nice work, still some more to remove by the looks but that's sweet
Thanks Jay, yeah still got a bit of CFA left (see how dark it is!) and I got a few bad scratches as well. I reckon I'll try polishing the CFA off on the second sensor instead of scraping, hopefully I'll do a better job with it.
I must admit, I think these mono conversions are very brave. Looking forward to the cooled completed project, Jo.
I have had a lot of success with the electric sensor defogger and plan on adding a coated (clear) glass cover. This should achieve two goals. 1. Reduce the power requirements and 2. improve performance, by reducing the cooling air mass around the sensor and warming the external glass cover.
one thing myself and the others found the hard way is that in cameras other than the 350D, scraping the blue area causes irreparable damage and renders the sensor unusable.
so i'd suggest staying away from the blue for 450d and above.
mono 350D is proving quite a performer with its largish pixels with some good examples. so a cooled 350D should be very usable for deep sky imaging and especially Narrow band.
one thing myself and the others found the hard way is that in cameras other than the 350D, scraping the blue area causes irreparable damage and renders the sensor unusable.
so i'd suggest staying away from the blue for 450d and above.
mono 350D is proving quite a performer with its largish pixels with some good examples. so a cooled 350D should be very usable for deep sky imaging and especially Narrow band.
are you running the camera without the body?
Cheers
Alistair
I accidently scraped off a big bit of the blue stuff and was worried that I'd wrecked the sensor it's good I got a 350d then aye
I'm running the camera fully assembled at the moment, I don't wont to damage anything before I get it safely rehoused.
I wont be trying it out just yet, though I am tempted. I have a spare 1000D sensor!!!
I am presently applying myself to the reckless task of converting a used 450D to a full spectrum mod cooled OSC. I've decided that APS-C is my thing. Cooling conversion #4. The software is in draft form. Everthing else is on the 1000D test bed.
As you can see, I've changed my original plan of having the TEC and heat sink on the side and have put it on the back instead, it is a lot more balanced and lets me use a bigger heat sink. By mounting the TEC on the inside of the case and the heat sink on the outside I'm using the case to get rid of the heat as well. At 11v 8A the 55w TEC keeps the case and heat sink about 2 to 3 degrees above ambient, and the cold finger around 28 degrees below. Is this alright?
I'm hoping to make another cold finger when I'm able to get some copper plate.
The camera turned out to be around 8mm to thick for the case to close, but by sanding 3mm off the front of the camera and milling 2mm off the back of the case where the TEC goes, I got the gap down to 3mm which was taken up by the rubber gasket I made.
It actually worked out really well, because when I screw the lid on tight the rubber is compressed just enough to push the camera, cold finger, TEC, and case together tightly.
That's a fine piece of work and ingenuity, Jo. Take my hat off to you, sir. Looks like the heatsink/case combination is living up to expectations. I see that you have siliconed the gap between the sensor frame and chassis and sealed up the sensor at the front. I might look at a gasket of some sort around the sensor frame.
3C above ambient is a very efficient differential for the hot side. 28C differential is very flexible on the cold side, if you intend using temperature control? Consistency between frames makes a big difference. At 28C diff, it should regulate nicely at about 24 - 25C below ambient.
You may experience one problem, The heat sink is connected to the case, so all that heat will go back onto the case. I had a similar design started but I ended up using a Thermoset plastic case instead of Die-cast for that very reason.
I think that the intention is to conduct heat to the sealed sensor cavity. It's also a method for increasing heatsink performance. When Jo gets time he might measure the heatsink exhaust ambient air differential, which is a measure of TEC efficiency and thermal resistance of the heatsink.
very nice work.
silly question, does the camera work without its housing?
is the sensor sealed in the housing?
does it fog up?
cheers
Alistair
Thanks Alister, yes the camera works without its housing, the entire case is airtight (or will be, I haven't sealed off the wire hole yet) I'm pretty certain I'm not going to have any problems fogging up.
That's a fine piece of work and ingenuity, Jo. Take my hat off to you, sir. Looks like the heatsink/case combination is living up to expectations. I see that you have siliconed the gap between the sensor frame and chassis and sealed up the sensor at the front. I might look at a gasket of some sort around the sensor frame.
The entire case is airtight so I only sealed off the front of the camera with the window (52mm multi coated UV filter, 54mm would have been perfect) I have avoided the use of silicon as I've heard it not good with electronics.
Quote:
Originally Posted by rcheshire
3C above ambient is a very efficient differential for the hot side. 28C differential is very flexible on the cold side, if you intend using temperature control? Consistency between frames makes a big difference. At 28C diff, it should regulate nicely at about 24 - 25C below ambient.
Temperature control would be nice, how difficult would it be to do? I only know a very basic amount about electronics but have got a large collection of components I've desoldered off PCB's
Last edited by nebulosity.; 19-10-2013 at 07:28 AM.
I think that the intention is to conduct heat to the sealed sensor cavity. It's also a method for increasing heatsink performance. When Jo gets time he might measure the heatsink exhaust ambient air differential, which is a measure of TEC efficiency and thermal resistance of the heatsink.
Yes this is correct, I would be interested to know the efficiency of the TEC, so what exactly do I do?
it's good I got a 350d then aye 
albeit with limited success . 
