pixueto

yes I dont think its worth risking it with the epoxy

if you start scraping from the middle with the lowest mag on the microscope you should be able to control the hand movements so you avoid the wires.

I just got my 600d replacement sensor so will be try the heat gun to get the glass off and a wooden tool.

the sensor unfortunately has a column defect so there's a line but it'll do.

pixueto, I'd suggest keeping subs to 8 mins max to keep noise manageable

cheers

Alistair

I tried 10 minute subs and the histogram was to the left at the edge; even with 20 minute subs, the histogram was at about 1/4 to the left of the horizontal axes. It goes without saying that the noise was terrible.

This is new territory for me guys. I always try to get the histogram at about 1/3 to the left of the horizontal axis. Alistair, Luis, if I limit the exposures to 8 minutes, is that going to be good enough? As I said, the histogram was completely to the left.

Thanks

That epoxy is the prime suspect now that heat is out of the equation particularly considering how badly I've treated my 1000D sensor and it's still working.

Thanks Luis. Could you elaborate on this?

'next input a generic name, this is what I do, I put "A" on input and "B" on output generic name and so on, so the previous output generic name will be the input generic name on next step, go for a, b, c, d ,etc...'

Can you explain those steps? Not sure what I'm supposed to do with input the previous output?

I have now the ED80 out with the 1000D debayered and a 7nm H-alpha 2" filter. I'm taking 20 minutes subs. We'll see what comes out.

Gina, try to avoid scratching the sensor as those will come up in your subs. See attached a 4 min sub with the monochronme sensor. If you stretch it you'll see the scratches and defects. What I don't know is if the flat frames will correct them. I'm still trying to get IRIS to stack the control frames.

Hi Luis, I'm obviously doing something wrong when stacking in IRIS. This is what I got with a stack of only two images (you can see they aren't properly aligned). used 9 offsets, 9 darks, and 9 flatframes. I think I did what I'm supposed to do but, obviously, the result isn't right.

I had a couple of doubts:

-when preprocessing it asks for an 'output generic name'. Where does this file go? What about the cosmetic file? What's that for?

-for 'add a sequence' what's the 'input generic name' ?

-for 'stellar registration', what should I choose for 'input generic name' and 'output generic name? Should I tick the box for 'select a zone'?

Thank you very much for your help. Inow know I'm close to successfully processing this in IRIS but I'm finding the different file options confusing.

Hi Gina, as Alistair has said, the glass covering the sensor in the 1000D is the easiest one to remove. Proceed with caution, though. You should be able to remove it intact.

As for the removal of the CFA, you may want to wait until I finish processing the subs with my debayered 1000D (Luis is giving me a hand doing this with IRIS as DSS is no good for that). I took those the other day with an astronomik light pollution CLS clip filter and the SW200P. My results may help you avoid some of the mistakes I've made. You'll see in my pictures that the scratched areas do come up but the uneven illumination should be sorted with the flats which the computer seems to be able to process.

I used the wooden tool and then fine car windscreen polish and isopropanol to remove and clean the CFA leftovers. I made some scratches and left the sensor a bit uneven in the middle central band but there are intact areas so there must be a way of producing an entire clean debayered sensor. Tonight, if it's clear, I'll take some subs with the 7nm Baader H-alpha CCD filter which just arrived today.

Hi Luis, managed to get the thing working. I have some questions, though. When I go to preprocessing, there are several options; I went for automatic preprocessing 1, I think.

Also for stellar registration, Iris is asking me to enter the name of the original file/files? Are those the light frames?

Obviously, I'm doing something wrong as the final image is completely white but the individual lights are OK -however, once saved and brought to Photoshop, it seems to be fine.

Thank you for your help

Hi Luis, I'm dragging the raw files to the box but it won't take them. Any idea about what the problem may be?

If I understood correctly, the lights are processed at the end; not at the start, right?

Hi, great to hear you have a working sensor

I allways use IRIS for image stacking / callibration, this gives me best results, you can't do the "convert a CFA sequence" step, or else you will loose resolution due to interpolation, just load your light frames bias / dark and flatfield calibration, align by one or more stars and stack using you favorite method, I use #sigma median" with 2 iterations and "sigma coeficient 2".

If you need a hand with Iris please let me know.

Cheers,

Thanks Luis.

What type of files do you use in IRIS? Do you use dcraw or other equivalent software to convert the raw file to another file, say fits without demosaicing prior to process them in IRIS?

Having a look at IRIS and I don't find it that obvious.

Thanks

I've managed to take some pictures with the scope tonight. Trouble is, DSS is giving me bizarre results. I converted the raw files to Tiff without demosicing using dcraw. I did the same for the darks, flats and bias. When I put the lot in DSS, I'm getting grainy pictures.

Luis, how did you stack your mono lights?

Thanks

Or you could then remove the IR filter on the sensor replacement and sell it to the amateur astronomers community; if the mod goes wrong, you could even make a small profit!

