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Can't focus on stars my Skywatcher Heritage 130p


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Hi

I am very new to this star gazing world. I have Skywatcher Heritage 130p. I can focus pretty good on moon, but when i try to focus on stars when using 10mm eye-piece or 25mm eyepiece with barlow, i find it impossible to focus. I only achieve good focus with my 25mm eye piece i.e in 26 magnification. Anyone got an idea why i fail to focus... ?  i have done collimation using laser collimator. 

//Rizwan 

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Use a bahtinov mask  without the barlow on a bright star , get your spiking the same length on all sides that's focus. If it doesn't check your collimation. I used to use a laser collimator but, since found that my pinhole eyepiece does the trick with less fuss. Make sure the black dot is in the absolute center of the donut ring.

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It's possible the seeing condiditons did not allow for higher magnifications. In my 10x50s or 9x50 finder the moon is always sharp, but in my scope at 36x or higher I start to see wobbling due to atmospheric seeing.

If at these higher magnifications the moon still looks sharp, but the stars do not, it may be collimation.

I had found when I looked at the double cluster in my scope that dimmer stars tend to look less sharp than brighter ones, probably due to the way our eyes see detail in low light?

    ~pip

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Hope you don't mind me asking but are you using it outside?  Through the glass of a window would cause all sorts of problems.

Focusing with one ep should be the same as with another.  - though the 10mm might be harder to use.  If you can focus on the moon with the 10mm you should be focused on stars too - i.e. without touching the focuser.

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  • 4 weeks later...

Sorry for the delayed response. My problem stays as it is but may be now I can give more details

I am observing from my room with Windows open. The temperature difference should go away after few minutes. I did go outside as well. The problem stayed

Today I tried to focus on Jupiter from out doors . I could see its moon as well but I couldn't see the Jupiter bands and red spot. I couldn't see any detail on Jupiter. I was at 130x.

The problem is I don't get sharp images. I see I have trouble with Focuser. It is always shaky. Other than that I don't know. I am new to it and cannot judge seeing condition. I observed when I sky was crystal clear

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Out of a window will have thermals as the room will be constantly heated by the rest of the house and heat will be constantly radiating from the walls of the house.

When outside did you give the scope half an hour to cool down?

You can try making the focuser easier to use by adding something to make the knob bigger. I've seen various posts on this forum where people have used lollipop sticks or marmite lids to provide a bigger leaver and better fine control.

The red spot is very hard to see and it won't be red at that aperture but you should be able to see the main bands if seeing is good and you are well focused / collimated.

The sky can sometimes be very clear but high level winds will stop you achieving good focus at high magnification.

/Dan

Sent from my iPad using Tapatalk

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Though you let the temperature stabilize in the room before trying to view, you can still be inviting a great deal problems. Other places in the house are still warm, and this will disturb the air-currents in close range to the building itself. Outdoors is the place to be, and do let the telescope adjust for awhile before viewing. As for the sky being clear, this can be deceptive. There can still be turbulence in the upper atmosphere that remains invisible to the naked eye - though a magnified view through a telescope reveals it. Sometimes the sky will appear rather murky, but have excellent 'seeing' conditions. It takes practice to get a good idea of what you'll likely see, or not.

I would suggest you try your telescope during the daytime on a distant object with both the 25mm and 10mm. If you get sharp views, this will help us begin to rule out your focuser. Do check the bolts though to make sure they are snug - but not overly tight.

Don't worry, you'll get this sorted in due course.

Dave

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You may not have a problem, apart from the obvious things people have already pointed out. The quality of your ep will make a massive difference depending on what it came with.

The thread below will give you a really accurate view (no pun intended [emoji846]) as to what to expect visually:

http://stargazerslounge.com/index.php?/topic/196278-What-Can-I-Expect-to-See%2E%2E%2E%2E%3F/page__view__findpost__p__2060941

Clear skies!

