Hi
I've been thinking of this for a while after reading similar attempts at the SGL, so I bought a 350D off ebay and a USB microscope and successfully removed the CFA.
The Camera still works and opening the CR2 file in Maxim displays a monochrome image as expected.
the whole rationale behind it was to get a decent sized mono sensor without the thousands. I know it still won't compare to a 16 bit astro ccd camera, but it should fit in between and should make narrowband more affordable.
this was more of an experiment so I can then move on to a newer model with a larger sensor and convert it to mono, replace the IR filter and cool it with a cold finger.
any suggestions on which medium level DSLR sensor has reasonably high QE?
I have a 10inch F4, so smaller pixels would suit.
the 1100D and 20D have their glass screens glued on and are almost impossible to remove to get to the sensor so they're out of the question.
I just followed the 350d filter mod guide to open up the camera and get to the sensor.
after that, I removed the IR filter.
the sensor is behind another piece of glass. It was next to impossible to lift this without breaking it, so I stuck some tape and took it apart in pieces.
that exposed the sensor surface. no damage done to the sensor itself.
For a tool, I used the top end of a wooden paint brush, sharpened. this was to prevent permanent scratches to the photosite layer although its actually quite hard.
gentle scraping removes the microlens layer which is almost like a sticky coating and easily comes off.
the CFA is a bit harder but once you get an opening, the rest just comes off. its quite brittle.
I used the microscope with 500x to make sure I didn't touch the wires at the two sides as that could render it dead.
I managed to scrape off the cfa in about half an hour. so assembled and ready to test, I find out that the battery is flat and the battery charger was'nt included.
I was getting a bit impatient, so I snuck two wires into my 1000D's battery and connected it in parallel to the 350D battery and it was charged half in about 15 minutes.
enough to test.
here are a few test shots. i used a 18-55mm lens with manual focus so the focus may be a bit off but I was pretty happy with the results.
the 350D doesn't work too well with backyardEos, so I'll have to get the timer for longer exposures.
close ups show that there are still bits of the CFA left. I need to do go over it with the microscope a give it a proper clean.
I'm aware that there will be a drop in sensitivity with the microlenses gone, but it should more than make up for it with the 4x increase as now all 4 pixels are used for luminance.
With the IR filter removed, it should also suit narrowband.
Here are some videos of the "scraping".
http://www.youtube.com/watch?feature...&v=aJ65Ve4bdOg
higher mag, you can see the bayer matrix here.
http://www.youtube.com/watch?feature...&v=E9kxsYutm5U
now to do some real tests without the IR filter and the 10inch F4.
Will post results once I get some clear skies, and also when I move on to the next camera.
I might get a 1000D off ebay for its 6micron odd pixels and size and give that a go as well.
comments welcome.
Cheers
Alistair