Is that at Surplus Gizmos? If so, good to know.
One note, the coolers need to be sized for the heat load and cooling desired, then add some extra. The photometer has 3 stage cooler (just checked) listed as a max delta-T of about 110c, I get about 85c at the cold finger. If you just want "some cooling" and temp regulation, then it's easier and a surplus cooler would fill the bill.
hippieua, I've only seen analog circuits on the few scientific cameras I've seen. The coolers will be mostly on anyway... The driver on the circuit I posted is low resistence and doesn't get hot when cooling my flea3 or Skyris (whole camera). Regulation is quite good, better than 1c in cruddy service (whole camera) and probably closer to 0.2c With a little tuning in a camera should be well under 0.1c. One of the circuits I borrower from claims 0.01c, but need to see that to claim it... :-) I'll know more when I connect it to the Photometer.
Mitch, I agree PWM would be more efficient and the drivers will run cooler, but probably not the issue when counting electrons. Not saying you couldn't make it work, but the analog works well and is proven. Peltiers aren't supposed to like PWMs much either, but as you say, some edge shaping maybe some extra caps would help on that front.
If you want to lower the power required, the best way is to lower the cooling requirement: delta temp, heat load. Temp is easy, heat load is conduction (slots, small wires, few wires, vacuum but it takes a good vacuum).
As always, YMMV