Debayering a DSLR's Bayer matrix.

[russellhq]

SMDs! Better not file them away then

[Gina]

I've edited the post to show the photos.  NO don't file them off

[Gina]

I use some thin, hard plastic to keep the cold finger away from those tiny SMDs.  This was from offcuts from secondary double glasing sheet but any thin, hard plastic will do.  I made a T shaped piece so that the lugs stuck out beyond the gap and stopped the plastic sliding in too far when inserting the CF.  Plastic in first then CF between plastic and sensor with thermal paste on the CF.  The SMDs and plastic insulation limit the thickness of copper sheet for the CF - I used 0.7mm.  In spite of the thin copper I managed to get the get the temperature down to -15C with an ambient of +14C.

[russellhq]

I use some thin, hard plastic to keep the cold finger away from those tiny SMDs.  This was from offcuts from secondary double glasing sheet but any thin, hard plastic will do.  I made a T shaped piece so that the lugs stuck out beyond the gap and stopped the plastic sliding in too far when inserting the CF.  Plastic in first then CF between plastic and sensor with thermal paste on the CF.  The SMDs and plastic insulation limit the thickness of copper sheet for the CF - I used 0.7mm.  In spite of the thin copper I managed to get the get the temperature down to -15C with an ambient of +14C.

Thanks Gina, just the info I was after. I've been prototyping with 1.2mm copper (which is a pain to bend!) and that's a tight squeeze with the dead sensor. I've ordered some 0.55mm copper and 0.5mm plastic which should sort me out. I think I'll use double sided tape to secure the plastic in place before sliding in the cold finger. I probably put electrical tape on the back of the CF for a bit of extra protection as well.

[GuillermoBarrancos]

Man Man.... what a work!   The more I read..... the more I keep saving up for a Nice mono CCD camera instead.

[Gina]

Man Man.... what a work!   The more I read..... the more I keep saving up for a Nice mono CCD camera instead.

Good thinking   Mono CCD cameras are great and more sensitive than DSLRs though the image sensor is often smaller, depending on how much you pay.  We who are doing this debayering project are dedicated DIY nuts (or machochists) - with apologies to the others - I'm really just speaking for myself   I'm an addict for difficult projects

When you save up enough I can definitely recommend Atik mono CCD cameras.  eg. the 460EX is very low noise and one of the best.

Edited May 5, 2014 by Gina

[GuillermoBarrancos]

Good thinking   Mono CCD cameras are great and more sensitive than DSLRs though the image sensor is often smaller, depending on how much you pay.  We who are doing this debayering project are dedicated DIY nuts (or machochists) - with apologies to the others - I'm really just speaking for myself   I'm an addict for difficult projects

When you save up enough I can definitely recommend Atik mono CCD cameras.  eg. the 460EX is very low noise and one of the best.

I already have a list of 3 potential CCD candidates. G2-8300, G2-4000 and 460EX.

[pixueto]

Dear all,

I've been pretty busy these days with the monochrome mod. This is what I've found and where I am at the moment:

-I have debayered a Canon 1000D with the rotary tool method and the felt tips without leaving any CFA leftover. Now I am in the process of achieving a perfect flat frame throughout the sensor. I have achieved this in the central area of the sensor  (I didn't go any further yet as I wanted to avoid damaging the delicate edges. I wanted to check if the sensor would take it). So, it is then possible to achieve a perfectly uniform debayered sensor. The trouble is finding the right tool to go near the edges to remove the final anti-reflective coating -I have tried the dental silicone tips that Rinaldo suggested but they are too hard and will damage the surface (I tested this in a duff sensor). The rubber tips won't do either. It seems to me that the felt is the only option. I need now to find a high precision felt tip. The CFA in the 450D sensor is very similar to the 1000D so these results can be applied to that camera.

The canon 350D is a completely different type of beast. The CFA is much, much weaker and the rotary tool will damage the sensor very easily. I think the solvent approach might work with the 350D. Taking into account how much different the 350D is from the 1000D and 450D model, it is possible that the CFA on the 1100D sensor is very different too but I haven't tried with a 1100D yet.

Finally, after what has been discussed here, I am a bit confused. Maybe you can help me with this. It has been said that the loss of the microlenses could account for 30-50% of the sensor sensitivity. Yet, here you have a comparison of pictures taken with my 1000D debayered and a Baader modified 450D. Even if the cameras are different, I would expect the 450D to be superior to the 1000D so I think my point stands. These are the set of photos in twos; comparing both cameras: greyscale camera jpeg from the 450D versus custom WB jpeg from the 1000D. Also raw from 450D versus raw from debayered 1000D. I think they are interesting. How is it possible that the 1000D has lower sensitivity if in all the comparison photos, the result is invariably brighter? By the way, all photos have been taken with the same lens and the same settings: ISO 200, F5:6, same speed (I don't remember now)

Sorry about the debris in the 1000D. I haven't cleaned it properly as this is an ongoing project. As I said; it is only the central area, where the camera has been not onl;y debayered, but with the entire anti-reflecting coating removed completely without any visible damage.

