Debayering a DSLR's Bayer matrix.

[flolic]

I found locally produced paint stripper, "Chromos - Desol" that by MSDS contain 50-100% of dichloromethane. I will try that

[billhinge]

I found locally produced paint stripper, "Chromos - Desol" that by MSDS contain 50-100% of dichloromethane. I will try that

you can buy 99.5% pure dichloromethane on ebay for a few pounds, also MEK and acetone, I thought the challenge was to match the appropriate solvent to the solute?

I tried nitromors on a panny sensor and it didn't work for me

[Gina]

Yes, I tried Nitromors on my 1100D sensor - no affect whatsoever!

The girly pink hot air gun came today - it's bigger than I thought, being about 9" long with a half inch nozzle. I may get to try it this evening. I think I'll make a guard with a small hole in it for the sensor job though. I think quarter inch or less (6mm). A piece of sheet aluminium with a wooden handle, I think. I could do with an asbestos sheet to work on but I'll have to find something else. I think I may also make a guard to cover the sensor connections.

Edited August 8, 2013 by Gina

[Rottweiler]

Looking forward to the results with the gun, Gina. I did a sensor today as an experiment with some new tools we made, I tried a plastic 'scraper' (made from a sensor swap) and glass polish, so the CFA was removed entirely by abrasion. It eliminated the tiny scratches you can get with even a gold scraper, but I have to admit that it comes with a lot of practice. I suspect this is a the best method for solvent-proof sensors. The results are quite satisfactory, the flats are really nice, although still a bit uneven. I dont think we will ever get a perfect method for the solvent-proof sensors. I was told by a chemist that it may be possible that no solvent will touch these CFAs once they are 'set', or whatever the terminology was.

Here is the sensor (some bayer still visible at the bottom, removed after taking the picture )

Now here is the interesting part. I think maybe someone can write a script to eliminate this. There is a definite 2x2 pattern, possibly due to preamps correcting for the spectral response and what the camera is expecting to hit a particular pixel. As we no longer have red, green or blue. The camera does not know this though. Even in monochrome mode it would be performing some correction surely? I hope someone with more knowledge in this area can contribute.

You will note also a stripe artifact near the bottom, meaning this sensor is destined for the bin. Not sure what caused this, perhaps slightly too deep with the abrasion although it is not visible on the sensor. The camera was in pieces down to board level on the desk, so no shielding, etc was present.

[Gina]

The hot air gun seems to produce plenty of heat. Found a copper plate with about a 7mm hole in it which I placed over the edge of the glass at the end and applied heat for about a minute. I did this several times around the ends gradually moving along the edge and letting it cool between heat runs. The whole assembly got quite hot - almost too hot to touch. I wonder if the components would survive this. I can't tell because this is already a dead sensor assembly. So far no sign of anything happening.

[alistairsam]

Hi Gina,

that's not good news. was this a 1100D sensor? so it did not turn white at all? how about trying to pry it with a knife after it cools. even if it doesn't turn white, the bond should've weakened after the heat and cold treatment.

I wonder if cooling it rapidly with a wet cotton bud would help in weakening the bond.

if heat doesn't help, then I think finding a method to break the glass in one piece is the only other way.

i was thinking of sticking a metal piece on top of the glass within the outer edges and applying pressure upwards away from the sensor.

The glass is fairly thin so shouldn't be too hard. maybe do the operation with the sensor upside down.

I have a replacement 600D on its way and I only have one chance at this cause its getting expensive (I decided to stick with the 600D rather than the 1100D).

Cheers

Alistair

[Luis Campos]

Hi Gina,

that's not good news. was this a 1100D sensor? so it did not turn white at all? how about trying to pry it with a knife after it cools. even if it doesn't turn white, the bond should've weakened after the heat and cold treatment.

I wonder if cooling it rapidly with a wet cotton bud would help in weakening the bond.

if heat doesn't help, then I think finding a method to break the glass in one piece is the only other way.

i was thinking of sticking a metal piece on top of the glass within the outer edges and applying pressure upwards away from the sensor.

The glass is fairly thin so shouldn't be too hard. maybe do the operation with the sensor upside down.

I have a replacement 600D on its way and I only have one chance at this cause its getting expensive (I decided to stick with the 600D rather than the 1100D).

Cheers

Alistair

Hi,

I think the problem in heating the glass too much is thermal expansion, I did this to a Tou Cam web cam but with very localised heat (tip of a soldering iron) and the glass cracked just because of the thermal expansion...I guess this will happen also if the mirror is rapidlly cooled, if heated it has to be cold gradually at ambient temperature or it will crack.

