Dew Band for Camera Lenses

[Knight of Clear Skies]

In the past when a lens misted up I usually just switched it out and changed target. This was fine when I in experimental mode but now I'm aiming for longer imaging runs so I need to think about better dew prevention. I've searched for dew bands but am a little confused about what I actually need.

As I understand it, a short dew band would do the job but I'm not sure what size would be best. Also, I guess I would need a controller of some kind instead of plugging it straight into a battery box? Finally, I'm not sure what battery box and connecting leads I would need. My solution has to be as portable as possible as i already have quite a bit of kit to lug out to my imaging sites.

Any help or tips would be appreciated.

[Ant]

I bought a 3" band for mine, but you may find that the 2" EP version will fit - measure the camera lens to check.

Just to warn you its really fiddly as the dew strap covers the focus ring of the camera lens. So any movement in the dew strap could potentially alter the focus. I made sure that the lead was on top of the lens and ran it over the camera body and taped it in place with a little insulation tape, to prevent movement.

Cheers

Ant

[Knight of Clear Skies]

Good tip thanks. What do you use for power and control please?

[Ant]

I used one of these - http://www.firstlightoptics.com/astronomy-cables-leads-accessories/12v-dew-heater-supply-cable.html - its down side is that is effectively on 100% all the time.

But hey, i never had an issue with dew lol.

It will either plug into the car (for a limited time - obviously need the car to start), but for the garden I have a spare female ciggy socket on the mount, so i plugged it into that. My entire setup is run from a Maplins 13.8v regulated bench power supply.

Cheers

Ant

[Knight of Clear Skies]

Thanks. As you suggest, I'll measure some of my lenses first to see what size strap to order. Then I'll get a battery box and adaptor to connect to the phono connector on the dew strap. I can try plugging it in and out periodically to begin with and if that doesn't provide enough control or is too much hassle I can add a controller like this one later.