Dazzyt

Skywatcher 150P

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if you are getting good focus without the barlow it could be that 1) to much mag though this is doubtful as the 25mm+barlow is lower than the 10mm on its own (assuming its 2X)

                                                                                                    2) the focus point is simply not achievable with the barlow (this is my bet)

                                                                                                    3) faulty barlow

When I owned a 130p Heritage, I didn't use barlows as I preferred eps on their own. Not sure if this is of any help but it may point you towards finding a solution. best of luck :)

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have the heritage 130p also  and havent had much luck yet with stargazing.  i can get a nice sharp pinpoint on the 25m  but  way out of focus on the 10 and absolutly no luck with the barlow  alth its a 3x  so didnt expect too much.

checked yesterday afternoon with a look at the moon and was nice sharp defination on 25mm  but  couldnt realy seem to get the same sharpness with the 10mm.

also have some other eyepieces 12mm 20mm and 6mm  and view wasnt any better with these, alth they seem rather cheap n nasty (came with a jessop scope)  so didnt expect much.

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have the heritage 130p also  and havent had much luck yet with stargazing.  i can get a nice sharp pinpoint on the 25m  but  way out of focus on the 10 and absolutly no luck with the barlow  alth its a 3x  so didnt expect too much.

checked yesterday afternoon with a look at the moon and was nice sharp defination on 25mm  but  couldnt realy seem to get the same sharpness with the 10mm.

also have some other eyepieces 12mm 20mm and 6mm  and view wasnt any better with these, alth they seem rather cheap n nasty (came with a jessop scope)  so didnt expect much.

130p should look decent at 65x... My 130 (900mm) is good at 72x (barlow+25mm) (limited by seeing). Perhaps the faster focal ratio is more taxing on the 10mm EP for the 130p? I've also heard that the 10mm EP is pretty bad in general so that could be the problem.

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If you start with the focuser fully extended and then wind it in as you look at a star you should see a blurry disk that contracts to a sharp point at the focus and then expands to a disk again as you continue winding the focuser in. If you try this using the 10mm do you see contraction and expansion with no sharp focus point or do you just see contraction until the focuser cannot be wound in any further? If it is the latter option try reducing the amount that you are extending the main tube by about an inch/25mm and see if that allows you to find the focus point with the 10mm.

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I saw the Great Red Spot earlier this year with a 130mm reflector as Jupiter set at dusk at around 19° elevation.  So, conditions being good, when the GRS is actually visible (Jupiter's rotation) it should be visible at around 150x magnification with a 5" scope. Jupiter is notorious for getting 'woolly' and can look unfocused if there is atmospheric turbulence/thermal interference etc. I was lucky that time, and I knew the spot would be visible. In the dusk light it appeared a light brown colour, but I knew what it was.

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I've often found Barlow's are responsible for more beginners allowing their new telescope to end up gathering dust and the hobby being abandoned than other causes. Which is why I break with my usual habit of not suggesting the highest cost equipment like eyepieces and Barlows to newcomers when we come to the Barlow.

A good Barlow will neither dim or blur (vignetting) the image one is seeing though the eyepiece (EP). Many Barlows these days aren't bad - like they once were - but can still be an issue. I suggest one save their money and spring for a top-drawer Barlow like a TeleVue. They don't cost that much more than the middle-of-the-road models, and they are worth the investment as they will work as they should forever, with a bit of care. Higher powered EP's - those with short focal-lengths like a 10mm or 6mm - should also be chosen carefully. Talk to people with telescopes like what you have and see what they recommend. A mid-level Barlow and a generic short FL eyepiece can be a recipe for poor focus issues.

Clear & dark skies,

Dave

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I think Dave in Vermont is probably right about it being a faulty or cheap Barlow. This Sky-Watcher Barlow (below) was a give-away with one of my telescopes. It is virtually unusable due to focus issues. Even a decent Celestron shorty Barlow is far superior, although I agree about the TeleVues. 

IMG_20151030_190546_zps6ke6mkbl.jpg

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I've often found Barlow's are responsible for more beginners allowing their new telescope to end up gathering dust and the hobby being abandoned than other causes. Which is why I break with my usual habit of not suggesting the highest cost equipment like eyepieces and Barlows to newcomers when we come to the Barlow.

A good Barlow will neither dim or blur (vignetting) the image one is seeing though the eyepiece (EP). Many Barlows these days aren't bad - like they once were - but can still be an issue. I suggest one save their money and spring for a top-drawer Barlow like a TeleVue. They don't cost that much more than the middle-of-the-road models, and they are worth the investment as they will work as they should forever, with a bit of care. Higher powered EP's - those with short focal-lengths like a 10mm or 6mm - should also be chosen carefully. Talk to people with telescopes like what you have and see what they recommend. A mid-level Barlow and a generic short FL eyepiece can be a recipe for poor focus issues.

