I first got to know PolarPro cinema series ND filters about 1.5 years ago when I was conducting a GoPro Hero camera review fitted with their set of filters. (See my review here). Now they are venturing into the professional large diameter filter world (up to 82mm), essentially claiming a neutral color balance and near perfect optical quality. Is this claim true? Read on to find out.
In this review, I’m testing the new PolarPro Quartzline ND 64 filter and PolarPro ND16 / PL (polarizer) filter. Those filters are made of 99.9% fused quartz to ensure optical clarity with a very low refractive index. The frames are built from machined brass to ensure they thread on smoothly – very essential as I have experienced seized up filters from aluminium frames myself already. A very nasty experience …
PolarPro claims a neutral color balance, zero color shift and near perfect transmission by the optical coatings. For more information about the available filters and sizes, please head to Richard’s article.
Method of Testing
So lets see if this claim is true – I used my Blackmagic Pocket Cinema Camera in ProRes 4:2:2 for the following tests and added an additional front infrared cut filter from Heliopan for all of the scenes to eliminate IR pollution.
In order to get a neutral starting point I used the color match feature in DaVinci Resolve 14 along with a DataColor Spyder Checkr in the frame (figure 1). All the subsequent scenes are using exactly the same grade to identify any differences.
Comparing the Images
The below image (figure 2) shows a comparison of no ND vs. the PolarPro ND 64 filter. Those two frames were shot just 15 seconds apart in a blue sky day, so there is no influence of the ambient light (I had to increase shutter speed and stop down the iris of my SIGMA 18-35mm lens without the ND filter to get a correct exposure, so the green background is of course more in focus when comparing to the image taken with the PolarPro ND64 filter).
As you can see, There is indeed a very subtle color shift towards blue – have a look at my face below. However, to be fair this is a very subtle difference and can be eliminated very easily in post.
I also included my Heliopan VariND in the comparison as this is my go-to solution for everyday run & gun work. The Heliopan VariND shows a strong color shift (at ~2/3 of the max. filtration) and the result is a more yellowish color cast, most noticeable on my face. (see figure 3 below)
Last but not least, I also tested the PolarPro ND16 / PL (polarizer) filter. Not only does it provides 4 stops of ND filtration, it also has a rotatable front filter element to adjust the polarization. This helps to get more saturated colors and eliminates reflections to an extend. (See figure 4 below)
Note: You have to be careful however to get the angle of rotation of the front element right. Hence, an external monitor with an accurate preview is needed in case your camera LCD and EVF are of a low res, otherwise you can get the opposite of what you want, meaning, desaturated colors.
A fixed ND filter will leave you with a less creative freedom as you have to stop down your lens (or adjust ISO if you can) to get the correct exposure. An ND64 is a very good starting point (6 stops of ND filtration), but not enough in bright sunlight to shoot with a low f-stop. If you use S-LOG2 on the Sony a7S II for example, you might need an even stronger ND filter like the PolarPro Quartzline 82mm ND100K (15 stopsof ND filtration).
All in all, I am sold on these new filters. They are not the cheapest, but if you want a high quality sturdy filter which has almost zero color cast, those filters are for you. Shooting the sailboat footage in Croatia was a joy, especially a while later in front of my monitor when grading the footage.
Do you have experience using any of the new PolarPro Quartzline ND Filters? Share with us your thoughts in the comments below.