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Visual observing with LS60 - ghosts, eyestrain?

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#1 avalys

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Posted 18 February 2013 - 07:42 PM

I just got my LS60 - single-stack, pressure-tuned. It is my first solar telescope. I also got a Lunt zoom eyepiece since I didn't have any zooms in my collection.

The views are great, but I find it is very tiring to use. I have been observing at night for years without any problems, but I find that after as little as 15 minutes of observing in the Lunt I start to get pretty severe eyestrain in my left eye (I observe with my right). This manifests in sort of blurry vision in that eye that takes quite a while to clear up. It's not something I've ever experienced before with night-time observing.

I think it is a combination of factors - a) observing faint details in a fairly dark image in direct sunlight means it is much harder to block out distractions from my left eye, so I have to either scrunch my eye closed tightly or use my hand, and b) observing itself is rather tiring on my right eye, there is some kind of glare or double-image that shows up in the eyepiece (sort of a blurry, reduced-intensity ghost of the sun) and I find myself moving my head around constantly to try to get it out of the way of the image.

I bought a light-blocking curtain that I can drop over my head, but my observing site has fairly bright ground, so that only helps so much. Plus, if there is any wind, I have to use one hand to keep the curtain from flapping around too much, which means I can't use it to cover my eye.

Observing at night, I don't have a problem relaxing my left eye while my right eye is observing, and I can usually block out the image from the left even without closing it. This is impossible in daylight. I guess I could buy an eyepatch, but I'm sure passers-by already think I'm slightly insane, sitting on a stool on the sidewalk with a curtain over my head and a tripod. The addition of an eyepatch won't help this.

I have tried other eyepieces in my collection to see if they improve the double-image, but they don't, really. I can't tell if it is coming from the eyepieces or the telescope itself. Because it changes position with my position relative to the eyepiece I have been assuming it coming from the eyepiece. I thought the Lunt Zoom was supposed to have internal coatings to block this sort of thing?

#2 enes

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Posted 18 February 2013 - 08:19 PM

I think you should give Lunt Solar Systems a call . I do not get any ghosting in my LS6o pressuretune telescope . I use many eyepieces and nothing as you describe have I seen in my eye pieces . You do need to pull the diagnal out some what from the draw tube almost half way and lock it in with bottom thumb screw and then adjust focus with focus dial till you can see a sharp edge on the sphere of Sun . Then you just turn pressure tune dial till you can see prominences or surface detail . Takes a little practice just like a new Car . I hope my experience with my LS60 PT telescope is a help for you .

#3 raylal

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Posted 19 February 2013 - 07:18 AM

Another suggestion is to unscrew the pressure tuner to relieve the pressure inside and rescrew it back in all the way, then adjust to your liking. I do this every time I set up. This might help.

Ray

#4 la200o

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Posted 19 February 2013 - 08:01 AM

Try an eyepatch.

Bill

#5 bunyon

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Posted 19 February 2013 - 09:19 AM

I second the eyepatch suggestion. It's also very useful for nighttime observing.

#6 Jim Rosenstock

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Posted 19 February 2013 - 10:17 AM

+2 on the eye patch. Any decent drug store will have them for two or three bucks; no need to pay Orion's marked-up price (and shipping!).

Solar viewing comfort is all about preserving contrast, which in turn is about blocking out all possible ambient light. For my H-a observing, I use (1) a foam-board screen mounted on my OTA to shade the focuser area from direct sunlight, (2) an observer's hood over my head to block out ambient light, and (3) an eyepatch for my non-observing eye. My observing comfort is definitely enhanced by using all three!

The foam board sunscreen also helps you to not heat up too fast under that hood!

If I walk away from my solar scope for a while, I'll switch the eyepatch over to my observing eye, and naviagate the bright environment with my non-observing eye....

These measures are easy to do and get used to, and enhancing your observing comfort increases your observing time, which increases how much you see!

Sunny skies,

Jim

#7 Bill Cowles

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Posted 19 February 2013 - 11:19 AM

I use this Solar vest, really helps.

Bill

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#8 Bill Cowles

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Posted 19 February 2013 - 01:26 PM

:waytogo:.I always use my foam core board and I have added an image of the Sun as seen in an HA scope, for showing people what they will be seeing and to point out different features, like filaments.

Too, for me at my age, bino's are a way to reduce seeing floaters and give a more relaxed view, this plus the hood allow long viewing times.


Bill

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#9 rdandrea

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Posted 19 February 2013 - 01:41 PM

+3 on the eyepatch. It helps with distractions around you. I also use a piece of foam core board to keep the direct sunlight off my face. Between the two of them, I have no eyestrain problems.

How is the Lunt zoom? I have been thinking of buying one.

