Debayering a DSLR's Bayer matrix.

[Gina]

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.

I see - thank you

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.

With Peltier cooling to freezing or below I would get condensation on the sensor cover glass until I succeeded in getting the RH low enough in the enclosure. Trouble was that my sealing wasn't perfect and after a week or two the moisture that got in would mean I could no longer cool to -10 or -15C without dewing up. I think I can probably conquer that with a new design and then silica gel bag(s) will suffice. Probably easier to use desiccant than purging anyway. Edited August 9, 2013 by Gina

[alistairsam]

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.

hi

did you notice a difference in the way the cover glass is bonded in the 450d, 600d, and 1100d?

I will get a hot air desold station for the 600d.

as for the 2x2 pattern you mentioned earlier, could that be because there was no shielding.

with the 350d, there is definitely no pattern.

also, any tips on an err70 on a 600d?

we're having the first clear weekend in almost 2 months so I'm headind out to a dark site tomorrow to truly test the debayered 350d with rgb data from a qhy8l or the 1000d

thanks

Alistair

[Gina]

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

Yes, I have various thickneses of aluminium and copper sheet and that wouldn't be a problem

[Gina]

I have made a nozzle for the hot air gun - I just need to secure it better in the gun nozzle.

[Gina]

I wedged the nozzle in with a sliver of copper sheet I cut off the nozzle and it's now quite secure.

Been having a go at freeing the glass on the 1100D unit. I placed the nozzle a few mm away from the glass and applied heat for a few seconds while I moved along the edge about a cm or so. As it cooled I could see moire fringes in the bond area indicating that a minute gap had formed. As the glass cooled it cracked but the breaks seem clean and I don't think there are any fragments.

[Gina]

Later...

The white area to the left is where I tried the Dremel grinder.

Edited August 9, 2013 by Gina

[Gina]

Finished - gone all the way round. The bond break can be seen either by moire fringes or a lightening compared with the bonded part.

Now I 'm going to find some strong adhesive tape to apply to the glass in the hope of removing all the bits at the same time.

[Gina]

Done it :) Glass off all pieces in one go with ultra sticky double sided foam pad. Nice pristine sensor all ready to be bebayered Rotten photo of the removed glass but it shows the result.

[pixueto]

Done it :) Glass off all pieces in one go with ultra sticky double sided foam pad. Nice pristine sensor all ready to be bebayered Rotten photo of the removed glass but it shows the result.

Where did you get that sticky foam pad, Gina?

[Gina]

It's actually off a roll of it that I bought from a local "cheapo" shop some time ago.

[pixueto]

By the way, the glass covering the sensor in the 1000D fits perfectly on top of the 350D sensor. If you have a dead 1000D, I should remind you that the cover sensor in this camera is very easy to remove intact and it can be used on a 350d (which cover glassseems to be near impossible to remove in one piece). I'm hoping the dichloroethane will remove the CFA in the 350D without scraping. Still haven't decided about the best way to apply it on the sensor.

[alistairsam]

Done it :) Glass off all pieces in one go with ultra sticky double sided foam pad. Nice pristine sensor all ready to be bebayered Rotten photo of the removed glass but it shows the result.

nice work Gina

this is significant progress indeed.

thanks filipo and rottweiler.

do you think the glass can come off in one piece if you alter the heating method slightly

did you heat just the edges or centre of the 3mm bond area

rhanks

[Gina]

nice work Gina

this is significant progress indeed.

thanks filipo and rottweiler.

do you think the glass can come off in one piece if you alter the heating method slightly

did you heat just the edges or centre of the 3mm bond area

rhanks

Thank you

It might be possible to take the heating a bit more slowly and avoid cracking. That would certainly be better. I heated the centre of the bond area.

[Gina]

With bright daylight this morning I've been examining the sensor and all the fine gold wires. It's still difficult to see the gold wires but I think one of them is broken which may be why the sensor stopped working before. Another thing is that the gold wires actually stick up well above the level of the sensor and very close to the cover glass - I would estimate at less than a tenth of a millimeter. I have a USB microscope which I'll try to set up and see if that works. As I recall it's not a great improvement on the "no.1 eyeball" and a high power magnifier and lots of light but I might be able to show things better in posts than with the DSLR (another 1100D with 28-80mm zoom lens at 80mm and macro).

[Gina]

Got the USB microscope working

As can be seen there are a couple of broken wires and the second photo shows the way the wires come up from the sensor before being folded over and across to the pads.

