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Debayering a DSLR's Bayer matrix.


RAC

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I notice that bright dot is aligned with the vertical dark line so I surmise that the damage that caused the line also caused the ultra hot pixel and that was during the coarse abrasive phase.

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Going through all my debayering stuff I've come across three 450D sensors.  Two are totally duff but the other is fine and has already had the cover glass removed.  So another candidate for debayering :)  I'm going to see if this sensor will succumb to the fine abrasive regarding microlenses and CFA.  Meanwhile, I've fitted it into my test camera and run a 10m dark.  As before, I used the maximum ISO of 1600.  Image stretched extensively to show the noise.  No bright dot at the bottom on this image and noise seems pretty constant across the frame :)

post-13131-0-69385600-1449951346_thumb.p

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I think the scraping method is better than the polishing method you are trying. Honestly I am surprised you are still trying I would of given up after 6 dead sensors.

if bits of glass are still stuck to the frame, take a flat screwdrier and heat it up on your stove till tip is red hot 

touch end of screwdriver to scrap of glass and it will eventually come loose, that is how I got rid of my left overs.

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I couldn't get the scraping method to work.  The scraper was either too soft and wouldn't touch the CFA or too hard and made deep scratches.  Polishing seems to leave the sensor clean and pretty flat.  I think flats will take care of the remaining variation.  Cover glasses seem to come off 450Ds without any problem and the CFA seems softer.  I don't think I'll be able to tell how well my debayered 450D sensors work until we get some clear night skies and I can try on some DSOs.  My MN190 is all set up and ready to go in the obsy - it would just be a matter of swapping cameras.

I expect to get back to 1100Ds shortly but want to see how well 450Ds do first.

Edited by Gina
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Actually, I'm thinking all of this is a waste of time and money unless and until we get some clear night skies!!! :rolleyes::huh:   It doesn't look like that will happen this year :(

Edited by Gina
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Well it looks like I can debayer the 450D sensor adequately but I see no point in proceeding any further until we get something I can test it on so I'm going back to my other projects.  In the meantime it's quite likely that my Baader 36mm unmounted OIII filter will turn up.

And having pretty much sussed out debayering the 450D I may think about a triple imaging system using 3 cameras.  I have bid for and won a 75-300mm Canon zoom lens so that (x3) could provide the optics.  I shall have to work out which DSOs the APS-C sensor and this range of focal lengths will accommodate.  I know a zoom lens is not ideal for AP but I can't find any prime lenses at a reasonable price.  Of course, two more SW Esprit scopes to go with the one I have already would be ideal but too expensive :D  The advantage of a triple rig, apart from triple light gathering, is that I wouldn't have to accommodate a filter wheel and a Canon lens can be attached directly to the mount, preserving optical alignment.  As can a telescope, of course.

As for the OIII filter and debayering, I think it's dubious that debayering would give much advantage in a triple imaging rig.  I know it will use only 3 of the 4 pixels in the quad and that sensitivity is reduced by being off-peak but the microlenses should make up for that and the sensor will effectively be binned 2x2 (almost).  The Ha should give the resolution.  But all this is up for experimentation later :D

On a general point - I'm finding it very difficult to generate any interest in astro projects with the continuing dull, dreary, damp and depressing weather and the nil prospect of any astro imaging in the foreseeable future :(

Edited by Gina
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t might be a challenge to get three zoom lenses all set to exactly the same f/l?

Search out the PrinzGalaxy 400mmm f6.3 - lots on ebay, affordable and it might stop you inflating the cost of s/h 450Ds while I'm looking for one. This is what I've managed with mine:

post-43529-0-28430000-1450005337_thumb.j

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t might be a challenge to get three zoom lenses all set to exactly the same f/l?

Search out the PrinzGalaxy 400mmm f6.3 - lots on ebay, affordable and it might stop you inflating the cost of s/h 450Ds while I'm looking for one. This is what I've managed with mine:

attachicon.gifAndromeda Galaxy M31 M32 M110_filtered.jpg

Very nice image :)  and thank you for the suggestion :)  And yes, I've thought of the problem of getting 3 zoom lenses to the same FL but it's not too critical - the software takes care of it and I'll just crop to the smallest image of the three.  I've finished bidding for cameras now :D

Edited by Gina
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  • 4 weeks later...

I'd like to share, once again, the key points of the conversations with couple of mod attempters.

1. Do not burn your sensor - It doesn't like that.

2. Do not damage the golden bonding wires - They're in fact there for reason.

3. Do not scrape the blue/yellow border areas - There are things that are not there for aesthetics.

And you are in trouble if you break any of these rules! So be careful!

