Full review here: http://www.freshdv.com/2013/01/gearin60-formatt.html
There are a number of tools that I bring in my gear kit for almost every shoot. One of these is the Formatt Hitech Modular Holder. This is a screw-on filter tray for 4×4 filters, and I use it most often with Formatt’s lightweight resin filters.
This is a great combo for lightweight cameras that lack built-in Neutral Density filters…cameras like DSLRs and the Sony FS100 come to mind. It allows me to clip on a filter tray and resin ND that weigh just a few ounces. And with several stages in the tray, I can stack NDs, or add grad filters to hold a bright skyline. I like the resin filters, as they weigh less than glass filters, as well as being thinner and less fragile when dropped. In my opinion, Formatt offers the perfect filter solution for shooters on the go.