UPDATE: Cheap TEC results.
I've just done a 30 minute run with Unit #2 - the one with the Chine (EBay) TEC. Bleahh!
After 30 minutes with the camera in place but no switched on, temperature dropped only 6.7C and by that time, the graph was getting pretty flat.
The only difference between this unit and Unit #1 (see my posting earlier today for those results) are:
1. the different TEC; and
2. Different camera (but this is neither here nor there); and
3. this box is unlined inside whereas Unit 1 is fully lined.
I've let it run and plan leaving it to run overnight - a torture test - and see where it lands but my guess is that I won't see much more that 7 or 8 below ambient. Pretty disappointing.
I'll try lining the box on the inside and run the test again before I pronounce the Chinese TC a waste of money.
Here's an update. I just checked again - an hour later and only another 3.5C so a total of 10 C in 90minutes. What a dud.
Still, I'll line the chamber tomorrow and run it again but I think I know where this is going to end up.
The US TEC costs US$83. plus post but it seems to be worth it.
Is that a Tellurex module, Peter? It would be nice to improve the power consumption of my system, exchanging the Jaycar model with a better quality unit.
15C is quite a very respectable reduction, despite the sensor temperature issues. There is no way around that, other than a cold finger, which is intrusive and risky. But your cooler box design looks to be a winner.
I ran the unit during a brief gap of clear skies this morning - a real-world test. Ambient 18, chamber temp 5 and sensor 12. Happy with that although it occurs to me I may have a condensation problem inside the chamber rather than inside the camera when ambient temps get down a bit. Oh well, a few bags of dessicant should fix it.
Not all EOS cameras have a temp sensor. The 350D doesn't and I'm not sure about the 450D but subsequent ones seem to.
You get the data from the EXIF data and I use a tool exiftool to get it although most imaging programs have the ability to tell you the information stored with each file.
In case anyone might be interested to try this design, I've done a rough cutting guide for making the metal box. It's been carefully measured and cut to suit a 350D and a Custom Thermoelectric TEC. If using other cameras or TECs, you'd have to check the measurements before starting and redrawn the cutting template.
This box is my 3rd version and looks to be the best yet. The TEC will sit only 2-3 mm off the back of the camera and the unoccupied air volume inside the chamber (i.e. not occupied by the camera, styrene or TEC) will be the absolute minimum. SO cooling should be optimized.
I've used 2 of those Coles eskys in this to get the flat styrene sheets I want for insulation inside and outside.
I decided to ditch that Chinese TEC and have ordered a second one from the states. I know those work and as far as I can see, the Chinese one is a waste of space.
If anyone would find progress photos of this version 3 build useful, let me know. I'll take a few but won't post them if they aren't wanted.
I received the TEC system that I ordered from Alibaba (China) for $19 (free postage). Photos are attached. I ran a test this morning and it works (which is a surprise given the drink can cooler I bought previously that did not work at all).
Anyway in the few short minutes I tested it (ambient was 30C) , the cold side (small fan side) dropped quickly to 20C and the hot side went up to 32C. I suspect the cold side would have been much better if it was actually boxed in as the ambient was flowing around the sink. I will get it boxed in foam for the next test, then work out how to attach the cold side to my cold finger from the laptop.
I received the TEC system that I ordered from Alibaba (China) for $19 (free postage). Photos are attached. I ran a test this morning and it works (which is a surprise given the drink can cooler I bought previously that did not work at all).
Anyway in the few short minutes I tested it (ambient was 30C) , the cold side (small fan side) dropped quickly to 20C and the hot side went up to 32C. I suspect the cold side would have been much better if it was actually boxed in as the ambient was flowing around the sink. I will get it boxed in foam for the next test, then work out how to attach the cold side to my cold finger from the laptop.
That looks awfully like the one I bought. Good luck with it.
Here's a couple of shots of my final build. It's only waiting for the TEC (en route from the states) and a power supply for the camera (en route from China) and a T-Ring and DSUSB (en route from Bintel). As you can see, there's more still coming than here.
Peter
I received the TEC system that I ordered from Alibaba (China) for $19 (free postage). Photos are attached. I ran a test this morning and it works (which is a surprise given the drink can cooler I bought previously that did not work at all).
Anyway in the few short minutes I tested it (ambient was 30C) , the cold side (small fan side) dropped quickly to 20C and the hot side went up to 32C. I suspect the cold side would have been much better if it was actually boxed in as the ambient was flowing around the sink. I will get it boxed in foam for the next test, then work out how to attach the cold side to my cold finger from the laptop.
