DSLR cooling box - help in locating aluminium sheet

[niko]

Hi all,

I want to make on of these peltier cooling boxes for my DSLR.

http://ghonis2.ho8.com/rebelmod450d16d.html

In the plans he discusses 1199 grade alumiunium sheet at 0.635mm (0.025") thick.

For the life of me I can't seem to source this. Does anyone have any suggestions?

many thanks

niko

[hikerbob (Bob)]

niko, Action Aluminium have 0.6mm sheet listed in their catalog. The victorian store is in Dandenong. www.actionaluminium.com.au

Bob

[niko]

Thanks Bob

I spoke to them but they don't have 1199 grade and according to site the purer the better the thermal properties

[niko]

WOW! I've been reading up on aluminium grades - there are heaps of them!

Can anyone advise if the thermal conditions of each grade are pretty much the same?

It seems 1199 grade cannot be had for love nor money but 5083 seems readily available.

If covered in insulating foam will there really be any disadvantage to using a "lower" grade?

many thanks

niko

[leon]

No I don't think there would not be much of a difference, have you considered thin copper sheet, conducts the cold really well.

Leon

[niko]

Thanks Leon.

I found a piece of 5083 grade for $8. The same in copper was $100. I'm afraid that was champagne for my beer budget!

Cheers

Niko

[Saturnine (Jeff)]

Hi Niko

Bunnings sell thin aluminium sheet, about 500 X 300mm I think, the grade of aluminium wont affect the thermal properties too much.

Jeff

[2stroke (Jay)]

The aluminum really does nothing more then serve as structure, the internal fan heatsink assembly moves the cooling off the TEC, just as the external one moves the heat of it. I might wack one up myself as i havent had time for a coldfinger mod, to many things and not enough time lol.

[niko]

thanks guys

everything ready to go - just waiting on the heatsink to turn up

[niko]

So, I finally got the cooling box built

http://ghonis2.ho8.com/rebelmod450d16d.html

Not quite as polished as this one but not bad. I'll post some photos.

I haven't quite got the seal around the t-ring extension tube sorted out but I plugged the hole as tested the system on the weekend.

I got it down to 2.8 degrees and wonder if that will provide any appreciable advantage over no cooling.

What are other's thoughts?

cheers

niko

[wasyoungonce (Brendan)]

Hi Nicko. Following your exploits...well done.

To quantify how well your image noise has improved you need to take darks at various temperatures and to a std deviation pixel count on those darks. I used imageJ (freeware), converted the darks to TIFFs using DPP then measured in Image J.

There are other methods to do this.

What you want to do is compare std deviation of noise across differing sub lengths and ISO's to get an idea what's best (lowest noise) Vs sensor sensitivity for you.

The other issue I found with DSLR coolers is that they cool well when run with the camera but the nose piece conducts and lowers thermal efficiency quite a bit. You will need to insulate/cover this area of the focuser DT. This also decreases thermal efficiency somewhat and I found it can be an hour to cool the DSLR to acceptable temps. About 1/2 hr if not connected to the scope! Probably why some people use qty 2 peltiers coolers on DSLR cool boxes!

That said any CMOS temp (use Exif data) below around 10~8 C will see vast improvements in lowering noise on Canon DSLRs.

[niko]

Thanks Brendan.

I take your point about the nose piece. I'm not happy with that area of the whole rig - will have to work out a solution.

One day the sky will clear and the ambient temp rise so I can test it!