Eyepieces fogging up with binoviewers

[GavStar]

I thought I'd post a note of some recent experience I've had in case it's useful for someone. I've been using binoviewers for over a year and found the views excellent for bright objects. However in the last few weeks I noticed a significant and annoying halo appearing around Jupiter. My first thought was that there was a problem with the binoviewers or eyepieces. However since the halo took a few minutes to appear I worked out that it must be due to my eyepieces dewing up. Also I think my use of wing guards made the situation worse but it's a bit odd that I don't remember this last year. So I ordered some eyepiece dew straps from flo this week, they turned up yesterday and the halo did not reappear when I used them yesterday - success. I've got a few more wires to deal with but very pleased that the issue has been resolved.

Incidentally there was some very good seeing at times last night. I had extremely crisp views of the GRS and could count 11 different regions across the surface. Views were much like the attached with a bit less detail in the bands themselves (GRS was  brighter orange and stood out more though)

[iPeace]

Dew straps rule. No sense in putting up with what happens without them.

Jupiter was indeed excellent last night. Great views.

[Knighty2112]

Think I got a similar problem last night looking at the moon (not with my binoviewers though). In the EP fov there was a slight halo or mist in front of the moon, yet looking by naked eye the sky looked nice and clear. Might have to invest in a dew strap too for my EP's. 

[John]

I just keep my eyepieces in their foam lined case which retains a bit of heat and keeps them just above the outside temp. My EP's are all longish eye relief ones now which keeps the eyeball that little further away from the eye lens. When I have had fogging issues it's been with eyepieces that got too cold and had tight eye relief - the warmth from the eye causing the fogging.

I don't use electrics with my scopes so dew / fogging prevention needs to be of the passive type !

 

[GavStar]

43 minutes ago, John said:

I just keep my eyepieces in their foam lined case which retains a bit of heat and keeps them just above the outside temp. My EP's are all longish eye relief ones now which keeps the eyeball that little further away from the eye lens. When I have had fogging issues it's been with eyepieces that got too cold and had tight eye relief - the warmth from the eye causing the fogging.

I don't use electrics with my scopes so dew / fogging prevention needs to be of the passive type !

 

John, yes I think the lower eye relief of my panoptics compared with the mono eyepieces I use such as ES92 and Leica zoom is causing some of the problem. But after a fair bit of experimenting the panoptics are my favourite bino pairs and the wing guards (which also don't help I think) create a very immersive view so I'm resigned to use of electrics. But since I also use a dew strap on the telescope it's not too much extra work. 

[iPeace]

2 hours ago, John said:

I don't use electrics with my scopes so dew / fogging prevention needs to be of the passive type !

Well, it's all right for some...if you should fog up all you have to do is pull out another frac.

[mikeDnight]

23 hours ago, Gavster said:

I thought I'd post a note of some recent experience I've had in case it's useful for someone. I've been using binoviewers for over a year and found the views excellent for bright objects. However in the last few weeks I noticed a significant and annoying halo appearing around Jupiter. My first thought was that there was a problem with the binoviewers or eyepieces. However since the halo took a few minutes to appear I worked out that it must be due to my eyepieces dewing up. Also I think my use of wing guards made the situation worse but it's a bit odd that I don't remember this last year. So I ordered some eyepiece dew straps from flo this week, they turned up yesterday and the halo did not reappear when I used them yesterday - success. I've got a few more wires to deal with but very pleased that the issue has been resolved.

Incidentally there was some very good seeing at times last night. I had extremely crisp views of the GRS and could count 11 different regions across the surface. Views were much like the attached with a bit less detail in the bands themselves (GRS was  brighter orange and stood out more though)

I've had exactly the same problem! It's never happened before but this year the halo appeared after the binoviewer and eyepieces grew cold. The warmth from my face caused the problem, so i resolved the issue by sticking my head in the freezer for fifteen minutes. ? The eyepiece  dew straps sound like a better idea! (I was only joking about the freezer thingy by the way, just in case anyone says "well Mike does it!")

Mike 

[Stu]

48 minutes ago, mikeDnight said:

I've had exactly the same problem! It's never happened before but this year the halo appeared after the binoviewer and eyepieces grew cold. The warmth from my face caused the problem, so i resolved the issue by sticking my head in the freezer for fifteen minutes. ? The eyepiece  dew straps sound like a better idea! (I was only joking about the freezer thingy by the way, just in case anyone says "well Mike does it!")

Mike 

Is that why the grin is always frozen onto your face Mike?  

[mikeDnight]

I've never really noticed the grin Stu!

I've heard that it takes fewer muscles to smile than frown, so i guess its an indication of me being lazy.