Nikon® Lens Design
Nikon is very fond of the alphabet there big fan of letters and I'm sure within the company they have like the vibration reduction team and they're like we got this new technology can we put it in the lands yes you can put it in the list do we get a letter on the lens do we get a letter on the lens yes can it be here or can it be there do can we get a gold plate? We want a gold plate on the lens well okay you can have a gold plate on the lands and so I'm sure there's all these little battles about where they get to put things because there's a protocol that they don't exactly adhere to so you're going to see a number of differences so we want to go through and figure out what all these mean and how important they are in different aspects so let's let's think about designing a lance alright let's imagine that we're the new design team that nikon and we want to construct the lance ok all right so if we were going to design a lance and I know you don't have the microphone throughout an an...
swer and I will just say what you said what is something that we would want to have as far as a quality of the lens what would we want to have in this lens? What would we want it to do? Clarity of image so the sharpness resolution very good something very important what else would be important in the late what's that fast speed let in a lot of light very good yes good glass without going to the resolution but that can cover a lot of care categories lightweight lens we wantto lends its lightweight easy to carry around we don't want something too heavy these air good things anything else? Okay well let's look at a list of kind of goals that you have a good resolution yes we want a lens that's really, really sharp we also want a list that has contrast contrast is different than resolution it's close and sometimes we can fake having good resolution by having good contrast so if you're going to make a picture look sharper you can just increase the contrast we want really accurate color okay? We want to make sure the colors are accurate right? We don't want any distortions we talked a little bit about distortions that pin cushion and barrel distortion we don't like that in lenses we wanted to be a smallest possible so that we can carry it around we could buy as many of them put a lot of men are camera back we want it to be lightweight of course simple the use and maybe to build us well because that's going to mean we could make more money selling these lenses and being low cost if it's all into that together and so these are some of the ideas that are going to conflict with each other when you do this, so resolving we wantto lends that resolves as much detail as our sensors and our future sensors are going tohave and this is one of the things that has been changing on the nikon lenses because digital sensors have gotten higher and higher quality and they have increased and their resident resolving power from the old film days. And so there are some old film lenses that you might have had a very fond memory of using back in college, but you put it on your new thirty six megapixel camera. Now this doesn't really seem as sharp as it used to be and that's because our sensors have gotten sharper, they've had to keep pace, which is why they're constantly coming out with new lenses contrast ratio deficiency in transmitting light with minimal reflections. When you have a lot of internal reflections the dark era, the dark areas of the image are lightened up just a little bit and that reduces the contrast and we typically want ah high contrast amount of light coming through the image we want our dark stark and our brights bright and so what's gonna happen is that every light air ted glass surface is going to refract and maybe reflect the light and caused potential flare issues or contrast issues. And so we want something that lets the light cleanly through the glass, and that has to do with glass properties as well. It's the construction of the inside of the glass flare kind of what we're just related to talking about here. Light coming from a sharp angle hitting the front lands bouncing around, causing these flare patterns that are going toe, not help your photo at least diffraction. We talked about this before light waves bending as they passed by going by that aperture, the shape of the aperture. The position of that aperture in the lens can affect the amount of diffraction thatyou have. So you could have two fifty millimeter, one point four lenses that have different diffraction values because the glass and the aperture is different in the lens. Chromatic aberration. This is a big problem with a lot of the older lenses on newer cameras distortion. When colors do not converge at the same point, you'll notice it when you were shooting subjects that have bright backgrounds. What happens is that the light is it comes around. That subject in this case on the underside of this beam is very red in color, and on the top side of it is very blue or teal ish in color. Now this can be corrected for in post for instance, dobie light room has a little slider system if you know how to work the sliders, you can fix this problem, but it would be better if we didn't have a problem to fix and a lot of lenses suffer from c a or chromatic aberration another problem coma co matic aberration and this is a variation in the magnification over the entrance pupil and this is basically where things were slightly distorted and you'll notice this when you shoot nighttime shots your star points are not exactly points they're kind of all belongs and it looks like I'm taking lots of photos of saturn here because it looks like there's kind of rings going out and that will be very common you'll see this on the edges of wide angle lenses with nighttime shots astigmatism light's not quite focused correctly as it goes through different parts of the lens, so we're gonna have focus but not complete focus in that case the distortion we talked about this a little bit before barrel distortion and pin cushion distortion. We're more likely to get barrel distortion with wide angle lenses and pen cushion with tele photos and were more likely to see this in zoom lenses than in prime lenses, but all lenses have it to some very small degree vignette in can be a problem it's a darkening of the corners this is a natural effect you'll notice it very much on wide aperture lenses like a fifty one for an eighty five one four personal note here's a photo of my great grandfather urban and my great great father amos and this photo suffers from vignette ng a lot of those old photos remember a lot of old totals were in ovals and that's because it didn't have the sharpness or the resolution as we went around this is my great great great grandfather jesse and I mean this is why people would put them in ovals because we weren't getting very good information down here lenses were just not letting the light through and so that's a vignette ing