Debayering a DSLR's Bayer matrix.

[Gina]

I agree that the blue edge of the sensor seems to be the part to avoid at all costs.  My experience too has been that many of my sensors have worked until I've tried to get that last bit of image round the edge clear of CFA and just strayed over the border.

So from my experience, the causes of failure have been :-

1. Breaking the gold wires
2. Straying into the blue border
3. Going too deep into the imaging area

I shall definitely be working on the 450D sensor and will try to confirm that this sensor can be successfully converted to mono in the central area - leaving a good margin round the edges.  Unfortunately, epoxy resin is far too soft to afford any protection to the sensor border and there is no benefit in covering this with resin.  In fact it would be detrimental in that you couldn't see where the critical border starts.

[StuartJPP]

I always crop my images to remove stacking artefacts so it probably wouldn't make much difference anyway if you leave a border around the sensor.

[pixueto]

I agree that the blue edge of the sensor seems to be the part to avoid at all costs.  My experience too has been that many of my sensors have worked until I've tried to get that last bit of image round the edge clear of CFA and just strayed over the border.

So from my experience, the causes of failure have been :-

1. Breaking the gold wires
2. Straying into the blue border
3. Going too deep into the imaging area

I shall definitely be working on the 450D sensor and will try to confirm that this sensor can be successfully converted to mono in the central area - leaving a good margin round the edges.  Unfortunately, epoxy resin is far too soft to afford any protection to the sensor border and there is no benefit in covering this with resin.  In fact it would be detrimental in that you couldn't see where the critical border starts.

Actually, once the epoxy sets, if you apply frog tape over that epoxy protecting the blue edges, you will have a very good protection against the dremel and felt tips. You can apply two or three thin stripes of frog tape for extra protection and then you can run the dremel an felt over that area to debayer the sensor entirely. This is what I learnt with my last sensor. So getting 100% of the sensor debayered wouldn't be a problem, I think (that's why I say that if the 450D can take the dremel and felt tips, then the mono mod can be done). The reason why I advise not to go anywhere near the edges now is to make sure we avoid a delicate area and we can determine first if the 450D can take the dremel treatment. Then we can move forward and apply the method I am suggesting to debayer the entire sensor.

Again, the epoxy stage isn't really a problem. As I said, if you use the sensor swab (with microfiber on it) you can place the resin wherever you want as you will have plenty of control in the process. In my sensors, I know the blue edge starts right where the epoxy is (as you can see, the resin can be placed where you want with absolute precision using this method). You want epoxy on the gold connectors so you can put frog tape on top of it without risking damage. Maybe, you could avoid using the resin on the other edges and directly apply 4, 5, 6 stripes of frog tape for protection but I haven't tried this yet.

The annoying thing is that with all the work I put into this mod, I can't say if the 450D can take a severe abrasion method like the rotary tool and felt yet, just because I unfortunately managed to touch the blue edge. I can tell you, though that the 1000D can take almost anything; as long as you use the dremel at the lowest speed using only felt tips and you don't touch the blue edges. If someone devises a way of removing the anti-reflecting coatingS or part of it without any gradient so you can achieve perfectnflat frames, I would be very interested to know how (in the 1000D).

Notice that these sensors don't have only one layer of anti reflective coating; they have several.

Edited May 24, 2014 by pixueto

[Gina]

Had a funny few moments and decided I fancied having another go at removing the cover glass from an 1100D sensor.  Took the filters off the front and held the frame with sensor in my "helping hands", got the Dremel gas torch and quickly ran round the edge of the glass with minimum flame.  In a few seconds a light area spread round most of the bond but at the same time a strange pattern of cracks appeared in the glass.  It hardly had a touch of the flame    Anyway, it all came off except for one corner, well clear of the image area.  The sensor still works but the colours are strange but as I expect to remove the CFA this shouldn't be a problem - it could be due to UV as there were no filters.

