1. Introduction to Digital Photography – Part 1


hello everyone welcome to computer science e 7 my name is Dan Armendariz and this was all about exposing digital photography and I thought so before we begin I would actually have you say cheese and what I’m going to do is take a photograph here that I will describe in just a second I know this is dr. have to walk all the way over here and all the way back but I forgot my phone and I’ll explain why this is important in a second but don’t worry if you think that you will be in the photo you don’t have to correct your hair except old people on that side of the room oops all right hold on and okay and you should have been here last semester when I put up this big block of cheese on the first day and I just I just choked I said why on earth did I put a big block of cheese up there I couldn’t figure it out for the life of me but thank goodness you now have a much more refined version of the lecture available to you say okay so what is going on here with the camera over there that you can see has something oddly reflective taped on top of it and I put a big block of cheese up there I am basically taking what’s called a pinhole photo and this is a facilitative digital will be able to see the results much more easily than if it was just film and I had to go home do one hour rush processing and then come back and all of a sudden it would be all set but basically what this is meant to show is that this is very basic lens on the front of the camera even though it’s somewhat hard for you to see from here there’s a photo here of what was originally the part that is on top of or rather in front of the camera at this point right now and while all this is is called a body cap and so you’re probably familiar with lens caps which are you know the plastic pieces that go on the front of lenses could protect them but slrs or single-lens reflex cameras also have body caps which can protect the body from any damage as well and that is what this is and basically took the body caps drill the hole in the mill and tape the piece of aluminum foil on it and after much trial and error and after a lot of toil use a very fine needle to a whole and as straight in its middle of Thea of this aluminum foil as was possible and the reason that I did this rather than just using a drill hole is that this way I could get a much finer hole in the middle of this this body cap and the idea here is that not a lot of light is being led through as you can imagine this very tiny pinhole but still what you will be able to see is that we’re still able to capture an image and basically what is what this implies is that we can really use a lot of things to try to take an image or to try to take a photograph luckily or rather it’s not that easy these days to try to make a digital camera from scratch but you can make fairly easily a pinhole camera all you really need is a box of some kind that less than no light a very small hole at one end and some film or some way of recording the light on the other end and in fact people have used something like Legos even to try to create a pinhole camera and this is a pretty fun thing to do is especially if you want to if you want to teach well this is separate from what I’m doing now but if you want to just teach the more basic concepts of photography this is very fun thing to do and just can just try it out and you can see that there’s a whole variety of steps here and the reason that I’m showing you this is that partially camp digital cameras today are very very expensive I know with the economy being what it is we want to make things as cheap as possible so here’s your version one of the camera that you can use for this for this class but really all this is meant to show is that there’s a variety of cameras available you can make your own even if you want to and what we are teaching throughout this course applies to just about every type of camera that there is they’re all bound by the same laws of physics a lot of the the photography terms have converged such that even if you are familiar with film photography terms they’re still applicable to the digital photography terms of today so I mentioned that’s on behind this pinhole lens that I’m using is an SLR so here’s a representative photo of an SLR I’ll be it’s a much fancier one than the one thats hanging on the tripod over there but all of SLR really means is that you can take off the lenses you can change lenses so you can have really small lenses like this which I actually will highly recommend this particular lens if you’re new to digital photography and you can get much more expensive in much larger lenses like this and swap them out easily so that you will be able to get a variety of different effects different focal lengths out of one body or one camera and this is actually a really nice thing because now you can have an investment in in a camera and some lenses and you can add on to that investment rather than having to purchase an entirely new camera an entirely new system you can just purchase a lens so usually when you get to this sort of grade of stuff where you’re getting lenses that are this big and camera bodies that look like this then you’re talking about plunking down quite a bit of money into each of these things so usually when we see a camera like this an SLR more generally we consider it to be a professional camera and this is typically if you see someone walking around with this you might say oh wow this is that that person knows what he’s doing has a really nice camera there are generally bigger faster more expensive they have much more battery life they’re much heavier they’re usually water-resistant considerably stronger a variety of these things but also the big cons I listed of course are the weight and the price and so those are the downsides to these that their little cousins don’t actually have to deal with so much so compact cameras and for this course we’re going to very generally classify cameras into two types SLR it’s like the one I just showed you and compact cameras which can include pretty much everything else besides maybe camera phones which could arguably be in there in a class of their own and compact cameras are what they sound like they’re smaller they’re more compact they’re cheaper they’re lighter but also for a variety of reasons they have not as good battery life their optical quality is not that good they have problem but there are many exceptions to this so don’t take this as sort of you know oh I have to get doubt the best quality have to go buy an SLR many things in photography are have and are exceptions and this is one of them and all of these things are give and take your giving some things and taking others away when we’re talking about cameras especially and though a lot of this course because we really start diving into a lot of the specifics of digital photography even going into a little bit of math nothing that you have to worry about trust me it’s just a little bit of math so that you can start to understand what’s going on behind the shutter or underneath the hood digital or compact cameras they’ll have their use today and in fact they are they’re very good for a variety of things and I really don’t mean to discourage them and as an example there’s this website it’s what I called shape am and there was a I think it’s a blog of some kind that I don’t normally frequent but I love linking to this because of the content of this one particular blog post and basically some people had given some some folks from a village in Africa I believe it’s lesotho is the name of the place I forget a sub seen in this village or or the municipality or what have you and they gave these folks not just compact cameras but one time use cameras to you know the five ten dollar cameras that you go by CVS you you know take 30 30 shots or so and then you give them back to to get your photos printed and what they got back after they were done taking photos because they’re very simple as you know you look through the viewfinder you push the button when you want to capture that one particular shot what they