!

Tom.

juno_first · 5 Jul 2011 at 20:00

Hey nice sharp results there.
It boggles me how a Jessops CP filter costs £50 but my 3 filters inc CP cost £16.30.
I was going get a battery pack next, but im tempted get a descent CP filter now, although I'll run some tests with/without the CP filter first to make sure.
I bet the girl shot was interesting to use with the CP filter, what with the water/foreground wood reflections & sky.

juno_first · 5 Jul 2011 at 21:07

Ok, I just did a simple still life of some detail.
Both shots the same except with non CP filter the exposure has been corrected.
Now obvious that with JUST the cheap CP filter theres a drop in sharpness.
Hopefully when I get a Jessops CP filter there wont be such a drop in sharpness?

NO CP FILTER

WITH CP FILTER

Steve M · 5 Jul 2011 at 21:17

I bought a Hoya cp filter for £20 off ebay (brand new sealed). If i'm honest i cant say i've noticed it make any difference!

Here is one i took at the weekned using it on my Panasonic G1. Image is straight off the camera and all I did to it was a very slight crop to the right hand side in CS5. I was led to believe the contrast would be boosted and the sky bluer? Photo looks pretty bland to me:

P1030971 by Steve Millward, on Flickr

Not noticed any issues with sharpness though.

juno_first · 5 Jul 2011 at 21:41

Nice & sharp there SteveM. The 4/3 sensor is quite good.
Well I used to work in a photolab years ago & that pic is what we used to call '1 button cyan'.
I've been learning how to use Lightroom tonight & I hope you dont mind me giving your pic a little more punch:

Steve M · 6 Jul 2011 at 09:51

Good work.

So what's the definition of a '1 button cyan' then?

ishamy · 6 Jul 2011 at 10:23

Now I feel that's how many of my pictures come out 'bland' in the same way and what you have done to that makes it immensely improved. Now the big Q HOW? haha, and also what is 1 button cyan, sounds interesting.

Hodders · 6 Jul 2011 at 11:44

Steve M said:
I bought a Hoya cp filter for £20 off ebay (brand new sealed). If i'm honest i cant say i've noticed it make any difference!

Here is one i took at the weekned using it on my Panasonic G1. Image is straight off the camera and all I did to it was a very slight crop to the right hand side in CS5. I was led to believe the contrast would be boosted and the sky bluer? Photo looks pretty bland to me:

Not noticed any issues with sharpness though.

Did you play around with the rotation of the filter to get the results you wanted ?

Hodders · 6 Jul 2011 at 11:48

I think that where filters hurt images are in conditions that the lens finds challenging - shooting into bright lights for example.

In easy conditions most filters will do a cracking job. In harsh conditions ALL filters will degrade the image, just some less than others.

I only ever use filters in harsh conditions (rain/sand/beaches) or if I want a specific effect (CP for example). It just seems strange spending money on a 24-70L or a 85mm prime and then compromising it's performance. Spending top bucks on UV filters for three 77mm filter thread lenses will just about pay the excess on my insurance policy.

Plus lens hoods do a great job in protecting front elements on all but wide angle lenses.

juno_first · 6 Jul 2011 at 11:55

When I used to print photos in a 1hr lab back in the late 90s the Fuji printer I worked with corrected cyan, magenta, yellow. If your original shot printed like that we would reduce cyan by 1 or 2 buttons which is the same as adding red, or in modern language changing the tint to more warm.
I also added more contrast and adjusted blacks etc.

Steve M · 6 Jul 2011 at 12:13

Hodders said:
Did you play around with the rotation of the filter to get the results you wanted ?

Yes, like i say, it made no difference. There are no markings at all on the filter (fully on ect), should there be to indicate what effect the filter would have?

juno_first · 6 Jul 2011 at 17:55

Steve M said:
Yes, like i say, it made no difference. There are no markings at all on the filter (fully on ect), should there be to indicate what effect the filter would have?

If moving the CP filter made no noticeable difference then theres probably not many reflections to remove, although it should still give a more saturated image.
Why not test a landscape with/without.

rG-tom · 6 Jul 2011 at 18:10

watch the sky as you rotate the CP, it will get darker at one point

bloodhunter · 6 Jul 2011 at 18:18

I use a Hoya Pro Digital Polariser. How dou you all rate those??