Hi Glen. Any further results from your Alibaba TEC? I'm sure it's the same as mine - which is listed in ebay as:
Functional Thermoelectric Peltier Refrigeration System Kit Cooler Fan TEC1-12706
I just did a second test in case I stuffed up the first and the results were only marginally better. I built a small aluminium box about 80mm cube, insulated it on the outside and sealed it. The temperature dropped by 12C in about 10 minutes and stayed at that level. Ambient was 30C. The idea behind this test was to mount a DSI II CCD in it and use it for planetary/lunar stuff. I suppose if I can get the temp of the camera down by 10-12 degrees it should show up in the sensor sooner or later. I was hoping to avoid doing a cold-finger mod on the camera hence this workaround.
I ran my test build last night, Mk II vers. 2.
It took ages to pull the sensor down by about 10* but it had no internal fan and no contact with the camera, just a big cold plate surface.
It managed to maintain the sensor about 5* below previous imaging sessions where I had gotten up to 30*c, so about 24-25* for a nearly 2 hour run with 90 second exposures and virtually no breaks.
Not a great result really for the effort but I may try an internal fan to get cold air circulation and I think I can rig up a sliding contact to the tripod screw plate so when the enclosure is shut it connects it to the cold plate as well.
Simple but might help a bit more.
Turning the camera off\on is a nuisance though and changing the battery is a pain. I make sure the battery is at full charge at the beginning of the night. I am looking into an AC adapter for the camera. Does anyone know if just turning the power off/on is likely to cause any issues rather than using the camera control ?
Mine is the 12706 also. Variously rated at 50 or 60 watts depending on who is selling it. Factory specs are 50 IIRC.
Peter
Its odd that your box has insulation on the inside??
I thought the entire aluminium box would work to cool the camera - but thats not possible with yours?
The Gary Honis cooler is bare inside. Whats going on??
Peter
Its odd that your box has insulation on the inside??
I thought the entire aluminium box would work to cool the camera - but thats not possible with yours?
The Gary Honis cooler is bare inside. Whats going on??
GlennB
See Post #74.
My design makes use of air-to-air TEC assemblies whereas the Honis design uses air-to-plate. Difference in approach.
Just about given up on cooling the DSLR with a box. takes forever to get anywhere and the difference is minimal and shortlived. As soon as you start using it the temp starts back up again. I guess you gain a wee bit but not worth all the effort. Also no control.
Only real solution is the cold finger system for consistent and effective cooling IMHO. I'll look into it when I finally get round to the IR mod.
Just about given up on cooling the DSLR with a box. takes forever to get anywhere and the difference is minimal and shortlived. As soon as you start using it the temp starts back up again. I guess you gain a wee bit but not worth all the effort. Also no control.
Only real solution is the cold finger system for consistent and effective cooling IMHO. I'll look into it when I finally get round to the IR mod.
Hold on for a tick before you start cannabalising your DSLR. I've got my much-reduced dimensions box waiting on the arrival of a good quality air-to-air assembly from Custom Thermoelectrics in the States. The one I already have is doing good stuff in a bigger box and I believe will do even better with my newer design. The trick - I continue to believe - is not trying to cool the whole box but to blow cold air directly onto the back of the camera and, if it also cools the box a bit well and good but cool the camera first. That isn't the Gary Honis method, I know, because he uses an air-to-plate design that is the byproduct of pulling a car fridge apart.
The device should be here this week and I'll post some results super pronto.
I have not posted here but I am working on a design of a box as well. I am just trying to fix my workshop first. In all most of the cooling is required on the the sensor but there also need to be some cooling of the electronics as well. A box is the best way to do it.
I hope to post my experiments as well. I have heaps of peltier modules and I also have neat heat-sink and fan assembly. I will also be experimenting with dual Peltiers as well. I feel it is all about the box designs as well. I am not using metal at all where possible, this is key as any metal outside the box even with inside insulation will remove some of the cold away from the system.
My last design was all plastic or insulation exterior with a large metal plate internally to get more surface heat absorption area but no internal fan. I could try that as well but the real issue is to get the cold into the sensor area and DSLR's being designed to protect the innards for the user is not a good candidate for air cooling where it is needed most.
I added a copper finger contact to the Tripod base mount to get some metal to metal path but no measurable effect. I'm tossing up about adding some holes to the DSLR case, turn it into a seive. Might improve matters somewhat and maybe get some copper path options as well.
Bugga, I've gone a bought another plastic enclosure for a Version III prototype. Can't stay away from it. This one is deeper and provides a better access to the camera for battery and PC connection requirements. I want to try and get better internal cooling efficencies so fans and a big thermosink plus a redesign on insulation.
how about two peltiers ? one on the bottom and one on the side. i guess alot depends on if you have to carry or move it much or not . or a bucket of dry ice and a chute on the side of your enclosure to drop some dry ice into it one bit at a time.
