Debayering a DSLR's Bayer matrix.

[Gina]

I know the feeling Gina

I'm constantly. looking for 350 or 450's, not sure why

I'm going to try my 600d soon.

I'll try scraping the edges first and then mild heat around the edges

Alistair

Just missed winning a faulty 350D someone got in in the last couple of seconds and just pipped mine which went in at 10s to go. It went for £72 + £8 P&P - so that's £80. Quite a lot really.

[alistairsam]

for those thinking about filter wheels to use with a mono dslr for narrowband, I think this is a good alternative. https://www.teleskop-express.de/shop/product_info.php/info/p6025_TS-Canon-EOS-T-Adapter-with-Filter-Quick-Changer---Low-Profile.html

this filter draw comes with an eos bayonet ring on one side and a T2 on the other and is only 9mm thick.

since this is 9mm + 1mm, and the cmos sensor is 45mm inside the canon body, that gives a total of 55mm and is perfect for a baader mpcc if using on a newt.

since its close to the sensor, you can also use 36mm unmounted filters by getting the appropriate filter draw. it also has a 1.25" filter draw.

a 36mm x 7nm Ha unmounted filter is only 120 euro opposed to 200 plus for 2" or 299 for a clip filter.

I would have gotten this for my rig, except that I use the TS9 OAG. that's adds another 9mm more giving a total of 64mm which is outside tolerances of the mpcc.

so I'm getting the RCC1 which needs 94.6mm backfocus from its M48 thread..

I have the 15mm filter draw from TS, so spacing to the RCC1 from a 350d/450D/600D would be

45mm + 10mm (EOS-T2 adaptor) + 15mm filter draw + 9mm OAG.

so all that's needed is a 15mm M48 spacer to go after the TS9 OAG.

Alistair

[Gina]

for those thinking about filter wheels to use with a mono dslr for narrowband, I think this is a good alternative. https://www.teleskop...ow-Profile.html

this filter draw comes with an eos bayonet ring on one side and a T2 on the other and is only 9mm thick.

since this is 9mm + 1mm, and the cmos sensor is 45mm inside the canon body, that gives a total of 55mm and is perfect for a baader mpcc if using on a newt.

since its close to the sensor, you can also use 36mm unmounted filters by getting the appropriate filter draw. it also has a 1.25" filter draw.

a 36mm x 7nm Ha unmounted filter is only 120 euro opposed to 200 plus for 2" or 299 for a clip filter.

I would have gotten this for my rig, except that I use the TS9 OAG. that's adds another 9mm more giving a total of 64mm which is outside tolerances of the mpcc.

so I'm getting the RCC1 which needs 94.6mm backfocus from its M48 thread..

I have the 15mm filter draw from TS, so spacing to the RCC1 from a 350d/450D/600D would be

45mm + 10mm (EOS-T2 adaptor) + 15mm filter draw + 9mm OAG.

so all that's needed is a 15mm M48 spacer to go after the TS9 OAG.

Alistair

Since the 1000D and 1100d are 55mm and right for the SW 0.85 FR/FF backfocus and the same lenses focus properly on both these models and the 350D then surely the 350D must have a backfocus of 55mm?

[JamesF]

Are you sure they're 55mm, GIna? I was fairly sure they were all 45mm. Obviously they all have to be the same otherwise the lenses wouldn't be interchangeable.

James

[Gina]

I was just adding an edit to my last post to say that it's been quite a while since I used a DSLR for AP and might be confused. (Then the edit disappeared!)

[Gina]

I've just checked up and found where that missing 10mm went - the adapter to connect the 48mm SW FR/FF to the Canon bayonet - http://www.firstligh...ng-adapter.html

That makes it much easier to add a filter wheel I shall be using 36mm unmounted Baader filters (from FLO) in a DIY slimline filter wheel.

Edited September 3, 2013 by Gina

[Tf2k]

Damn, i need more patience. Scraped toooo deep into the sensor... (NEX-3, only one pink picture).

But at least, my D80 is working. Oh, lets say, half working. scraped a bit blue frame, two dead rows. I think i haven't removed everything from the CFA, reading on one spot little different values from the colour channels.

To end my camera massacre, last two chances. Two defect D40 with working sensors are on their way, to get back to the camera, i started with.

Going the Dichlormethane route one more time, but now with more patience and less aggressive

[Gina]

Further to the lens/camera back focus distance. The Pentax/Praktica M42 thread mount lenses I use for widefield AP have similar back focus to the EOS so when using lenses with a mono DSLR I won't have that 10mm extra for the filter wheel

Two options that wouldn't need much, if any, reduction in back focus in the mono DSLR :-

1. Use my twin ED80 + FR/FF rig with two DSLRs
   
2. Use 3 mono DSLRs with Ha, OIII, and SII filters and 3 matching lenses
   

Edited September 3, 2013 by Gina

[Gina]

Damn, i need more patience. Scraped toooo deep into the sensor... (NEX-3, only one pink picture).

But at least, my D80 is working. Oh, lets say, half working. scraped a bit blue frame, two dead rows. I think i haven't removed everything from the CFA, reading on one spot little different values from the colour channels.

To end my camera massacre, last two chances. Two defect D40 with working sensors are on their way, to get back to the camera, i started with.