The Frog Tape I ordered arrived this afternoon so it could have been that that triggered my attack of debayering fever

I have a feeling though that I might not be 100% successful with a debayered 1100D and I'm putting my money on a 1000D for mono and an 1100D for colour.  In fact I think I have three 1000Ds so if my debayering goes well with that model I could have three mono 1000D cameras.  I also have at least 3 bog standard Canon zoom lenses.  Now I know the zoom lenses have a lot more glass than prime but they could provide me with a triple imaging rig for widefield.  I do have Pentax thread prime lenses but mostly in pairs.  I might be able to afford some more second hand Pentax lenses later on though.  Anyway, it all depends on how things go.

[pixueto]

Gina, who knows? Maybe the fact that in the 1100D the CFA is more firmly attached, could be an advantage in debayering using the dremel and felt tips method. Maybe a perfect finish can be achieved. However, the fact that it's a more expensive camera and the difficulty removing the cover glass really puts me off.

[Gina]

Gina, who knows? Maybe the fact that in the 1100D the CFA is more firmly attached, could be an advantage in debayering using the dremel and felt tips method. Maybe a perfect finish can be achieved. However, the fact that it's a more expensive camera and the difficulty removing the cover glass really puts me off.

I found I couldn't use the dry Dremel method as it just didn't touch the CFA, however long I tried and using polish went through the CFA but didn't stop there and went too far, killing the sensor.  I did manage a CFA removal without killing the sensor using polish on a piece of cotton cloth over a thin plastic tool, by hand.  But the result was far from perfect and great care was needed to avoid going too deep.

In my many attempts with the 1100D I have never succeeded in removing the cover glass intact as I recall.  It won't come off without heat and great care is needed to avoid cooking the sensor too much. 

I have given this my very best shot and cannot afford to buy any more cameras even as dud ones from ebay auctions.  I have just one untouched 1100D sensor left and I intend using this as a cooled OSC camera for astro.   I shall continue with the sensor I'm currently working on but that is my very last chance of CFA removal with the 1100D.

I agree with you regarding the 1100D - I don't think it's worth it. 

Edited May 28, 2014 by Gina

[Gina]

There were a few tiny pieces of glass that somehow got onto the sensor imaging area in spite of keeping the sensor pointing slightly downwards while removing the cover glass.  Turning the sensor to face the table and tapping the frame didn't shift them so I tried blowing them off - some were removed but not all, they seem well stuck to the sensor.

Put sensor back in camera and now there are problems   EOS Utility takes a picture and displays it then says Err 70.  Also, apart from the shadows from remaining glass bits, there are several horizontal dark lines of dead pixels.

I might try removing the CFA in the middle without bothering to apply epoxy resin to the wires - I'll just stay clear of them.  OTOH maybe my time would be better spent on other things   Like the 1000Ds.  I'm obviously bashing my head against a brick wall trying to debayer 1100D sensors

Sorry folks but I've lost the battle with debayering 1100D sensors and now I've run out of ammo   All I can say is that I gave it my best.  It is evidently possible but I don't pretend to be the cleverest person around or it may help to have special equipment.  What I can certainly say is that it needs heat to remove the cover glass and it needs polish to remove the CFA.

[flolic]

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...

Sent from my GT-I9100 using Tapatalk 2

[Gina]

That sounds good - looking forward to your findings - thank you

[Gina]

Took a photo of my 1100D sensor for what it's worth

[Davey-T]

  I also have at least 3 bog standard Canon zoom lenses.  Now I know the zoom lenses have a lot more glass than prime but they could provide me with a triple imaging rig for widefield.  I do have Pentax thread prime lenses but mostly in pairs.  I might be able to afford some more second hand Pentax lenses later on though.  Anyway, it all depends on how things go.

Hi Gina I have a  M42 thread 200mm SMC Takumar somewhere around the place, your welcome to it if it's of any use to you.

Dave

[Gina]

Hi Gina I have a  M42 thread 200mm SMC Takumar somewhere around the place, your welcome to it if it's of any use to you.

