USB Lens Warmer, Lens Dew Heater Strip with Temperature Regulator, Condensation Prevention for Telescopes Camera DSLR Lens Telescope Eyepieces Less Than 3.15 inch (80mm) in Diameter

Keeps the lens warm like it should

I use this when doing nightscape photography and it does a great job of keeping the dew from forming on my lens. It has low, medium and high settings and so far I’ve only had to use medium. I power it with a usb battery bank. (Not included) Comes with a pouch that’s perfect for storing hit and the battery together.

I've used this lens warmer many times during cold and warm humid nights while doing night sky time lapse photography. It has performed flawlessly, keeping the lens clear for hours when conditions were such that the lens would have been rendered unusable within the first hour. I won't be without it during nighttime photography now.

I bought a previous version which has worked well for three years. This has a new controller and I can't get it to reliably turn on, the lights indicating power do not reliable respond?Edit : although similar in appearance, this controller is different in function. Finally read the new directions (press and hold the on button for two seconds) and got it to work.

I waited a while to write this to make sure I put it through its paces first. It works and does great. It makes a huge difference when doing any night shooting. This is an extremely useful piece of kit that has earned its spot in my small bag (an accomplishment for me).

Astronomy. New to the hobby... and I am so glad these work as well as they do;-) Anyone who stares through a telescope on a winter night would understand.No drama, just plug it in and does the job nicely. Comes with a nice bag (some don't, I have others), has a nice cord that is easy to manage when cold. And the cord has been long enough to work fine for my needs (8"dob with a battery at it's base).I leave it on all night. In the beginning I checked the temperature regularly but now have just settled in to taking it for granted (sigh of relief)

Lo recomiendo. Vivo en Florida, la humedad es muy alta y a veces el lente se empaña y tarda mucho en volver a la normalidad; pero esta cinta eléctrica actúa rápido.

This product works well ON THE HIGH SETTING. However, the low and medium settings are probably going to give your battery packs problems. The issue is that the temperature regulator regulates the temperature by adjusting the duty cycle (turning the unit on and off very quickly). This will give your power bank fits as the power bank has internal regulators to keep the voltage constant. Depending on your power bank, this behavior will probably cause your power bank to shut down after a certain amount of time. I have tried both Anker and EcoFlow power banks and they both shut down on the medium and low settings. The high setting provides a constant load (power draw) so they do not shut down on the high settings.At first, I could not understand what was going on until I purchased an EcoFlow River 2. It has a display on the front that shows the output power. I can see the power oscillating when the unit is on the medium and low settings. In my opinion, this is a design flaw. If your heater appears to cut off after an hour or so, switch it to high and it will probably solve your problem.