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The Gadget Bag: Neutral Density Filter

Another type of filter that might be of use for certain types of purposes is the neutral density filter and what this is, is it's a filter that is dark, that's it. Adds no color, that's what's the neutral part of it and it's just dark, that's the density part and you might wanna use these if you wanna use slower shutter speeds than you cannot truly get to with your camera settings. It'll allow you to shoot at preferred aperture settings or it might allow you to shoot with shallower depth of field. Those are three options that you can use these for. There's a variety of them out there. So in this situation, our first shot is at f5. at 125th of a second and we've decided, we wanna do that slow motion of the water type look so what do we do? We're gonna close our aperture down to let in as little light as possible on one side and then we want to let in more light by going to a longer shutter speed, gets us down to 1/4 second and that's the absolute limit. If we wanna do a one second expos...

ure, we can't do it here. What we could do is we could put on a three stop neutral density filter. Now, if I had three stops to work with, I would be thinking; I don't like to be a f32 just on the aperture side because I get in that diffraction and less sharp of an image. It would be better if I could back off to f because depth of field-wise, I don't need f32 in this case and so I might use three of my stops that I get to spend and then another one over on the shutter speed where you get to 1/2 second and they make these ND filters at different levels; two stops, three stops, four stops and which one is right for you kind of depends on what you do. The one that I have goes six stops and so I was able to get down to a four second exposure at f16 in this case. Now, what's the difference between this and the shot that we had previously at 1/4 second? Let's switch back between the old shot here which is pretty nice, has a nice flow to it and let's go back to the longer shot here. Alright, you can be the judge as to which one you like but I'll tell you what I like; and that is the option to choose between the two and so if you have the neutral density filter, you can kind of set it really exactly where you want it so if you wanna do this type of photography; something in a four stop to six stop ND filter is gonna allow you to slow that water down, really slow in situations where you may not normally be able to get to do it. And so, examples of some photos where I used it as a really long exposure; in this case, it's a five second exposure and just in case you're wondering, I did use a neutral... A graduated neutral density to darken the top part of it which I'll be sharing with you in just a moment. Get in a very slow shutter speed in this case, four seconds. One of the general rules of thumb for nature photography is; don't shoot moving water in bright sun. It just generally doesn't look very good and this is an exception to the rule. I wanted to break one of those rules of thumb. I wanted to shoot moving water in bright sun but in order to get this really smooth flow look to it which is a one second exposure, absolutely required a neutral density filter. Shoot this on your own without an ND filter, you're gonna be up around a 60th of a second as the slowest shutter speed that you can get so very necessary in that situation. There's just a lot of fun that you can do with these if you are around water and you like that really slow shutter speed look. This is one of my favorite waterfalls up in Banff, Canada. I believe it's Tangle Falls. Six second exposure. I love having options, choices to make. Alright, let's talk about the Neutral Density Filter in the power that they are so what you mainly wanna be thinking is the f-stop reduction. How much light is it blocking from coming in the camera? How many stops of light is this working on? And the way these are sold and marketed, varies depending on the manufacturer. Sometimes they will market them under optical density where point three is equal to one stop of light. Six f-stops is equal to 1.8. Another system that they might use is their filter factor and so what they're essentially talking about here is their exposure time needs to be twice as long or four or eight times as long and so just make sure that you understand what type of filter you're getting. Now, there is also a variable filter which can be very handy because you can adjust it exactly where you need it to be. I have found those to be optically not as good and typically they often have a little bit of a color, shift on them that I don't like and so I am not a big fan of the variables but people who shoot video do like the variables because people who are shooting video are often trying to get to very specific shutter speeds and aperture settings and this allows them the most versatility and with a little bit of adjustment in post level to correct for any sort of color problems that they might have and so it depends on your use. As I said before, I have a six stop and I have bought it for doing waterfalls and rivers and things like that and I am 100% happy with the six stop. I think one and two stop is just not enough for that type of work. Maybe very good for other types of work but not the work that I was doing. Alright, the Graduated Neutral Density Filter. This is a filter that helps a lot of travel and landscape photographers deal with the issue of the fact that the sky tends to be relatively bright and the land tends to be a little bit on the darker side and so in this case, it's very hard to see the clouds and the texture in the sky so let's go ahead and add a neutral density filter and see how it changes this photograph. What's in the bottom third of the frame doesn't really change that much but what's in the top has gotten a little bit darker and it's easier to see and so this is a good use of a Graduated Neutral Density Filter. Now, the filters themselves look like this and so they are graduated. It gradually changes from a neutral color so it's not colored here. It's neutral density down to the bottom and you're gonna hold this up right in front the lens so you have your lens, there are adapters so that you can mount it in front so you don't have to hold it in front and this is something that you might wanna do if you're gonna be set up for quite a period of time and if you're just quick moving, you can just handhold it in front which is what I do most of the time. Now, one of the things that people will see this is like, "Don't you see that it's gotten darker?" Well, I'd like to do a test with our own camera here and so I got my little filter pack here and I got a the three stop ND filter here and so it's darker on the top and lighter on the bottom and let's go ahead and walk it right into the camera and you can see, if