Lost my best shot of the Veil Nebula to a lens fogging at Cherry Springs

Drove 3 hours up to Cherry Springs last month, perfectly clear sky, my tracking was dialed in. Got about 40 minutes into a 2 hour run of Ha subs when the front lens just fogged over completely. I didn't catch it until I checked the preview and every frame looked like a soft white blob. My Dew heater strip broke the week before and I figured the dry air would save me, nope. I ended up throwing out 80% of the data and settled for a noisy 20 minute stack. Has anyone here rigged up a backup dew solution that actually works, or am I just stuck watching the forecast before every trip?

2 comments

2 Comments

oscarc121mo ago

That "soft white blob" line hit me right in the gut, man. I read a post on Cloudy Nights last winter where a guy swore by sticking those little hand warmer packs to the outside of his lens shade with rubber bands, just as a backup to his dew heater. He said it bought him an extra hour before frost started forming. I've also seen people rig up a cheap 12v hair dryer on a timer, but that seems sketchy. Honestly, your best cheap insurance is just carrying two of those USB powered dew straps, even the cheap ones from Amazon, and testing them at home before you drive out. The forecast thing never works, I've learned that the hard way too, humidity can sneak up on you even when the radar looks clear.

tessa_murray1mo ago

So @oscarc12, did those hand warmer packs actually stay put on the lens shade, or did they end up sliding off halfway through the night? I'm curious if the rubber band trick is worth trying or if it's just a wasted 20 minutes.