Micro_1.jpgMicro_2.jpg

Edited by Herra Kuulapaa
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Cheers all!  I've been following this thread with great interest for some time.  After a month+ of rain and scraping the ice off my windshield here in 'warm, sunny Florida' in the U.S., I decided the only way I'm going to fulfill my astronomy interests for the foreseeable future is to butcher a camera.  I have a stock 6D, a 60D with a full spectrum mod pending and a 40D that was modded with a Baader filter some years ago.  Soooooo I decided it's time to attempt Bayer filter removal on the 40D.  Just ordered a spare sensor ($40US) because I looked askance at the gold wires on the original and scared the hell out of one, so it broke.  I've no hope of fixing that, but it gives me a test subject for Bayer removal, and $40 is a fair price for admission.  Cover glass came off the sensor rather easily with a gentle persuasion from a razor blade, gradually worked two corners and the side between them loose, used a toothpick to dribble some acetone at the edge of the cover glass, it wicked under the glass and shortly after that the whole thing just popped off.  Neither plastic nor wooden tools helped much for microlens/Bayer removal, time to try a Dremel and polish.  My goal is to get comfortable enough with this to try it on an XSi(450D) or maybe T2i(550D).  I'd like to have one body that is more or less full resolution Ha/SII sensitive, the 6D and 60D do fine for visual/OIII.  The camera disassembly / standard filter removal mod is relatively straightforward, rule #1 is keep the cat out of my work space.

Ed Magowan

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Hi,


i´d like to share my experience. i did many tests with different canon dslr sensors and it seems that every sensor is a little different with scratching. i didn´t get a real good result. either the sensor was death or had sratches, but no one was useful. so i start to give the polish method a try. What can i say? every sensor i debayered was a fully success. so here is my howto list:

- remove the sensor and the top glass (heat helps a lot to do this)

- use "uhu endfest 300" for the bonding wires to protect

- use some leather rods, meguiars plastx and ethanol (to thin down the plastix) to remove the microlenses and the cfa (takes 30 minutes for rough pollish)

- q-tip, plastx and ethanol for fine polish the hole sensor

- ar-coated glass from edmund for top cover

- ar coated glass with heating wire instead of the shutter cleaning piezo and low pass filter


Here some pictures (sorry for the bad "screenshots"):


Picture of a streched flat before i fine polish the sensor extensively:

4swf-174-d13c.jpg


Here after 10 minutes fine polish, both picture are streched to max in fitswork:

4swf-175-49cf.jpg


Heres the first test, 5 x 600 seconds with 12nm h-alpha filter (without cooling):

4swf-173-2cc8.jpg


So after this successfull test i start to build the active cooling with a high quality 2 stage peltier from quick-cool. these peltiers are much more efficient than the cheaper chinese ones. many parts are made out of carbon fiber. there is also an arduino controller for the little display i added inside the flash-head. here´s a picture of the nearly finished camera:

4swf-178-f8aa.jpg


and here the display in detail, it shows the sensor temperature, the surrounding temperature, air pressure and the current through the peltier. i get a delta of nearly 30°celsius:


D=Digital

a= astronomy

c= cooled

m= mono-debayered:


4swf-17a-5b00.jpg


markus
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I’ve been using a CNC to remove cover glasses from D600/D800 sensors, but the issue has been the brittleness, high risk and cost of this method. You may have noticed that the cover glass material is almost like tempered glass, hard and brittle. But what if we could use it for our benefit?

Issue with the Nikon FX sensors (D600/D800) is the high release temperature of cover glass resin. Enough to kill the sensor :( So I tested a heat shock approach with a frozen D600 sensor on molten lead bath (>330C). Cold cover glass pressed gently on molten lead so that the heat shock can work through the glass. Not a very delicate method I know and there is a risk involved, but it worked. Sensor survived it and is fine.

Glass is shattered into small pieces with this method. It stayed in one piece on sensor though so I sucked it off with a vacuum cleaner without shards rolling on sensor surface/bonding wires. I really don’t know if this is a viable method in long run and what kind of risk it holds, but an interesting test anyway. I'd consider the eye protection very important if you wish to pursue this method.