you get this right up to the front of the lens that it looks darker in the top half and you don't even see the gradation, I'll move this up and down a little bit and you can just come to get to set wherever it is that you need to be and so these are really handy because you can move these up and down and they are square because you want to be able to adjust where that horizon line is. Whether you have a high horizon or whether you have a low horizon. Here's how I would use it out in the field. I have some flowers in the foreground that I like and I have a beautiful sunset. You guys see the beautiful sunset there? Okay, let's try a different exposure so that you can see the beautiful sunset. It's a very different exposure. It's much brighter than the foreground. So the way that I take this photo is I set it up for the lighter foreground because that's the clear part of the filter and so here's where I have it set up and then I just take my filter and I drop it down in front and I darken the sky and I get the best of both worlds. Now this can be done, in post-production by shooting multiple photos and comparing and working with them and combining the best parts of either one but this way, you get to see it and you get to do it out in the field and you get to capture it in a single image which is very helpful if there is anything that is moving in the photograph because you have captured it in one single photograph. Images that will show you bright mountains in the background and shadowed areas in foreground. That's just near impossible to do on its own. Alright, you gonna have to have some help in here and this is where I use the neutral density filter and if you did it write, nobody but an experienced photographer will be able to tell that you did it. It just looks natural because if you were standing in the spot yourself, you would look up at the mountains and your eyes would adjust for the brightness. You look down at the foreground and your eyes would adjust for the darkness down here and readjust and so this is very much mimicking the way that your own eyes see but it's not the way that our cameras see and so a situation where our mountain is overly bright, we've got it set for the foreground. Let's bring that filter on and we're darkening the top part of that frame and that's why it's nice to have a filter that's a little bit larger than your lens so that you are able to move it up and down. Alright, there's a sky that's too bright. Let's darken it a little bit and now we can see some nice texture in there. Big difference between before and after. Now, you can get different types of filters that have different gradations of whether it's a quick gradation, a hard gradation where it changes very quickly so that's one option whether it's soft or hard edged... Filter, you can also adjust how... Well, you can get different filters, you can't adjust it. You can get different filters for how much neutral density it's adding; either one stop, two stops or three stops. Two stops is one of the most common. I carry a two stop and a three stop so that I'm able to darken either two or three stops the top of the frame. And I have found a number of situations where I've been creative with using this. I've had a situation where I needed to darken the bottom part of the frame or I could tilt a little bit according to the hillside that I was on, moving it a little bit off to the side and so you can hold it or mount it however you want in the frame but effectively helps out a lot especially at sunrises and sunsets where you want to get a little more texture into the skyline. In this case I'm in the forest. First thing I was thinking about is all these reflections off the ferns here and so what I did is I used a polarizer so let's go ahead and polarize the right side of the screen and you'll see these, reflections off the ferns going away but I also felt that the back third of the... The top third of frame was a little too bright and so I added a neutral density filter even though I was in the forest just to darken that backside a little bit, I thought the balance was a little bit better in that final photograph. Keeps your eye more in the foreground where I thought it should be. You can play around combining some of these. Ideally, I don't like to stack the filters but in some cases there's really no way to get around it. They are just completely different filters and they are combined into one filter. Here's what a two stop and at three stop would look like. Gonna darken those skies. It's gonna compress the tonal range a little bit so that you can actually capture it in your cameras. I prefer it over HDR for most of the time. Works good for moving subjects as well. John before we go on, Yeah. We do have a number of questions about polarizers and filters-- Good time. I know this is a really big topic for especially for people who might be kind of new so grab a mike if you have any questions here but can you tell us again, this is from George Clayton, why is it that you use a UV filter other than not having the cap because he's heard that if you aren't buying a nice one but you have nice glass and a lens, that you're actually degrading our image quality. Is that true? Right, well yeah, of course. That's always true. Anytime you take and add another piece of glass to it, it'd be pretty much impossible to improve on the image quality of the lens by adding another lens in front it. What my argument is, is that the image degradation is so small that you're unlikely be able to see that difference with your own eyes and so that's the small hit that you're gonna pay is an invisible amount of detail and I'm unwilling to deal with an invisible amount of detail change and so there is the thought process and generally, the argument goes; why would I put a cheap piece of glass in front of my high-quality lens? Well, first off you don't have to buy a cheap piece of glass. You can buy a nice piece of glass and put it in front of your lens and secondly, designing a lens is a very complicated process. Designing a straight, clear piece of glass is a whole lot simpler to do and so designing a clear filter is not rocket science. I mean, they probably do use rocket science technology in making these things to be honest with you but it's something that can be done fairly easily. I do use B+W filters. It's a German brand of filters. And there's a number of cheap filters that, you know, I really don't like to use and one of the things that I do like is a filter that has a brass ring to it and I think, even though these aren't UVs, these are polarizers. One of the things that they just feel heavier and if we have a microphone nice and close to the table here, we can do the spin test and if we're all really quiet, you can hear the beautiful sound that brass makes on glass. (brass clinks) And aluminum makes a much much different noise. It's very easily and