Lens Accessories: Teleconverters
Next up, let's talk about tele converters, so this is a way to magnify the focal length of our lands. Nikon has three different tele converters available for you one point for one point seven and a two times converter and one point seven is kind of unusual. Not too many companies have a one point seven. In fact, I think nikon is the only one, and so each of these is just a different step in increasing the magnification. Now, the way this works is it works very much like the extension tube's that we just talked about, but these clearly have glass elements in them, so you can add in any one of the different extent our tele converters that you would want in general, I wouldn't recommend doubling them up, although it is physically possible if you use an extension to because these actually protrude into the front of the lens in front of them so you can't just stack these together, you would have to add an extension to so that it has space for these lens elements to go into you will be limit...
ed in some aspects of how you use the camera, but in general, for quality reasons, I generally don't recommend it, so you're going to add the least one that you need to because the mohr elements you put in there with lower your going to degrade your image so just as an example of what tele converters do here's a shot of our beloved city of seattle within eighty five millimeter lands and we're going to use a full frame camera at three hundred and we're going to use a crop train camera at three hundred so that's our crop of you it's a little different angle of you even though it's the same lands so let's try using a three hundred millimeter lands here is what we get let's try a three hundred with a one point four converter we're going to be in a little bit closer now over on the right hand side. The numbers that I'm listing are effective focal lengths these air not the actual focal lengths because it's a three hundred millimeter lens but this is what a three hundred millimeter ends looks like on a crop frame camera and then finally we'll use a three hundred with a doubler on it for getting closer and so a variety of ways of getting closer and so one of the things that I wanted to do a little test on is what's one is the sharpest because we have different things pushing and pulling us to where it's going to be the sharpest so one argument would say full frame is better than crop frame because pixels are bigger the image sensor is better we should both supposedly get better image quality off full frame but with a crop frame were enlarging the image less because the images larger if we're going to go in and see if we can identify somebody up here on the space needle, we need to enlarge it less with the crop frame camera so that's an argument over there then there's the argument of well if we don't use a tele converter that should be the best cause it's just a great lands without anything in the way and if you use a tele converter that lowers the image quality so we have reasons for any one of those to potentially be the best. So I decided to run my own tests I wanted to do it on the space needle, but the wind was blowing and I wasn't able to get ah steady set of shots with all the different combinations and so the combination I wanted to shoot was all these crop frame full frame and then going in and looking at a small little portion of the details and the results end up being whatever you need to enlarge the least is going to give you the best quality and so if you need to crop into your image, you want to do so as little as possible and so the worst image was with the full frame camera with no tell a converter because I was trying to magnify a small portion of that frame as much as possible and it's simply got better with the effective focal length what angle of view it appeared to have, so I'm trying to get the subject as large as possible. And so what this means is if you are trying to shoot a little bird or wild animal way out in the field, crop frame body might just be better than a full frame body using the longest lens you can with the dubler. If you're trying to get as close as possible now, it would be better if you could use a full frame camera. It would be better if you didn't need one of those tele converters, but if you have to use them, they are necessary and they will get you a little better quality if you're trying to get as close as possible so the different converters that they have the one for the one seven and the two point oh are losing a little bit of light, so you're going to have to adjust your shutter speed or your s o in orderto let in a little bit more like to compensate for adding these are these tele converters on now? These are not recommended to be used on white angle, they don't even fit on the white angles and so there's a whole list of tele voter. Tell a converter compatible lenses that I have up on screen now, and so generally these air lenses that air out two hundred millimeters and beyond there's a few exceptions, like the one or five micro lens, but for the most part, two hundred millimeter lenses and up is where you want to use thes. I would be cautious about trying to use these on zoom lenses like eighty two, four hundred. I think it may work, but image quality may suffer quite a bit when you add it to a zoom. I think the seventy two, two hundred to eight is such good quality, but that's one that would be an exception to that rule. Now, having been excited as a young photographer about telephoto and trying to get the tele converter, I did did get a tele converter with my original camera purchase, and it was just total garbage. It was just one of the worst pieces of junk ever had, and what I have found almost without fail is that all of the aftermarket tele converters that air out on the market are not worth a penny just not worth a penny. If you're going to do it, you got to do it right, you gotta have good glass to start with, and you gotta have a good tell a converter if if you're going to try something else, just I warned you it's not going to look good now you may disagree with me but that's my opinion all right so you're going to use these on good lenses they're going to be great for extending