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What do I do with this frost on my lens?


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Hi guys,

 

I am currently out in the field, and I noticed this after I came to check up on my scope. 

Theres spiders of frost all over the lens. Inside and out. Is it my session finished for now? And is it a major problem? 

 

Haven't got the foggiest idea how I would begin to deal with the cause of the frost on the inside of the OTA.

 

Best,20191130_015536.thumb.jpg.8e1fc19a086ed93bcdf8758787e283a3.jpg

 

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Last night, I had similar problems with my kit. The dew was very heavy, close to, but not quite, freezing. I even had to clear the water off the top of my observing stool. I started with my Star Travel 120 refractor, and when this misted up, I replaced it with my 127mm Mak. At the end of the session I had 2 tripods, 1 mount with handset, and 2 OTAs with their finders; all running with water (I had kept the eyepieces in my pockets). I moved them all back into my unheated, but dry, garage, and left them overnight with all the lens-caps off. When I checked them this morning, they were all dry; with no sign of moisture, and clear lenses. So I put the lens-caps back on, and stowed the various bits in cupboards and cases.

It is important not to touch the glass surfaces, and, if possible, not to take cold items into a warm house. A garage or shed is fine, provided that it is normally dry inside.

Geoff

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5 hours ago, 5haan_A said:

Hi guys,

 

I am currently out in the field, and I noticed this after I came to check up on my scope. 

Theres spiders of frost all over the lens. Inside and out. Is it my session finished for now? And is it a major problem? 

 

Haven't got the foggiest idea how I would begin to deal with the cause of the frost on the inside of the OTA.

 

Best,20191130_015536.thumb.jpg.8e1fc19a086ed93bcdf8758787e283a3.jpg

 

Happens to us all - just take back inside, take off all the caps and let it dry out.

You might want to add another dewshield for extra prevention and/or a heated dew strap.

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i have  obsevered in -25c in winter. and doesnt happen much

how long wre you outside for?

also as guy above asked how long is the dewcap? it should be 8" long if not get an aftermarket one like kendrick dewcap thats best kind with the felt linned inside.

oh ya it wont harn your scope just bring in inside as the night is dne for u and let it dry.

joejaguar

Edited by joe aguiar
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17 hours ago, 5haan_A said:

Hi guys,

 

I am currently out in the field, and I noticed this after I came to check up on my scope. 

Theres spiders of frost all over the lens. Inside and out. Is it my session finished for now? And is it a major problem? 

 

Haven't got the foggiest idea how I would begin to deal with the cause of the frost on the inside of the OTA.

 

Best,20191130_015536.thumb.jpg.8e1fc19a086ed93bcdf8758787e283a3.jpg

 

Last night it was well below zero and mount, scopes, tripod, computer, computer  bag and everything else was frosted worse than that pic.

Both my scope and guide scope had a 'hot hands' handwarmer bag held close to the lens cell with a rubber band and I( didn't get any condensation or frost on the lenses. Cost about £0.50p per night, and at the end of the session a friend and I were both able to warm our hands with the bags.

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16 hours ago, Stub Mandrel said:

Last night it was well below zero and mount, scopes, tripod, computer, computer  bag and everything else was frosted worse than that pic.

Both my scope and guide scope had a 'hot hands' handwarmer bag held close to the lens cell with a rubber band and I( didn't get any condensation or frost on the lenses. Cost about £0.50p per night, and at the end of the session a friend and I were both able to warm our hands with the bags.

Great shout. I have just placed an order for some hot hands and rubber bands.

  • Haha 1
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