K&F Concept 10 Stop ND Filter
One of them things I’ve been wanting for a while is a 10 stop ND filter, and it’s been on the want list even though I don’t really use anything above three or four stops usually. Then last year I was off on holiday and decided to grab one quick off Amazon, and came across the K&F Concept 10 stop ND… Never heard of the brand, but it was cheap and if I could get the one or two shots I’d got in my head with it and it was reasonable then it didn’t matter if I tossed it… So after 9 months with it, here’s a bit of an in use review.
First off, I did say 9 months there, so it’s not something I bought yesterday and the “new toy” smell has worn off it; and as it’s still in my kit bag after 9 months it must have something going for it.
What it is, is a slimline filter holder with a chunk of (from what I can find) Schott glass in there, the holder is thin, the glass has a green tint to it, there’s plenty of images on line of them without throwing another few up (or worse, ripping them off from somewhere else!). It’s coating does well to repel some liquids, sometimes though they just bead but now is not the time to take apart viscosity or droplet size; and after having it kicking around on the beach and in dusty environments it hasn’t scored or scuffed up.
The one I bought is an 82mm ring, it cost me about 60€ from Amazon, add it to a set of stepping rings and it’s good to go on anything with a “common” filter size.
In use, at 10 stops, it seems to work out a bit off the value; not much but does require a slight tweak in the exposure timings on a daylight image. I’ve not calculated it exactly, but somewhere around the high 9 stop region or about half a stop push in post; however other brands as well seem to have this quirk.
Vignetting, it does emphasis a bit (as in the image above) but nothing too major that can’t be controlled in post, but this will vary a bit to what type of lens you have on the camera as well; some lenses are naturally darker than others. I found that the vignetting was noticeable more on the Fuji 18-55 F2.8 when I was using on an XE-2s that compared to when I was using it on the Sigma 70-200 F:/2.8 on a D810 (as in the first image on the post), so don’t quote me as saying “it definitely casts vignette” as it doesn’t.
In terms of colour cast, again it’s not 100% perfect, it does cast a little blue, and the images can appear slightly cooler than normal; but a quick tweak of the white balance and that’s out of the way.
When working with this filter, it doesn’t seem to show any pronounced nasty in terms of reflections or ghosting, nor does it seem to emphasis any naughty behaviour when working in ranges which are closing on to IR; though as I don’t run a full IR kit, just a hAlpha mod then I’m not running in to things fully head on.
Last thing… Sharpness.
I’d be lying to say that this filter didn’t reduce some sharpness in things; it does. It’s not a killer problem with it, a bit of time in the post capture workflow will bring a lot back in to it; just takes time to get the head around. Personally I find after a bit of sharpening in LR that it’s perfectly acceptable for putting images up on the web and also printing them out up to a decent poster size; but then again I don’t know if a more expensive filter would do a vastly superior job compared to this. Personally I wouldn’t want to spend a few hundred notes to find out as an ND10 isn’t something I use every day.
So, summing up; it’s a sub 100€, 82mm ND1024(ish) filter and for the price I paid for it I wasn’t expecting something super spectacular, but what I got was something that was pleasantly surprising, well constructed and a filter where the quality punches above the price paid for it by a good margin.
But for all them words, the 9 months in the kit bag (so far) is all that needs really to be said.