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SpaceFinatic

Problem with Eyepiece

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Hey, newbie here. I want to thank anyone in  advance for helping me. I recently bought an accessory kit for my 12” telescope, which came with 1.25” eyepieces and filters. However, when I went out to use them, the image I got was very blurry and white. Saturn didn’t show to have rings, and Jupiter was just big and white. My telescope has a focal length of 1500mm and I used the 6, 8, and 13 mm eyepiece, but got fairly the same view. I am old of age, so any one who can help will be appreciated, thanks.

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You have a 12" telescope which is enough to view anything with any eyepiece, so I don't know what is going on. Maybe you haven't focused your telescope properly?

Nice telescope,

Edited by Spacecake2
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Welcome to SGL, Can we know which telescope you have?

 

Edited by toshapetriji
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He/she has the 12" Lightbridge Plus has a focal length of 1524 mm, 304 mm is the aperture. (read it in another topic)spacer.png

Edited by Spacecake2
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4 hours ago, SpaceFinatic said:

Hey, newbie here. I want to thank anyone in  advance for helping me. I recently bought an accessory kit for my 12” telescope, which came with 1.25” eyepieces and filters. However, when I went out to use them, the image I got was very blurry and white. Saturn didn’t show to have rings, and Jupiter was just big and white. My telescope has a focal length of 1500mm and I used the 6, 8, and 13 mm eyepiece, but got fairly the same view. I am old of age, so any one who can help will be appreciated, thanks.

Have you checked the collimation ?

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Can you get focus on distant objects (say over 1/2 a mile) during the day?

Other than the eyepiece there's no other tubes (barlow or anything else) in the focuser, is there?

Presumably you've moved the focuser all the way from fully in, to fully out, and still can't get a sharp focus?  When you've got the focuser all the way out, try undoing the eyepiece and gently move it outwards whilst looking through the eyepiece. Can you now get focus?  (I'm wondering if there just isn't enough travel on the focuser for some reason).

Do you have any other eyepieces that do give a sharp image?

Cheers,

Mark

 

 

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6 hours ago, Starwatcher2001 said:

Can you get focus on distant objects (say over 1/2 a mile) during the day?

Other than the eyepiece there's no other tubes (barlow or anything else) in the focuser, is there?

Presumably you've moved the focuser all the way from fully in, to fully out, and still can't get a sharp focus?  When you've got the focuser all the way out, try undoing the eyepiece and gently move it outwards whilst looking through the eyepiece. Can you now get focus?  (I'm wondering if there just isn't enough travel on the focuser for some reason).

Do you have any other eyepieces that do give a sharp image?

Cheers,

Mark

 

 

Hey, I haven’t tried to look through the telescope during the day, and I don’t have a Barlow lens attached. I have a higher mm eyepiece which gives me a really sharp image when properly focused. However when I switched to my smaller mm lens (6mm, 8mm) planets seem to be white and blurry.

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9 hours ago, Spacecake2 said:

You have a 12" telescope which is enough to view anything with any eyepiece, so I don't know what is going on. Maybe you haven't focused your telescope properly?

Nice telescope,

I used my higher mm lens to focus on stars, but then when I switched to my smaller mm eyepiece, it’s just a white planet (Jupiter, Saturn). However, i tried looking at Mars and I was receiving red colour so my thoughts is that I’m just viewing a blurry image.

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I would also like to add that I keep my telescope in my garage which could get a little cold during the night. does that have an effect on the image?

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It might be that the seeing wasn't very good. I don't know where you're located, but right now in the UK, Saturn and Jupiter are low in the sky meaning the views of them are fairly poor much of the time (lots of atmosphere to look through).

If your 6mm and 8mm eps focus nicely on stars and other objects, that's almost certainly the reason.

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That's sounds like the effect you get when one or more of your optical surfaces has become fogged or misted up. Either one of the mirrors or the eye lens of the eyepiece ?

If you keep eyepieces in a cold place, they can fog / mist up really quickly as the warmth of your eye approaches the eye lens.

Do you use a light shroud with your scope ?

I found one more or less essential when I has a Lightbridge 12.

 

 

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1 hour ago, Starwatcher2001 said:

It might be that the seeing wasn't very good. I don't know where you're located, but right now in the UK, Saturn and Jupiter are low in the sky meaning the views of them are fairly poor much of the time (lots of atmosphere to look through).

If your 6mm and 8mm eps focus nicely on stars and other objects, that's almost certainly the reason.

