In this video, I go through a step-by-step process for how to build your very own Schlieren setup. First, I go through the basic theory and overview. Then I describe all the materials you'll need. Finally, I walk you through the full setup. By the end of the video, you should have no problem getting some nice pictures or videos with your at-home system.
00:00 - Introduction
00:36 - Theory
03:19 - Materials
09:39 - Initial Placement
12:19 - Finding 2f
14:28 - Add LED Mask
15:27 - Add Camera and Alignment
20:12 - Bathroom Mirror
Note: I will sometimes say 'laser' when I actually mean 'LED'. You will have to forgive me; I work with lasers in my research and have become accustomed to saying 'laser' whenever talking about some sort of source.
Below are some website links that I found useful/referenced while going through my own setup.
General Schlieren Knowledge
goo.gl/gI1YQq
goo.gl/pLwii8
goo.gl/uonkOt
goo.gl/RFCSuG
goo.gl/hegJHF
goo.gl/YD0i0c
Interesting Mirror Articles (slightly advanced)
goo.gl/t16ePi
goo.gl/BAL6Bj
Want some more theory? Here's a video with some great visuals to aid your understanding.
goo.gl/b31aOS
Other Papers (you can search on Google for these)
"Hypersonic Application of Focused Schlieren and Deflectometry"
"Flow Visualization for Supersonic Flow Past a Wedge"
"An Overview on Schlieren Optics and its Applications"
"Design, Assembly, and Calibration of a Focusing Schlieren System"
"Introduction to Shadowgraph and Schlieren Imaging"
Below are little sections about the materials and where to find them (Amazon affiliate links).
LED Light Source (goo.gl/bPbJx9)
You can find tons of LEDs on Amazon. You will only need one, and I prefer a bright white LED, as seen in the link above. If you buy these, you'll end up with 49 extra, and who doesn't want an extra 49 LEDs lying around their house? I personally bought a single white LED from Radio Shack before the store closed at the mall.
Resistors (470 Ohm) (goo.gl/XNH8u9)
To build your own LED circuit, you'll need this particular resistor. The value comes from the fact that you are using a 9 volt battery, and that the white LED has a forward voltage of about 2 V and a current rating of about 20 mA. Using these values, you would need a resistor of 350 Ohms, but I've found it is better to be on the higher resistance side, and 470 Ohms is the next highest resistor you can use without having to wire together a series or parallel circuit to get the most accurate value. It's a compromise between simplicity and efficiency. Above is a link to a pack on Amazon, although you'll only need one.
Circuit Board (goo.gl/tKNaFH)
If you're making your own circuit (like I did), you'll want a circuit board to solder all your materials together. This one from Amazon seemed like a good bet. I bought mine straight from the Radio Shack at the mall.
9V Battery Connector (goo.gl/oL7M3g)
To finish off the circuit, you'll need some way to connect the 9V battery. Above is a link to a 9V battery connector.
Knife Edge (Single Edge Razor Blade) (goo.gl/zCyNt1)
This is again one of those items where you only need one, but you'll end up buying a thousand. Above is a link on Amazon, but they sell them at any store like Target.
Mirror (Spherical Concave)
It looks like the mirror that I use has officially been fully sold out (from both Anchor Optics and now Edmund Optics). I'll be looking for an inexpensive alternative with the same quality, and will update this section if I find one. If you find an option, please leave a comment letting me know so I can update this section! Small focal length mirrors won't give you the sensitivity you need, so make sure to get a longer focal length mirror. Note that Z-type systems will use two parabolic mirrors, while this double-pass system uses one spherical concave mirror (parabolic is okay too).
Camera (goo.gl/KmPwy7)
I personally use my Nikon D3200 DSLR camera with its 18-55mm f/3.5-5.6 kit lens. I use this lens so I can zoom in on the mirror. I also have a 35mm f/1.8 prime lens, but it can't zoom (obviously), so I don't see that being as useful. Above is a link for the camera I have on Amazon (newer model).
I have used my point-and-shoot camera and Samsung S6 phone to get videos and pictures as well. I mention this just so you realize you don't absolutely need to buy a DSLR camera. However, I will say the quality of the DSLR videos/images was much better than the other two. It gives you more control over settings, and will make your life much easier.
Tripod (goo.gl/oKmyU8)
I use two tripods during the video. The tripod that I use to mount the LED and knife-edge is a cheap plastic one that I got a while ago. I purchased a higher quality tripod recently, and if you're looking for a low-cost, good quality tripod, I would recommend the one provided in the link.