Dave

Thank you very much    I'll see how the debayering goes and let you know. 

[Gina]

Following stripping down my latest duff 450D with a broken shutter, I have a 450D sensor for debayering.  First stage completed - removing the cover glass.  This can be done cold with this model with a craft knife and carefully working round the edge of the bond.

[libraryman]

That looks very good, are you convinced that pysicaly scraping of the matrix is worse than using the dremel and buffing?

It seems such a aggressive method to my mind!

Ray

[Gina]

That looks very good, are you convinced that pysicaly scraping of the matrix is worse than using the dremel and buffing?

It seems such a aggressive method to my mind!

Ray

Actually, no I'm not.  Personally I would prefer the gentle, if slow, approach.  That certainly worked better with the 1100D sensor.  Without a virtually endless supply of sensors I'm finding it hard to decide which method to use for the 450D and 1000D though it seems to me that "slowly slowly catchee monkey" should be safer.

[libraryman]

Given the very limited space and delicate borders, it almost requires robotic accuracy to control the process!

If when using a rotating head, I would think that one needs to set a depth or pressure and move the sensor rarther than the rotating head, more control that way but so difficult to achieve.

Ray

[alistairsam]

Hi All

Been a while since I posted.

I've started debayering a 450d with just a plastic tool and m halfway done. I don't bother with the epoxy, just use the frame without the glass.

Tested. The sensor, working fine.will continue tmrw.

I believe Luis here has done a few 450d's with good results,

Cheers

Alistair

[libraryman]

Hi Alistair, do share any photos, it sounds as though it's going well for the moment.

Ray

[alistairsam]

hi, I'm 3/4th way through the 450D sensor. attached is a pic taken with it. background is blue. 

I'm sticking to my paintbrush tool method, although its plastic, so no polish although I'm curious on how it'll work cause the cfa layer is definitely more stubborn than the 350d, but similar to the 1000D. doesn't come off that easily, so I will persevere under a microscope. I've comfortable watching the microsocope feed live on my laptop and controlling the tool. that way I can control how far I go. 

after busting two 600D sensors due to the blue area, I'm heeding to all the warning about the sides. 

interestingly enough, you don't need to go all the way. there is about a millimetre or so between the edge of the frame in this pic when compared to the sensor. 

I'm using the frame with the glass removed to protect the golden wires, thanks for the idea Gina. 

will post progress as I go. 

Cheers

Alistair

[Luis Campos]

Hey Alistair

Indeed the 450D's are the best model to debayer IMHO, altough not quite as sensitive as the oldie 350D the noise free and good sensor behavior at 1600 ISO makes this one the best allround for NB work.

As you said I've debayered quite a few by now using the wooden tool method, I killed also a couple sensors during the conversion, it's all a part of the process I'm afraid

The difficult part is to get a clean sensor as the CFA remnants are really attached to the sensor surface, but what I do is polish just using the tip of the wooden tool at the same spot until I see no signs of CFA in that area, and I use one of those magnifier with a led ligh for electronics work, it's very helpfull, this is very time consuming but very effective, just go by areas untill you do all the sensor, polish, polish and then some more polish And I mean dry polish just appling moderate pressure on the tool as you go.

See here a couple of flats and images of some of my 450D's:

https://www.flickr.com/photos/37419943@N08/

Best,

Luís

Edited June 19, 2014 by Luis Campos

[Luis Campos]

And here some more steps of the process:

Cheers,

Luís

[alistairsam]

Thanks Luis, 

you've got some amazing images with it. 

I must admit, I wasn't very impressed with the 450D before debayering compared to the 350D. strange, I thought the 350D was definitely sharper and had more contrast. one big difference is the bigger pixel in the 350D which is what I like about it and of course its a piece of cake to debayer, well relatively speaking. 

with the 450, do you manage to get your cover glass intact, after debayering, do you stick it back on or leave it naked, do you have a flat taken with a 450D, how many have you done so far and finally how easy is it to cut a cold finger?