Edited May 5, 2014 by pixueto

[Gina]

Um... I see no ships... I mean images....

[pixueto]

First jpeg files right from the camera: grayscale Baader modified canon 450D and debayered 1000D with custom WB to get a grayscale picture for comparison:

[russellhq]

Finally, after what has been discussed here, I am a bit confused. Maybe you can help me with this. It has been said that the loss of the microlenses could account for 30-50% of the sensor sensitivity. Yet, here you have a comparison of pictures taken with my 1000D debayered and a Baader modified 450D. Even if the cameras are different, I would expect the 450D to be superior to the 1000D so I think my point stands. These are the set of photos in twos; comparing both cameras: greyscale camera jpeg from the 450D versus custom WB jpeg from the 1000D. Also raw from 450D versus raw from debayered 1000D. I think they are interesting. How is it possible that the 1000D has lower sensitivity if in all the comparison photos, the result is invariably brighter? By the way, all photos have been taken with the same lens and the same settings: ISO 200, F5:6, same speed (I don't remember now)

You are probably experiencing differences in brightness because you are not imaging the same scene with the same settings and sensor.

My previous post demonstrated the sensitivity loss on the 1100D to be around 50% on a pixel by pixel basis. In this case, I used a camera with a sensor that had half of the CFA removed, this guaranteed that the same settings and light conditions were seen by the debayered and original pixels. I also used narrowband filters to ensure a straight comparison could be made between the pixels with CFA and those without. The RAW images files are linked to at the bottom of the post if you wish to inspect them.

http://stargazerslounge.com/topic/166334-debayering-a-dslrs-bayer-matrix/page-81#entry2308747

[pixueto]

And now the raw files right from IRISwithout any adjustment whatsoever (resized to 50% and converted to jpeg):

[pixueto]

Guys, the settings are the same: ISO 200 Speed 1/125 F5.6 Same lens

I'm not contesting that there is a loss of sensitivity brought about by the removal of the microlenses. I just want to make sense of all this.

Edited May 5, 2014 by pixueto

[pixueto]

You are probably experiencing differences in brightness because you are not imaging the same scene with the same settings and sensor.

My previous post demonstrated the sensitivity loss on the 1100D to be around 50% on a pixel by pixel basis. In this case, I used a camera with a sensor that had half of the CFA removed, this guaranteed that the same settings and light conditions were seen by the debayered and original pixels. I also used narrowband filters to ensure a straight comparison could be made between the pixels with CFA and those without. The RAW images files are linked to at the bottom of the post if you wish to inspect them.

http://stargazerslounge.com/topic/166334-debayering-a-dslrs-bayer-matrix/page-81#entry2308747

All the parameters are the same, apart from the sensor and I don't expect this to be a factor that influences the result that much. When I first debayered my 1000D, I couldn't use the auto settings as all the photos would invariably come up overexposed; I had to go to manual and lower the ISO or speed to get the right composition so, with the same settings than the stock camera, the photos definitely turn out overexposed. 

Now, doesn't that mean that the sensor is more sensitive to gathering light? If not, what's going on here? I'm trying to understand this.

We knew the removal of the microlenses would bring about a loss in sensitivity but we also knew that the removal of the CFA would increase it. This is more in line with what I would expect. Nevertheless, the tests with the narrowband filters in the 1100D show a different story and I don't really expect the results for the 1100D to be very different from other cameras, really.

I have a 7nm H alpha filter and I'll be able to replicate those with the 1000D but I need a stock1000D for that. If I manage to get perfect flat frames by removing the entire anti-reflective coating all over the sensor then I might get another 1000D. The idea is to do H alpha with the debayered camera and 'colour' the picture with the stock 1000D.

Edited May 5, 2014 by pixueto

[Luis Campos]

Hi guys!

Been awhile

By now I've debayered quite a few sensors (350D, 450D, 1000D, 1100D) and what I founs is this, the older cameras with bigger pixels do have a gain is sensitivity due to the large pixel size, the loss of microlenses is offset by the removal of the CFA and by quite a bit specially on the 350D, the 1000D is also very noticeabble as Pixueto has pointed out, it is correct that the light meter does overexpose the images on a debayered sensor, so this means that there is a gain in sensitivity, also I have some images done with half sensor debayered that prove this

For the "newer" cameras there is a very slight loss in sensitivity unfortunately, but it's not much but for me exposing maybe 10% more and get a full resolution image in narrowband full of detail is well worth the slight sensitivity loss

BTW, the 1100D sensor is BY FAR the most difficult one to debayer, the CFA is so stuck to the surface that is really complicated to remove!

