Aligning CP Filter

[dusty montgomery]

This morning I went to watch my wife and dog run in a Canine 5K. After I got home and loaded the images, I was dissapointed to notice I had misaligned the CP. One top corner of the image was blue while the other was white. I remember consciously making sure that the mark on the polarizer was at a 90 degree angle to the sun, so I do not understand why this happened. I also tried adjusting the filter for best effect while looking through the view finder, but that did not work either. (I still find it difficult to gauge when to stop rotating the filter)

Is there a fool-proof method for aligning this filter?

Thanks!
Dusty

[Douglas Barnes]

Dusty, were you using a wide angle lens? These can cause issues with polarizing filters >> lots ‘o’ sky. I would suggest to always view the effect through the lens, the 90deg. thing is just a guidline.  Watch your subject for changes as they may be different depending on what you’re trying to achieve. If you want to kill a reflection, look right at the water/window/whatnot and rotate till you can see through it. Ya want the sky more blue, compose and watch your sky (through the vf) till its darkest, (or use Photoshop). Hit the DOF button and look again. Remember that it may be impossible to cut water reflection and deepen the sky in the same capture.

I would ultimately endorse not using a filter of any kind unless required. Especially with digital and of action.

Hope this helps.

db
http://www.nowpicturethis.com

[dusty montgomery]

Douglas,
Yes, I was using a wide angle: 17-40 f/4 L on a sub-frame Canon. I think the CP is 77mm. So, can I assume this effect would be minimalized, if not absent, if I would have used a 70-200 f/4?

Thanks for the insight Douglas,
Dusty

[Douglas Barnes]

Dusty, yes I believe so.

However, I’m sure it wouldn’t happen at all if you took it off and used a proper hood (which is difficult with any lens while trying to use a polarizer). Save the CP for when you’re on the water.  For example on a bonefish flat in the tropics where you want to cut through the glare, deepen the sky, and there’s tons of light to make up for the two stop loss.

Better yet bring me along and we’ll do an on site demo…. 😀

Loose the filters. Use your hood.

db

[dusty montgomery]

Douglas,
I forgot to mention this morning that I did have the hood and the CP filter on. It was the hood that came with the lens. Is this hood sufficient?

Thanks,
Dusty

[John Bennett]

The hoods fine Dusty.

Using a CP is a personal choice, I use a CP alot.

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