Now, I don't know how reliable those second hand sensor sellers from USA are.

I bought my 1000D for £120 Gina. I don't thing you'll get it much cheaper than that. However, second-hand 1000D sensors are sold at £42. You could buy a 1000D and if the mod goes wrong then replace the sensor for resell. You'd end up spending £42.

Someone asked for flat frame from my camera:

https://dl.dropboxus...flat_newton.jpg

This is one stretched flat frame through my 8" f6 Newton (that's the reason for some vignetting).

It was me, thank you Filip. It looks really impressive! Congratulations!

Did you polish the sensor with something? Can you elaborate a bit on the procedure you followed?

Many thanks

Interesting comment Makes me wonder whether it would be worth buying a used 1000D to play with before continuing with my 1100D experiments. Need a lot of thought

Somehow the 1000D sensor seems more robust. I've been pretty ruthless debayering it first with the wooden tool and then the windscreen polish even on the edges and it's still working fine. Yes, I didn't go anywhere near the golden connectors yet because I want to see what works and what doesn't. If I hit a golden wire I'm going to be wondering what could have worked or spend more money on another camera/sensor. Also, you can buy 1000D sensors from ebay at £42 -but they come from USA, apparently.

The cover glass on my practice 450D sensor was removed pretty much intact too without applying any heat but it wasn't as easy as with the 1000D. Both the 1000D and 450D have similar CFA in terms of difficulty removing them.

I'm not sure, but if you do give it a go don't do it indoors as this stuff can give off carbon monoxide as a by product and then there is the link to lung, liver and pancreas cancer! Yes I've been reading wiki

Thanks starfox. Yes I've been doing all this in the garden with a paint mask on top of a surgical mask, goggles and nitrile gloves. That Dichloroethanething is freaking me out.

Would the Dichloroethane disolve the epoxy resin? I'm thinking about surrounding the sensor with a wall of epoxy so I can leave a pool of solvent over the sensor overnight.

Do you think it's worth going for a H-alpha clip filter with that flat frame?

I'm a big fan of the canon 1100D for astrophotography. However, My advice would be to stick to the 1000D or 450D for this mod, at least until we understand what is causing all those sensor failures. In both the 1000D and 450D you can remove the glass without heat where there are more chances of being successful. Possibly, the 1000D would be the best candidate to perfect the procedure as the glass comes up relatively easier and it's cheaper. Once we have a method, my view is that it can be easily applied to the 450D. By the way, the 450D is a hell of a camera for astrophotography so nothing is lost here.

Dear all,

I've been working today on my 1000D sensor. I have used fine car windscreen polish and 99.999% pure isopropanol as suggested by Rotweiller. Initially, I tried to dilute the polish in the isopropanol but it wouldn't disolve so I ended up applying the polish with a sensor cleaning swab cut to half size and a microfiber pad. Then I cleaned the area with another sensor swab soaked in isopropanol. The isopropanol is brilliant for cleaning the sensor; I thoroughly recommend it. After the procedure, the sensor still works and I managed to remove most of the CFA leftovers but, I must say, that I didn't apply myself very hard to that. I wanted to know if I could clean the sensor and remove the bayer matrix leftovers with those 'ingredients'. I also wanted to know if I could do it without damaging the sensor. So, it can be done and this is the positive aspect of all of this.

However....

Somehow I didn't manage to polish the sensor evenly. There is a band from left to right in the middle of the sensor which went deeper than the rest. I don't understand very well how this happened as I applied equal pressure in all areas. This band is very obvious when you inspect the sensor visually but it wouldn't come up in the photos I took of the sensor. You can see it in the flat frame attached at F22. You can also see some scratches but I think those were there before I applied the polish.

I also attach two photos taken after the procedure. One at ISO 800 (the bottles), and the street one at ISO 1600. Both photos have been processed from raw files with DCRaw to avoid demosaicing.

I would very much welcome any comments. I wonder what would be the effect of the uneven sensor in the astrophotographies. Maybe someone with the knowledge can comment on how this can degrade the photos -I would imagine it will.

I also applied Dichloroethaneon my non-working 450D sensor to see if it would remove the CFA. I think we may be on to something good here as some bits of the CFA seem to have disappeared. Again, I applied the Dichloroethane with a sensor swab cut to half and a microfiber pad. I have the feeling that for this method to work, the sensor must be submerged in the Dichloroethane overnight. Any ideas about how something equivalent could be achieved without killing the sensor?

There must be another way to get the cover glass off other than heating the adhesive to 300-400C! I noted earlier that Gina used a sticky pad to stop shards of glass breaking the gold wires, I don't know if the following would work: cut a sticky pad to fit inside the glued area of the cover glass, then score the glass around the outside of the sticky pad repeatedly unitl you could lift out the glass using the sticky pad. I bit like using a router and a guide fence. The glass doesn't look that thick so maybe a simple blade might work to score it?