Best,

[Luis Campos]

BTW, check here the last image of M51 I did last saturday with my cooled mono 450D:

http://www.astrobin.com/94428/0/

Cheers

[russellhq]

Guys, the settings are the same: ISO 200 Speed 1/125 F5.6 Same lens

I'm not contesting that there is a loss of sensitivity brought about by the removal of the microlenses. I just want to make sense of all this.

I would hazard a guess that as you are gathering 50% more red light and 50% more blue light and have no loss of green light, then since you're imaging sun light your image will be brighter with the debayered sensor.

[pixueto]

Hi guys!

Been awhile

By now I've debayered quite a few sensors (350D, 450D, 1000D, 1100D) and what I founs is this, the older cameras with bigger pixels do have a gain is sensitivity due to the large pixel size, the loss of microlenses is offset by the removal of the CFA and by quite a bit specially on the 350D, the 1000D is also very noticeabble as Pixueto has pointed out, it is correct that the light meter does overexpose the images on a debayered sensor, so this means that there is a gain in sensitivity, also I have some images done with half sensor debayered that prove this

For the "newer" cameras there is a very slight loss in sensitivity unfortunately, but it's not much but for me exposing maybe 10% more and get a full resolution image in narrowband full of detail is well worth the slight sensitivity loss

BTW, the 1100D sensor is BY FAR the most difficult one to debayer, the CFA is so stuck to the surface that is really complicated to remove!

Best,

Thanks Luis. have you removed the anti-reflective coating in those debayered sensors? I suppose flat frames can sort out imperfections but I'm  obsessed with having a nice perfect golden sensor.

BTW, you wouldn't have a tutorial for a deep cooled 1000D, would you? I haven't found anything online for this model.

Edited May 5, 2014 by pixueto

[Luis Campos]

Thanks Luis. have you removed the anti-reflective coating in those debayered sensors? I suppose flat frames can sort out imperfections but I'm  obsessed with having a nice perfect golden sensor.

BTW, you wouldn't have a tutorial for a deep cooled 1000D, would you? I haven't found anything online for this model.

Hi,

No I do not remove the clear coat, with the scarping method it stays there, it can have some micro scratches but they don't show up on the final callibrated image, nor the litle specs of CFA, so don't get too obsessed with that, if you do you will kill the sensor Just make sure you dither the subs quite agressively and you will be ok.

The 1000D is exactly the same as the 450D, so any on the 450D will be apliable on the 1000D

Cheers

[Gina]

Hi guys!

Been awhile

By now I've debayered quite a few sensors (350D, 450D, 1000D, 1100D) and what I founs is this, the older cameras with bigger pixels do have a gain is sensitivity due to the large pixel size, the loss of microlenses is offset by the removal of the CFA and by quite a bit specially on the 350D, the 1000D is also very noticeabble as Pixueto has pointed out, it is correct that the light meter does overexpose the images on a debayered sensor, so this means that there is a gain in sensitivity, also I have some images done with half sensor debayered that prove this

For the "newer" cameras there is a very slight loss in sensitivity unfortunately, but it's not much but for me exposing maybe 10% more and get a full resolution image in narrowband full of detail is well worth the slight sensitivity loss

BTW, the 1100D sensor is BY FAR the most difficult one to debayer, the CFA is so stuck to the surface that is really complicated to remove!

Best,

Thanks for that and welcome back Luis   You're certainly right about the 1100D - not just the CFA but the cover glass is super-stuck on - with a vengeance!

[Davey-T]

Does anyone the power consumption in amps of a cooled DSLR  ?

Dave

[pixueto]

Thanks for that and welcome back Luis   You're certainly right about the 1100D - not just the CFA but the cover glass is super-stuck on - with a vengeance!

It can't be harder to remove than the glass in the 350D! I nearly fried the sensor with the blowtorch and yet, I  couldn't remove it in one piece!

Edited May 5, 2014 by pixueto

[russellhq]

Does anyone the power consumption in amps of a cooled DSLR ?

Dave

A 2A TEC seems to work. So TEC + fan + camera + controller would be about 3A.

[Gina]

Yep

Edited May 5, 2014 by Gina

[Gina]

It can't be harder to remove than the glass in the 350D! I nearly fried the sensor with the blowtorch and yet, I  couldn't remove it in one piece!

I have various other camera models that I can debayer, I think, so I might have a play with those - all good fun   I'll see what I can find.   I have bought 300D, 350D, 450D, 1000D  and 1100D models.  Trouble is, some are in bits and I may have a problem working out which bits go with which

Actually, some more practice on other sensors would be a help before I go further with the 1100D one, now that I have more facilities.

Edited May 6, 2014 by Gina