Cold Air Source for Hobby Type

vortex tube maybe?

Control may be an issue

http://www.globalspec.com/productfinder/findproducts?query=vortex%20tube

That was my thought also, I have used them in the passed. He would need a compressed air supply, control will be a proplem, and I am not sure if they get that cold.

You are chilling the insects so they don't move, with the intensions of releasing them unharmed at a later time, right? That leaves out zapping them with a CO2 fire extinguisher.

They do consume quite a bit of air.

Ahh, can you turn down the air.

They come in different sizes some as much a 2 CFM. They will cool to 0 °C but that depending on the temperature of the compressed air. Most the best they can do is a 50 deg temperature drop from the temperature of the compressed air.

Might be the best bet because he can then use the heated air to blow against the outside of the tube to keep it from fogging up.

I like the idea of a used refrigerator, GA. He could even enclose the condenser into a cristal clear plastic box and illuminate it with white LEDs.

Place the specimens inside a desktop refrigerator for a while and photograph them while the door is open and the interior light is on, perhaps?

_{Only trying to help.}

If you want control look at the manufacturer "Melcor" and google terms "thermoelectric module", "solid state heat pump" and "peltier effect". These parts are easily available at Digikey, Mouser & others.

A much easier method would be to have two boxes connected by a tube. Dry ice goes in box #1 and insect goes in box #2. Have a hole in box #1 big enough for a small fan (approx 3", 12V fan from an old PC, wall wart power supply from Digikey, Mouser, etc.) to blow through. If you want control then do not attach fan to box #1. Have vent holes in Box #2. To chill box #2 point fan toward big hole in box #1 and open up vents in box #2. For control turn the fan so it blows more or less air into box #1.

If in a mood to experiment then remember that cold air is heavier than warm air. Possibly having the dry ice box higher than the insect box will allow the cold air to sink down onto the insect. Control temperature by changing the number of books you take from the bookcase and place under the dry ice box.

Won't dry ice, being frozen CO2, displace the oxygen from the insects box, thus harming the insect? The OP didn't clarify but I am assuming he does not wish to kill the insects or he could do so to photograph them, dead bugs don't move.

What about a little shot of N2O or chloroform, that should slow them down....

If money is no object you could go this route, for around $550....

or you could just go to a cold place....it's currently 23º in Helsinki....

Temperatures around the world....

anything is possible if you have enough money, You're going to have numerous problems including frost. hope you're patient, you're in for a lot of trial and error

What about chilling a piece of metal (iron / aluminum) in a freezer? Once the desired temperature (test & error) is achived, the chunk of metal is placed inside the plexiglass box. Depending on it´s mass, you will have more or less cooling time / effect.

I agree with TCMTECH. You can buy a smallish peltier cooler from sporting goods sources. They were meant for cars and trucks to cool food and drinks. Fed from the cars battery. Plenty of power to go below freezing point too, adiustable. Feed it from a DC power source.

Replace any part of the styrofoam with plexiglass. Insert light sources as needed. I suggest the 10 or 20Watts under cabinet "hockeypuck" lights for correct color rendition. Some have dimmer too in the electronic ballast. See Home depot. Set air moisture content at your liking. Mix in CO2 if desired.

No air movement. Insects might not like a slight breeze.

Nothing invented.

Enioy your pictures.

You will have a problem with Condensation on the outside of the Plexi far more than on the inside. Your best bet is to put the Plexiglass box with the bug in it in the freezer and close the door. Then wait a 5 Min or so till mr Bug slows down. Open the door and as fast as possible take the picture of the box and bug in the freezer. After you get the picture then take the box and put it in a plastic bag for 15 Min so it does not collect Condensation while warming back up. Now you got your picture and use what you already have. Or almost eveyone has a refer and Freezer. The idea is to put the thing in the Freezer and close the door ASAP. Then wait a few min for it to cool of and then be ready to take the shot when you open the door before condenstion has a chance to build up. If you want to make sure there is no condensate at all put the box in a plastic bag before puting in the freezer. then take it out of the bag leaving it in the freezer be ready to take the picture ASAP with the box in the Freezer. This will give you time to have clear Plexy without condensation if you work fast. Good luck. Jim

K.I.S.S. Put the insect in a clean dry plastic water bottle, put the bottle in a fridge or freezer depending on the temp. needed. If you want you can use a digital temp. gauge with remote sensor, put the sensor in the bottle, the wire on the sensor should be long enough to keep the digi gauge outside the fridge/freezer. Once you reach your desired temp. take the insect out the bottle and put it in a nice place to take the pics. The time it takes the insect to absorb enough heat to start moving should give you plenty of time to make the pics.