I was thinking, why do we need the mirror box assembly at all with the dslr's? we could possibly extend the ribbons and keep it outside the body just for the electronics to work or make a shutter emulator. that way, you can house the whole sensor and pcb in a sealed box with a T2 thread. something i'll be testing later. 

Cheers

Alistair

[alistairsam]

oh and one more question, have you done any comparisons of LRGB vs RGB, that is adding L from the mono dslr, vs RGB from an IR modded DSLR. does the mono provide detail to the DSO? 

Thanks

[Gina]

You don't need the mirror box but you do need the shutter.  You can remove a lot of the DSLR for astro use

See my thread Removing all unwanted parts of a DSLR to make a minimal weight and volume astro camera

Edited June 19, 2014 by Gina

[Luis Campos]

Thanks Luis, 

you've got some amazing images with it. 

I must admit, I wasn't very impressed with the 450D before debayering compared to the 350D. strange, I thought the 350D was definitely sharper and had more contrast. one big difference is the bigger pixel in the 350D which is what I like about it and of course its a piece of cake to debayer, well relatively speaking. 

with the 450, do you manage to get your cover glass intact, after debayering, do you stick it back on or leave it naked, do you have a flat taken with a 450D, how many have you done so far and finally how easy is it to cut a cold finger?

I was thinking, why do we need the mirror box assembly at all with the dslr's? we could possibly extend the ribbons and keep it outside the body just for the electronics to work or make a shutter emulator. that way, you can house the whole sensor and pcb in a sealed box with a T2 thread. something i'll be testing later. 

Cheers

Alistair

It's like you say, pixel size of the 350D is a good match for most systems and seeing conditions, it it wasn't for the amp glow and 12 bit the 350D would still be a winner

Regading the 450D, I like a lot it's simplicity and very low noise performance even at 1600 ISO, with a cooling system this one is a killler!

Yes, the cover glass comes out intact on the 450D just by working all around with a thin blade, this original cover glass is very, very bad reflection wise, it has no AR coatings at all, so for the MONO versions only I replace it with a astronomik clear glass filter, this one is IMHO the best filter available for this type of mod, it's very high qulity and excellent coatings that minimize reflections on bright stars, even RGB cameras will benefit from having one of this in place.

I have several flats, this flat is from a camera that stil has some bits of CFA but it gives you a nice idea of what can be acheived with just polishing with the dry tip of the wooden tool:

https://www.flickr.com/photos/37419943@N08/13434966625/ 

So far I did about 11 or 12 450D's most of them for mono conversion and some just cooled (RGB cameras)

The cold finger is very easy to do, I do mine with a 2mm aluminium plate and grind the sensor contact area with a Dremmel tool till it fits on the sensor gap (about 1.3mm) but you also have to modify the camera's chasis (nothing special...) I don't have the measurements here now but I'm thinking on making a detailed tutorial on how to do the full cooling mod on the 450D once I have some good free time

By now I have a working system with ZERO sensor fogging problems even under sub zero temperatures, tested at -10Cº during winter with no problems whatsoever, took me a loooooong time to figure a sollution out but I'm proud to say that it works amazingly well!

I like to have a "normal" camera with all functions accessible as original, so for me this system is tops, I have a cooling system attached to a normal looking camera with all original functions, including remote cable access, this is because you don't really need to supercool the sensor to have a very clean image, I see no benefict or much difference between 0cº or -10Cº on noise levels, so the sweet stop of cooling in a DSLR is somewere around 0Cº.   

I don't have any comparo with RGB filters buit I supect that noise levels will be lower with a mono camera and LRGB filters especially lower color noise (less blotchy) and a bit better resolution, the mono camera even in simple LUM. is a tad sharper due to the fact that it doesn't interpolate pixels and therefore resolution is increased a litlle, now narrowband is a whole different story, even with a tad less sensitivity the 450D has amazing resolution and the same is true for the oldie 350D!

Cheers,

Luís