Deal 7: How to make money through your photography
Welcome to the first lesson in Photography 101 – A Basic Course on the Camera. In this series, we cover all the basics of camera design and use. We talk about the ‘exposure triangle': shutter speed, aperture and ISO. We talk about focus, depth of field and sharpness, as well as how lenses work, what focal lengths mean and how they put light on the sensor. We also look at the camera itself, how it works, what all the options mean and how they affect your photos.
This week’s lesson is Light and the Pinhole Camera
Light is everywhere, even where you can’t see it. Without delving too deeply into the mysterious physics of light, there are some basics that are helpful to know as a photographer:
These observations are pretty basic, and most of them are either obvious or should have been taught in the science classroom. As straightforward as they are, these basic points are at the heart of photography, and understanding them is very important. Throughout this course, and through your adventures with the camera, you will be working with some or all of these essential principles of light. If you are unclear about any of the above points, it would be helpful to do a little bit of independent research. You’ll find some good links for further reading at the end of today’s lesson, and I encourage you to explore further by searching the ‘net.
The central point of photography is turning light into an image. An image is actually just an illusion. Anything that is a representation in light of a real thing is an image. So how do we turn light, which scatters randomly around the universe into an image that we can recognise?
Fig 1.1.2 – Imagine a typical outdoor scene with the sun shining brightly on a tree. The light from the sun travels in parallel rays, shown here in black. When they hit the tree, the light is scattered in all directions, shown in grey. This is known as “diffuse” light. Because of diffuse light you can see the pretty tree, as some of this scattered light hits your eyes.
Fig 1.1.3 – Now lets imagine we pitch a tent with perfect light blocking material and a tiny hole in one wall. To keep it simple, a single ray hitting the tree will diffuse in all directions, but only a very tiny sliver of that light will go through the small hole. If you were sitting in this tent in the middle of the floor and you closed one eye and looked through the hole from there, you would only see a very tiny part of the tree at once. If you move to the right a bit, you will see the left of the tree. If you move up, you will see further down the tree. Your view of the tree is opposite to the direction of your movement.
Fig 1.1.4 – Of course there is more than one ray of light hitting the tree. These rays reflect diffusely in all directions. This is why you can see more of the tree by moving around inside the tent. If we were to set up a screen in the tent opposite the hole, which is made of nice bright white material, we would actually be able to see an image of the tree, projected onto it! For the reason that we saw parts of the tree in the opposite direction when we moved, the projected image of the tree appears upside down.
The room we just made in our imagination is called a “camera obscura” and you can make one just as I have described. Instead of a tent, you could find a room in your house with one window, and cover the whole window with thick card or foil. Then make a tiny hole (1-5mm) in the cover and look at the opposite wall. You should see a very dim, upside down image of the world outside.
The image will be dim because only a small amount of light can pass through the hole. If you make the hole bigger, the image will be brighter, but less sharp. Why is this? A small hole is very good at restricting the direction from which rays of light can enter the room. If the hole is bigger, then more light can get in, but that extra light comes from a bigger range of angles, and it overlaps nearby parts of the projected image.
Fig 1.1.6 – A small hole through which the light passes, restricts the possible angles of light reflecting from a certain part of the tree. The overlap of light rays on the projection is very small and the result is a sharp image. The trade-off is that the image is dim.
Fig 1.1.7 – A large hole allows a greater variety of angles of reflected light from a particular part of the tree to pass through onto the projection. This means that much light from neighbouring parts of the tree overlap each other. This results in lower contrast and a blurry image. The benefit however, is that more light can get through and the projected image is brighter.
The camera obscura is a very old idea, first built around 1000AD in what is now Iraq. A variation on the concept is the pinhole camera. This shrinks the room of the camera obscura into a handheld box, and is the simplest possible camera. Pinhole cameras can easily be made of almost anything. All it needs is a light-proof box, something to project the image onto, and a tiny hole. There are countless projects online to make your own pinhole camera, or make a pinhole “lens” for your DSLR. Due to the tiny hole used in these cameras, one advantage is that they have is an enormous depth of field.
To help you get a feel for the issues discussed in each lesson, I’m going to be assigning some homework. Naturally it’s completely voluntary, but you learn by doing, and practical exercises will certainly help you improve your photography. I list a few assignments below, and you are welcome to do any or all of them. Please post links to your completed homework assignments in the comments on this post.
Photography 101 – Lenses and Focus.
February 19, 2012 06:51 am
Thank you very much for your lessons.
Here some of my "homeworks" or experimentations.
Thanks again !
January 26, 2012 04:54 am
Hi from Spain! We are making a Camera Obscura Course several times during 2012, a good pretext to have a long weekend holiday. Cheers!
camera obscura course Andalucia: http://www.lei4sure.es/camera-obscura-weekend-in-seville/
July 26, 2010 06:08 pm
great article, thank you very much!
Will give it a go some day, looks very interesting
June 24, 2010 11:17 am
This site has been more informing than most of the books I've read. Thank You.
February 8, 2010 08:47 am
Will be helping my young son create a pin hole camera for his upcoming school project. We'll both benefit for this project! Thanks.
September 3, 2009 12:54 pm
Hi, I just wanted to thank all of you for putting your time in this. This really is helpful for a beginner liker myself. Thank you so much!
July 14, 2009 10:57 pm
Hi. I am about to start my studies on phtotgraphy and found these quick lessons very helpful and my understanding is already much better, I especially love the pinhole camera and am going to make my own one to experinment with.
June 16, 2009 10:26 pm
I am just beginning to venture into the photo world beyond "auto" settings but there is so much confusing stuff for a novice out there! (novice with really big dreams :)
Your tutorials are fantastic and the best I have found at making everything "simple for dummies". Great work and excellent website!!! Thanks again.
