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Debayering a DSLR's Bayer matrix.


RAC

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So far no success in processing the data. First I tried to create linear tiff files with DCraw (same flags as Gina published some time ago) but DeepSkyStacker failed to find any stars. Strange as I can mark stars manually...

And when I fed it with raw files the final image is rubbish. I'll try later after some sleep and work. and thinking about changing settings and such.

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This is a great thread!

I'm in the process of doing this myself and have one question for you guys who have removed the sensor before.  When removing and reinstalling the sensor board from the main body, is there a more effective method for ensuring that the sensor is installed perfectly perpendicular to the optical axis?  I'm counting the number of turns from the screws when I take it out and measuring the length of the pegs, but I'm not sure this is the most accurate method.  I feel like even a slight misalignment will cause optical defects in the final image.

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10 hours ago, Gina said:

Canon use shims so if you keep them in position or mark which is which the orthogonality shouldn't change.

Thanks Gina,  at least on this 550D (t2i) there do not appear to be shims - or maybe I'm just thick.  I just see the sensor is mounted on three spring loaded mounting pins.  I'll give it a go anyway, thanks!

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After some more forum scouring it appears that the 550D and one other model are the only Canon DSLRs which use this setup (springs instead of shims) for mounting the sensor.  Oh well, I'm just going to set them back as close to the original configuration as possible.  I guess worst case is that I'll have to spend an extra night going back and forth between the workbench and telescope to get it perfect.

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Hello everyone,

I am new to this place .

 if  I read this post before I presume to make debayering !

I would save 2 sensors 700D : :(
But now it's done . I had seen the video of Russell , who  removal  cursed Sensor Glass seemed relatively simple.

But it does not come off even with a hammer .On the second sensor I had the patience to stay there at least 5 hours with butan pen. But nothing happened  . Now I'm waiting for a new 1100D  to test again . In recent days I came across this wonderful 3D and I have learned many things , I think.

But especially in many incredibly good people who  share their experience . You are fantastic!! I will update you with my misfortunes ! :)

 

clear skies

Franco

 

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Sensor manufacturers, models and generations have very different cover glass glues what comes to the release temperature.

Some of them just drop off easily while other stay stuck no matter how much you heat them. Be careful with the heat though. You know to have applied too much when SMDs starts to fall off ;)

Edited by Herra Kuulapaa
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So I finally got around to making my first attempt at the sensor modification.  It's great to have 92 pages of R&D to go on!  Just wanted to add some more bits on this chain to give back a little bit.  My first attempt was not a 100% success, but the sensor still works.  I've ordered two more sensors (just $100 for the pair) and feel much more confident now.  I plan to use the current sensor as a tester for any new ideas.

Cover glass and CFA removal for the 550D definitely seem to fall on the harder end of the difficulty spectrum.  Cover glass was on tight, but in the end defeated by a butane torch and a razor blade.

For CFA removal I first tried the scraping method using a wooden tool but did not have a lot of success here.  For the sensor on this model, the CFA did not break away as it seems it does on some other models and I felt like I was doing more harm than good.  See Image 1 for a representative flat taken after about 30 min of scraping.

You can see from that image that this also resulted in 2 dead rows of pixels.  Once I saw this I gave up any hope that I could limit this endeavor to just one sensor and became much more carefree about the whole process. So, I got out the dremel tool....

Using some glass polish and the felt polishing bit, I polished the CFA away using the dremel tool.  I also experimented with some glue to protect the gold wires.  I used Loctite Go2 glue and it seems to have worked fine.  I had been worried about the glue breaking the wires as it cured, but seems it's OK.

The other two images are a flat and dark frame after dremel polishing and glue application.  You can see I over polished in a few spots, and there's a hot pixel and row, but I'm confident I can mitigate those issues on a second attempt.  It could be better, but I'm hoping the lessons learned from the 'Mark-1' will translate into better results on the next go-around.  I plan to try some dry polishing using the dremel to clean up the edges.  If successful I may go without the glass polish on the next attempt.

 

Thanks again guys! 

Img_1.jpg

Img2.jpg

Img3.jpg

Edited by MattC867
fixed a typo
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On 2/12/2016 at 00:29, RAC said:

My 60d had springs.

