Carole's DSLR Cooler

[carastro]

Following on from Francis' thread on his peltier "Chiller Box for DSLR camera body", I will answer the questions put to me there in this thread.

For those who haven't read the other thread I ordered one of these:

https://www.teleskop-express.de/shop/product_info.php?products_id=4824#ebericht

When you say the hole at the front is too small, does it not allow the camera t mount through the aperture ?

The T ring is up against the hole but not through it and my WO flattener is too wide to pass into the hole in order to screw to the T ring. I E mailed the tech support people in Germany who said it would be OK to enlarge the hole, but a) It would be a tricky task, and not much to play with as the hole is close to the bottom of the box.

Does the camera fix directly to the box ? is there a socket to allow cables to pass though fro the camera to say your PC ?. sorry about all the questions

The camera sits inside the box and there is a screw which passes through the bottom of the box so you can screw into the thread underneath the camera.

There is a small hole through which cables can be passed.

I decided to purchase a new Flattener as I didn't really have the right one for my telescope anyway (but had not planned to splash out on that just at this moment), and have ordered one that will pass through the hole which is 65mm diameter.

Lastly, you cannot change the DSLR battery without taking it all apart which is not convenient during a run of images, so have also been forced to order an "electric battery" as well.

An expensive few days (But things I needed).

I did however test out the cooler which has a thermometer telling you what the outside temperature and the inside temperature is, and it was definitely cooling OK.

I'll try to take some photos tomorrow and once I get the Peltier Coolbox up and running will post some comparisons. Do you want to see stretched master darks, or just final images?

Carole

[swag72]

This is an interesting thread Carole and the box itself is a great concept and I look forward to seeing the difference in real life.

I have worked on a 'cooling system' with the help of a couple of other members on here (AndyUK being one of them), a much cheaper system with insulated boxes and ice packs. Total cost, less than £20. I can't help thinking (as I was about one of these peltier coolers) that once I had spent that much and additional bits to get it sorted out, I could almost get a OSC QHY8 by selling the modded DSLR.

Did you look into this or were you wanting to keep the DSLR?

Stretched master darks for me please Carole!!

[carastro]

Hi Swag72,

I also tried making a cool box with ice packs, but I when I tried it out with a thermometer I could not seem to get the temperature to drop. It could well be that the cool box wasn't sufficiently insulated, but I was trying for lightweight. Then this gadget came along already made with a peltier which seemed far superior.

I can't help thinking (as I was about one of these peltier coolers) that once I had spent that much and additional bits to get it sorted out, I could almost get a OSC QHY8 by selling the modded DSLR.

Did you look into this or were you wanting to keep the DSLR?

Yes I had in my mind planned to get a Cooled OSC CCD camera next year, But then a few knowledgeable people tried to convince me that this wasn't a good idea, so decided to stick with the DSLR and cool that. Now having done so, I am getting other people saying I must be mad, I should have got a one shot colour CCD.

You can't win. Oh well, too late now.

additional bits to get it sorted out

Yes well I didn't know that was going to happen.

Carole

[swag72]

I guess there are doubters in all camps eh Carole?!!

I look forward to seeing the results, I hope it works well (But not so well that I want one )

[SpookyKatt]

Hmmm I'm quite interested to hear how this box performs

and how long it takes to cool the camera down. Yeah

some master darks would be cool especially if you take

them at 10-15 minute intervals to see how quickly it

takes.

Kathleen

[fwm891]

The unit looks more serviceable than mine, I hope it turns out well for you.

As a guide with mine cooling the camera from ambient took about 2.5 hrs to get noticeable results in test dark frames. The housing cools quite quickly but it takes time for the camera body to release all the stored heat - hence the reason I pre-cool in a fridge! Francis

[carastro]

Yes, I think the makers of this coolbox suggest putting the camera in the fridge first as it takes about 30mins to reach the maximum low temperature apparently. Guess I'll have to put the coolbox on while I'm setting up, so by the time I am ready to image it will nearly be there.

Sorry I haven't had a chance to do any photos as packing to go to Astro camp and leaving in about half an hour, will do them end of the weekend.

Carole

[AstroGnome]

HI Carole,

I didn't know anyone was making these coolers commercially. Could have saved myself hours of work, never mind.

I was impressed by one home built cooler from last years Salisbury Party (hopeless with names and have forgotten who's it was) and decided to have a go myself.

I ended up butchering a cheap cool box minifrdge from Argos (£20) a sheet of polystyrene from B&Q (£1) some bits'n'bobs from Maplins and lots of glue/gaffer tape.

A couple of things I did different to most others who've tried this, I put a mains supply, a thermometer and all the controls in a separate unit and so saved some weight off the scope. I also attached the camera body to a cold plate which was directly in contact with the cool side of the peltier so it directly cools the camera rather than the air in the box so no internal fan/heatsink needed, and kept the volume of air in box very small. Cool down time from 'warm' day temperatures to sub zero is about 45mins (in tests I got about 25deg below ambient).

M....

