Gina

That looks well baked - nice and brown

Thank you Russel I think I'll have another go but with a lot less cooling. I thought the thermal gradient would help with the glass removal but it didn't - I think it may have caused the glass to crack. Last time I tried this I just had the cold finger attached to a large heat sink - no active cooling. Did the sensor work after you "cooked" it?

Thank you Louise I've checked all the settings. Now with the same camera and ribbon cable, just swapping sensor assemblies, the untouched one is working fine with EOS Utility but the one I removed the cover glass from is giving Err 70 and a black/blank image. I have yet to comfirm this with the other camera. Edit... Same now confirmed for the other camera - untouched sensor works - glass-less one doesn't. I conclude that I have proved beyon all reasonable doubt that the sensor sans glass is dud That is as far as I am going today. I now have two cameras with untouched working sensors that I have available for AP (in addition to the one I use for general photography). If I want to keep one for OSC that leaves just one for debayering. The "Last Chance Saloon" beckons

I took the cold finger out and swapped the ribbon cable for the one out of the working camera, checked all the ribon connections and it still gives "Err 70" after displaying a black image. So I think I have to assume the sensor is faulty. I've had another close inspection of the sensor and gold wires and it certainly looks like all the gold wires are intact with no sign of disconnection of any of them but there are a couple of scratches on the surface of the sensor that show as little gold lines. I wouldn't have thought that little bits of glass touching the sensor would go very deep but who knows - a candidate for sensor destruction I guess I can't see that it was the heat that did it in view of the cooling - there was ice on the cold finger. My only though is - could it be too much thermal gradient?

Thank you Louise Yes, you're right, that error can also be due to a bad connection or broken ribbon cable etc. so I'll carry on checking.

EOS Utility works fine with the working camera. But the one with the cover glass-less sensor takes an exposure, displays a black picture and says Err 70 (which means sensor fault). So it seems I've succeeded in destroying yet another sensor I guess one of those dreaded gold wires must have suffered even though they look fine. I don't think the sensor got overheated with all that cooling and ice on the cold finger.

Tried with a known-to-work camera and getting the same problem with APT So this seems to indicate it's not the sensor in the other camera. Possible culprits :- APT settings (not been altered), laptop, USB cable, "the nut behind the wheel" (me).

I have the camera back together but without the cooling as there's no point in testing with cooling unless the sensor works without it ATM I'm having a problem with the camera. I can't get it to work properly with APT - takes an exposure sometimes but then says "Busy" and won't do anything I've checked the ribbon cable connections and they seem alright. I'll do some more checking - I can't blame the sensor quite yet.

Thank you The 1100D has the most difficult cover glass to remove of all the Canon DSLRs I reckon I have worked on 300D, 350D, 450D, 1000D and 1100D, and the 1100D is the worst by far. With some such as the 450D, the cover glass comes off without heating quite easily.

Well the cover glass is all off now - in lots of bits Close inspection shows that all the gold wires are intact I have now replaced the filter frame complete with filters to protect the sensor and gold wires while I reassemble the test rig and see if the sensor still works. The cooling caused some condensation on the sensor so the image won't be perfect but the water marks will clean off after I've applied the epoxy resin - I'm not going anywhere near those fragile gold wires! PHEW!!! That was hairy

Cover glass removal in progress Procedure on hold ATM due to district nurse tending to Tim. Glass has cracked but the glue has turned white so I expect it will come off. I'll tip it up more though to avoid any pieces of glass touching the gold wires. Not bothered about cracked glass as I already have two spare ones. Fortunately they're all the same across the Canon models I have

Here's a couple of photos of my rig.