Clear & dark skies,

Dave

I think Dave in Vermont is probably right about it being a faulty or cheap Barlow. This Sky-Watcher Barlow (below) was a give-away with one of my telescopes. It is virtually unusable due to focus issues. Even a decent Celestron shorty Barlow is far superior, although I agree about the TeleVues. 

IMG_20151030_190546_zps6ke6mkbl.jpg

I don't seem to have any problems with my SkyWatcher 2x barlow (give-away with my 130 EQ2) and even when I combine it with the SkyWatcher 10mm that came with the scope for more magnification than people would normally recommend for its aperture (180x) the image is kinda fuzzy, but definately not unusable or unenjoyable. Why, just tonight I was looking a the moon at 180x and found it the best combination of glass I put in my focusser. Although the really low exit pupil may have made me a little biased (0.7mm)... since it removed the need for me to wear my glasses at the eyepiece.

Considering that my scope has a spherical mirror (as opposed to parabolic), is combining both a famously "meh" barlow and 10mm EP, I was surprised that it was usable at all... Mind it's the only scope I've ever looked through so my standards may not be as high as other's...

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I don't seem to have any problems with my SkyWatcher 2x barlow (give-away with my 130 EQ2) and even when I combine it with the SkyWatcher 10mm that came with the scope for more magnification than people would normally recommend for its aperture (180x) the image is kinda fuzzy, but definately not unusable or unenjoyable. Why, just tonight I was looking a the moon at 180x and found it the best combination of glass I put in my focusser. Although the really low exit pupil may have made me a little biased (0.7mm)... since it removed the need for me to wear my glasses at the eyepiece.

Considering that my scope has a spherical mirror (as opposed to parabolic), is combining both a famously "meh" barlow and 10mm EP, I was surprised that it was usable at all... Mind it's the only scope I've ever looked through so my standards may not be as high as other's...

Sky-Watcher give-aways are pretty good for what they are. The 25mm MA is quite usable and the 10mm isn't that bad. My SW Explorer has an 'unfashionable' spherical mirror as well, and find it works fine. I don't think there is much need for a parabolic mirror under 150mm anyway, plus the spherical 130mm  gives a better f/l.

Sky-Watcher diagonals are quite usable. It could be that the quality control varies with some products. I know two people personally who have similar problems with their SW Barlow give-aways, yet I've talked to several on forums who are completely happy with them. 

BTW, depending on whether you believe that you shouldn't exceed 50x or 60x per inch of aperture, the maximum resolution magnification with a 130mm mirror would be 255x or 306x respectively. I've had pretty sharp images of the Moon (although thermals were evident) with my 102mm Mak at 236x (11mm TeleVue Plossl plus 2x TeleVue Barlow).

Using the 130mm (5.1") Explorer (with the aforementioned unfashionable spherical primary) I have had sharp images of Jupiter and Saturn at 180x, and good images of Saturn at 270x (10mm Luminos combined with 3x Barlow), so don't be afraid to push your Explorer a bit. 

rocketgrenade1_zpsoq2n1v5f.jpg

The 10mm Luminos has an AFOV of 82°, an eye relief of 12mm and a field stop of 17mm. And you'll need all that just to keep Saturn in frame at 270x due to RA.

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Spherical mirrors are not unfashionable, I gather reading posts work fine in longer length telescopes. They are cheaper to make so keep the costs down. Short f5 telescopes are better with a parabolic mirror and the shorter focal length also make them fussier for better eye pieces.

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I was joking about spherical mirrors lol. I believe you are quite correct though and they are easier and cheaper to manufacture. Under six inches I think there is no difference compared to a parabolic and in fact can be less troublesome. As far as I can tell parabolic mirrors are the norm in scopes above six inches and keep the focal length manageable with OTA size. Astrophotographers also prefer faster scopes. There is a parabolic 130mm Explorer version with a 650 f/l. It shortens the OTA somewhat but a 10mm eyepiece will only give 65x. Believe it or not, I've read on forums where people have returned scopes less than 150mm with spherical primary mirrors to be replaced with the 'superior' parabolic version. I think the confusion arises when manufacturers try to aggressively advertise certain telescope features. Celestron really push the concept of their AstroMaster 130 having a parabolic mirror. Fortunately I'm too cynical to be taken in by advertising most of the time. Well ... mostly lol.

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