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

After a fogging incident on my 14mm the other night, I thought I would give a lens warmer a try. It worked well. For less then $20, problems solved. Used my BLUETTI EB 55 as power supply, but a smaller 10,000 amp power supply would have worked fine.

Did the job as described

This is just what I needed for my astrophotography where the camera is out all night in changing temps I would have to go out every thirty min to wipe off the lense and spray anti-fog now with this its is a dream come true I can leave my camera outside the entier night with this plugged into a power bank and not worry that the lens will get fogged up it never does

Functions well in terms of its core purpose to keep your lens warm and condensation-free. The ergonomics of the two switches is poorly executed though. Each teeny tiny button is very difficult to engage. And the labeling of the buttons is very hard to see. I encourage a re-design of the controller. Make it 25% larger with better tactile feel.

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.

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)

I used this USB powered Dew Heater on a 8mm lens for night sky photography, an it kept few from forming on a humid night with temps in the 60s. It heats quickly on the High setting, but Low is recommended for my conditions. I used a 20,000mah portable power supply for over 2 hours continuously without any problems. This power supply has 10W USB-A output, so it has no problem running the heater. I didn't try to measure current, but I did plug it into an old phone charger that has a LED on it, and this heater apparently needed more power than its stated 5v 1000ma (5W) output because the light constantly switching between dim and bright. That tells me that a small, lightweight USB battery probably cannot run this thing, and that may be something you need to consider before heading out for a long photo session.

After using this 4 or 5 times, the heater stopped working. When I went to the Support Page provided on Amazon, I was presented with a 404 error page. Ie: No support what so ever. I don't recommend buying this product. I have found it to be a waste of money.

Fits my 61mm refractor nicely. The temperature control feels nice and the cable is very soft even in cold temperatures which i like. Heat level at high settings feels very warm and kept my optics dew free all night.

As an astrophotographer lens dew is an issue when shooting the night sky. I purchased 4 of these in the spring and use them regular. Temperature is controlled with a button press for 3 setting. I typically use a low setting for mild dew, when it gets heavier I switch to a High or medium. One thing to remember is that it takes a 3 second press on the temperature control to turn them on. I paired these with a cheap 10,000 mAh power band and the bands keep the lens warm all night long.

The instruction print is a bit small. To turn on hold the button for about two seconds. What's nice: it's long, and it comes in a nice pouch. Con: It may be just me, but I prefer my cables to be modular, this isn't.

It's cold in Manitoba, this lens heater did the trick by being able to stay out longer.

I purchased this product as a hummingbird feeder heater to prevent the nectar from freezing in a rare cold snap in BC