Join Justin Reznick for an in-depth discussion in this video Stacking filters to get the best water effects, part of Chasing the Light at New Zealand's Lake Wanaka.
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- I've gone ahead and taken the 10-stop filter off. I've gone back to aperture priority, and I've also made sure I'm shooting RAW. So that means I'm at ISO 200. Now, looking at the settings here, we have f/18, ISO 200, 1/80th of a second. I caught an image at two minutes I really like. Let's push it. Let's go somewhere in the eight to ten-minute range, really get out there and see what the sky looks like. It's really hard to imagine. The best thing you can do is experiment and see for yourself.
Now, we know that adding the 10-stop filter is not enough. We can stack filters. Because I've got the step-up ring larger than the filter thread, remember, it's an 82-millimeter step-up ring on a 72-millimeter filter thread, what that means is, I can stack filters and not worry about vignetting. So, I've got with me a 10-stop, a 5-stop, and a 3-stop. What I want to do is pull out my calculator again. I'm going to use a different application, because the 10-stop only worked with the 10-stop.
This one is called Long Time, and what I can do is add 15 stops, and I was at 80th of a second, actually, I'm going to go to a 60th of a second, so that's going to be f/20. And that's going to give me eight minutes, okay? That's what I was talking about. Somewhere in that range. So, if I stack my 10-stop filter and then add my 5-stop filter, I'm going to get an eight-minute exposure. I also felt like the other one was a little bit dark. And I'm going to take a guess here and say that trend will continue.
So I'm going to compensate, and I'm actually going to do a 10-minute exposure, and once that comes back on the histogram, we can adjust if needed. So the next step is add the filters. Here we go. Starting with the 10-stop, always do this with two hands. The last thing you want to do is drop a filter. These are not cheap.
This is a B+W 10-stop filter at 82-millimeter thread. I do not want to drop that. Now, we're going to add a 5-stop filter. This one is the Singh-Ray Mor-Slo filter. The reason I like this one, it's thin-mount. So it even helps with vignetting, in addition to being on the step-up ring, it's also a very thin ND filter. So I like this a lot. So we've got a 10-stop and a 5-stop.
We're going to go to bold mode on the camera, okay. And remember, 10 minutes. I'll see you in 10 minutes. (camera clicks) (birds chirping) I've patiently waited the 10 minutes. And now I'm looking at the back of the screen and seeing an image. It's not quite as strong as the two-minute exposure. Let me tell you what happened here. The sun is pushing through the clouds here and there, just kind of giving me a little bit of glare that's creeping up in the lower, right corner of the image, and that look is not appealing.
In the two-minute exposure I avoided that. Now, the key point here is the clouds look very similar in both exposures, and what that tells me is two minutes is all it takes for these clouds to form a nice streak. So with that in mind, I'm better off with two minutes, less chance of problems, variations of light, light leakage from the corners. It's just a better exposure. I'm really glad I did the experiment. It's great to be able to compare the two. And whenever you're doing long exposures, I really encourage you to do multiple times.
Do 30 seconds, two minutes, five minutes, 10 minutes, and more, if you want, and really compare, and you'll start to learn more about the movement of the clouds and what shutter speeds really work and kind of getting, doing an eye test, being able to look up in the sky and giving yourself a nice, kind of, guesstimate of how long you think it will work with. So the more you do it, the better you get. I want to mention something called long exposure noise reduction. I didn't have that enabled on my camera. I tend not to. The reason I don't use it is that it, for a 10-minute exposure, it takes another 10-minute exposure to reduce some of the noise and take away some of the hot pixels.
That 10 minutes is crucial to me when I'm shooting. So typically I like to do that in post, I'll reduce noise myself in post, and I can take out any hot pixels. I just wanted to mention that, because you'll notice that I didn't use that feature. If you do like to use it, I don't have a problem with that. But for me, I need that 10 minutes. It also helps drain down the battery, which worries me as well. A lot of times when I'm doing long exposures and it's 10 minutes, I don't want to wait another 10 minutes. So you know, this was a lot of fun. You can go in your back yard and shoot long exposure clouds.
You know, water and clouds are fantastic and really, really change their appearance when you do the long exposures. So what we're going to do now is we're going to give the tree a little bit of a break. We're gong to come back later, in different conditions, and see what else we can do.