<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>tomkinstinch</author><text>I attempted this before, even on Kickstarter:&lt;p&gt;&lt;a href=&quot;http://www.openspectrometer.com/&quot; rel=&quot;nofollow&quot;&gt;http://www.openspectrometer.com/&lt;/a&gt;&lt;p&gt;&lt;a href=&quot;http://www.kickstarter.com/projects/makerhaus/open-spectrometer?ref=live&quot; rel=&quot;nofollow&quot;&gt;http://www.kickstarter.com/projects/makerhaus/open-spectrome...&lt;/a&gt;&lt;p&gt;Unfortunately we did not hit our fundraising target, and it&apos;s now a dead project. I&apos;d love to see this new Kickstart project succeed, especially the online spectral database. Commercial databases of spectral signatures are expensive (thousands of dollars), and they shouldn&apos;t be.&lt;p&gt;Part of our problem, I think, was that we were attempting the project while taking classes full time, and working.&lt;p&gt;We were planning to release two different designs at different price points. One would have used inexpensive ruled transmission grating, while a more expensive unit would have used a concave holographic aberration-corrected reflective grating. The latter would have had better system efficiency, less &quot;smear&quot; across pixels, and better linearity. Each would have made use of a linear CCD array with good sensitivity (the same chip used in the Ocean Optics units). Concave gratings add a couple hundred bucks to the price, but are well worth it if you need to do UV.&lt;p&gt;A challenge we didn&apos;t get to solve was how to make something DIY that could be used to detect UV. It&apos;s difficult to sputter a uniform phosphor coating or remove a sensor window without specialized equipment.</text><parent_chain></parent_chain></comment><story><title>Public Lab DIY Spectrometry Kit</title><url>http://www.kickstarter.com/projects/jywarren/public-lab-diy-spectrometry-kit</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>zdw</author><text>I&apos;m no optical scientist, but seeing as the diffraction grating being used is recycled from a DVD and the sensor is a consumer webcam, I wonder how accurate/reproducible the results would be.&lt;p&gt;A conventional diffraction grating is pretty inexpensive ($2.50): &lt;a href=&quot;http://www.rainbowsymphonystore.com/difgratfilsh.html&quot; rel=&quot;nofollow&quot;&gt;http://www.rainbowsymphonystore.com/difgratfilsh.html&lt;/a&gt;</text><parent_chain></parent_chain></comment><story><title>Public Lab DIY Spectrometry Kit</title><url>http://www.kickstarter.com/projects/jywarren/public-lab-diy-spectrometry-kit</url></story>