Thank you Russel - that's very helpful - little bits of heating, long and slow

I now have a rig set up for removing the cover glass. I have arranged cooling of the sensor using the cold finger, TEC and CPU cooler with the sensor assembly with CF held onto the TEC etc. with wire. (Elastic bands are unsuitable with a blow lamp around ). The cooler is placed on the copper box from the 450D project to raise it off the table. The cover glass is tipped slightly forward of vertical to help it fall away from the gold wires. My heart will be in my mouth shortly

Absolutely amazing piece of work and image Congratulations! :icon_salut: Truly "out of this world" in both senses

5m subs at ISO 6400 is beginning to show noise CF showing -7C. Anyway, I think all this proves the sensor is fine at -8.5C which is good enough, so I think I can move on to the next stage - removing the cover glass

With nighttime approaching I can get 2m subs with little illumination showing up so I'm now running 5 min subs. A few hot pixels are beginning to show up With no imaging I'm getting -8.5C but with continuous imaging the CF temperature drops tp -7.5C. Once I get proper thermal insulation I'm sure I can get down to -10C sensor temperature which is quite sufficient Edit - 5m @ ISO800 is fine so I've upped the ISO to 3200.

You can control the power input to the TEC using a power MOSFET driven from one of the PWM outputs of an Arduino - see circuit diagram in my 1100D debayered with added cooling, FW and OAG thread. With such a high power and inefficient TEC you will need a very good cooler to get rid of the heat from the hot side.

Now have cooling added to the test rig though without any thermal insulation so the cold finger is gathering a thick layer of ice. I am obtaining -8C on the CF with ambient temperature of 23C. So that's a delta T of -31C. I'm running 60s exposures using APT and the 1100D sensor is fine. Without the camera being in a box there is considerable light leakage and the image is showing a medium brightness at that exposure. I'll add some plastic foam as thermal insulation and see if I can get down to -10C on the CF. May also add a DS13B20 digital thermometer to the heatsink to see just how well the cooler is working. I using the MCPE-127-10-25 - PELTIER COOLER, 19.6W with 60x60x40mm finned CPU cooler with fan as shown in my 450D cooling thread. I'm running the TEC at 15v and 1.75A - just below it's maximum rating.

I've tested the white light flats and have a working setup with standard Canon zoom lens and tissue held on with elastic band. Using APT to control exposure and capture data. I need to clean the sensor cover glass before using the results as there are several bits of dust on it. Probably the best time to take the calibration data would be after removing the cover glass or after adding the epoxy resin ie. just before attacking the sensor surface.

Thank you - I'll take a look at RawDigger - looks like the very thing I'm not sure about the antireflective layer - depends on how things go. It may turn out that it gets removed in places anyway. But I'll certainly keep it in mind and make a decision later.

I shall be setting up a proper test rig with cooling to test the sensor at each stage of debayering and will post the results. I will post the details of the cooling system in my own 1100D debayering, cooling, FW and OAG thread and keep this thread on topic with debayering info only.

I intend to debayer half the sensor area too - with an 1100D sensor. I will also provide and area where just the micro lenses are removed. Then for testing I will use white light for one test with diffuser over lens to provide a flat. I propose to repeat this test with an Ha filter in the light path and again with SII and OIII filters. I will then see if I can take the various image areas and select a few pixels from each and make a composite image with these adjacent to each other. The comparison of untouched sensor with the CFA and micro lens removed areas will be the most interesting. It would be nice if I could find a way to actually measure the image brightness for these areas. Oh, and flats taken before any debayering to confirm that the sensor area that will be debayered is actually the same sensitivity as the other side.

I was going by figures and graphs posted above but once I get a part debayered 1100D sensor I shall be able to do some tests. Then we shall see Someone else could well beat me to it though

As I said above, if you want to use the camera for RGB only there would be only a small benefit i debayering and not worth the effort. But if you have the actual resolution from the sky and optics you are using then using a debayered camera for luminance will double the resolution in both axes and if this is used to control intensity in the RGB colour image obtained from an (unmodified) OSC camera then the overal perceived resolution is increased. Narrow band is a totally different matter. The sensitivity of the red pixels is increased for Ha by removing micro lens and red CFA filter. The increase is even more for SII and for OIII it is increased slightly due do the wavelength falling on the sides of the G and B spectral responses. Having two green pixels per quad halps with OIII in the OSC version but by my reckoning this doesn't quite make up for the attenuation from the colour filters. The improvement in sensitivity for Ha and SII is considerable - being around 2x. Then on top of this we have four times as many pixels receiving photons giving the aforementioned increase in resolution. If binning were possible with a DSLR we would gain 3 stops for the same resolution by binning 2x2 over the OSC version.