effect that you're getting okay, I mentioned focused breathing earlier this is a change of magnification when you focus, so what you see up here is actually a video and I'm gonna go ahead and start the video and you can see that I'm focused now on the foreground but notice the size change and how it's changing a little bit in the framing and all I'm doing is focusing the lands and so this lens suffers from focus breathing this is something that's a little bit more important to those shooting movies because when they change focus they don't want to change the composition they want to leave people exactly where they are and so this is not a big issue for still photographers but it does affect things sometimes when you get into macro photography okay, you know, I find this really interesting I have a degree in photography and not once in college was the word okay ever mentioned and for some reason it became much more popular term about fifteen, maybe twenty years ago and so this is the quality of the out of focus area and so we have good okay? And we have bad okay and it's all a matter of opinion but generally there's some things to look for in the bad. Okay, we're going to see the aperture, the kind of the reflection of flare of the aperture we talked about that when we talked about flair and also in the out of focus area, it appears to be a little bit more clumped or jittery were as in the good okay it's a more smooth roll off and every lens will have its own little odor of bo kay and some people really like, oh, this iceland's has a really good okay, but I don't like this one or this one is better than that one and it's a matter of personal but it's something it's not just the amount of out of focus areas, the quality of it and then there's the overall construction of it the plastic lens mounts I'm not a big fan of they make things very lightweight and inexpensive, but for long term durability, it's nice having those stainless steel lends mounts the size, the focus ring on a number of other amenities that we will continue to talk about in the section. And so this is all things that are going into the lens design, where they're trying to design the right compromise. What all of these features now, if we want to build a lens, we're going to start off with basically a powdered chemical compound that will have up to one hundred different ingredients that we need to mix in order to make just the right thing. Now, some of these materials are very costly, and they're going to cost quite a bit of money per pound or kilograms in here, we're going to need to decide how many elements, what material are we using? What order are the elements going to go in? And are they going to be in different groups? And this this, to me, is part the magic part of lenses and then to make the lands this is just in a sample of the process where they have toa mics, heat cool and go through all these refining processes where they're heating it up, cooling it down, getting it up, clean it down, shaping grinding at polishing all these different things. And your lenses don't have one element in them they're gonna have five, ten, fifteen, twenty elements and every one of those needs to be just right on both the front side and the back side. So there's a lot of things that need to go right in order to make a sharp lands. One of the letters that you're going to see is e d remember I had a needy lands and my buddy came up and said, hey, my name is on your lands and cut it out get away from me I'm shooting pictures so e t stands for extra low dispersion glass well, when you use standard glass sometimes when you shape it and use the right certain materials and they're not all the focus points meet up on the plain of where it's supposed to meet and so by using this special e d glass, all of them meet up in the same spot and you get sharper images and this is kind of what I grew up with you wanted in the td lance because edie had the special glass they put that only in their best lenses and so superior sharpness is going to be one of the characteristics of this going to get less chromatic aberration on here because it's going basically correct for that and it's stronger than these calcium fluoride crystals, which is another way of doing the same technology the problem is is that these florid crystals which they did use an earlier lenses cracked more easily and so if you were really hot cold environments and things we're changing because of the heat and cold contraction on so it proved to be very durable system and so there is a fairly long list of e d lenses in fact they have diluted it in my opinion because everything has edie on it the fifty five to three hundred has e d on it all sorts of lenses where is that the eighteen to fifty five they're one of their cheapest lenses has edie glass in it and so it's just a different type of glass to address image quality in a number of west one of their more recent introductions is f l which has nothing to do with florida fluoride lands this is a model crystal which is a really dense crystal material and it is just being used in a number of their very new high end telephoto lenses and so that eight hundred that I was picking up playing with earlier that's got the f l technology in it very high transmission rates so it's letting in a lot of light to the lenses which is a topic we're going to talk a little bit more about us we get in here corrects for chromatic aberration and it's lighter than standard glass one of the things about these big lens is that you know I've been picking him up showing you how heavy they are but they're actually quite a bit lighter weight than they used to be just a few years ago but it is a challenge to manufacture takes about twice a cz long to grind the glass the glass is much more expensive and so you want a better quality lens yeah absolutely we could do it and you're going to pay for it all right so you get what you pay for and so much more expensive all of these lenses are multi thousand dollar lenses okay so now we got the materials for the winds now we need to shape the land's most lenses are put into a spherical shape its rounded it's very easy to grind and get things very very round all right but the problem is with certain types of glass we mentioned before we talked about edie things don't land in the right spot the light rays from red green and blue don't land in the right place and the way that they found a corrected is to make an ass spherical element which is much more difficult to make is the grinding process is completely different but with these you can fix certain types of problems that you wouldn't be able to fix with other part other types of glass so it's going to eliminate coma reduced distortion and wide angle so you'll see this more commonly in wide angle lenses and it can help reduce the size of the lens, which are all really nice things tohave. And so if you look on the list, there's a long list of a spherical lens is that