High magnification issue ??

I have a 12.5 inch, open truss, f4.9 Dob.

When I am using it at lower magnifications (50x - 150x) everything is as expected.
Even at about 200X , moon views are as clear and steady as I expected.
However, the last few times I have been "splitting doubles" (200X to maybe 400x) I have run into an issue that I really don't think I had a few month ago.
As the pair moves across the FOV the image becomes very "hazy" for a second or two and then reverts back to "clear". This effect will happen 2 to 4 times as the pair moves across the field. At first I thought my breath was condensing on the EP, but that was not the case (I held my breath and it kept happening) . I changed out EPs but the effect remained, independent of the EP used.

I guess that the best description of what I see …. It looks just like what you might expect of a haze, condensation, on the EP. It appears and then goes away.

The primary looks Ok .. a little dust, but I am in Arizona: so what’s new.

The secondary appears to be suspect.
Issue #1
It has a lot of dust, or something, that won’t blow off with my best efforts using my hand squeeze pump ( I guess that’s are reasonable name for it).
Is this possibly due to condensation on the secondary?
It has been pretty cold here (for Arizona anyway ) and maybe I was not careful enough going from the outside to inside. But it would seem to me the primary would suffer more from condensation than the secondary ….. yes ?
Also….. it may be dust and other atmospheric crud.. I don’t have a separate “bag” or cover for the secondary when the scope is not in use. Almost all of the “storage time” is while fully assembled, with shrouds covering all the open truss and optical openings. All storage time is indoors.
Should I have a secondary “bag”?

Issue #2
When I shine a light across the secondary at a low angle I can see several “lines”.
There are maybe 3 to 6 lines and they are 1 to 4 cm long. I assume these to scratches from a past cleaning ( I am not the initial owner) that was not done as well as it could have been. Is it possible these are the root issue? I thought ( I still think) that because you view the entire image from all points on both the primary and secondary, in a reflector, that minor flaws in either a averaged out.
Maybe this ain’t so true at higher magnifications … ?

Anyway ……
If this is a dust and dew issue I can gear up for my first “cleaning’ experience.
If it is scratches … I’m screwed and shopping for a new one …. , right ?
If it is something else …I’m clueless.

Comment/advise please.

Hi Brooks,
No worries, this is atmospheric disturbance and not your optics. Happens all the time. This is what people call moments of clarity.

Hi Brooks.
I hope you're enjoying the scope, otherwise.
That's a pretty high quality Antares secondary,
and I don't recall having any problems with it.
The coatings are durable enough that they should not be easily scratched.
In any case, I never found the need to clean the secondary,
though I did give the primary a good spring cleaning or two.
Sounds like you've developed a substantial dust layer,
and perhaps there are "scratches" in it.
Hard to say without seeing it. Can you post a picture?
Maybe a cleaning would help resolve things.
Let's see what other's have to say...
Linton

Brook
Sometimes spider webs can look like scratches. Once looking down on my primary it appeared to be scratched everywhere until I realized that a spider had taken up residence in my OTA.

Brooks:

As others have said, the issue here is atmospheric stability, commonly known as "seeing." The seeing changes with time, some nights the air is stable and images are rock solid once the telescope has cooled down. Other nights the stars are big fuzzy balls and there is nothing that can be done. Most nights are some combination of these with moments of near perfect seeing.

All the light that you are seeing from an individual star passes through a column of air that is 12.5inches in diameter and reaches 60miles or more to the outer edges of the atmosphere. If that air is not stable, then it can cause small pertibations in the path of the light which disturb your otherwise fine views.

Seeing is the reason it was worthwhile putting the Hubble into space.

Jon

What was the temp outside when this happened? Reason I ask is that this has happened to me on occassion where everything "looks" like the EP has gotten fogged, but it has not. For me it only happens when it's cold outside and my eyes are producing tearing due to the cold. So when it starts happening I just rub my eye dry and all is fine again until the tears from the cold start up again.

If you don't already use this it helps you get an idea of what your viewing session may be like for any day. Bookmark it as one of your tools.

http://cleardarksky.com/c/Phoenixkey.html

There is a comparison I have read for looking out of the atmosphere from sea level, imagine you are on back at the bottom of a pool in 8 feet of water and looking up. The amount of water between you and space is comparable. Kind of odd way to look at it, but it brings the visual home, now the other thing I have read is that when you get to 10,000 feet above sea level you are above 33% of that water in the atmosphere. Food for thought when picking a dark sky site to observe from.