Chris

Both the canon 1000D and 450D have cover glasses that can be removed intact without applying any heat. It's the 1100D and 350D the ones that seem to give trouble. A pity because the 1100D is a very powerful camera and, as for the 350D, there is a chance that the solvent may remove the BCA without scraping (I'll let you know if that's the case when I try it).

However, the 450D is an impressive camera for astrophotography. If the CFA leftovers can be polished, and the scratches removed while the flat frames are good in my 1000D, there is virtually no difference between that model's sensor and the 450D (I know that because I have been practicing with a dead 450D).

Oh dear

I feel for you having such bad luck after all the effort you've put in its a lot of dead sensors and expense so far on this thread, its definately given me second thoughts about giving this a go with my next ebay camera, I might just good old fashioned mod it!

Well, it'll be me the next one to have a go. I'm now going to polish the 1000D sensor that is already partially debayered with fine glass polish diluted with 99.999% pure isopropanol as suggested by Rotweiller. I'll apply it with a sensor swab cut to half size. Then, I''ll move on to the 350D and I'll try the Dichloroethane approach with that one. I've got all the ingredients ready. Trouble is removing the glass over the 350D sensor using heat. That is a big worry after the recent senor failures with that procedure. As I said earlier, I'll avoid using the epoxy (with the heat, I'm afraid I have no choice but I'll be using a torch pen). I won't remove the CFA completely from the fringes until I see if I can remove all the bayer array leftovers without damaging the sensor. And if I succeed with that (remains to be seen), I'll inspect the kind of flat frames the camera is producing.

I think if you're going to use a polish, you will want to use one that breaks down as you apply it so you don't polish away the silicon! Something used for car paint for example (not T-Cut as it doesn't break down) may work.

It's for removing the CFA leftovers while removing some scratches at the same time.

What I've learned so far:

-cover glass comes down quite easily with the help of hot air (350 to 390C), carefully applied around the edges through small nozzle (3mm).

-golden wires and blue border of the sensor are very fragile, slow setting epoxy applied to those parts protect them excellent.

-only scraper hard enough to attack CFA, and soft enough not to scratch too deep is wooden one. Any metal is (imho) too risky.

-when you have your sensor's glass removed, epoxy applied and hardened, and CFA scraped off with wooden tool, any remains of CFA

can be easily cleaned by polishing. Because all sensitive parts of sensor is protected with epoxy, just put a small drop of polish paste to the

sensor surface and very gently polish it with soft cloth and your finger. I've used Xerapol paste for polishing polycarbonate plastics, but I am sure

there are better products with finer and smaller abrasive particles. Polishing takes only minute or so, you have to remove only CFA remains and

not underlying layers! So, wipe few times with polish and then clean and inspect surface. Every progress will be quite obvious, because you can see

the difference if you look at the surface against the light under various angles. My advice is to polish, clean and then install the sensor into camera

and take few test shoots to see progress. And then repeat that until chip is clean.

Filip, Can you show us a flat frame say at F8 with your 450D? Do you think car glass polish will do the job?

Thanks

I thought I didn't do justice to the camera with the photos I posted before so, here I go again, this time paying attention to light metering to avoid overexposure. The photos have been taken with a 50mm 1.8 nifty-fifty lens on a tripod. Again, the images were in raw format converted to jpeg without any demosaicing applied (apart from the overexposed) using DCRaw.

The image has been reduced to 26% (because of file size) but I'm showing too a crop at 100% showing the central region. I also show the original image that the camera took with its automatic light metering. You can see it was badly overexposed. The removal of the CFA has increased dramatically the sensitivity of the sensor. The camera estimated a exposure of 1/25 and ISO 800 but I had to go to 1/40 and ISO 400 to get the composition right. Thus, I had to go to manual, lowering the exposure time and ISO significantly in order to achieve a correct histogram. All photos were taken at F8.

I can't see any scratches coming up in the photo. As I said, I,ve also run a test for dead pixels with a number of dark frames at different exposures and ISO 1000. The test was both visually and using software which returned 0 dead pixels so the sensor seems intact despite the scratches created with the wooden tool?

Thanks for looking. Any comments welcomed.

I thought it may be worth recalling an earlier post I made with monochrome images with my partially debayered 1000D sensor. As you can see in the pictures, there is no CFA left on the left and right sides (apart from the bits close to the golden connectors). I was quite ruthless removing the CFA in both sides completely unaware that those where supposed to be sensitive areas. The camera is still working; no problem whatsoever.

My point is that there seems to be an unusual amount of dead or damaged sensors since we have started applying epoxy on the golden connectors -or the heat used to remove the glass. I know the sensors worked immediately after the procedure but it may be something that takes some time? I think I'm going to skip that step with my 350D and take my chances trying to avoid the golden connectors.

Also Gina, for dcraw to work you must have the Microsoft SP2 or SP3 installed.

Here it is.