I need to put together a set of 77mm filters and I noticed the firecrest are half price at B&H. I've been using 52mm Hoya uvir with standard tiffens, but need better above 4 stops so I though I'd grab the 4 stop and 8 stop in that size. For the starter 77mm I was thinking 2, 4, 6 plus the uvir firecrest. Hoping the clear filters are close enough in colour rendering to not have to replace the 52mm Hoya. I'll also be using the clear filters to control tungsten light, and sometimes need to roll 2 cameras. Also these firecrest round ND's aren't specifically marked IRND, even though the claim to control ir evenly, so I assume they can be stacked.