Yeah I can easily focus on stars with a different eyepiece, it was just be the atmosphere

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1 hour ago, John said:

That's sounds like the effect you get when one or more of your optical surfaces has become fogged or misted up. Either one of the mirrors or the eye lens of the eyepiece ?

If you keep eyepieces in a cold place, they can fog / mist up really quickly as the warmth of your eye approaches the eye lens.

Do you use a light shroud with your scope ?

I found one more or less essential when I has a Lightbridge 12.

 

 

Yes! That has happend a couple of times. Usually I clean the lens with a glasses cloth and it helps. No I don’t use a light shroud, does it help with viewing?

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1 minute ago, SpaceFinatic said:

Yes! That has happend a couple of times. Usually I clean the lens with a glasses cloth and it helps. No I don’t use a light shroud, does it help with viewing?

I'd be careful about rubbing eyepieces or mirrors with a cloth if they are dewy. Better  let them dry naturally or use a hair dryer on them.

I found that a light shroud produced a number of benefits:

- kept stray light off the secondary and primary mirrors which gave me much better contrast on deep sky object. I have a fair amount of stray light my back garden !

- kept my body heat out of the light path of the scope

- kept dust / debris off the primary mirror of the scope

It made a lot of difference in the performance of the scope in my circumstances.

 

mead12lb.jpg

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3 minutes ago, John said:

I'd be careful about rubbing eyepieces or mirrors with a cloth if they are dewy. Better  let them dry naturally or use a hair dryer on them.

I found that a light shroud produced a number of benefits:

- kept stray light off the secondary and primary mirrors which gave me much better contrast on deep sky object. I have a fair amount of stray light my back garden !

- kept my body heat out of the light path of the scope

- kept dust / debris off the primary mirror of the scope

It made a lot of difference in the performance of the scope in my circumstances.

 

mead12lb.jpg

thanks for the heads up! I’ll make sure to let the mirror/lenses dry by themselves from now on. Seeing as a lot of people recommended me to get a light shroud, I’ll look into it! Thanks!

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It helps to remember the three "C"s:

--Collimation.  what tools are you using for collimation?  how are you doing it and in what sequence?  Do you check the results in a star image?

Remember, it will have to be done every time you set the scope up.

--Cooling.  Are you running the fan on the mirror all the time you observe?  it can take a large heavy mirror like yours a few hours to cool down to the ambient temperature,

and until it is at ambient temperature, the images will be poorer, especially at high powers.  Put the scope out at sunset and let the fan run.

when you start observing later, the images will be much better than if you just set it up and zoom to high powers immediately.

--Conditions.  The steadiness of the atmosphere is all-important to get clear and sharp high power images.  This will vary from night to night.  First, reduce the "local" seeing problems by

setting up on grass or dirt instead of concrete or asphalt.  Heat will rise from the hard surfaces all night and ruin the high power views.  Don't look at a planet right above a rooftop.

Roofs release daytime heat most of the night and cause turbulence in the air.  Don't look at a planet below 30° altitude if possible--the air is twice as thick at 30° as it is straight up

and it is 10x as thick at the horizon.  If you must look at something low in the atmosphere, look at it when it crosses the N-S meridian in the sky, where it will be highest. And be aware 

that when you look through a lot of air, you will also be looking at a lot of dust, smog, and water vapor, not to mention a lot more atmospheric turbulence.  Use a shroud on the scope to keep

your body heat from drifting into the optical path of the scope.  Start with low powers and slowly work up to the maximum power that yields a clean sharp image, above which the image becomes blurrier.

That point will be different from night to night and even from hour to hour.  In most places, the seeing settles down after midnight, though that is too late for Jupiter and Saturn.

But it will be ideal for Mars.  and Mars, being farther north in the sky, will rise much higher.

 

i think it sounds a lot like the atmosphere just wasn't steady enough for high powers.

On your scope, low powers are 48-120x (32-13mm eyepieces), medium powers are 120-240x (12-7mm eyepieces), and high powers are 240-360x (6-4mm eyepieces), and above that "thar be dragons", i.e. the number of nights you will be able to use and magnification up to the theoretical maximum of 720x will likely not exceed 1 or 2 per year.

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A simple way to check for atmospheric or local thermal effects on seeing is to focus on a bright star and defocus it to spread out its light into a circle.  Is the circular image nice and steady or does it wobble and constantly change?  If the latter, you're never going to get sharp images at high powers.  I'm not saying that is what is causing your issue, but it can be easily diagnosed and eliminated as a cause with this technique.

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