I'm having another go at a 350D tomorow, this is from a friend of mine, let's see how it goes

Cheers,

Edited August 9, 2013 by Luis Campos

[Gina]

Hi Gina,

that's not good news. was this a 1100D sensor? so it did not turn white at all?

No but nor did it when I applied heat from my big hot air gun, sufficient to singe the PCB and melt the solder on the sensor connections. It wass only after everything cooled down that I found the remaining glass bits could be simply pushed off.

how about trying to pry it with a knife after it cools. even if it doesn't turn white, the bond should've weakened after the heat and cold treatment.

Yes, I plan to try that once I've worked my way round the edge of the glass. But doing it 6mm at a time and allowing cool down in between, it's going to take a looooong time But that was the advice from the professional (JTW).

I wonder if cooling it rapidly with a wet cotton bud would help in weakening the bond.

Yes, I wondered that too.

if heat doesn't help, then I think finding a method to break the glass in one piece is the only other way.

i was thinking of sticking a metal piece on top of the glass within the outer edges and applying pressure upwards away from the sensor.

The glass is fairly thin so shouldn't be too hard. maybe do the operation with the sensor upside down.

Might work.

I have a replacement 600D on its way and I only have one chance at this cause its getting expensive (I decided to stick with the 600D rather than the 1100D).

Yes, that's the problem - sensors are just too expensive. Used bodies are the cheapest way but still expensive. When I was experimenting with cooling I spent more than an Atik 314L+ would have cost But it was fun and I enjoy messing about like this so it wasn't a waste of money - just money spent on a slightly different hobby You could say that my astronomy hobby is split into two parts - capturing and processing images AND playing with the hardware, devising new ways of doing things etc.

[Gina]

Hi,

I think the problem in heating the glass too much is thermal expansion, I did this to a Tou Cam web cam but with very localised heat (tip of a soldering iron) and the glass cracked just because of the thermal expansion...I guess this will happen also if the mirror is rapidlly cooled, if heated it has to be cold gradually at ambient temperature or it will crack.

I'm having another go at a 350D tomorow, this is from a friend of mine, let's see how it goes

Cheers,

Does it matter if the glass cracks? I have a 350D to try as well. Needs stripping down first.

[alistairsam]

Does it matter if the glass cracks? I have a 350D to try as well. Needs stripping down first.

it shoudlnt matter as long as the particles dont land on the sensor surface cause they could get lodged between thr golden wires like what happened with my 600d and worse is when you're scraping, you could cause major scratches.

btw I didnt realize the 600d is very similar in specs to the 60da. so the small pixel should'nt be too bad with an F4

http://www.digicamdb.com/compare/canon_eos-60da-vs-canon_eos-rebel-t3i/

you mentioned you could push the glass away. which stage was this at?

[alistairsam]

Does it matter if the glass cracks? I have a 350D to try as well. Needs stripping down first.

I think almost all of us in this thread with a 350d cracked the glass.

just make sure you stick some strong tape on top.

and possibly work vertically with the golden wires on the sides and let gravity handle the small bits.

I am going to get a glass cutter, score a rectangle on the inside, and do the heat treatment, but mildly. the scored lines should make a cleaner cut with the heating and cooling.

wish we could get some compressed air in there to pop it upward . how easy would that be!

[Luis Campos]

I think almost all of us in this thread with a 350d cracked the glass.

just make sure you stick some strong tape on top.

and possibly work vertically with the golden wires on the sides and let gravity handle the small bits.

I am going to get a glass cutter, score a rectangle on the inside, and do the heat treatment, but mildly. the scored lines should make a cleaner cut with the heating and cooling.

wish we could get some compressed air in there to pop it upward . how easy would that be!

Yeps, I broke mine into pieces, but I had the tape covering it so it was ok, no problems with bits of glass on the sensor.

But it sure would be nice to be abble to aply again the cover glass, on my case as I'm on the cooling dept. this would seal the unit again and prevent from dew on the sensors face, as long as I can remove all the air inseide first, wich I think I can

Cheers,

[Gina]

But then the dew forms on the glass instead Unless you can get the environment quite dry, of course. I've been looking into that again. Looked for compressed nitrogen but couldn't find anything suitable. I was wondering if the air in the compressed air cans is dry. It might be possible to purge the enclosure of damp air that way.

If I can debayer an 1100D sensor I plan on making a new, more compact imaging unit and purge it of damp air or maybe just use dry silica gel bags as before. As long as I can seal the case well. I'll need a filter wheel and propose to build one into the outer case with a sealed inner enclosure. The whole assembly will want a front to sensor distance of 55mm or less if I'm to use it with my ED80 plus FR/FF. To use it with M42 vintage SLR lenses would require 45mm - even worse. Of course, I'm looking well into the future here - this is quite some project

Of course, if I took this even further and produced three debayered and cooled 1100Ds I wouldn't need a filter wheel - just Ha, OIII and SII external filters and 3 matching lenses for widefield NB DSO imaging.