By the way I have one CNC processed fully working completele flat field Nikon D600 mono sensor without any use for it if anyone is interested. :)

Edited by Herra Kuulapaa
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Very interesting Herra :)  Now that is really brutal :D  I'm going for Canon EOS 450Ds for debayering but may attempt 1100Ds again later.  The cover glass on the 450D can be removed without heat with a craft knife worked carefully round the joint :)  I haven't had quite as much success removing the CFA though and produced some damage on the two sensors I have worked on recently.  I hope to be testing these with a Baader Ha filter mounted on my EQ8.  Tries with the NEQ6 indoors through a window were unsuccessful as the mount wasn't polar aligned - the EQ8 is.  I'm hoping the ground is firm enough to get out to the observatory tonight or whenever we get a few hours of clear night sky.  Orion is in a favourable position to try this on M42 :)

Edited by Gina
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Been taking my gear back out to the observatory but realised I need to sort a few things out before I can test the debayered camera attached to the EQ8 mount, so I think I may get set up with an Atik camera and check that I can get things to work after goodness knows how many months since last time.  The power system is set up for use with the MN190 ATM and will need a new box for connecting the 450D.  The current box is attached to the MN190 dovetail bar.

If I can find the right adapters I should be able to hang the 450D off the MN190 for first tests (that's f5 which is much the same as the tele-zoom lens).  This scope is equipped with OAG and guide camera so guiding should work.  This will mean I can try longer exposures without worrying about eliptical stars (though if the polar alignment is good enough it might not be necessary with this size image sensor).  Exposure length will be determined by noise as I haven't arranged cooling yet.  Mind you the ambient temperature won't be much above freezing :D  The filters are 1.25" so may get some vignetting - I have Baader 36mm filters for the "proper job" with DSLRs.

Edited by Gina
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Not sure if it will be of interest to you Herra but full frame has been reckoned to offer 2 to 3 stops better noise performance than APS.  There is a problem though. As their pixel count gets higher and higher that becomes less true. Where is was true is cameras such as the canon 6D but at the 3 stop level even that one may be dubious. In the case of levels like the D800 one of the aims seems to be to do away with the anti aliasing filter as the lenses do that anyway. It looks like this has been absent on compact cameras for some time.

All very confusing though. Sensors have improved but so has noise removal software. I own an interesting example of the effect. A Nkon V1 with CX sensor. They did a cheaper Nikon 1 with less pixels and lo it has less noise too. My most used "dslr's" now are olympus m 4/3. I haven't touched aps for some time now.

The 6D isn't very well rated by serious photographers - af and etc is too simple. My last ff was a 5D and no interest any more so no idea of used prices.

John

-

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Not sure if it will be of interest to you Herra but full frame has been reckoned to offer 2 to 3 stops better noise performance than APS.  There is a problem though. As their pixel count gets higher and higher that becomes less true. Where is was true is cameras such as the canon 6D but at the 3 stop level even that one may be dubious. In the case of levels like the D800 one of the aims seems to be to do away with the anti aliasing filter as the lenses do that anyway. It looks like this has been absent on compact cameras for some time.

All very confusing though. Sensors have improved but so has noise removal software. I own an interesting example of the effect. A Nkon V1 with CX sensor. They did a cheaper Nikon 1 with less pixels and lo it has less noise too. My most used "dslr's" now are olympus m 4/3. I haven't touched aps for some time now.

The 6D isn't very well rated by serious photographers - af and etc is too simple. My last ff was a 5D and no interest any more so no idea of used prices.

John

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Hi John,

Yes, they (D600am and D800am) are performing very well. I've been using them in true raw mode in which all raw data manipulation has been disabled.

I was actually expecting Nikon D600 to be slightly better in terms of noise based on larger pixels 6um vs 4.88um, but haven't seen any real noise difference, resolution is of course larger.

http://stargazerslounge.com/topic/250891-nikon-d600-monochrome-images/

http://stargazerslounge.com/topic/256183-california-ha-nikon-d600am/

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I feel as Gina always needs some encouragement. :happy8:

My

1st sensor: shows some image in live view but unable to take a shot. damage during the process (scratched the edge?)

2nd sensor: dead before I started (unfortunately water damaged camera) but scraping went well

3rd sensor: I broke sensor surface with screwdriver when removing pieces of cover glass

4th sensor: glass smashed into pieces, CFA scratched off with wooden stick but impatiently - leaving about 10% of CFA all over + edges. I tried to clean the rest with white spirit but not successful (some disappeared). Still working but unusable without further treatment. Sensor showed some weird red noise in long exposures before my attack (shortage with thermal compound) = test sensor.

5th sensor: glass broken again, sensor not working at all though wires and surface intact. Too much heat applied I guess. First time I managed to break the bound on one edge of glass without tipping it. Remaining sides were worse then ever = shatter. I'll keep it untouched to test that Meguiar's plastX once I get that. If successful than return to number 4.

Sensors number 6, 7 and 8 are waiting for their time to come. All are from Sony nex 5 or 3 (similar sensor). Once I develop reliable technique I plan to start with Nex 5N - that sensor is much much better (more sensitive, less noise - but that might be just because it's -10°C or less...).

But I'm not giving up! :icon_razz:

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