What about those chillers they use in pubs/bars too chill the beer. You could try picking one of those up secondhand.

Just want to say thank you very much for all these enthusiastic ideas, which have given me some good food for thought! Your inputs are very much appreciated! This is the sort of scale I operate at:

Sawfly, by Johan J Ingles-Le Nobel

Yes, the goal of this device is to preserve life. I'm experienced enough at imaging preserved specimens, but the naturalist inside me makes me prefer not to have to kill them, and insects exhibit different things when caught in a natural, alive pose.

• CO2 is definitely a possibility and I've considered funneling some into the device in addition... but it makes for strange pose positions.
• Peltiers seem doable, but I think I can repurpose a cheap ebay tabletop freezer cheaper and it's likely to be a better construction, knowing my (lack of) engineering skills!
• Condensation is definitely problematic, which is why I will need a small battery fan to blow air over the lens as I shoot

My hunch would be is that tabletop freezer (ebay £10) with air circulating through use of fans and pumps through to a second posing chamber with twigs and creature will be the way I go in the end, as there's no reason why it shouldn't actually work?

As has been said, I think there's a lot of trial and error involved before it all works how I need!

Many thanks again!

I would get some of these cold packs:

And either place them in the container with the bugs, or put them in a separate area, and utilize one of these to move the cold air.

Total cost would be about $15 US, and it would be completely reusable. For temperature control, a simple on/off switch for the fan would do the trick.

if I understand him correctly he wants to be able to set various temps, not just a random cooler temp. with such a small box to condition he's going to have trouble controlling a tight temp band, he'll experience wild temp swings without a pretty precise setup.your suggestion will produce a "cooler condition but he think he wants a lot more

Why various temps?

He just wants them to stay still long enough to take a picture. Being cold blooded, the temperature at which insects stop moving around is pretty much the same across species. I'm thinking somewhere around 50F.

A thermometer affixed to the inside of the container would let him know if he needs to hit the fan and give them another little blast.

A dessicant pack in the cold container, combined with an anti-fog wipe on the inside of the insect chamber should take care of fogging problems.

I also think that he's going way too cold. Freezing temps will kill them. He just wants it cold enough to stop movement. This way, they will retain their natural looking state.

This guy has the same idea, but with far less mobility and control.

http://www.outdoor-photography-topic-gallery.com/insects.html

With Lepidoptera, I always put them in the fridge, and they're always alive overnight. The ideal temp is around 35F (1-2C), as close to freezing as I can manage but just above. Freezing is a no-no. In fact, using this or freezer blocks was the first arrangement I thought of, but I switched my thinking to a 'created cold' source rather than melting blocks really to ensure the temperature stayed low enough but also to be able to regulate it above freezing.

As it was electric I could keep generating more cold rather than it running out. For a stack (ie combining say 250 images) I'm looking at a couple of hrs of taking shots, every 20s, move by a few μm, repeat, etc. Hence the need to keep generating cold.

Fwiw here's a diagram I did

I've been reading a bit more about Peltiers in the meanwhile this morning, a couple of these with a fan and temperature diode on an Arduino look like they might do the job, and a fun learning project too. I just don't know if they have the juice to cool a 30*30*30 space down by say 35 degrees (midsummer max), nor do I sadly even know how to find out. Argh!

http://www.novatecproducts.com/iceprobe_accessories.htm

Having done all sorts of reading, I'm starting to lean towards 2 Peltiers, 2 hot sinks with a fan on each driving warm air away, 2 cold sinks inside the sealed unit driving air to be chilled onto the peltiers, 1 fan circulating air over the lens inside connected through a adapter mechanism, with a motor-driven XYZ stage inside with a servo(s) controlled 1440 degree of rotation universal stage to be able to move the twig holding the bug. All this would be controlled through arduino, with the addition of a temperature sensor (so I can set a target temperature and monitor the temp) and a CO2 sensor (to be able to measure that if I add CO2). Pretty ambitious, but if I pull it off pretty unique too.