Debayering a DSLR's Bayer matrix.

[pixueto]

there is one way you can protect the connectors.

Simply leave the frame where the filters are

When you are removing the array. I'm talking about the plastic

Where the filters are attached. Just leave it on top of the sensor

And you won't be able to see the golden connectors.

just a thought.

[Gina]

That's amazing Great minds think alike I was going through my box of bits and picked out an 1100D sensor and filter frame and came up with the same idea. Took some photos to illustrate the point.

Edited September 1, 2013 by Gina

[Gina]

Double post

Edited September 1, 2013 by Gina

[pixueto]

However, I think we are focusing too much on not hitting the golden connectors but the fact remains that the difficulty is in removing the CFA, leaving the surface even and possibly without scratches. I think only Luis has managed to do that (twice) with a 350D. I have a feeling that this is something it can only be achieved with this model -or possibly one of those nikon DSLR with the CCD sensor? Anyway, Luis is now debayering a 450D so we'll see how that goes.

The problem in the 350D is to remove the glass on the sensor more or less intact but, if the epoxy was responsible for those sensor failures, maybe we can apply heat to remove the glass now?

Edited September 1, 2013 by pixueto

[pixueto]

One of the things I've learnt from my experience with the partially debayered 1000D and the 7nm 2" H-alpha filter is that I can't use live view. The image is too dim. Another reason for going right for the 350D.

[Gina]

However, I think we are focusing too much on not hitting the golden connectors but the fact remains that the difficulty is in removing the CFA, leaving the surface even and possibly without scratches. I think only Luis has managed to do that (twice) with a 350D. I have a feeling that this is something it can only be achieved with this model -or possibly one of those nikon DSLR with the CCD sensor? Anyway, Luis is now debayering a 450D so we'll see how that goes.

The problem in the 350D is to remove the glass on the sensor more or less intact but, if the epoxy was responsible for those sensor failures, maybe we can apply heat to remove the glass now?

I think I managed quite an even CFA removal without leaving any scratches before I went too far and caught the wires.

Since I have a 350D that works apart from the sensor I'm considering bidding for a non-working 350D for the sensor and seeing if I can produce a debayered 350D. I'm not bothered about live view since I do mainly NB imaging.

[pixueto]

Yes Gina but the problem with the 350D is the glass covering the sensor. Apparently, it's one of the hardest to remove -that's why I haven't started debayering mine.

Luis, have you managed to remove it intact in your last conversion?

[flolic]

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...

[pixueto]

to be precise, i only use a spray which contains dichlormethane and some other additions.

its a very viscous spray, which is like foam after applied, so i spray it on the sensor and wait for a little time.

In my opinion, it could be that the leftovers react in the wrong way with the spray.

So that we have a small timeframe, in which we can remove everything, when we leave this timeframe, the CFA "hardens".

Contents of the spray, (from a german safety datasheet):

Dichloride 50%-100%

Propan 10-25%

Methanol 1-10%

Toluol 1-10%

What about this workflow then: remove the majority of the CFA with the wooden tool without applying too much pressure in order to avoid scratching the sensor. Then apply dichlormethane to remove the leftovers with just a q-tip or sensor swab.

Just a thought

Edited September 1, 2013 by pixueto

[Luis Campos]

I MADE THE 450D SENSOR, IT'S ALIVE!!!!!!! HA HA HA.......

yes, it's true took me 6 hours but finally managed to debayer the 450D sensor, it is very good with only a couple minor scratches that dont even show up, I used the proven wooden tool, and another bonus...I removed the cover glass intact, it was glued like on the 350D but I worked all the way around with a thin x-acto blade to cut the glue around the glass, it begun to turn white, and with some patience I eventually removed it in one piece, very very happy with this one

Well, tomorow I will post some pics of the procedure but for now just check out these stunning macro shots, I'm BLOWN AWAY!

Cheers,

Luís

[Luis Campos]

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...

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

[Luis Campos]

THE END

I'm so sorry Gina...darn, if you lived nearby I would gladly try my luck on a sensor for you!

Have you tried the wooden tool, maybe you can try on the CFA leftover in one of the sensors just to see how it goes for you, I honestly believe this is the best method but it requires a very, very steady hand near the side and near the wires, i don't use epoxy or even a microscope, all is done by eye, and ocasionally with an inverted 25mm eye piece just to check for CFA leftovers.

Cheers,

[alistairsam]

I MADE THE 450D SENSOR, IT'S ALIVE!!!!!!! HA HA HA.......

yes, it's true took me 6 hours but finally managed to debayer the 450D sensor, it is very good with only a couple minor scratches that dont even show up, I used the proven wooden tool, and another bonus...I removed the cover glass intact, it was glued like on the 350D but I worked all the way around with a thin x-acto blade to cut the glue around the glass, it begun to turn white, and with some patience I eventually removed it in one piece, very very happy with this one

Well, tomorow I will post some pics of the procedure but for now just check out these stunning macro shots, I'm BLOWN AWAY!

Cheers,

Luís

well done Luis

way to go

when you say you scraped the edge with a knife, do you mean there was glue outside the glass edge that you scrapef away?

