How to fix the polariser effect in panoramas?

[whited3]

Sorry for the clumsy title!

This pano was taken just after dawn and comprises ~8 images spanning ~120°. Question is; how do I remove or even out the effect of the CPL?

Cheers.

[Colin Southern]

Hi Mark,

The short answer is "don't shoot them with a polariser" for this very reason I'm afraid. Also, for this kind of shot, you need to use manual exposure.

The only other thing I can think of is GND filter in Photoshop ACR.

[whited3]

The short answer is "don't shoot them with a polariser" for this very reason I'm afraid. Also, for this kind of shot, you need to use manual exposure.

I knew you (or someone) would say that But I did use manual exposure

I'll give ACR's GND a go.

Thanks Colin

[Colin Southern]

I knew you (or someone) would say that But I did use manual exposure

I'll give ACR's GND a go.

Thanks Colin

I know that a lot of people swear by CPLs, but I'm afraid that I'm one of the ones who swears at them

Keep in mind the the GND tool only works from "the outside in" (so you can't start it over the troubled area) - but - you can start at the outside and change everything else apart from the problem area, and then apply global adjustments that bring everything else up to where you want it.

PS: Awesome shot by the way

This is how skies look without a polariser ...

[lenelg]

My attempt:
1 Opened up the shadows with a heavy dose of Adjustments > Highlights/Shadows (abt 70%)
2 This left the image a little flat, so I did a local contrast enhancement, with Amt=15%, radius=60 and threshold=0

[whited3]

Had another long-winded attempt in ACR doing exposure spot adjustment. Not entirely happy but it's an improvement me thinks.

[cosmokev]

A simple highlight change after roughly selecting bright area.

[Markvetnz]

I'm with Colin on this one. I used to think CPL's were the bee's knees but now I hardly ever use them. Too much hassle on a wide angle lens. I do use them on grey overcast days for a little colour enhancement and to sort out minor reflections. Nik Color Efex Pro has a polarising filter than can be applied during PP to panoramic images.

Are you using a panoramic head??

[whited3]

I'm with Colin on this one. I used to think CPL's were the bee's knees but now I hardly ever use them. Too much hassle on a wide angle lens. I do use them on grey overcast days for a little colour enhancement and to sort out minor reflections. Nik Color Efex Pro has a polarising filter than can be applied during PP to panoramic images.

Are you using a panoramic head??

Yes, I've learned my lesson re polorisers! The pano in question is made up of 8 handheld images taken in portrait orientation.

[Glenn NK]

The other problem with polarizers (you know the first one) is that they don't just darken the image, they change the properties of the reflected light.

They are extremely effective on images taken with longer focal lengths, where the change in polarizing effect when the change in angle between the sun and lens axis is small, and particularly so with images of non-metallic surfaces, where they considerably reduce spectral highlights (glare).

Their effect can look very nice on a landscape (not many metallic surfaces), if the focal length is limited.

A month or so ago, someone suggested that any filter could be duplicated in PP, and used the neutral grads as an example. True, but their isn't yet an equivalent of the polarizer in PP that I'm aware of.

Glenn