Multicoated circular polarizer questions

[Suzumushi]

My DSLR finally arrived tonight, along with the Kenko(Hoya) Pro1D multicoated "wide band(?)" circular polarizer. Of course, the polarizer's package had popped open and it was loose in the box. I don't see any scratches or damage, but there is a bit of dust on it now.

I have two questions:
1. Are there any special precautions in cleaning a multicoated filter? Should I use water or lens cleaner or alcohol or my breath or keep it dry? Are glasses cleaning tissues acceptable for camera gear?

2. When looking through the filter and turning it, I see a change in the character of the light coming through. I would expect that for a linear polarization, but I thought circular polarization was meant to prevent this. Is this filter defective? If not, will that cause problems with lenses that rotate while focusing?

 

[Mav]

I just use a microfiber cloth and lens cleaner solution to clean my filters. Works great and sucks up the crud nicely. And the CPL filter behavior sounds normal to me. Yes, you'll need to be careful with it on lenses that rotate while zooming or focusing. Same with a grad-ND filter or any other filter that's sensitive to orientation.

 

[Judge Sharpe]

To clean lens- Brower's rules for long lens life:
1. Blow dust and loose crap from lens- I like a hand blower with a camel hair brush on the end. I do not like caned air because you do not know what is in it.
2. GENTLY use the brush to remove loose particles that do not blow off, work from center to edged.
3. Put a DROP of good quality lens cleaning fluid on center of lens and GENTLY and in a circular motion clean from center to edge.
4. repeat step three
5, Polish with good quality lens tissue or microfiber cloth.

cautions: do not use tissue on dry lens
do not use paper towels
do not use facial tissue or TP.
do not use t-shirt, handkerchief, shirt tail, window cleaning fluid, alcohol, or anything not formulated for lens cleaning. In a pinch pure water is OK but leaves streaks.
The less cleaning you do the better.
small dust spots sill not show up on image so leave them alone until you can do it right.
Anything you can not remove as above, take to a PRO>
Your glass is your life and the easiest way to screw it up is with bad cleaning.

 

[AndrewG]

My DSLR finally arrived tonight, along with the Kenko(Hoya) Pro1D multicoated "wide band(?)" circular polarizer. Of course, the polarizer's package had popped open and it was loose in the box. I don't see any scratches or damage, but there is a bit of dust on it now.

I have two questions:
1. Are there any special precautions in cleaning a multicoated filter? Should I use water or lens cleaner or alcohol or my breath or keep it dry? Are glasses cleaning tissues acceptable for camera gear?

2. When looking through the filter and turning it, I see a change in the character of the light coming through. I would expect that for a linear polarization, but I thought circular polarization was meant to prevent this. Is this filter defective? If not, will that cause problems with lenses that rotate while focusing?

You can buy lens tissue from your photo retailer. Don't use any fluid.

The change in light character you are seeing is exactly what you need in order to see the effect that the filter is having on your subject; if you point the camera at the sky and rotate the filter you'll see the blue darken. The amount of darkening is for you to decide on.
If your lens rotates while focussing you will need to focus first and then adjust your filter to taste.

 

[WDodd]

I wouldn't use any liquid either. Microfiber cloths and lens tissue is the way to go.

And in case you are out in the field anywhere and get something on your lens I have a microfiber cloth in my bag but I rarely will clean anything off outdoors.

 

[TamiyaGuy]

I'd suggest that in order to clean your filter, use a blower/blower brush first, then if that won't work, a microfibre lens cloth, and only use a lens cleaner as a last resort. It probably won't do any damage, but if it does, it'll do a hell of a lot more damage than air can (barring a tornado, possibly ).

From what you've said, the CPL is behaving fine. The difference between a circular polariser and a linear polariser is that a circular polariser will not affect your camera's autofocus system. They both have the same effects on light; when rotated a certain way, skies will become darker & bluer and reflections will be decreased. Enjoy!

 

[tirediron]

If the blower or brush won't clean it, a huff of breath and a micro-fibre cloth.

With respect to your question about the filter being defective, no, it's supposed to be that way. I'll let Helen wade in with the technical details, as they're far above me, but that's what you should see. Remember that you'll get maximum effect when the sun is lower in the sky and at right-angles to the axis of the lens.

 

[Judge Sharpe]

Lens cleaning fluid is formulated to clean lens with out harm. It removes the mocro dust particals that may be on the caoting. rubbing a dry cloth on this, micro or otherwise is just sanding the caoting.
All optic labs use the formulated lens cleaning fluid as a protectionto the lens.
Judge Sharpe

 

[Suzumushi]

Thanks everybody! Looks like lots of good info here.