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Dew Protection

Cold weather observing has become my favorite time of year. It's not that I really enjoy the cold weather.? But the cold brings galaxy season and crystal clear weather conditions at my observatory.? As I observe with folks, I find that they are never prepared for the cold weather.? Make sure that you read the review on cold weather clothing on this site.? On this page, we will be looking at heaters and dew protection.

Kendrick Dew System.

If you want the best in dew protection for your optics in cold and wet conditions, you'll be looking at Kendrick's products before long.? The system consists of four basic items.? First and foremost is the dew shield.? Kendrick makes the best flexible dew shield.? It is made of a black rollable plastic as is the Orion model, but Kendrick goes one step further and lines it with a black felt.? It makes the shield stiffer and less prone to light reflections.

Components two and three are the controller and dew heaters.? Kendrick makes several heaters that can be plugged into the controller.? The controller has four RCA female sockets to receive plugs from the heating elements.? Heating elements come in a wide range of sizes.? If you are using a mounted scope, make sure to get one for your objective and your eyepiece.? You will also want to get one for both ends of your guidescope and one for your Telrad pointer.? Oh... that's five heaters and just 4 plugs.? You can get an RCA splitter at Radio shack for a couple or three dollars.??

The elements' craftsmanship is first rate. Each is enclosed in protective fabric. The slick side goes against your optics/ The fuzzy fabric side out. On the end of each eyepiece/objective element, is some elastic material and velcro for easy attachment to itself when you wrap it round. The elements are sized by diameter.? I use 2" heaters for my eyepieces.

They work well for all of my 1.25" eyepieces and will barely fit around my large 2" eyepieces (Naglers). The 2" heaters will fit around most other 2" eyepieces with no trouble.? If you view mostly with large Naglers, you may want to consider using 3" heaters instead.

The Telrad heater is sort of a rectangle shape.? When you look at it, you may ask, "How does this thing attach?".? It's very simple.? You put it on the side of your Telrad, where it fogs up, and secure a rubber band around it and the telrad.? The rubber band sometimes gets in the way of your switch, but it is a minor inconvenience.

For a look at how these things appear when setup, take a look at my observatory setup in my observatory pages.

Kendrick also makes a fine battery pack.? I consider them somewhat expensive.? Power is power and a sealed battery is pretty much the same wherever you go.? Wallmart and Costco sell emergency battery jump kits for around 60 to 80 dollars.? I purchased mine at Costco.? It has a 34 amp hour battery, and emergency light, nifty LED's that give charge status, two 12 volt sockets, and cables to help start my car in an emergency.? The Kendrick 17 hour pack comes in a very nice Cordura pack and is somewhat compact.? Costco... $57, Kendrick $109.? Take your pick.

The cheaper route? Chemical heaters

Okay, you don't want to spring for the Kendrick system. The costs for all those heaters adds up.? A controller, battery pack, power source for recharging.... it can get to be a real hassle.

A great solution is to use Grabber handwarmers.? These are available at REI for minimal cost ($1.80 / pair).? I frequently use these with my Obsession.? The big dob scopes don't lend themselves well to having a battery and cable hanging off them.? In addition, the primary and secondary tend to dew up far less frequently than the eyepieces.

To use these chemical warmers, carefully slice open the top of the plastic envelope that they come in.? Save the envelope!? Shake up the warmer to get it started. Place the warmer next to your eyepiece, place the plastic envelope on the outside of that, and a rubber band around the two to secure them in place.? The plastic envelope helps redirect the heat to your eyepiece or objective.? If you are using one of these heaters on a primary objective, orient it on the bottom side of the scope tube as opposed to the top side... they work better that way.

On a really cold night, these chemical heaters can really come in handy as pocket warmers too!? Imagine that.

The really cheap solution

It's hard to imagine that there is a very simple solution for a problem as serious as dew.? Just keep your eyepieces in your pocket and your finder covered when you aren't using it.? I've learned to use the telrad even if it is covered with dew.? It isn't optimal, but it isn't terrible difficult.? If you layer your clothing, your inner shell should be a down parka or polartec jacket. A pocket in that inner layer is always nice and cozy.? Eyepieces love it there.? Yes, even I sometimes take the really cheap route when it comes to dew!