flolic

I agree, that CNC machine Z axis should have tolerances and precision in a sub micron range.

I don't have that precision on my machine, but it should be quite capable in surface polishing if I ever produce precision spring loaded tool...

Not lathe but CNC mill (or router).

So, what exactly we are looking here?

How long is total exposure time under UV lamp?

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I think strong UV exposure would be best possible solution to "debayer" sensor. I remember reading in some Sony CCD datasheets that prolonged exposure of sensor to strong UV radiation will fade out color layers.

Question remains of how strong is to strong, and how microlenses will react to UV. I think they are made of some sort of epoxy plastic, but what if they turn opaque?

Also I don't think exposing peripheral circuitry is very "healthy". That circuitry is masked (blue area) but I think UV radiation will penetrate that.

If I find another sensor, I will try to mask all but the small part of the image sensitive area. That way I will have something to compare.

Now I had a Canon 1000D’s sensor and this high pressure mercury lamp. I broke the outer glass as only the inner glass is quartz (pure SiO2) which will pass hard uvc. The sensor was now 30h under the 40W lamp and brightens up! I have spotted some dark parts where dust has covered the sensor. So I will give it some more time the bleach even these parts. (The sensor reaches about 60°C during the treatment and is hopefully still alive)

I tried exactly that method over 10 years ago on Philips Toucam webcam. Unfortunately sensor died after short exposure to strong UV light...

I used 125W HPM lamp with broken outer glass (I originally used that lamp for EPROM erasing).

I hope you'll have better luck.

There may be a mechanical way to remove the glass, high precision cnc or something, but it cannot be done by the methods described in this thread.

 

Yes, CNC with high speed spindle and diamond coated tool should cut through the glass easily. I may try that some time...

I am just in the process of finishing my CNC router. My plan is to mill aluminium or hard plastic frame that will cover whole top of the sensor, exposing only light sensitive area and protecting everything else.

Router is almost finished, still waiting for some details.

I will try this idea and let you know if it works...

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lol that was the one I was watching, missed the bid as i was working agreed its just a bent CF pin and may work over usb still anyhow so an ideal candidate for modding. Hope you have better luck this time Gina

Keith

300D USB transfer rate is so low that it takes over 30s to transfer one raw image, if I remember correctly. Last time I used one for astronomy was 6 or 7 years ago, and it was real pain...

I have one laying around and I don't even want to touch it anymore

fantastic work filip.

how was the noise for 5min subs. if the sensor was at -15, you could've gone longer.

Thanks!

Sensor was at -5C, I have bunch of dark frames made at that temperature, and I didn't want to go any lower. (Camera can go 28-30 degrees below ambient and is PID thermostat controlled).

These were 10 minute subs, and noise is not problem at all. I could easily go with 30 min or longer, but that increases the risk of bad tracking. I can tolerate one lost exposure of 10 min, but not 30 min

My friend with CentralDS cooled 5D MkII often goes with 60min exposures

just WOW Filip....

What an amazing performance, I can only imagine all your buddies drooling for a mono sensor he he he....

yep, I now what you mean about a 2" Ha filter...I'm in the same boat...waiting for some $$$

Congrats on such a fine image, BTW what telescope have you used?

Cheers,

Luís

Thank you Luis!

I used my homemade newton 200mm/f6 (with GSO mirrors). I have Badder MPCC on it, but must fabricate longer spacer because current one is ~7mm short...

Gina, I am sorry for another dead sensor...

Last night I was at PGSP (Croatian largest star party, Petrova Gora Star Party) with my debayered cooled 450D.

Everything went great and I managed to capture 2 hours of exposures of Cocoon nebula.

This is full image, just cropped around edges to eliminate CFA remains.

12x600s, ISO800, camera sensor at -5 degrees C. Calibrated with flat frame only, no darks.

https://dl.dropboxus...tack_L_full.jpg

All that remains now is to save some money for 2" filters...

IIRC, there are few microfuses on power board. Also, check contacts on SD card door.