Edited August 9, 2013 by Gina

[Gina]

Now where can I put that second observatory?

[Gina]

Only joking

[RogerTheDodger]

Gina, on the 1100d, is the audible noise when you take an image actually the shutter mechanism or is it electronically generated?

[flolic]

I think you all are afraid of heat too much...

Like I said before, I used hot air rework station set to (I think) 370C and with small nozzle of 3mm. By applying very hot air on small area of glass, you create localized hot spot and tension forces combined with weakened glue break the bond between glass and sensor package. You start in one corner and as the glue becomes white just continue all around the glass. In the end glass will just fall off by itself. Whole procedure is finished under 3, 4 minutes. From my experience, this procedure works excellent on 10D, 300D and 450D sensors.

I work on a daily basis with IR BGA rework station, ALL chips can easily handle temperature up to 230C, and I think CMOS sensors are no exception.

But what's more important, if you follow my procedure, sensor will not even reach 200C.

[flolic]

Gina, compressed "air" in a can is not air at all. It's some form of fluorocarbon.

But I think it is dry enough for purging the sensor

[Gina]

Thank you Filip

Do I gather then that you work all round the edge of the glass and not wait for it to cool down? I can make a smaller guard so that I'm heating a smaller area. I think the hot air from my gun will reach quite a high temperature a cm or two from the nozzle as it uses an electric element that glows red hot when on and air going over it.

Edited August 9, 2013 by Gina

[astromerlin]

Hi Gina, How about getting one of these to fix to your hot air gun which will localise the heating.

http://www.ebay.co.uk/itm/Screw-Locking-Circular-3mm-Nozzle-for-850A-Hot-Air-Rework-Station-/130914744041?pt=UK_Home_Garden_PowerTools_SM&hash=item1e7b2076e9

[Rottweiler]

Now where can I put that second observatory?

In my garden

Great to see Filip had success with the desoldering station. Also confirmation of our heat method, more than one way to skin a cat! Gina, I would not recommend you try to remove all the glass at once with a heatgun or pen torch, I can confirm if you try to do too much in one run it will crack the glass. i don't think it is worth the risk for the time you will save. I try to do no more than a few seconds at a time. I like Filip's solder rework station better than a pen torch though.

As for a purge, you can also buy bottled argon/CO2/nitrogen mixes at a welding supply store in quite small bottles for hobby sized welders. Not sure how dry it is, I imagine dry enough, I suppose you could put that through a cannister of dessicant first then through a tube to the camera? Do you have problems with fogging of the inside of the sensor? This is something I have not seen before.

[Luis Campos]

But then the dew forms on the glass instead Unless you can get the environment quite dry, of course. I've been looking into that again. Looked for compressed nitrogen but couldn't find anything suitable. I was wondering if the air in the compressed air cans is dry. It might be possible to purge the enclosure of damp air that way.

If I can debayer an 1100D sensor I plan on making a new, more compact imaging unit and purge it of damp air or maybe just use dry silica gel bags as before. As long as I can seal the case well. I'll need a filter wheel and propose to build one into the outer case with a sealed inner enclosure. The whole assembly will want a front to sensor distance of 55mm or less if I'm to use it with my ED80 plus FR/FF. To use it with M42 vintage SLR lenses would require 45mm - even worse. Of course, I'm looking well into the future here - this is quite some project

Of course, if I took this even further and produced three debayered and cooled 1100Ds I wouldn't need a filter wheel - just Ha, OIII and SII external filters and 3 matching lenses for widefield NB DSO imaging.

I'm a lucky man, I have a Nitrogen supply oin my workshop, I use to fill the bicycles rear shocks

That will cure the inside of the filter, on the outside I have an array of 8 22 Ohm resitors welded toghtere to heat up the "air chamber" inside the Baader MPCC and front of the sensor filter, before i opened the sensor it worked very well, even in extra damp conditions

Can't wait to see that finished project

Cheers,

[Gina]

Gina, on the 1100d, is the audible noise when you take an image actually the shutter mechanism or is it electronically generated?

The shutter and mirror I think. Edited August 9, 2013 by Gina

[Gina]

Hi Gina, How about getting one of these to fix to your hot air gun which will localise the heating.

http://www.ebay.co.u...=item1e7b2076e9

Takes too long from HK and probably wouldn't fit my gun but I could make something similar.

[Rottweiler]

Takes too long from HK and probably wouldn't fit my gun but I could make something similar.

Maybe knock one up with some folded aluminium foil or thin copper sheet?