discernible as a lighter weight metal and the problem that I have with aluminum is it's a softer metal and if anyone's had problems trying to get a polarizer or any of these other filter off their camera, "Right now because the light's really good." You don't ever wanna deal with that again and so I do not like the aluminum rings that those cheaper filters are in. Thank you. Go ahead. So when you're using your filters, especially like the polarizing filter, do you know automatically that you're going to need it or do you take a shot first and then say, "Okay well, I may need it for this instance "or another instance," because I'm thinking more of like fashion photography that's outside, being able to add that filter but not knowing when. So what would your recommendations be for that? Well, remember the polarizers is gonna have the most effect when you have strong directional lighting. Typically, that's gonna be on a sunny day. It's not gonna have much impact on a cloudy day because light's bouncing everywhere and so first off, doesn't meet that first requirement. Secondly, before you mount up on your lens, just take it out and look through it. You'll see exactly what it does, holding it up to your eye and so that would be the quick test before you have to put it on and look through and shoot a test shot. And what about neutral density filter, same thing? Neutral density, that one is pretty easy to figure out. You can look at it and once you get pretty good at judging in those situations how bright the sky is, how dark the ground is. Is there direct sunshine down here? No, it's all in the shadows and that's really bright up there. It's gonna become quite obvious. You may need to shoot a photo just to really go, "Oh wow, okay. It's brighter than I expected." And you can see it in the histogram because the histogram will be way over to the bright side and way over to the dark side and this will help you maybe bring those two; if you can separate those two with a single line and that's the big problem with the neutral density filter. You know there's always been the joke that people would develop filters that have one tree and then two trees and then a building and a tree so that you could have a specialized filter for every imaginal scenario and that's basically where HDR photography comes in. Got it. Thank you. So this is a polarizer question. Does the camera's internal light meter compensate for the two stop force of light so does... Because you're putting on the... Right yes, so you're putting it on the front of the lens and the camera's reading all the light that's coming in the lens and so it's blocking light from coming in the lens and so your camera will be relatively accurate on the metering system. You may disagree with what looks good. You're more likely to disagree with what looks good with a polarizer so you may need to over or underexpose, according to your taste in that shot. A couple of more quick ones. Do I need to buy filters for all of my lenses? Can you talk a little bit about the size. Alright, there are different size filters on different lenses. If I just randomly grab two lenses. This one is a 67 and this one is a 49 millimeter and so these cannot share filters. Well, I can get a UV filter and for each one. If I wanna get a polarizer, I could buy a and I could buy a 49 to 67 step up a rate so that I could use the big filter on the little one and that's way too much of a pain to use on UV filters so if you wanna use UV protection filters, find one that fits and that's it. If you're on a budget, buy the biggest polarizer that you need and you can step-up rate. If you're switching back on forth on lenses, it will become a hustle. I don't have that many different lenses that I usually I'm carrying with me so I'll usually carry a polarizer for that size of lens so when I go out, I'll have a 67 and I'll have a and that way I don't have to try to use some sort of adapter between the two of them. Does putting a filter or polarizer on there change white balance? So this region we're saying, "It looks like it's changing." Like a colder temperature. Is that affecting that? Well, it is changing the colors that you are recording. It's quite possible that you may want to change the light balance. I haven't found that necessary. It's gonna be more of your personal taste as to what you like or dislike about it but I have not found that as a necessary step on changing. Great, thank you. You can keep going. Alright. Let's talk about the lens hood. This is one of the most misused items by amateurs or one of the ones that should be used and what this is for, is for reducing flare and optimizing the image quality that you are getting into your camera. So here's the problem. Let's say you're taking a photo of a light and light goes through the different lens elements of your lens onto your sensor and let's say it has a perfectly black background. Well, what happens inside the lens is in theory, all the light goes straight back to the sensor but in reality what happens is some of the light hits the surface of the glass and it bounces off and goes off the other end and then it comes in and it makes the black a little less black. It adds a little bit light leak to that and then the light might refract through the glass not quite in exactly the right way and now, we're having less and less contrast and maybe even the light from the light itself, bounces off the back of the back element of the lens back onto the sensor, causing a loss of contrast and so hopefully your lens doesn't do this and it's gonna get as clean of image through here as possible but when we have light coming from the side, it could cause a problem so when you have your camera pointed at a subject, you have an angle of view that you are photographing and you might have the sun in there and that's gonna bounce around and your lens is as corrected as they could make it. It's the best that they could do with dealing with those and so if you have sun in the photograph and you want it there, you're probably gonna get some flare issues that you really can't do anything about other than moving the sun out of the frame. Now, clearly you don't need to worry about the sun or bright lights coming from behind you because that light is not going in or hitting the front of your lens but between these two is what I call the flare zone. This is where you need to worry about bright lights that might be striking the front of your lens. Any sort of bright light hitting the front of your lens might have light bouncing around, in the frame causing a loss of contrast or flare problems. This is of course solved with a lens hood, blocking all of that light in so this is the correct position not reversed on the lens which is convenient for storage purposes. You wanna be using it like this anytime you are using it where there're any sort of bright lights anywhere around you.