Are Polarizing Filters a Scam?
Let’s find out if RAW shooters need to worry about polarizing filters.
Let’s demystify polarizing filters. A better name for them would be: Occasional Highlight Control Filters. Operation wise they work like a Variable ND does; you spin the disk until you move it to a position where you like what you see on the viewfinder.
But hold on, can’t I just restore these highlights in post? We’re going to find out today on both .jpeg and RAW files.
Do you need one?
I’ve always heard landscape photographers don’t leave the house without their polarizers. Having caught the nature bug last weekend with a hike to Brandenburg, I invested in a not-too-cheap Zeiss T* Polarizer for €130 euro. By the end of this article, we will figure out if you should get one.
I went for the Zeiss T* brand because of Roger Cicala’s test which showed the T*’s add negligible amounts of distortion to the image. He examined UV filters specifically but I figured it was a safe bet. I’m not going to carry a 800g zoom lens with me if I don’t squeeze out every last drop of quality from it. Armed with my new circular friend, I went out on another 15km hike starting from Wannsee and ending in Potsdams Central Station.
I don’t know about you but living in a big city is taxing. Mentally, physically. Emotionally? Probably. I travelled for about an hour using public transport to get to the starting point from my apartment and by then the stressors we’re getting to me. I don’t like hanging around too long on noisy trains, especially on a Saturday morning. Even upon reaching Wannsee, a seaside resort compared to the usual crack dens many of the underground stations can be, I encountered another unfortunate and aggressively drunk, lost soul.
It wasn’t until another 20 minutes when I realised, wow.
Breathing a sigh of relief.
I was among nature now.
So far it does exactly what it says in the manual “higher colour saturation and richer contrast.” At this point I should mention, that all comparison images are jpegs SOOC. Retouching them would make the comparison less useful.
The hike continues among a forest for some time. Although I’m having a blast and stopping every ten steps to take a photo, I do not have that same feeling of solitude I had from last weekend. My girlfriend later tells me; these forests are a neighbourhood of the city. I see hikers, joggers, cyclists. It’s not full by any means.
This ended up being an advantage as I could no longer follow the instructions of my German hiking book and asked two ladies for directions.
They pointed me toward the river. I was excited. This is the reason I went on this hike in the first place. Polarizers essentially block light that comes off-axis. 90 degrees is where the effect is strongest.
After the reflection in the water was distrubed by an elderly couple rowing, I carried on through some charming and wood-ish inns. You could have fooled me that I was further than 20km from a capital city’s centre. I briefly dreamed of going somewhere closer to nature on holiday, then some sun arrived to bless us.
I followed the path to the left, making sure it copies the path of the hiking book. Right around the bend lay a “No Entry” sign. I couldn’t read most of it but I could tell it was from the foresters. It saddened me that for the second time on this hike, I stifle my instincs of where I want to go for the sake of being a law-abiding citizen.
Regardless, the forest filled me with good vibes. I was a lone wanderer with a wood on my right and a formiddable lake on my left. I shuffled down the slope towards the bank of the lake for my first proper break. It was warm enough to take off all my extra layers and sunbathe. In front of me was a varitable show of ducks and cranes splashing in a mirror of the sky.
On the other side of the bank lay some houses and I briefly entertained the sombre thought of whether it’s possible to own something like that in my lifetime. Would having a more direct access to nature alleviate some of my troubles of living a desk job life? Would other concerns come in to replace the existing ones?
Rattled, I decided it was time to continue and I followed the path along a steep wooded incline. It was “busier” than ever before but still nothing like Alexanderplatz U-Bahn at rush hour.
Eventually I came across a tree fallen along the path. Perhaps this is what the forester’s warning was all about. An old lady had dismounted her bicycle and had to lift it up over the tree. I spoke louder so my voice could cross the distance.
“Wenn du willst, ich kann hilfe dir.”
She was sweet and boggled as to how to old my 1.3 Kg camera and lens package. By now I had figured out how to properly carry an X-T5 with the 16-55mm. Having tried Peak Designs Slide Lite and Leash, the correct answer is without any sort of strap at all. When I use a strap, despite the initial comfort, the repetitive weight in a certain position always ends up hurting at best and losing feeling in a body part. By carrying the heavy gear strapless: my body constantly changes where the load is carried. There are so many different ways to grip a camera. By changing the grip as often as it feels like, I can carry this formidable stack for longer.
Helping the lady over the tree really felt good. In the city I am rarely exposed to such moments of altruism. I get the impression people are too suspicious of strangers, after having been exposed to so many who are down on their luck.
RAW vs Polarizer
At this point in the story, things become rather uneventful and it’s time to look at if I can get the polarizing effect without… well, a polarizer. This shot should be easy to examine.
RAW adjustments were done by applying the same film simulation as in the jpeg then adjusting the exposure sliders, tone curve and HSL sliders. My observations are such that the hue doesn’t exactly match, and there is also more texture on the window shutters than in the polarized photo. The level on the ground floor window also differs. Let’s try another example.
In this case the RAW adjustment was only the exposure and HSL sliders. It dawns on me that it’s not a totally fair comparison. We are comparing 8-bit jpegs with 14-bit RAW files which is apparent in the third image’s top right corner. There is a lot more information in the sky. But overall it’s discernible that there is enough data in the RAW file for you to be able to get the “polarized look” without the filter.
On the other hand, if you are a jpeg shooter, it’s worth investing in one. Or is it?
Let’s try achieve the polarizing filter’s effect with a jpeg.
This time I took a screenshot so you could see that the adjustments were not drastic at all. With the polarizer there is more contrast in the water but the jpeg + adjustment has more contrast in the sky.
To Filter or Not To Filter
Once I started seeing castles, I knew I was approaching the end of the hike. Although the hiking book says 12km and 3.5 hours, my legs feel like 15km and it’s been five hours. In the gardens of Schoß Babelsberg, there are people all around me but it feels different. No one is rushing. People are at leisure, walking at that pace in the city - you’d get run over. There are smiles and a carefree vibe nestles the air.
I am at a quandary with my filter friend. Was it worth buying it? Here are my observations:
Bad
It’s not free
Cannot wear a lens hood
Even on the off rotation, you lose 1.5 EV
Sometimes you want highlights, making the filter obsolete.
Good
If you don’t like re-touching photos, it gives you the opportunity to “re-touch” in camera
It protects the front lens element.
My biggest gripe is that it is one more step I must take before I can press the shutter. I get it, landscape guys and girls probably are happy with setting up the tripod, being meticulous with every step in capturing the image just right. They probably lock the ISO at base and set the shutter to auto, so in effect, they only adjust the aperture, exposure compensation and their polarizer.
I was going up and down on the ISO because it was a cloudy day and I didn’t bring a tripod. Even with the reported 7 stops of stabilisation on the X-T5, I didn’t go below 1/30 of a second. Especially on a partly cloudy day, on occasion I had missed my shot because the light had changed by the time I adjusted everything.
Perhaps this is not the spirit of landscape photography. What I did was as much about the movement as the photographs.
Thanks for reading.
