Hi everyone .

I recently noticed that when I look into my scope at say jupiter for the first few seconds the image is a little blurry then the image deteriorates to a fuzzy round blob with no definition . When I look away for around thirty seconds the image gets better when I look back in the scope but not great still then agian deteriorates into a fuzzy blob . I recently had my eyes tested and they were fine I do wear glasses and have a slight stigma from I was 22 I am now 34 . Has anyone had this problem and is there anything that can be done about it .

Thanks Mark

What you describe sounds like bad astronomical "seeing". 

http://homepage.ntlworld.com/dpeach78/seeing2002.htm

http://www.skyandtelescope.com/howto/diy/3304176.html

http://www.cloudynights.com/item.php?item_id=587

http://www.weatheroffice.gc.ca/astro/seeing_e.html

Dave Mitsky

DaveMitsky:

What you describe sounds like bad astronomical "seeing". 

Or you're breathing on the EP. 

 Could it be floaters in your eye?  In case you don't know, those are those dark things that drift across your vision especially as you get older.  Sometimes they can persistently come into your central vision.

Have you determined which eye is your dominant eye?

I had some newcomers have the same problem, when I showed them how to determine which one is their dominant eye, and they then used that eye at the scope, the problem disappeared.

To find out which eye is your dominant eye, stare at an object at least 25 ft away.

Place either your left or right hand with your index finger extended, directly in front of you at arms length, so that it makes a straight line between you and your nose and the object that you are starring at.

Now while holding your finger still, and keeping the object just behind your finger, close one eye then the other, the eye that does not show the object moving to either side of your finger is your dominant eye.

Dennis

Thanks guys I do have floaters but don`t think that is the problem and I already use my dominant eye so can`t see that as the problem . Its a weird one alright .

If the image always gets worse after the first few seconds, and never clears up until you move away and then come back after 30 seconds, my guess is that you are fogging the eyepiece.

A simple way to inhibit fogging is to wrap a hand-warmer around the eyepiece (assuming you do not have a dew buster strip). Or you can try keeping a reserve eyepiece warm in your pocket, and switching out when you first start viewing ... this will delay fogging of the eyepiece for a while. Swapping out eyepieces like this every few minutes can help extend your observing time.

An eyepiece-sized dew buster strip is a very handy thing to have around.

The seeing effects Dave mentioned are generally random and variable. The view won't always be blurry, and will usually get better, then worse, then better, in a random order (unless the night is a really good one or a really poor one, in which case it won't vary much).

Sometimes I find that a combination of fatigue and eyestrain makes my eyes tear up to the point where even if I blink, or turn away and dry my eye and then go back, the view is too blurry.

I have to think that any fogging of the eyepiece would be obvious.  I've never had it happen to me that I didn't notice it almost immediately.

Dave Mitsky

I agree, Dave, but you and I have been at this for awhile. My first experience with this sort of thing happened so long ago I can't remember my thoughts about it, but I'm sure it at least momentarily confused me.

I still get brought up short by the sort of fogging that occurs merely by bringing my head close to the eyepiece (not breathing directly on it).

All that pales by comparison to the heavy dew we're having in Texas this Fall. I've never seen anything quite like it. Within a couple of hours of sundown everything is covered in dew -- even out on the Plains where we're essentially in the desert. We have had a great deal of rain, comparatively, this year and it's really starting to show up in our observing areas.

Thank I`ll check if that is the problem tonight although I don`t think it but you never know . That sounds nice being out in the desert this time of year I am sure its pretty amazing dark skies .

Mark 

Its definately not fogging guys .

That's an interesting problem, Have you tried a polarizing filter?

You mentioned that it seems to only happen when looking at Jupiter,  IF you do not have a polarizing filter, you can try to stack a couple of colored filters to reduce the glare and dim the planet.

I'm thinking that maybe its just too bright for your eyes to adjust to, give that a try and see what happens.

If this fails and it's not fogging, and your collimation is done well, and the seeing conditions is  good, then you may want to go back and get your eyes checked again. even under decent seeing sometimes an inversion layer can move in above you and temporarily cause problems with fine detail.

I sure hope that you can eventually figure this problem out,

Dennis

Have you noticed this problem when looking at star clusters?

Eye Strain!

Get yourself an eye patch from your local pharmacy and cover the eye you're not using so you can leave it open relieving the stress on the eye that you are using.

Other than that if it's not lens fogging then it is astronomical seeing and coincidence that it looks better for a short time when you take that short break and return to the eyepiece.

Star Dragon:

You mentioned that it seems to only happen when looking at Jupiter,  IF you do not have a polarizing filter, you can try to stack a couple of colored filters to reduce the glare and dim the planet.

I don't believe that the OP said that.  He used Jupiter as an example.

Dave Mitsky

It could still be fogging. Just because you don't see it when you pull your head away only says that it wasn't so bad that it took a significant amount of time to clear. Once you exposed the eyepiece to the open air again it clears up, sometime that can take a little time while others it can happen instantly. Try if you can backing off the eyepiece a little. This is another advantage to long eye-relief eyepieces. They allow air to circulate over the eye lens.

HI Dave,

I concur, my bad!

It does sound as though it may be fogging or eyestrain or, he got hit by a combination of those two along with poor seeing.

I sure hope that he can figure it out, I also have astigmatism in both eyes and I have to strain to see any detail on Jupiter, unless I have my glasses on, then all is fine, what puzzles me is that he states that fogging is not the issue.

So the only conclusion that I can come up with is that it may be eyestrain, or, he is sensitive to the bright image of the Planet and he may need to dim it a little.

I'm sure that all of us here would like to help him out.

Dennis

What kind of telescope is this? If it's a Newtonian are you keeping the object in the sweet spot, Centered?

I think the darkest things will definitely affects your eye. You are trying your best to do something to refrain away from it.

Its a skywatcher newtonion 130 mm and yes I am keeping it in the center sweet spot .

Mark

It doesn`t just happen with jupiter its with all objects . Its hard to explain every object has like a colouring fringing of orange  light like ghosting and the brighter the objects the worse it gets .