Circular Polarizer Filter

I've read Bryan's review/recommendation on the CPF, but I've never used one, so I'm just looking for some more information from you all.


Currently I only shoot with the 70-200mm f/4 for equestrian photography and portraits (it's such a great lens!). I shoot outdoors only with natural light. A fair amount of my pictures contains blue sky so I'm thinking the CPF would help out with that aspect.


Is there any adverse affect on skin tone with doing portraits with a CPF? Can I still use my lens hood? Any how difficult is it to remove on a cloudy day or during lower light situations?


Eventually I will add the 100-400mm to my camera bag - I've read on a few sites about buying for your largest diameter lens and using a step down ring for smaller lenses. Has anyone gone that route?


Many thanks for your imput!

I think you'll find that a polarizer will improve color saturation across the board when used properly. Skin tones included. The greatest effect is gained when the subject is 90 degrees to the sun.


One downside of using a polarizer when doing portraits is that it can make the eyes look dull from the loss of reflective sparkles. The solution here is to use a flash or a bounce card.


Polarizers can get tight since you are turning them in use. I've not had any real trouble getting them off though. It only takes a few seconds to remove them when not needed. I keep a strip of grippy shelf liner material in my bag and it works wonders to get sticky filters off.


Buying a larger filter and ringing it down for your smaller lens makes good sense when they are close in size. This will not work on the 70-200 lens with the 77mm polarizer you would need for the 100-400 lens. The size difference is too great to be practical. The hood won't fit with a filter that large on it. 2-3mm difference you would be able to get by with but not 10mm.


Chris Medico

my biggest complain for 70-200 f4 with CPL is you can't rotate when hood is on, and when the hood is off, my layers of CPL and UV(that i keep on at all time) makes the image appears soft focused in high light area. by the way i share the filter with 17-85.


great for sky and skin tone. and for me its a pain to remove, since for a near $100 piece of class i can't just take it out and put it in my pocket, it takes time to put it neatly back in case and DOH i miss my shot.. so i usually leave it on. or take it off.. clouds don't usually change that often.


(P.S. usually the CPL is on 17-85 since i don't use 70-200 that often for any landscape but when I do I painstakingly take it off 17-85 and take off the lens hood of 70-200 again u get the point.)

I've been looking into getting one also.


I just picked up the Canon 300 f4L and will be shooting some motorcycle racing, which normally has plenty of light.
My concern is that with the reduced light and in conjunction of having the 1.4x converter on that I might start to have some issues.


Also, having not used a CPL before, what is the turning part of the filter? What does it change and how do you know where to have it rotated to? Trial and error?

from my relatively limited experience with CPL's there are two rings to the filter, one ring is the part which threads into the lens, the second ring contains the actual glass. Many have markings as for what is 'right side up' for the glass. the way polarizing glass works is it is essentially many parrallel 'lines' in the glass (this is from my old physics class) these lines reflect light stopping it from entering through the filter and reaching your eye or the sensor. By twisting the front ring you change how those 'lines' are oriented and thus how much light is filtered through (I believe optimal light reduction is 90 degrees from the lines) so by rotating different amounts you can change how much reflection you are eliminating from the image.





and if i've muddled that up at all please correct me i'm fairly positive i'm remembering this all right but then again I may be making up the fact that I remember this.

Yes, The filter will reduce light by 1-2 stops. I've used them with the 300F4L for sports and it was no problem at all. Plenty of light to overcome the loss of the polarizer (even with the 1.4 extender). The improvement in the picture is well worth it. I've got some example images that I'll post tonight for you to see.


Adjustment - Once you get your filter and install it you will have no problem seeing what it does when its turned as you look through the viewfinder. Adjusting it with the hood extended isn't practical.


Just remember if the sun is to your back it has little to no effect. You want the sun over your left or right shoulder for maximum effect. Also at high noon it will have less than earlier or later in the day. Its all about the angles.


Here is an example of what a polarizer does to the sky (I'll never be a hand model):





http://farm4.static.flickr.com/3027/...c846f0999d.jpg

yes all about angle, at times it'll seem to have no effect at all directly at sun or behind it, but i often find with sun behind I'm still able to get some reflections or certain parts of sky to turn blue. when you put it on you immediately realize the scene through view finder is darker, and it's very dark indoors. the position of the filter marking is almostirrelevant(at least for me) since you would look through the view finder, focus, zoom, and rotate the CPL to get to the desired sky or color an shoot. I never bother looking at the rotation of the CPL since like the above post, different angle to the sun different rotation, and the only way to tell is to look through the view finder. Hope that's more clear.


I got Heliopan instead of Hoya(I think somewhere in the review, there's another brand that's very well regarded.), hard that Hoya flakes off after few uses, I doubt that'll ever happen but i'm not really to risk my shots with such expensive glass and cheap filter.

Great.


Thanks everyone. (sorry to OP for jacking this thread a bit) :)





Another CPL question:
Should the UV filter be removed prior to using the CPL, or is it fine to use them in conjunction?

as mentioned above I've used them in conjunction and it seems to have produce "glowing/ soft focus" look on high lights(reflections) where as when I tried shooting again using just CPL I'm not seeing the effect.. not so sure if using them both is causing this issue or it's just happened by chance, maybe someone can verify,

You have to be careful stacking filters for a couple of reasons.


Reflections between the filters can degrade image quality (get good AR coated filters if you are going to stack).


Second you can start having trouble from the rings themselves causing vignetting.


In generalI use only one filter at a time.


If you are going to stack you need to test your configuration before hand to know if it has any negative impact on your image.