Someone asked for flat frame from my camera:

https://dl.dropboxus...flat_newton.jpg

This is one stretched flat frame through my 8" f6 Newton (that's the reason for some vignetting).

What I've learned so far:

-cover glass comes down quite easily with the help of hot air (350 to 390C), carefully applied around the edges through small nozzle (3mm).

-golden wires and blue border of the sensor are very fragile, slow setting epoxy applied to those parts protect them excellent.

-only scraper hard enough to attack CFA, and soft enough not to scratch too deep is wooden one. Any metal is (imho) too risky.

-when you have your sensor's glass removed, epoxy applied and hardened, and CFA scraped off with wooden tool, any remains of CFA

can be easily cleaned by polishing. Because all sensitive parts of sensor is protected with epoxy, just put a small drop of polish paste to the

sensor surface and very gently polish it with soft cloth and your finger. I've used Xerapol paste for polishing polycarbonate plastics, but I am sure

there are better products with finer and smaller abrasive particles. Polishing takes only minute or so, you have to remove only CFA remains and

not underlying layers! So, wipe few times with polish and then clean and inspect surface. Every progress will be quite obvious, because you can see

the difference if you look at the surface against the light under various angles. My advice is to polish, clean and then install the sensor into camera

and take few test shoots to see progress. And then repeat that until chip is clean.

Failure is not always a total failure

And full frame

I finished my camera, everything is working great!

I leaved some CFA remains on the edges because I didn't wanted to push my luck this time. But I can easily crop this.

I am going to dark location tonight, unfortunately Moon is big but I just want to see how this work.

Last night I did some test exposures to see if cooling works. I can get 30C below the ambient without any problems with condensation.

This is 100% crop, stacked 10 exposures at ISO1600 and with sensor temperature of -5C.

Details and resolution is outstanding

So far so good

I am now letting this aside until tomorrow, waiting epoxy to finaly set so that I can finish the corners and polish the remaining CFA flecks.

I just finished applying epoxy around all the edges. I covered every little bit of sensor except light sensitive area.

I just hope this one will be fine...

My dead sensor. I was working on the left edge, scraping and polishing near and on that blue layer and that killed it.

(ignore the fingerprints)

Full size image, if anyone is interested:

https://dl.dropboxus...ke/IMG_9169.jpg

Left side of sensor with something sensitive:

Dear all,

Has it occurred to you that it may be the epoxy itself the responsible for the malfunction? Am I right thinking that all the working sensors after being debayered in this forum (totally or partially) don't have epoxy over the golden connectors?

My sensor was working great until I tried to remove small leftovers of CFA. I don't think epoxy can cause any damage.

Gina, I'm so sorry

Yes, this is expensive sport, but I don't want to give up until I finish one functional BW camera. I feel that you think the same

I just removed cover glass from new 450D sensor candidate, so here we go again. Wish me luck

Btw. I think I know what possibly kills our sensors. On the edge of shorter side of sensor, under the blue mask there is some circuitry visible (thru clear "window").

I think that part is very sensitive and should be avoid when scraping. My sensor was ok until I wiped few times with polish paste over that very area.

Sh*t! Another expensive mistake! I managed to kill my 450d sensor somehow... :sad:

Most probable cause was too deep cut while trying to remove CFA leftovers around the edge. Wooden scraper was of no help, so I decided to add just a small drop of Xerapol plastic polish and try with that. Yes, that removed CFA but obviously also some critical layer underneath

Biggest mistake was that I applied polish paste to my wooden scraper, that cut it too deep too fast. I should have gone with polish paste applied to soft lint free paper and gentle rubbing the whole sensor area...

I tried that method afterwards and I think that will clean the sensor very nice and in a very uniform fashion. Epoxied wires are essential for this because you can treat the sensor with much less mental stress

I have one more sensor (and another one in my everyday camera ), I must try my luck again

Fingers crossed for all CFA scrapers

hi

does the weight of an epoxy drop move the golden wire at all?

how did you apply the epoxy?

cheers

Alistair

Not at all. Epoxy just seeps between the wires and fill the empty space.

I used wooden toothpick with the sharpened tip.