I must get myself a 450d. seems to be the best compromise for everything

14 bit, 12MP, decent pixel size, possibility of cooling, relatively low cost.

and I thought best to get two.

one for mono and other, remove the ir glass, and you'll have a spectrum enhanced camera for rgb data with rgb filters already on it

so rather than spending on a filter wheel and lrgb filters, just switch cameras for rgb data

and since the imaging scale is the same, easy to stack.

look forward to your images luis.

tonight is the first clear night for us in a month, so will try my debayered 350d and qhy8l

[alistairsam]

What about this workflow then: remove the majority of the CFA with the wooden tool without applying too much pressure in order to avoid scratching the sensor. Then apply dichlormethane to remove the leftovers with just a q-tip or sensor swab.

Just a thought

yep I like this workflow as well but rather than using the chemical, why not try gina's method with ajax and the cleaner? seems to do a clean job. maybe you could use a soft wood tip rather than a sensor swab. the wood should soak up the liquid and dispense with slight pressure.

[alistairsam]

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...

fantastic work filip.

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

[alistairsam]

hi Gina

this is the link to the exposure length calculator for ccd's

http://starizona.com/acb/ccd/calc_ideal.aspx

this has the actual formula which could be used for dslrs if you the dark current and read noise

http://www.wilmslowastro.com/software/formulae.htm

a lot of people I know use these to maximize precious imaging time using optimum exposure lengths to get the best out of their ccd

Alistair

[alistairsam]

Pixueto, this could serve as a guide for exposure lengths for uncooled mono dslr's.

• 
  Take 2N-1 exposures of t_ORN/2 duration.
  

In other words, if you determine the sky limit exposure time t_ORN to be 10 minutes, instead of taking five 10-minute exposures and median combining, take ten 5-minute exposures and use the Sigma Clip combine method. And be sure to dither the exposures. This will result in excellent noise reduction from all possible sources (assuming you take a sufficient number of dark frames, and taking a flat field or three couldn't hurt).

http://starizona.com/acb/ccd/advtheoryexp.aspx

[flolic]

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...

[flolic]

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

[Gina]

Yes Gina but the problem with the 350D is the glass covering the sensor. Apparently, it's one of the hardest to remove -that's why I haven't started debayering mine.

Yes, I realise that. The 350D has the advantage of larger pixels hence higher sensitivity, other things being equal but I'm not sure they are. It has the disadvantage of only 12bit data depth. Lack of live view would not be a problem for me. But I'm going for the 1100D as the most viable astro DSLR and I already have cooled ones. The other option would be to just replace the sensor in the "was working" 350D and sell that. Either option would mean that the non-working 350D on ebay would have to be available below a certain limit and current signs are that it will well exceed that. Edited September 2, 2013 by Gina

[Gina]

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...

That looks very good indeed As for filters, Baader do 36mm unmounted NB filters which are a considerable saving on 2" ones and well big enough for APS-C size sensors. I have Ha and SII but couldn't get the OIII. FLO are now showing them as available so I've just sent them an email to check.

[Gina]

I'm so sorry Gina...darn, if you lived nearby I would gladly try my luck on a sensor for you!

Have you tried the wooden tool, maybe you can try on the CFA leftover in one of the sensors just to see how it goes for you, I honestly believe this is the best method but it requires a very, very steady hand near the side and near the wires, i don't use epoxy or even a microscope, all is done by eye, and ocasionally with an inverted 25mm eye piece just to check for CFA leftovers.

Cheers,

Thank you Luis Congratulations on debayering the 450D - superb image So far I haven't found any wood hard enough to remove the CFA but the idea of using wood with abrasive is certainly worth a try. I use a magnifier/ring light anglepoise type lamp to see the sensors. Edited September 2, 2013 by Gina

[Gina]

hi Gina

this is the link to the exposure length calculator for ccd's

http://starizona.com...calc_ideal.aspx

this has the actual formula which could be used for dslrs if you the dark current and read noise

http://www.wilmslowa...re/formulae.htm

a lot of people I know use these to maximize precious imaging time using optimum exposure lengths to get the best out of their ccd

Alistair

Thank you Alistair

[Gina]

My plan now is to debayer one 1100D sensor and leave another as OSC. Both cameras cooled with Peltier TEC and cold finger with Arduino set point cooling. They will need a sealed and desiccated enclosure for the camera and sensor - I dont think it's possible to separate the imaging assembly from the rest enough to put the seal between. The debayered camera will have a filter wheel just outside the sealed enclosure with 36mm unmounted filters. Construction details will be posted in my own thread on debayered and cooled 1100D.

The two cameras will be used with a pair of matching SLR lenses to provide widefield imaging. My Atik cameras cover narrower objects such as galaxies.

I was impressed by how much more sensitive the camera was in the debayered area even on terrestrial colour images. The difference for NB I expect to be quite amazing as has been shown on here already. And as for noise performance, I have shown some time ago that exposures of 30-60 minutes could well be practical with the cooled 1100D .

[Gina]

The duff 1100D has arrived so I expect to try debayering it's sensor soon. I'll test the sensor in my working camera first, of course. Then there's the cover glass That'll be fun!! Have 36swg nichrome wire - have glass cutter - have craft knife. NOT using heat and NOT using epoxy resin. I'll use the filter frame to protect the fine gold wires and stay clear of the end with the tiny circuitry that's exposed. I'll be using Ajax in water and the paint cutting abrasive.