Filter Query

Zoomboxer

Zoomboxer

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Name
Steve
Edit My Images
Yes
I have 2 filters - a CPL and a polarizing. (sp?)

Do I just add one of them - dependant on what I am photographing or do I put both of them on? If so, is there an right order to put them in?

Thanks - had a quick search but could not find the right answer.
 
A CPL is a 'Circular Polariser', so in effect, you have the same filter twice.
 
As Jonathan says it is one and the same.

They're useful for enhancing the blue of a sky (a nice contrast between blue sky and fluffy white clouds), reducing reflections from non-metallic surfaces such as water and glass and even foliage and trees.

They do however reduce the amount of light coming in so you'll probably lose a couple of stops (eg if your shutter speed was 1/500th you'll end up at 1/125th). Also you'll only get the maximum effect at 90 degrees to the sun, and be careful using them on ultrawide lenses.

Very useful thing to have for landscape photography.
 
Good job I asked then :)

The CPL one is clear, whilst the other one has a darker tint - to my mind they are completely different things. Well, that just proves that I am wrong.

Thanks for the replies much appreciated :clap:
 
A cpl shouldn't be clear, so I'm guessing its a UV you are talking about and not a CPL. A CPL should have a rotating front part, if it doesn't then it's not a CPL!
 
All polarizers have a rotating front part; the difference between a circular and a linear polarizer is that a circular one re randomizes the light after polarizing it to allow the AF and meters of some modern cameras to work properly. It's possible to use a circular pol and a linear one together as a variable ND. Put the circular pol on the camera then the linear on the front of it. You'll lose an appreciable amount of light, even with the polarizing planes alligned but as you turn the front of the linear pol, you'll see the viewfinder image darken (or lighten) as you do so.
 
TCR4x4 said:
A cpl shouldn't be clear, so I'm guessing its a UV you are talking about and not a CPL. A CPL should have a rotating front part, if it doesn't then it's not a CPL!
Click to expand...

Thanks - had a look at them - the CPL one is the darker one and does rotate.

The other one WAS a UV.
 
To get back to your original question (now that we are talking about a UV and a CPL) - no do not use them together!

On a modern DSLR a UV filter does not actually help filter UV, as digital sensors are not affected by it in the way film is.

However, there is an argument for having a UV or clear filter on your lens to protect the front element from damage.

The argument against is that any filter will degrade IQ to some extent (how much depends on the quality of the filter). It's really a personal choice, and depends on the conditions you will be shooting in, and how careful you are.

Either way, you should remove any UV / protection filter before putting on a CPL (since the CPL will do the same job of protection and stacking filters will add vignetting issues).
 
Personally, I use a UV as a protection filter when there's a lot of crud (dust, sand, spray etc) in the air or if the lens's front element is very close to the front of the lens. I used to keep one on the front of most lenses but that was back in the olden days of film!
 
My old Tamron 90mm had a front element set way back into the barrel of the lens, the Nikkor 105mm has the front element very close to the front.

Of course the 2 lenses with the most vulnerable front elements cannot be fitted with protection filters - their fron elements actually protrude from the barrels! (Sigmas, 8mm fisheye and 12-24 UWA Zoom)
 
markmullen said:
I know full well what a hood does, and how much better it is than a UV filter, I was puzzled by the suggestion that the front element of a lens could be anywhere other than near the front of the lens.
Click to expand...

As mentioned, a lot are.
The tamron 90mm being prime example, its recessed a good few cm. as is the Sigma 105mm
 
My Tamron 90mm is on long term loan to a good friend, so I don't have it here to measure the front element relief but the Nikkor 105mm Micro has very little, hence the protection filter.
 
markmullen said:
I know full well what a hood does, and how much better it is than a UV filter, I was puzzled by the suggestion that the front element of a lens could be anywhere other than near the front of the lens.
Click to expand...

Yup, stick a hood on a lens and the front element can be quite some distance from the front of the lens.
 
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