the focal length with these and if you do get the aftermarket ones you got to check to see if it passes through the electronics for auto focus and so forth and so be aware that now something that they have added in on some of these is the front and rear flooring coding so if you get fingerprints or dust any of that sort of thing they're going to be a little bit easier to clean which is great because these are very exposed elements when you take the lens caps off of so that takes care of our lens accessories and we'll check in on questions because I'm sure there's a few questions to be had in this arena all right well we're gonna have one in the studio audience but I'll start with someone on line can you explain this again? The question is when using an extension tube can the front of the lens get closer to the subject for example if I have a lens that has a minimum distance of say twenty inches when I add an extension tube does that change to say ten inches or increase or have no effect so the extension tube does not change the focal length of the lands decreases the minimum focusing distance so in their case from twenty inches it might bring it down to fifteen or ten depending on which lands in which tube they're using. So yes decreases the distance, which means you will be physically closer to your subject so that's what's causing the increasing magnification it's not a change in the lands it's a change in proximity you getting closer to your subject with the extension tube's in k we looked yesterday a lot of cases where they've done things technologically to make sure that color was sink, that everything was hitting the sensor yeah at the same time with wide angle lens zooms with face front only like that do I have to worry about coma or any color sync problems when I move the dwight defeat that you know, that's? One of the nice things is the image when the light is coming out of the back of the lands, but best to my understanding cause I don't actually design lands and his light goes through the lens it's doing all these sorts of things, but by the time it comes out of the back it's coming straight back to the sensor and so we can move that sense or back a little bit further and that image quality hasn't changed that question teo clarify from michael lustig does the auto focus an aperture work with the tubes on if you have the tubes that have the electronics built into them, you concede your apertures normally the camera can still auto focus, although I recommend manual focus as well talk about when we get into macro photography, but yes, auto focus will work should one by a lens first and then by the best camera for the lens and I ask you this question because I know you also have a class on how to choose your next dslr camera, but I thought it was an interesting question because we're talking about the importance of lenses so much and would you ever by the lens first? I don't, I don't think yeah, interesting question I don't think most people would it's just so hard to get their brain wrapped around how important the lenses that they're going to be fixated on the cameras will be hard enough just to pay attention to the words many people when they're buying cams, they don't even budge it for the last they think I'm gonna buy a camera you're gonna get a lance? Well yeah, whatever, but I'm going to get a camera it's like no, the lens is going to cost as much as the camera now why would I do that? I mean first, you know serious photographers, the budget is probably twenty twenty five percent camera and the rest in lenses and accessories now when you start out it's going to be closer to fifty fifty or at least it should be in some ways and unless there's a specific lens like somebody maybe somebody has a kid that's in swimming and they know that they swim in this certain arena it's dark and they have to be this far back they might be able to figure out maybe if they talk to another photographer about well I know I'm going to need at least two three hundred millimeter lens and so okay, I know I need this lands I know I need this aperture okay what what camera would work best with that and that might I might say well, you probably don't want to get the bottom of the line camera because you need better focusing in that sort of situation and so it is a bit of a chicken and egg dilemma about which ones coming first so there is a specific answer on that one but if there is something very specific you're going to do you should have an understanding of what lenses you are going to need in order to do that absolutely I mean I think when you when you do your point about sports photography say you are always shooting in low light you know or what have you I think it's an interesting thing to think so tell us about your class john on how you do go about picking a camera, right? And so it was kind of strange, actually creative live asked me that john, could you put a class together and how to buy a camera like, yeah, that's easy! I buy cameras all the time. I've sold cameras a lot, and so I have a special class on howto choose your first dslr camera, and for some people like I don't need that, I know howto buy camera, just go down the storm by camera, go online, find one that gets good reviews and I have found because I've worked in the stores and I sold cameras how often somebody would come in and they're just completely derailed on the proper questions to ask they're asking all the wrong questions about what's right? For them, they have a buddy at work that gave him some advice that may or may not be accurate or up to date, and suddenly they're fixated on getting something and you try to explain it, but it just didn't work out. So this is about asking the right questions and learning how to identify your own needs, and I go through the class name is a little misleading it's not just dslr as we talk all about muralist cameras as well everything that has interchangeable lenses and so I think, for anyone who really wants to make a smart choice and do the research and get the best camera for them. We go through all the current cameras and it's avery. Good class to help narrow down exactly what's. Most important, so that you can make the best purchase possible.