they have been using now a spherical lenses are a little bit lower on the totem pole with nikon when it comes to getting letters on the lens, so you're likely not to see a letter on the lens indicating whether it has an ass vertical element in it or not. But you might see it in the bullet point description at night cons website about what that lands features, and so they haven't seen the love from the naming committee. Yeah, because they don't get a big a s on their lenses, but it's possible, you might see it on one or two, but usually it's just a footnote. One of their latest innovation innovations is phase for nell technology. Now one concept. If you were a creative mind set, you might say, well, this is a nice lands, but what if we just made everything smaller made the barrel smaller and all the lens elements smaller? Can't we do the same thing? Just making it smaller and that's a great idea, but what happens when you actually get light going through it is that just when you make all the elements smaller they'd all don't react exactly the way you would want teo and so we have this point once again of the light rays not being focused on the right area so another solution and I've got to think it's one of the most creative solutions I've ever heard of is okay so this land's it goes blue green red but who would ever come up with this idea? I don't know but if we do it this way it does red green blue hey, wait what if we added this element and this element and then have those light rays correct for themselves and now we can do what we want this lens to do and have all the light meat in the right spot. All right, so this is what a face for now element is and a foreign element you might know from a lighthouse if you've ever seen one of those big focusing lenses that they put on those lamps and that's where the final comes from. So for instance nikon has a three hundred millimeter f four let's been around for a long time had several different upgrades over the years they wanted to make something that was notably smaller inside eyes and they did so with this brandy lends called the three hundred f or e p f e d v r last okay there's rpf phase for now. All right, edie, we've already talked about that one, okay? F s we've talked about that one. And so this is this new, shorter leads that is much shorter, but it's the same focal length and same aperture, because it's using this unusual lens design thirty three percent smaller and it's almost half the weight. If anyone out there is a private eye and you like to spy, you know, you sit in your dark car and you shoot photos of people walking across the street. This is the lens you want to get, because it doesn't have a big it's, not a big lens. It's, a tiny linds, but it's got a very long reach to it. Or just perhaps, somebody who's going out, hiking that once a long lens to shoot wildlife with. All right, so we got our glass it's all shaped right, but there's a problem every time that light hits a glass surface and it will hit it twice, we lose a little bit of light. Four to nine percent of the light is going to be reflected rather than transmitted through the glass. And so right here, we've lost eight to eighteen percent of our light going through just one element before it's hit our sensor, not only we have we lost eighteen per cent of the light? This light now hits the other side of the glass and bounces back onto our sensor, which is causing the loss of contrast and sharpness and then it's going to just keep bouncing around everywhere and they're causing problems and so if we put a code in on here, we can potentially improve the transmits how much light gets through the glass we'll minimize this flaring ghosting and we can optimize the color balance and so we can really improve the quality of the entire glass and everything that it does by putting the right tip of coding on here we can also put one on here just simply to provide protection like on the front of your lens so it doesn't get scratched, smudged and dirty and things like that so there's a number of different coatings that we can use now think about this a really simple lends might have six elements which is twelve surfaces, which means you're only getting sixty one percent of the light they're one of those big telephoto zoom lenses would result in only fifteen percent of like getting to it without proper coatings on the glass that's how important the codis khun b and so this is just sick s I c stands for nikon super integrated cody it's a layering coding system that they used on their lenses to reduce ghosting and flair it's, just really effective with lenses that have large elements, so you're going to see it on a lot of telephoto lenses, zoom lenses, a swell, I should say, and this is customized according to each element in the land you have a lens that has fourteen elements, they might have fourteen different types of cody's they might have twenty eight different types of coatings because you have the front in the backside as well. Now this was originally called just nikon integrated coating they making improvement, and then they got to call it a new name change. All right? And so every once in a while, you'll see lenses listed with this information florian coding he's going to be used on a number of lenses, not too many, but I have a feeling we're going to see this on a lot more lenses in the future, and this has nothing to do with image quality. This has to do with protecting our lens. It repels water, dust, grease and dirt and makes lens is much easier to clean. And so if you're going to shoot out in the rain, these would be great lenses to shoot out in the rain with because the water just doesn't beat up and stay on the lens quite in the same way, and it is much easier to clean. And they've also started to put it on their telecom voters as well. And so I hope to see this on mohr and more lenses and so it's just simply a coding. All right, this is gonna be the strangest coding you've seen it's the nano christo coding and it's this coating that has little tiny air bubbles in it which sound really strange, but they're smaller than the wavelengths of light that are coming in and what this is doing is it's impacting the way the light is refracting through the lands it's kind of changing the way it hits and shapes through the lens and so it's an ultra low refractive index and so we're going to be able to get light cleanly in the lands and so light hitting at strong angles that might cause a flare problem are going to be improved here less ghosting and flair and so there's a number of lenses that have and now nikon really likes the nano and so you will see lenses that have very bright, bold ends on them like this right here they put a big in on it that's a very special place for nikon is when it gets its own gold label on the last so nice is something they really wanna advertise but all it is is it's just too cody that's all it is, but it helps it makes things better