[carastro]

Well done AstroGnome. replying from Astro Camp sitting here in the dark waiting for polaris to arrive and the clouds to depart.

carole

[Sp@ce_d]

This looks very interesting, if a bit pricey..but a ready made option which appeals.

How do you find the extra weight? Looks like its twice the weight of my 1000D

[Astroscot2]

Carole, enjoy the star camp. look forward to seeing some pics of and with the new cooler !

Mark

[newman]

Since I'm relatively new at this and haven't really gotten into astrophotography yet, please bear with me..

While the SBIB dedicated astro cameras were designed to operate at very low temperatures to reduce noise, as far as I know Canon DSLRs weren't - they're just cameras intended for "normal" use that happen to be good at astrophotography (correct me if I'm wrong). Isn't there a chance the cold might actually damage the camera? I'm guessing the answer is "no" since you're willing to put yours in there, but I'm curious about this. Did Canon take astrophotography into account and designed the cameras so they can operate at really low temperatures? What about the battery? Batteries usually don't play nice with the cold..

Thanks in advance for the answers, really curious about this.

[ollypenrice]

Have a care not to overdo it; one of my guests froze his 40D into a coma in a cool box! It revived in the morning, fortunately.

Olly

[Zakalwe]

I wonder what impact (if any) such cold temperatures will have on the shutter and shutter curtain mechanisms? woulf th lubricants harden?

I would also imagine that using a good desiccant to keep the air inside the cooler dry would be a must, otherwise condensation will get everywhere inside the body?

[carastro]

I would also imagine that using a good desiccant to keep the air inside the cooler dry would be a must

Yes, the manufacturers also recommend dessicant as well. Well all I can say is I have used this camera in minus 5 degrees and had no problems, I probably won't need to use the coolbix in the winter, only during the warm weather.

One of our own members did his own peltier modification to the camera itself and had no problems except he set it too low to start with.

I had a reply on another forum from some-one who lives in Australia who says they use cooled DSLRs all the time there.

What about the battery? Batteries usually don't play nice with the cold..

Unfortunately the design does not allow you to change the batteries mid evening without taking it all apart which means losing your orientation etc etc and needing two lots of flats, olus a lot of faffing around, so I have ordered an electric "battery", these in themselves apparently generate heat so should also help in the winter when I am not using the coolbox.

Carole

[fwm891]

If you think about things how many of you have been out with your cameras mid winter taking snow scenes etc... I've been up inside the artic circle with my DSLR cameras and used them at -22º C with no problem (wouldn't work at -32 C but then nether did I!!!). These cool boxes will take cameras down to about 10-18º C below ambient - so about the temperature of a typical UK winter evening well within the tolerance limits of most DSLR's.

[Astroscot2]

Hello Carole,

Have you managed to do any test with your coolbox ? would be interested in an update.

Cheers

[carastro]

Sorry every-one for the delay, my new Flattener did not arrive until just before I was about to go on holiday (Replying now from an internet cafe in Majorca). My existing flattener would not go through the lens hole of the coolbox and so I could not assemble it to take photos until that had arrived). (I needed a new Flattener to go with my new scopes anyway so not an addtional expense thank goodness).

Will be home in a weeks time and will do photos and post them.

Carole

[carastro]

Back from Holiday and then a long weekend at a wedding, I have finally got around to taking some photos for you guys. I haven't yet had a chance to use the Coolbox, firstly because my Flattener would not fit through the hole and had to wait a while for a new one (I needed a new one anyway as the one I had was not designed for my current scopes).

I've attached a couple of photos of front and back:

[carastro]

I have bought myself a dummy battery with cable as you would have to dismantle the whole set up to change the battery and I use two full batteries a night at least.

Only snag now, is the box and cigarette lighter attached to the new dummy battery does not fit through the cable hole which you can see in the front and back images above (on the left side of the left image you can see a small hole on the left lower side of the rear section. This is fine for passing the camera cable through though. So what I have done is cut a small slot in the front hole (where the flattener passes through to allow the cable to come out of the front).

[carastro]

Looking through the front hole into the inside of the coolbox.

[carastro]

Looking inside with DSLR camera screwed in from below.

You can see the DSLR cable passing through the side.

[carastro]

The Flattener end of the box with the battery cable coming out of the same hole as the flattener. I have made a small slot in the round hole to accommodate the "battery" cable.

[carastro]

I now have one further snag to overcome before I can use this set up. My 12V 3 way splitter does not sem to be working, so now need to wait for a new one before I can try it out.

12V cigarette lighter plug for Coolbox

12V Cigarette lighter plug for cabled "battery"

12V cigarette lighter plug for dew heaters

N.B. You have to switch the DSLR "ON" before screwing the box up.

Will have to take the back off to do flats as I need to change the setting to AV.

Yes I should have stuck to my guns and got a OSC CCD, but too late now.

Carole

[Photosbykev]

it is possible to shoot down to about 1/5 second even in bulb mode so if you make your light source relatively dim you would be able to take the flats without opening the box.