found was honestly really quite striking really beautiful photos from people that maybe had not use the camera before maybe even had not ever seen one before but still they managed to capture what happens in their daily lives very very well and I think some of these photos are actually quite astonishing as far as photos go just because they’re interesting they offer insights into a place that I myself have never been and it’s just a really wonderful thing in film this is part of what makes photography so interesting you can have the most expensive equipments in the world but if you are not taking photos well this is a touchy subject but if you’re not taking photos that are interesting with that expensive equipment and arguably you have wasted that equipment and of course you could just be taking photos for yourself or for your family that’s you know that redefines what could be interesting in a photo but what I’m trying to say here is that you don’t have to spend a lot of money to be able to get interesting photos that’s really the whole point of this and I’m not trying to discourage you from spending money on it because as you can see I certainly have spent my fair share of dollar signs on some of this equipment here but they are tools a camera the lens the tripod all of this stuff is a tool for you to accomplish a task of taking a photograph and whether you have interesting scenes to take a photo of or not is a different story altogether and maybe one that if you had a lot of money maybe you could actually purchase interesting scenes but okay stepping away from all of that all of that stuff and I’ll talking more about some of the more technical details let’s take a look at the inside of a an SLR camera so here is frankly just a a Wikipedia image of what an SLR basically looks like and so we can break this down into a couple of different parts they see number one here there’s a couple of lens elements this year is just the lens that you are putting in front of your SLR and remember that you can change this of course though the length characteristics could be different you could have different numbers of glass elements here they could look different they could be concave convex any number of things and so on and so forth but then what’s more interesting beyond the lens is the SLR body itself so two through eight here so you’ll see that there is this diagonal line that’s marked as number two and what this line is is a mirror inside of the SLR camera and in about 40 seconds when the photo is done I’ll actually be able to show you example on the inside of an SLR if you haven’t seen one yet but there’s actually a mirror that redirects the light that’s coming in from a lens up and upwards above that is the viewfinder that basically bends the light and reflects around and does a bunch of things that eventually will then turn the light and shine it into your eyes that you can see what the scene is once you are looking at or what you are looking through the viewfinder okay so I have to take another trip to the other side of the stage over here where I can turn off this exposure alright going to wait a few minutes oh forgot to turn off the alarm first I got to say that’s a really annoying alarm and a great one to wake up through because you will get up in the morning anyway okay so the light is reflected by to up into these other parts five six seven and eight and so five isn’t really important to us now but it’s what’s called a focusing screen and in many SLR cameras you can change this focusing screen this is more important back in the film days before the advent of autofocus cameras where you could put focusing screens that were maybe a little bit crisper or a little bit duller or any variety of characteristics so it made it would make it easier to focus on something within the screen so usually we don’t worry too much about 56 is a condenser lens that just helps funnel delight in 27 which is the pentaprism which I mentioned reflects the light about and into your eye which is present beyond the diopter 8 your eyes probably over here somewhere and a number of cameras feature an adjustable and adjustable IPS and just will diopter number 8 there which if you wear glasses like me then you can actually adjust it so that it can be slightly the image can be adjusted to be slightly closer slightly farther away so that you can try to compensate for whichever direction your eye happens to be in unless you are actually like me and your eyes are so bad that it doesn’t really matter whichever way you go it’s not going to make any difference dolls and you have to wear contacts regardless okay so back to some of the more interesting bits number three and number four so you can see they hear that we have two lines number four is where all the magic happens once number 3 the shutter opens life is collected or rather light falls on number 4 and is collected by it it is the sensor or the film depending on what type of camera you have and this is um this is actually going to be really important to us the shutter and even the location of the film plane itself with number four because it’s these things affect the characteristics of the Cameron and will actually impact how your photos will look after you take a photo in certain circumstances at least okay so here you can kind of see if you take a step back and look at the overall shape you can kind of see what the SLR gets its distinctive shape where it has this sort of funny-looking hump on the top and then it has some stuff going on in the middle here all of this is because of just this set of circumstances that that camera manufacturers have used over time and I will also mention that for the most part you will see me using and referencing Canon and Nikon cameras and that just happens to be because they’re right now the leaders in the in the market and there are though very viable alternatives in the market today such as sony Sony sort of come out of nowhere especially in recent weeks with some very powerful very strong models in their lineup that are going to give Canon Nikon or run for their money but still there are reasons that I still don’t recommend some of these smaller companies and would rather recommend some of these larger ones for a variety of reasons Sony for example uses a proprietary mount and the mount is basically the shape of the back of the lens where the lens fits on the camera itself and so you I mean that is true with Canon and Nikon as well but canon nikon have a very wide selection of lenses where Sony doesn’t yet have that wide selection of lenses so the lenses are more expensive and also fewer to choose from which is bad for you so you could buy a very cheap camera from Sony but not necessarily yet have the lens choice that is available to you from Canon Nikon let’s just one example okay moving on there’s a there’s a special little icon on just about every SLR that you see and this exist not only in on digital cameras but also on film cameras and you’ll notice that it is this circle with a line through and this indicates the location of the film plane and what this means is if you take if you imagine that you have a plane you just go right through where that line is that is exactly where the sensor is inside of the body of the SLR so to remind you number four here the sense of where the light falls eventually and where it is captured by the camera is indicated by this focal plane icon on the Cameron and most cameras it’s not all will have this and this can actually be very very useful to you especially if you are making a pinhole camera or if you are modifying in some way the the the length of the lens on the camera body itself so typically you won’t need to know it when you’re just putting any random lens that fits on it onto the camera body but it is useful especially later when we start talking about some focal length calculations and some of these other things it is useful to know where this is okay I’m just sort of blowing through all this stuff but does anyone have any questions before I move on well good perfect alright

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