#10 StarStuff1

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Posted 19 February 2013 - 04:03 PM

I have a Lunt35 that uses a non-Lunt zoom. No problems. On my Lunt 60 (non PT) I use my regulae astro eyepieces. As others have said a shield can be a nice low cost accessory.

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#11 Bill Cowles

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Posted 19 February 2013 - 05:40 PM

The Lunt zoom is good and probably the best value, but I now use a Hyperion zoom, can't go wrong with either one.

Bill

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#12 Doc Willie

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Posted 20 February 2013 - 02:58 PM

Binoviewers were my solution. It seems like solar viewing, even with the measures above, e.g., a hood, is more strenuous than night time viewing. White light viewing not so much.

#13 brianb11213

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Posted 21 February 2013 - 03:12 AM

Binoviewers were my solution.

Some people find them effective. Personally I find BVs far more of a hinderance than a help, and I'm not alone.

It seems like solar viewing, even with the measures above, e.g., a hood, is more strenuous than night time viewing. White light viewing not so much.

Strenuous? Not really. You need more "eye training" to see anything in the deep red end of the spectrum & many people (the vast majority in my experience) will never see anything useful through a CaK scope / filter set but that's just because of the sensitivity of the human eye. The main issues with actual solar visual observing, in my experience, are sunburn and getting uncomfortably hot.

#14 bunyon

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Posted 21 February 2013 - 05:12 AM

Another possibility that I employ is a webcam (which I mostly use for imaging). However, even when I'm not imaging, I find it easier to see fine detail on screen in grayscale than through the eyepiece. So my imaging sessions are actually also observing sessions.

#15 WaterMaster

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Posted 22 February 2013 - 12:30 AM

When I first started using my Lunt I found I saw a ghost image as well. It finally became apparent that what I was seeing was a reflection of a reflection. The image is bright enough to reflect off of my eye, and I see this reflection from the surface of the EP. It's most obvious at low power (when the image is brightest). I use a hooded observing vest and that helps. What really helps is when I add the front etalon, which dims the image sufficiently so I hardly ever notice it.

Of course, the etalon can cause some reflections itself, which can occasionally be visible while tuning. But these reflections will move across the FOV as you change the tuning. The ghost image I described above does not move with tuning, but does move as I move my head. I've heard that binoviewers can help with this problem as well, as they decrease the amount of light striking your eye by 50%.

#16 brianb11213

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Posted 22 February 2013 - 03:35 AM

I've heard that binoviewers can help with this problem as well, as they decrease the amount of light striking your eye by 50%.

A neutral density filter is a far cheaper method of achieving a similar (or stronger) effect & the simpler optical design of a filter compared with a BV reduces the chances of extra ghost images being introduced by the "filtration".

If you're getting any perceived benefit from a BV then the cause has to be reduced eye strain, and that doesn't happen for everyone.

#17 Chucky

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Posted 23 February 2013 - 02:26 PM

<< The Lunt zoom is good and probably the best value, but I now use a Hyperion zoom >>

I have a 60DS. At one time, I tried my first generation Hyperion zoom, but couldn't stand the thing. Could never rid my views of the horrible reflection off my eyeball. Didn't matter if I used a hood or not. Now I just use several UO orthos. Perfect views with zero adverse reflections. Really wanted to use that zoom, but it just wasn't to be.

#18 avalys

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Posted 25 February 2013 - 07:58 PM

Thank you for all the advice and suggestions. I guess I will have to give in and go buy an eyepatch and simply ignore the pirate jokes.

I did call Lunt about another issue and mentioned the glare / double image. They confirmed it was the reflection of the image off my cornea. I have found that adjusting my eye position helps.

I like the idea of buying a DS module to solve this problem.

#19 frolinmod

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Posted 25 February 2013 - 08:52 PM

Darn, it looks like UO is now permanently out of orthos.

#20 avalys

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Posted 28 February 2013 - 01:45 PM

Tried out the eyepatch this morning. Wow, what a difference. No eyestrain whatsoever. I was able to observe for about 90 minutes straight without any discomfort at all. Thanks all. This is essential for solar observing, I think.

#21 rdandrea

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Posted 28 February 2013 - 02:00 PM

:goodjob:

An eyepatch has other uses as well. I am terribly left-eyed, yet my right eye is better. An eyepatch makes it comfortable to use my right eye, day or night.

Just be careful walking around with it on. With one eye, you have no depth perception. It's even worse at night.

#22 frolinmod

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Posted 28 February 2013 - 08:17 PM

Just be careful walking around with it on. With one eye, you have no depth perception. It's even worse at night.

That explains a lot of bad drivers (with seemingly no depth perception) I see on the road!






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