Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Don Y <blockedofcourse@foo.invalid>
Newsgroups: sci.electronics.design
Subject: Re: "Colorimeter"
Date: Sat, 24 May 2025 13:07:59 -0700
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On 5/19/2025 1:33 PM, Lasse Langwadt wrote:
> On 5/18/25 21:45, Don Y wrote:
>> On 5/18/2025 6:13 AM, Lasse Langwadt wrote:
>>> On 5/17/25 23:03, Martin Brown wrote:
>>>>
>>>> If you are serious about doing this right then a 2D CCD sensor and a prism 
>>>> hires grating combo at right angles will allow you to quantify the entire 
>>>> visible spectrum at ultra high resolution. 
>>>
>>> use a CD https://youtu.be/EoAZ-u6hn6g?si=Mv-DfJ5swtq2-j1X&t=98  :)
>>>
>>> eons ago we used some CCDs as detectors for X-ray fluorescence, some had 
>>> weird formats like 1024x64 pixels so I assume they were really made for 
>>> spectroscopy
>>
>> As mentioned elsewhere, how do they fare when light is shining directly on the
>> sensor?  How do you keep it from saturating -- dark lens to attenuate the 
>> signal?
> 
> or a shutter to limit the time light hits the sensor

There's still a limit as to the peak intensity that a sensor can
tolerate.  And, gating the light (instead of attenuating it)
means there is no signal when the source is gated off.

Fine if you are making a device with a button that says "measure now".
But, if you expect to be able to collect data at any time, you
want to be sure data is available.