[SpecialK]

I tried PP...
Plus it takes quite a lot of time to do so...

You are willing to invest thousands of dollars in equipment, drive somewhere, hike further, set up, adjust you polarizer, hike back, drive back, name, file and post your images for all to see - and not spend 15 seconds to make them special the way you want? (You should at least clone out the dust and level the horizon, anyway, so you already have the image open...)

Even with PP it's hard to get a uniformly blue sky.

Blue sky is not uniform, particularly with wide-angles where the sun is off to one side...

[lepiallou]

@ SpecialK : I took this shot during a three days hike in the Alpes and I shown this one as an example of what I don't really like, without any PP to show how it comes out of the camera.
But of course I will clone out the dust and level the horizon, I like this shot (and some similar ) nevertheless !!

So I will try some shots without CPL (certainly this weekend) to compare...

[goddo31]

The foveon sensor in sigma cameras doesn't see colour the way people see it, the blues are less saturated than what you get with current bayer sensors. There is always in camera sharpening applied to the red channel, which suffers from a loss of acutance due to lateral diffusion which is caused by the type of silicon they use in the in foveon sensors .

so I would recommend the DA15mm f/4 and a decent Hoya circular polariser, and a few Grad ND filters.

The OP said he was using the Sigma 10-20 lens right? Not one of the cameras with a Foveon sensor? Interesting information though.

I'm yet another fan of the DA15 limited. I've used a polariser before on the DA15 and managed to mostly avoid the changes in gradient of the sky. I did this by being careful about how much 'polarising effect' I applied with the filter and also watched my angle to the sun.

However the DA15 seems to produce very saturated blue skies anyway, without a filter. Also note that the sky will naturally change in tone/gradient depending on where you are looking at it.

Here's the closest thing I could find to 'Alpen' shots with the DA15:

No polarising filter - note the change in sky tone to the right (closer to the sun)



No polarising filter - this is facing roughly in the other direction, with the sun over to my left.

[Digitalis]

The OP said he was using the Sigma 10-20 lens right? Not one of the cameras with a Foveon sensor?

people often assume cameras with a foveon sensor automatically render things better than a camera with a bayer sensor, which simply isn't true.

I'm yet another fan of the DA15 limited. I've used a polariser before on the DA15 and managed to mostly avoid the changes in gradient of the sky. I did this by being careful about how much 'polarising effect' I applied with the filter and also watched my angle to the sun.

which is what I recommend. Most people are content with using their polariser continuously at it's maximum polarising effect and therefore their work has the same "look" to it. I personally avoid this, and in some cases I use my polariser to deliberately intensify the reflections in a scene. There is more to using a polariser than just having it set to its maximum polarising effect all the time.

Grad ND filters that are commonly available with square filter systems can help deal with bright clouds set against a deep blue sky, though they require a bit of cleverness to use with the DA15 because of it's annoying built-in lens hood, which often gets in the way.

[civiletti]

With film, I used a polarizer most of the time. With digital, I rarely use one. Given the problem with uneven sky tone at wide angles, I would forgo the filter and deepen sky blue in post-production. Differences in color rendition of almost any lens should be able to be overcome in PP.

[yeatzee]

Shoot RAW and save yourself some money. If you want even more control I highly suggest Viveza 2 for getting the colors how you saw it in person

[lepiallou]

Thanks goddo for the examples with the DA 15. I am quite surprised that the sky as homogenous colours.

So following everyones recommendations I will try to shot without the CPL filter and do a bit of PP.

[goddo31]

Thanks goddo for the examples with the DA 15. I am quite surprised that the sky as homogenous colours.

So following everyones recommendations I will try to shot without the CPL filter and do a bit of PP.

You're welcome. Just keep in mind that the ice in those shots probably caused the sky to appear a bit darker than it would in other scenes. Because the ice is so bright white in the sun.

[Ron Kruger]

There is another way to get what you want. Without the CPL, camera mounted on a tripod, take two shots, one exposing for the land, the other underexposing a couple of stops for the sky. Open the sky shot in PS, quick select and copy. Open the shot exposed for the land and paste the sky exposure over it. Fit it into place.