Good to know.  I ended up deciding to put the camera back together without the springs.  I just screwed the sensor assembly tight against the body.  I'll keep the screws around in case I need to make any adjustments.  Have you had any issues?

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On 19/02/2016 at 16:07, MattC867 said:

Good to know.  I ended up deciding to put the camera back together without the springs.  I just screwed the sensor assembly tight against the body.  I'll keep the screws around in case I need to make any adjustments.  Have you had any issues?

 

I only even removed the IR filter with my 60D and that worked fine but I ended up selling the camera before really using it. The only camera I ever made mono was the 1000d in the first post of this thread.

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  • 2 weeks later...

Hello all.  I'm glad to have just discovered this thread.  I'm working on a water cooled and mono-modded 600D.  I've LPF2-modded a 550D and the 600D and have the water cooling fairly well sorted out. I was setting out on the mono-mod part of the project until I hit the dreaded cover-glass-over-the-sensor snag (!!!).  A little research brought me here, so I don't fee so alone out in the wilderness anymore ;) .  I'll read through all 92 pages of the thread, and I bought a spare sensor off the bay for $50 to practice, but I look forward to moral support an hearing about success stories.    

 

Larry

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Welcome, keep your head cool and good luck :)

Here's a small comparison between Nikon D5100 full spectrum standard firmware and astromono pure raw. Full spectrum is already without IR/AA filtering so it's sharper than regular to begin with. In addition there is a RGB pure raw to show RGB pattern in greyscale. Images are all at 300%. I must say that I'm impressed how good demosaicing algorithm really is :)

Yes, it's a bit large I guess..

Difference.gif

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Thanks.  I just finished reading EVERY page of this thread.  Wow! 

I saw only a couple of references to the 550D, but they did seem to be reporting success, but only reference cover glass removal by "heating".   Would anyone whose worked with this model  be willing to provide specifics on the methods: torch, re-work station, heat gun, soldering iron?

Otherwise, based on everything I read, I plan to debayer using the wooden tool method followed with polishing compound by hand. No epoxy and avoid the blue fringe by 1-2mm. 

 

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The model I've have most success with was the 450D.  The cover glass comes of without heat and just very careful use of a craft knife round the edge.

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Gina,  If I read everything correctly, the 550D requires heat.  But, I've scraped off the excess "glue" around the cover glass and am trying to slowly work a razor blade under the glass - no headway so far...

 

 

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Well, I planned to order out a rework station and a pen torch, but I decided that I would try to work the cover glass off with a razor blade.  Very slowly I began prying just a bit under the corners.  After a few minutes I could see a bit of "white" as the glue ever so slightly separates, but no more than 0.5mm or so from the edge.  Then all of a sudden I thought the blade slipped and I was about to loose my thumb and finger holding the sensor bracket, but in fact the glue had just gave way and the blade slid 3/4 of the way under the entire cover glass!  I was able to slide the blade all the way to one of the long edges before the glass cracked.  It took a bit more to get the last large piece detached because the blade did not want to go under the two remaining corners, but again, all of a sudden it just broke through the corner section and the last piece of glass just fell off.  I think the last piece of glass slightly bent a couple of gold wires when it flew off the bracket, but they are just slightly bent and it's possible they were that way before.

 

The last piece of glass also left just enough of a slight scratch in the bayer/ML that served as my starting point to start scraping.  Using Gina's idea (I think it was Gina's idea) to use the plastic filter holder as a shield, it took about 30 minutes ti scrape away the ML and the darker bayer layer.  I then used a Q-tip to wipe the surface with denatured alcohol, then polished the bulk of the surface with some old car polishing compound I had around, then DNA again, then wiped with a micro fiber cloth. 

There's a bit here and there still to remove and I only went close to the green boarder insider the blue boarder (why are there two boarders?). 

However... there's always a "however"... the underlying sensor looks pretty scratches up, presumably from the toothpick I used for scraping (I tapered the end to have a slight flat). 

The next step is to replace the working sensor in my 550D with this one to see if it still works and how bad the scratches affect the image (if there is an image !)

The broken cover glass pieces (all of them - no small shards) are above the sensor in the pics below.

 

FullSizeRender(1).jpg

FullSizeRender(4).jpg

FullSizeRender.jpg

Edited by LarryC
left out important detail.
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