Polarizing Filters

[Colin Southern]

I think something else was changed in the second photo, which is partially why Colin isn't convinced.

No - not really the reason

I know I'm probably starting to sound like the "anti-CP police", but that's not really the case ... I appreciate (understand) the science behind them, but in reality I find that they generally only do two things:

1. Remove glare (thus improve saturation of foliage etc, and allow us to "see through water) etc, and

2. Darken skies (which is really the same thing happening, but I seperate it out here because it can be handled differently)

So with regards to #1 - if shooting in "the golden hour" (which is really the ONLY time to shoot landscape that's going to sell), glare just isn't an issue - so no CP required, and

With regards to #2 - what CPs give by way of more saturated skies (which is mostly darker skies due to a lowering of the exposure) one can achieve simply by under-exposing the sky a little - with the added bonus that one doesn't then get the issue of unevenness.

So "horses for courses" for sure, but personally, I can't think of any of my commercial landscapes that would have been improved by the use of a CP - and yet I know of many that would have been made a lot worse by using one due to the fact that I often shoot wide-angle, at which point a CP would have given badly uneven sky along with a truckload of uncorrectable vignetting / "outright obstruction" due to other filters (Vari-ND + GND etc) that WERE essential.

If someone gets a better result when doing "high noon" shooting then that's great - go for it! (As I did just the other day - and I got the darn thing stuck on the lens AGAIN!).

That's how I see it anyway

[Shadowman]

Hi Shadowman,

All I see is the shutter speed changing from 1/60 to 1/20, as you expect, by about 2 stops, a little less in fact.
I can't see the PP or RAW conversion settings, but that may explain the foreground difference.



No, because that would be a different plane of polaristion to the sea.

A potential third shot with polariser set for max. sky difference would show that, but also less effect on the sea.

One filter can't normally* do both at once, but with 24mm focal length, setting for the sky would give the uneven sky effect, which, to be honest I think is negligible on this second shot when compared to first. It certainly what I would call the classic problem, since it is nowhere near as bad as when someone tries to use the CPL to darken the sky on say, and 18mm (27mm equiv.) shot.

* OK, there will be certain compass orientations of sea/lake/river view in combination with sun angle that lead to it having a significant effect on both, but I feel it is less likely to be a problem in practice.

Cheers,

Thanks for the EXIF data Dave. I think if anyone tried to duplicate the settings David used they would not get the same results. I would have expected a darker image with the CP filter and a 0.04 second shutter speed wouldn't create the overexposed effect.

[David]

Shadowman, Dave - Thanks for the comments. I don't think the sky would be particularly affected by the filter in this case as the shots were taken at about 12.30 (+2 hours on EXIF time) when it would be at its zenith. The main effect is from polarised light from the sea. The land also may be giving off a glare. If I had known I was going to post on the matter I would have taken several shots with different angles set on the CP filter. I have not carried out any PP on the RAW files, except to convert to JPEG for this post. The key issue is whether or not a polarisation filter is an important tool for the photographer. In my view it is, because it allows information otherwise hidden by scattered light and glare to be revealed. It can show dramatic effects that can be aesthetically pleasing as well as scientifically intriguing. However, as with all tools and techniques, whether or not a photographer wishes to use such is up to the individual. Given the relatively small cost of such a filter, having one in your kit seems like a good idea.

Cheers

David