I wanted to try the Gobe ND filters as they seems to have a good reputation at a reasonable cost. In this review I want to test if the new kid on the block is an alternative to the usual and well-known guys.
TL;DR The Gobe flters I purchased are in my opinion a good set. They introduce a bit of a color cast, cooling down the images but it's not dramatic and it's easily corrected. They don't degrade sharpness, and they are very resistant to flare due to their multicoated glasses.
Prologue
Gobe is the project of two guys from Australia that after a year-long sabbatical pause spent travelling around the world taking pictures and having fun, realized how dramatic the deforestation is in some parts of the world. The so came up with the idea of producing lens filters and help the planet at the same time, and so their venture started. Every filter you buy, you help plant 5 trees in some parts of the world. I have to say, this was something that really intrigued me.
They offer their filters in three different qualities: one mountain - optical plastic, two mountains - japanese optical glass, three mountains - german optical glass. Not all filters are available in three mountains quality. The ND I bought are two mountains.
In this review I will test the ND8 and ND64 filters, 3 and 6 stops of density respectively, using my Sony A7 II. I will test the 43mm with a Voigtlander Nokton 40 f/1.4 and the 77mm with a Nikon 24-120 f/4. It's really a sort of field test, where I want to understand two main things: if the filters introduce artifacts (flares etc) due to poor coating, and if they have an impact on sharpness. Indirectly I will also see how much colour cast they add. But, first, let's unbox the filters and see how they look like.
The package
The filters come in a very nice cardboard box that gives the feeling of recycled material.
Inside, the filters are in another case. The 77mm filters were in a black metal case, the 43mm were a mix of a transparent square plastic case and the black case. Maybe they are two different lots with different production dates, who knows. Anyway, the package is really well done. You also get a microfiber cloth to clean your lenses and filters, which is a nice plus. Filters are made in an alloy called Magnalium which is used to make scientific instruments and it's more resistant than aluminum alone.
Let's start with the 43mm, center of the frame. Click on the image to see it large.
As far as I can see, there's no visible decrease in sharpness. But, the ND64 has a visible cast. To get the same white balance of the original picture I had to set the white balance point to 4300K. The filter is actually cooling down the image tone a bit. It's not a lot. The ND8 has a cast too, but it's really really subtle. Both cases are simple cast and can be easily corrected both in digital and on film (if you're scanning or wet printing). It's completely irrelevant in black & white. Also, consider we are shooting a white sheet of paper with some black ink on it. Not really something you shoot everyday. We'll see later if this is really a problem in "normal" pictures.
Now the 77mm.
Again, no visible decrease in sharpness, but the cast is not as pronounced as with the 43mm, it is actually not there. Only a bit on the ND8.
Resistance to flare and vignetting
This is also very important, you don't want a filter to introduce something that your lens doesn't have. These filters claim to have a 16 layer multi-resistant coating, let's test it. Here again, my camera was in A mode, lens set at f/8. Regarding white balance, I set it to Auto, but in the pictures taken with the NDs I changed it in Lightroom and set it as the one without filters.
I used the 43mm filters to see if and how the colour cast affected the pictures.
The filter resists very well to flare and vignetting is really limited. Also, there's no visible chromatic aberration either. The image white balance is indeed cooled down.
Conclusions
There's no thing like a perfect ND filter, even the most expensive ones show a bit of colour cast or vignetting or bring even worse problems. Gobe ND filters don't show major issues, represent a very good alternative and, as a plus, you help the planet and its reforestation.
January 2019
Disclaimer: I don't have anything to do with Gobe, all opinions are my own