Dew Management and Prevention (Science and the Fixes)

[@nn1982in]

Enjoy all the videos you have been putting out so far. Really helping me start with Astro. Hope to get my first light sometime soon.

[@PatriotAstro]

Glad I can help. Thanks for watching! Let me know if you need anything or have questions.

[@GregMcCall]

Hi, it would be great if you could revisit this but include dew controllers that better manage heat and power usage in place of the hit and miss manual controllers. I originally used a Kendrick which has an ambient air probe as well as probes for under dew straps so to keep the temp under the strap a controlled amount above ambient temp. Better solutions are dew point controllers. I currently use celestron 2x & 4x controllers and probes. Some others exist such as Prima Luci if you have their computer. A poor choice is the Pegasus devices as they have no temp probe for under the dew straps so no feedback loop. This would be particularly bad with say a guide scope small strap and a large refractor. While I like the pegasus construction and ability to control focus motors, dew point control with sensors providing a feedback loop is a higher priority. Dew point control is the goldilocks control of heat. Not too hot and not too cold. cheers and good to see you back

[@PatriotAstro]

You are definitely right. There are better solutions with tighter feedback loops. I considered looked at changing mine out but in the end mine are still doing what they are asked without issue so I guess it’s ‘if it’s not broken don’t fix it’ for me right now at least.

[@redabdab]

I have the Celestron dew shield on my Edge HD, but it doesn’t fit too well on top of the dew strap (which is on the scope first). Would it be ok to put the dew strap outside the dew shield instead?

[@PatriotAstro]

The answer unfortunately is 'maybe' :) The goal is the have the heat generated by the straps to raise the temp just above the front of the scope by a couple degrees. As long as the straps are able to do this through your shield, it is fine. I have seen some people use longer straps that can double up the about of heat generated and even dual straps to push it a bit. I'd say give it a shot. If you have a way to check the temp to see if you are getting a bump in the temp, start there as a way to check on it.

[@adyjoy]

Chad, I'm new to your channel, and loving this and all your Nina tutorials. I've got a simple dew controller with an ascom driver that can be controlled by Nina as a switch. Have you any plans on doing a video that would cover using it in a sequence? ( assuming you haven't already done one 😁)

[@PatriotAstro]

I don't have one, but since it is a switch, my thought would be to add it in the startup sequence and end sequence to ensure it is on at start and off at end. You can make an argument though that you may want it running until you personally cut off the power in the morning to limit the likelihood of dew before you bring it inside. (If you bring it inside)

[@jwbcsb822]

Thank you. Can you discuss voltage / amperage / watts control and temperature monitoring on the scope. How predict, for a given challenging dew control night, what will be a reasonable power draw?.

[@SunsparcSolaris]

It doesn't take a lot to warm optics above the dew point to where dew stops forming. The USB strap that I have has a maximum draw of 10 watts, but that's on high which is roughly 130F to 150F. Low mode draws a lot less at 95F to 113F.

[@Westlake]

Great topic and video Chad! Any ideas who makes shorter length USB heaters for smaller guide scopes?

[@PatriotAstro]

Search for “USB lens warmer”. There’s actually a lot out there. Read the reviews though, just in case. :-)

[@vinikrish]

Thanks for the tips and science behind it... I am having issues with dew forming on the filters (filter wheel). I already have dew heater for the scope and the camera (ZWO). Any tips to stop dew from forming on the filters? TIA

[@Fortanity]

I had used hand warmers when I did not have dewheater, and I still keep a few in my camera pack 😀

[@PatriotAstro]

It’s very smart to keep handy items like that around. They don’t take up much space and can save you in a bind. Plus they can keep your hands warm too. :-)

[@danielbrowniel]

Question can you make a video about telescope parts that are interchangeable and what the industry standards are. What are the pros of cons of using adapters in various situations. I find in this industry sellers do not care to educate beginners so they can be assured they are getting the right part.

[@carvrodrigo]

How about dew inside the camera sensor? I tried dissecants but still there when I cool the sensor

[@siegfriednoet]

Great interesting video again Chad, informative and well explained 👍 You say to warm up the air in front of the lens element, so does this mean you should put the dew band exactly on the lens element or just in front of it ?

[@PatriotAstro]

Either should work within reason since heat rises. I tend to put it either very close to where the lens is located, or maybe just above… But sometimes that just depends on the type of telescope and where I can comfortably attach the strap.

[@siegfriednoet]

@@PatriotAstro Thanx, will try it out

[@EmilyTienne]

Good information and dew management techniques. If I may, the editing breaks between each and every sentence creates a somewhat annoying effect where the video volume momentarily increases then drops off to normal. Would be better if you just read several sentences uninterrupted.

[@PatriotAstro]

I know what you mean. I'm pretty new at this and fighting with equipment a bit. This particular video was a bit worse too since I was travelling and had limited gear to work with. I'm hoping to address both audio and video soon. :( Thanks for the feedback! Clear Skies!

[@finskiandguns8534]

I was with up until you started using Fahrenheit lol