March 6, 2009 06:42 pm
great tutorial, thanks a lot!
February 18, 2009 05:58 am
Great tutoials,nice and easy to follow! Thanks.
February 15, 2009 10:22 pm
I've been searching for a long time such of this site where professional photographers shares their techniques and ideas. it helps a lot. God Bless those generous soul who share their ideas for free...
November 11, 2008 12:21 pm
This really helped to understand the concrpt of a pinhole camera! The pictures really really helprd me, too. Thanks!
June 5, 2008 04:17 pm
Thanks for the great class!
March 21, 2008 12:01 am
Here's my effort for lesson 1 homework, a little late but better late than never!
I wrote a post about it on my blog: How to make a camera obscura
March 19, 2008 02:14 am
Excellent article - very well written, amusing and informative. Thanks! :-)
March 18, 2008 09:38 am
This is excellent, I can save myself thousands of dollars going to a course by learning from you guys. Thank you so much, you guys are so inspirational.
March 15, 2008 01:39 pm
When I took photography my freshman year in high school, um..many years ago, we made cameras out of shoe boxes, using photo paper as film, it was a great learning experience. Also we made cameras out of card board and attched them to 110 film and took pictures that way. Another great learning experience!
March 15, 2008 01:38 am
Neil, my congratulations on your new undertaking! Illustrations are very professional, do you have some graphic background? BTW, here's a nice URL to go with this article: http://pro.corbis.com/creative/readycam/ - it has great DIY pinhole camera you can print and make out of photo paper and some film. They come in different designs with crazy patterns on them!
March 14, 2008 12:44 am
This is great. I really think I'll learn a lot from this site. I also can't wait to try out a pinhole lens on my next shoot. I'm sure I heard of them a long time ago, but never had any use for them so they were in the back dustbin of the brain, and you were able to bring out to the front. Thanks.
March 13, 2008 11:35 pm
Thank you so much for the information! I'm a beginner in the DSLR world, for all intents and purposes, and this will definitely help with developing a base of knowledge that I can build upon and use to become a more serious photographer.
March 13, 2008 09:41 am
Did the DSLR body-cap-to-pinhole modification during a Photo class last semester for interesting results. To those trying this out: Do not be discouraged if your pinhole is too "big" and you are getting very fuzzy images! You can always make a new hole, but the fun of the pinhole is to focus more on light, color, and form rather than "Kodak moments"--although a friend of mine got a darling photo of her aunt and baby cousin with this technique.
For the experimenters: Light-block tape is the best to use, but since I didn't have any at the time, I didn't think GREEN DUCT TAPE would make a difference... But it definitely did, especially in the sun. Everything took on a green cast which I liked over the landscapes I'd shot.
If you decide to leave this on your camera for a long period of time, put tape over the hole on the opposite side of the cover from pinhole-tape. Don't want dust getting in. :D
March 12, 2008 05:45 am
This is great. I've told all my blog readers to check this out and I'll be intently awaiting your next entries!
March 12, 2008 01:33 am
fantastic post - can't wait to see your camera and lenses tutorial next! thanks
March 11, 2008 06:27 am
I love this first lesson. I understand!
March 11, 2008 04:38 am
Very informative tutorial. It is good to get a basic understanding of photography as todays high tech stuff for beginners can be very daunting. It is important the user controls the camera, it should not be just a matter of settings and buttons and let the technology do the rest.
March 11, 2008 02:22 am
You're off to an excellent start! I'm already waiting for the next "chapter". Thank you!! :)
March 10, 2008 11:32 pm
This is a great first lesson!
I've heard of a camera obscura before but never looked into them. And I've never made a pinhole camera.
So I love the homework and can't wait to give them a go...
March 10, 2008 09:11 pm
For those of you with DSLR the camera lens cover makes a great device for making a pin hole camera.
Do buy a spare cover as you need to drill a tiny hole in cap.
This hole will be too big as it is best to find metal coated mylar or plastic type film. Use a tiny pin and with paper backing make a tiny hole. glue this on the back of the camera and Vola a pin hole camera. Due keep in mind that the F-stop is about 264.
Therfore if a normal shot at f8 was 1/100 sec then the new setting will be about 8 stops more or about 2 sec.
This is only an approximation to get you in the right ball park. Use the histogram to fine tune exposure.
March 10, 2008 06:26 pm
of to a good start thanks.
March 10, 2008 05:44 pm
By pure coincidence, I actually did this over the weekend with my Canon 30D and it's lens body cap, with a hole drilled in the middle and aluminum foil taped to the front with a pin hole it.
You can see the results here http://www.emmett-photography.com/gallery/4480148_H4oE3/1/263516714_E4JmJ
It's not a brilliant photo, but it's got me excited about trying this out more, with finer holes, etc. It was a great reminder to me about the basics of photography.
March 10, 2008 05:37 pm
Well done for picking that up! Yeah I proofread the thing five times, I got my wife to read it too, and I'm sure Darren had a look over. But we all missed it. And as soon as the story had gone live, I noticed *slaps forehead*. I've sent a couple of repaired images to Darren. So I'm sure he'll swap them soon.
March 10, 2008 10:32 am
Guys! Very nice post!
Only one thing: in fig. 1.1.6 and 1.1.7 the image formed by the light that comes through the hole should be upside-down
March 10, 2008 09:56 am
Good luck on your assignments everyone, I'm looking forward to seeing what you come up with!
March 10, 2008 08:53 am
A great tutorial, thanks!
One small thing - figures 1.1.6 and 1.1.7 need to have the image of the tree inverted.
March 10, 2008 03:53 am
I love you guys.. I am new to all this and these lessons are great.. My fav website so far.. thanks guys for all the hard work..
March 10, 2008 02:43 am
Keep them coming! :-)
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