Going the Dichlormethane route one more time, but now with more patience and less aggressive

Oh dear More patience is something I need too plus some common sense not to attempt this tricky job if I feel tired, had a bad night or am in any other way below par. Edited September 3, 2013 by Gina

[flolic]

lol that was the one I was watching, missed the bid as i was working agreed its just a bent CF pin and may work over usb still anyhow so an ideal candidate for modding. Hope you have better luck this time Gina

Keith

300D USB transfer rate is so low that it takes over 30s to transfer one raw image, if I remember correctly. Last time I used one for astronomy was 6 or 7 years ago, and it was real pain...

I have one laying around and I don't even want to touch it anymore

[Gina]

That's a long time! Still if youi're using 30 minute subs that isn't too bad

[alistairsam]

That's a long time! Still if youi're using 30 minute subs that isn't too bad

hmm but imagine focusing with 30s for every frame?

I'd probably cry!!

as for the distance, its 45mm.

there should be a marking of a line with a circle on top. I think that's the sensor position.

but I have measured with a depth guage on the 350d and its 45mm, 10mm for the t adaptor.

Alistair

[Gina]

Ah, I see what you mean

[pixueto]

Damn, i need more patience. Scraped toooo deep into the sensor... (NEX-3, only one pink picture).

But at least, my D80 is working. Oh, lets say, half working. scraped a bit blue frame, two dead rows. I think i haven't removed everything from the CFA, reading on one spot little different values from the colour channels.

To end my camera massacre, last two chances. Two defect D40 with working sensors are on their way, to get back to the camera, i started with.

Going the Dichlormethane route one more time, but now with more patience and less aggressive

Did you use Dichlormethane with the D80?

[alistairsam]

I found this pretty neat product for fitting a filter to a dslr without adding any backfocus.

with this, you can install filters directly to the EOS T adaptor so it does not add to the length.

https://www.teleskop-express.de/shop/product_info.php/info/p5913_Baader-Protective-Canon-DSLR-T-Ring-with-Clear-Filter-to-protect-the-sensor.html

it can also act as a humidity seal to prevent condensation when the sensor is cooled.

if i"m not mistaken, most EOS T2 adaptors have 3 grub screws that can be removed to reveal an M48 thread for filters to be screwed on.

Alistair

[alistairsam]

some links

http://www.baader-planetarium.de/sek...body-gross.jpg

http://www.baader-planetarium.de/sek...asst-gross.jpg

http://www.baader-planetarium.de/sektion/s17/s17-en.htm

[Luis Campos]

some links

http://www.baader-planetarium.de/sek...body-gross.jpg

http://www.baader-planetarium.de/sek...asst-gross.jpg

http://www.baader-planetarium.de/sektion/s17/s17-en.htm

Alistair,

This is exactly what we all need! This is essencial for cooled cameras as it seals the sensor "chamber" to prevent from dew, blimey...I didn't even knew of this sollution!!!

BIG THANKS Alistair

Cheers,

Luís

[Luis Campos]

It's even possible to swap filters directly on the T2 adapter...this is awesome guys!

It's not cheap, but considering a small filter for the sensor (Baader ACF) costs 85 eur...this is by far a better sollution, and far more adaptablle!

Cheers,

Luís

[alistairsam]

yeah, they also have an eos adaptor for the camera side of the ts9 oag which has an m48 filter thread so the filter sits inside the oag. that is so cool.

this means I can use my ts9 off axis guider, a 2" ha filter and maintain the 55mm to the coma corrector without a filter wheel, for a mono dslr.

so when I add cooling, it will keep moisture out.

The oag works wonders for long subs. I've gone 60 mins with no trailing.

[Gina]

It will keep the moisture out to some extent but the chamber is not air tight - there are small gaps for the shutter and axles for the mirror etc. I know this from my cooling experiments with the 1100D which is basically the same as all the EOS models. Cooling to near ambient temperature is alright but once you get a few degrees below you tend to get condensation. I shall be investigating sealing and desiccating for the various EOS models I'm debayering and have started a new thread for this as I think this is a different subject and is a bit off-topic in this thread.

[alistairsam]

hi Gina,

yes, it won't be airtight and cooling is not the context of this thread, but I just thought it might be of some use to seal the front of the camera without adding any length.

I wonder if a rubber or foam cylinder can be placed around the sensor so its compressed when you close the body and that provides additional moisture control.

with the debayered dslr, cooling is important so we can start taking long narrowband subs.

anyways, i will post results of my next debayering attempt.

Cheers

Alistair

[Gina]

Just missed out on a faulty 1100D (been dropped and LCD and mirror smashed) I put in a higher bid at 5s but someone else got in with just 50p more at the very last second. Someone must have a faster internet connection than me! Of course there was a risk that the sensor could have been broken.

Edited September 4, 2013 by Gina

[Tf2k]

Did you use Dichlormethane with the D80?

yes, Dichlormethane, which does a nice job if you have more patience than me

used the wooden tool after that, seems i didn't had a clean sensor, so it could be that glass particles got under the tool.

[pixueto]

yes, Dichlormethane, which does a nice job if you have more patience than me

used the wooden tool after that, seems i didn't had a clean sensor, so it could be that glass particles got under the tool.

Thanks. Why did you feel you had to use the wooden tool? wasn't it enough with a microfiber after applying the solvent??

Is it difficult to remove the glass in a nikon D80? I'm waiting for a sensor to arrive and have a go.

Many thanks

[Gina]

At last I've managed to win an auction