There are a bunch of web pages detailing how to go about it.
Essentially the job is dismantling the lens assy, removing the existing coated sheet glass IR filter and replacing with a suitable IR bandpass filter...exposed 35mm film or floppy disc are suggestions, or lab supplies IR BP filter sheet.
Silicon wafer also - hitran_application_note_october2013.pdf
Try Googling DIY IR Camera, DIY IR Webcam, DIY FLIR etc, etc.
How_to_Make_an_Infrared_Camera.html
Using+Webcams+for+IR+Radiation+Detection.pdf
in-depth-diy-eos-550d-infrared-conversion/
kickstarter-ir-blue-thermal-imaging-smartphone-accessory?ref=category
Probably a pocket camera that can be run in manual exposure/iris mode would be best.
This would enable greyscale calibration against an IR non contact thermometer ?.
Photoshop etc might enable grey scale colourising post processing to give FLIR like display ?.
Dan.
IIRC, a couple of decades ago, Sony got into hot water for releasing a HandyCam with IR filter that could be switched out of the light path....apparently it was good for ''X-Ray'' filming through clothing....
x-raycameras.com .get-a-flir-lepton-thermal-imaging-sensor-for-diy-projects/
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Most cameras can see the remote light blinking as you press the buttons.
I love showing that to the kids! 😎
Nice overview of the noise issues -----
www.wilambm/pap/2011/K10147_C011.pdf
The LF noise going into a ADC will affects it's lower limit to resolution across a wide freq range.
THx-RNMarsh
www.wilambm/pap/2011/K10147_C011.pdf
The LF noise going into a ADC will affects it's lower limit to resolution across a wide freq range.
THx-RNMarsh
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That link doesn't work for me Richard.
Some similar problems with high resolution convertors...
http://www.ti.com/lit/ml/slyp167/slyp167.pdf
Some similar problems with high resolution convertors...
http://www.ti.com/lit/ml/slyp167/slyp167.pdf
Manually, type it into your browser.
Nice TI pcb info..... 2nV = 24 bit LSB;
One may not being recording/playback to music at 10Hz but the noise is there going into the 24bit ADC.
-RM
Nice TI pcb info..... 2nV = 24 bit LSB;
One may not being recording/playback to music at 10Hz but the noise is there going into the 24bit ADC.
-RM
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Does anyone know of a schematic of line level amp (bal or unbal) with <<2nV/sqrt-Hz noise at 10Hz and <<-100dB THD re >1v into 600 Ohms? X10 gain.
THx- RNMarsh
THx- RNMarsh
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I think it could be done with 2 packages ADA4898-2
N.I. first stage, 3 op amp in par that make the *10,
1 op amp as inverting summer-driver with no additional gain.
The THD plots in the data sheet *start* at 100 KHz, maybe one
could get away with just 1 opamp.
regards, Gerhard
(I have discussed here a measurement preamp last summer
that was similar but used 20 input opamps.)
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Hi Sy
Umm dark well at one time I was looking at property where it was “pretty dark” and in driving distance etc. Here is a web site that shows a light pollution map which is useful;
http://www.jshine.net/astr onomy/dark_sky/
The best reasonably nearby (a blue area) but still a decent drive is up in the area in Wisconsin by an area called the driftless zone.
Closer by was out by a town called Winslow west of us (a green area).
I was out there on work biz and while it was impressively black out (I stopped in the middle of nowhere on the way home), it was also fully overcast.
As for Orion, unless you live closer to Chicago and it’s orange sky glow than I do, you can see the Orion nebula if you know where to look.
About 9 pm, if the snow has stopped and the sky is clear, look to the south about half way between up and horizon.
Look for three stars in a row and the figure shown here (normally the orange star is less colorful to the eye).
http://www.constellation-guide.com/wp-content/uploads/2011/12/Orion-Constellation.jpg
Now, this Orion guy is clearly well endowed (apparently mistaken for a sword) and at the end of his biz is the Great Nebula in Orion.
If you have a modern ccd camera with a telephoto lens (say 200mm) and a tripod mount, try taking a time exposure or three of it.
With a cable release, you would probably be able to take an time exposure out to 10-20 seconds before the stars are smeared (the telescope tracks the stars if motorized and polar aligned).
With a large telescope you can see some color with your eyes, without a telescope the more you look at it, the more clear it isn’t like anything else you see, kind of a ball of fuzz or, well take a look..
Sy, do you know where the Silo is, is that out your way?
Hi Max, marce
The latest CCD’s do get into the IR range pretty well, part of getting the quantum efficiency up so high now. In the LRGB images, IR shows up in the luminance frame as “brightness” while the color filters are usually band pass filters and do not pass IR.
Aside from the imaging debate about including IR an UV in ones exposure in the link below, an issue they touch on in the last paragraph is that if one is dealing wih a lens based telescope, then it is not likely that the focus point for IR is very closer to that for visible light even if it’s a good apochromatic lens. Mirror only based systems have a much broader bandwidh.
Astrodon Astronomy Filters - Articles & FAQ
Hi Richard
Thanks, my curiosity was gnawing at me. I have been known to get up in the middle of the night to measure something that had popped into my head. It looks like the gain is reduced with temperature like bipolar transistors .
My pondering was that CCD’s are silicon and really do benefit from cooling but cmos sensors don’t .
I suppose it not an issue as the noise levels you guys are talking about seem extremely good.
Best,
Tom
They are all silicon. State of the art back illuminated CCD's basically count electrons and are on another plane with respect to noise issues.
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Heard of the Silo, haven't eaten there. We're probably 20 mi NW of it.
I have a cool little star map app in my phone to find stuff, it's just the overcast that's the nearly perpetual issue. On a couple of our really clear nights, I was able to show my son the Galilean moons and Saturn's rings, but it's a rare night that we can see anything.
I have a cool little star map app in my phone to find stuff, it's just the overcast that's the nearly perpetual issue. On a couple of our really clear nights, I was able to show my son the Galilean moons and Saturn's rings, but it's a rare night that we can see anything.
Just a thought I recalled - using a lens telescope of modest power at home... very clear sky here and dark....... the first time I found Saturn and saw the colorful rings was a special moment. No longer was it abstract..... we are floating around in space with other planets became more real and sobering. And felt we are so insignificant in the big picture of things.
-Richard
Thank you... I'll look into them. I do recall your measurement preamp with 20 opa. Is there a discrete circuit somewhere?
THx-Richard
Is this suitable for audio? Low enough thd....?
www.beis.de/Electronik/LNPreAmp/LNPreAmp.html
or
www.mgte.com/files/elnp.pdf
-RNM
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Well, Scott. You know how time consuming it is. Doing a SIM of it would be my first choice.
I am first interested a.t.t. in testing for the most linear small signal devices with also the lowest noise. Or - which of the ultra low noise devices are the most linear?
And, then build around those devices.
-RM
I am first interested a.t.t. in testing for the most linear small signal devices with also the lowest noise. Or - which of the ultra low noise devices are the most linear?
And, then build around those devices.
-RM
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