##Basics##
A brief intro to [Spectral Workbench](https://spectralworkbench.org)'s new web-based capture interface, including absorption spectroscopy:
##Calibration##
Learn to calibrate your spectrometer with a compact fluorescent light (CFL):
See [Spectral Workbench Help](/wiki/spectral-workbench-help) if you have trouble.
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**Note: The above video walks through this process and is more up to date. The following instructions are for the older, deprecated version of Spectral Workbench**
##Older versions of Spectral Workbench##
The older, downloadable client for Spectral Workbench.
###Configuring your webcam###
You can skip this step, but it may be harder to compare baseline readings. Most webcams have auto exposure and color "correction" so that in dim light, you can still see. This will unfortunately change the exposure between readings, so for quantitative work, it must be disabled. On Linux, you can use the "uvcdynctl" utility [as outlined here](https://github.com/jywarren/spectral-workbench/issues/2).
On a Mac, you can download this utility: http://www.phoboslab.org/log/2009/07/uvc-camera-control-for-mac-os-x
###Launching the application###
Once you have [downloaded the software](/wiki/spectral-workbench-download), you should be able to open the "application.macosx" folder and double click **spectral_workbench**.
**Mac:** First you will be prompted to select a camera. Choose the webcam associated with your spectrometer, which may be "Creative Webcam Live ..." if you bought the [video spectrometer kit](/wiki/video-spectrometer). Select "None" under __Compression__.
> Linux users may experience trouble if they do not have a built-in webcam; if you are comfortable coding you can change the line "new Video(x,x,x,1);" to "new Video(x,x,x,0);" which will select the first camera, not the second one.
###Basics###
The software has 3 "modes" -- **Setup**, **Analyze**, and **Heatmap**. Setup lets you properly configure your spectrometer before using it. Analyze is the main mode you'll be using when testing samples. Heatmap uses a color gradient to display finer differences in your spectra, and is otherwise the same as Analyze.
###Setup###
Click the "Setup" tab at the top. You will see a small "preview" window indicating the height of the sampling row. You can drag to select the area you'd like to sample from, which will be averaged to produce your spectral data.
This is a chance to adjust the amount of light you're using as your source. If you have a dimmer, turn the dial until the red, green, and blue intensity curves are full height, but not "hitting the ceiling" -- which would mean you were losing data due to overexposure.
(see [plans for improvement](https://github.com/jywarren/spectral-workbench/issues/23))
###Store a baseline reading###
Now that your spectrometer is set up correctly, you can store a "baseline" reading of just your sample container with no sample material. Place your sample container between the light and your spectrometer and press the spacebar. The spectrum you were seeing should be "saved" as a red line which persists even if you remove the sample container.
###Measuring a sample###
Now place the sample in its container in front of the spectrometer. You should see the white line drop below the red line - this is because your sample is absorbing some of the light. A new, yellow line will appear, representing the **amount of absorption**.
###Saving a spectrum###
Before saving, name your spectra by typing a name. It will appear in the top bar. Press "Save" and the SpectralWorkbench.org website will open in a window and prompt you to log in and save your data.
For some, the "Save" function is not working properly, and although the data is uploaded, it is not attached to your account. To get around this, you can open the "spectra" folder which you will find in the same folder as your application. There you will find any spectra which you have saved, which you can upload directly at [SpectralWorkbench.org](https://spectralworkbench.org). ([read about this bug here](https://github.com/jywarren/spectral-workbench/issues/81))
(see [plans for improvement](https://github.com/jywarren/spectral-workbench/issues/23))
###Store a baseline reading###
Now that your spectrometer is set up correctly, you can store a "baseline" reading of just your sample container with no sample material. Place your sample container between the light and your spectrometer and press the spacebar. The spectrum you were seeing should be "saved" as a red line which persists even if you remove the sample container.
###Measuring a sample###
Now place the sample in its container in front of the spectrometer. You should see the white line drop below the red line - this is because your sample is absorbing some of the light. A new, yellow line will appear, representing the **amount of absorption**.
###Saving a spectrum###
Before saving, name your spectra by typing a name. It will appear in the top bar. Press "Save" and the SpectralWorkbench.org website will open in a window and prompt you to log in and save your data.
For some, the "Save" function is not working properly, and although the data is uploaded, it is not attached to your account. To get around this, you can open the "spectra" folder which you will find in the same folder as your application. There you will find any spectra which you have saved, which you can upload directly at [SpectralWorkbench.org](https://spectralworkbench.org). ([read about this bug here](https://github.com/jywarren/spectral-workbench/issues/81))