Edited August 10, 2013 by Gina

[russellhq]

Got the USB microscope working

As can be seen there are a couple of broken wires and the second photo shows the way the wires come up from the sensor before being folded over and across to the pads.

Think you could fix it?

[Gina]

Nope! Someone with a micro welder might be able to

Here's a Photoshopped version of the 2nd photo. One wire has come off and gone right underneath it's neighbour Must have been when I attacked it with a hammer and chisel

[Luis Campos]

Hi all,

One more image made with the Debayered canon 350D under a good sky, the Ghost nebula:

Thanks,

[Rottweiler]

You're welcome, Alistair!

Looks like the heat gun works, Gina. I think I will get one and also make a cute little nozzle for it. Shame the sensor has a broken wire, still good to practice on though. I tried several ways to fix this but never succeeded. Soldering tiny wires, pressing the gold back in place, all failed. Also a great shot from Luis! All the excitement of this thread got me back to the task too. Actually we found a method that avoids the gold scraper altogether, but is quite a bit slower. I wrote up a tutorial on it. http://www.jtwastronomy.com/tutorials/debayer.php

I really look forward to when this mod is as commonplace as the modified webcams. So many more people will be able to take great photos, when you look at the forums what these young kids are doing with almost no budget, it is amazing!

[Rottweiler]

BTW Louis, would you be so kind as to email me some of your flats? I would like to do a comparison, so we can figure out the best method.

[Gina]

I think I'll be trying again on one of my working 1100D sensore - see if I can avoid cracking the glass but first I want to make sure I can effectively and safely remove the CFA on the non-working one I've just got the glass off. Referring to an earlier post...

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.

I removed most of the CFA on my other 1100D sensor with abrasive (car paint scratch remover) but didn't get an even finish. Since it was a n0n-working sensor I couldn't check the image - only look at the front surface. Maybe with a working sensor I could tell better how it was going. However, my instinct would be to go for something that was softer than the silicon but harder than the CFA. I'll have to give it some thought. Anyway, I have the current sensor to play with.

[Rottweiler]

That would be ideal if we could find something like that! I know jewellers rouge is too coarse (found out the hard way), no idea about car polish. Glass polish works fine so long as you are careful. I wonder how things like the pitch that mirror makers use would fare? Or anything else used optically?

[Gina]

Looks like the heat gun works, Gina. I think I will get one and also make a cute little nozzle for it. Shame the sensor has a broken wire, still good to practice on though. I tried several ways to fix this but never succeeded. Soldering tiny wires, pressing the gold back in place, all failed. Also a great shot from Luis! All the excitement of this thread got me back to the task too. Actually we found a method that avoids the gold scraper altogether, but is quite a bit slower. I wrote up a tutorial on it. http://www.jtwastron...als/debayer.php

I really look forward to when this mod is as commonplace as the modified webcams. So many more people will be able to take great photos, when you look at the forums what these young kids are doing with almost no budget, it is amazing!

Thanks for the tutorial - very interesting The gold wires are welded on I expect. I worked in ministry labs for a while and we had a micro welder and a reel of fine gold wire. A 3D microscope enabled work to be carried out on micro chips with tiny gold pads and the technique was to spot weld the gold wire onto the pad, reel out some wire and then weld it to the bigger pad on the substrate. Then the gold wire was cut. This equipment enabled prototyping of miniature circuitry. The actual micro chips were sub-contracted to a chip manufacturer. Edited August 10, 2013 by Gina

[russellhq]

Maybe a technique like the one in this video might work?

[Gina]

That would be ideal if we could find something like that! I know jewellers rouge is too coarse (found out the hard way), no idea about car polish. Glass polish works fine so long as you are careful. I wonder how things like the pitch that mirror makers use would fare? Or anything else used optically?

Previously I used the Dremel with a polishing head because the polish I have is very fine and takes an age to get anywhere. I don't think I'd risk that without the gold wires protected. In fact it's so easy to twitch and damage the wires (particularly at my age) that I think I'll take your advice and use epoxy resin.

I've been playing with removing the CFA. The polish takes too long so I tried a piece of copper sheet - a thin offcut a few mm wide of 16 swg sheet. It takes the CFA off easily and AFAICS it's leaving a clean surface. I think the copper is softer than the silicon but hard enough and sharp enough to strip off the microlenses and CFA. I'll post a photo shortly.

Edited August 10, 2013 by Gina