Question about Meade ETX-90EC (325 x 90mm) Telescope

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I have a Meade EXT90. A black dot appears in the middle of every object I view (Jupiter, Mars, etc) with the exception of the moon. Any ideas on waht that might be? Thank you.

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The black dot means you are way out of focus.

In an ETX90 Mars will always be a TINY disk, except under extreme magnification.

Jupiter is also a small disk but a little bit bigger.

Next time you try for Jupiter focus on the MOONS until they are tiny points of light like little stars.

Also certain eyepieces have this as an unwanted trait. Try another eyepiece -- start with the one with the largest number written on it which will be your LOWEST magnification.

Posted on Sep 09, 2010

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How to use my telescope to stare better at moon, venus ...etc

1. Download stellarium at (free) This will tell you where to find the planets.
2. Do not use the erect image eyepiece for astronomy, It is for terrestrial viewing only.
3. Buy a moon filter. They are inexpensive ($12 at Agena Astro and others)
4. Huygens (H20, H12.5) are VERY cheap eyepieces,They have narrow field of view and low contrast. Purchase a good plossl or better eyepiece, you will really see the difference.
5. The SR4 (symmetrical Ramsden) is another cheap eyepiece. Avoid eyepiece designs that were invented in the 1700s. See item 4 above.

Mar 16, 2013 | Optics

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Cant see anything through the view finder

1. During the day, use the 17mm eyepiece on a object outside (telephone pole, water tower, etc) then align the finder to what you see in the scope.
2. Put in the 7.5mm eyepiece and fine align the red dot finder.
3. At night, point the finder at the moon (less than half moon or the image is too bright without a moon filter) Use the 17mm eyepiece.
4. Once you see the moon, switch to the 7.5mm lens and enjoy.
5. Download Stellarium or any free astronomy software and see what is in your sky tonight. Your scope should be able to see Jupiter and its moons easily.(Saturn, Mars and Venus when the time is right) Open clusters like Pleiades will be nice is this fast scope.
5. If stars are not sharp, you may need to collimate the scope. Look online for general instructions.

Nov 14, 2011 | Optics

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I have a meade 40AZ-P telescope How do you set it up to view objects. It shows nothing?

This is really not suitable for viewing objects in the night sky -- except for the moon possibly. It is only 40mm ---- a pair of 10x50mm binoculars has more like gathering power than this small refractor scope.

Just put the eyepiece with the largest number written on it into the diagonal at the rear of the scope (the focuser) take the scope outside during the day time and practice focusing on a distant object. The moon should be your first target at night. Again this scope is really not suitable for viewing the night sky.

Aug 13, 2011 | Meade EU-40 AZ-P Telescope

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Hi, a few days back I purchased Nexstar 4SE. I set it up exactly how it says in the manual still I cannot see any magnifying views from the eye piece. While aligning the telescope I can find the moon from...

Stars will always appear as points. It is not possible to magnify them enough to see them as disks because they are all extremely far away. A telescope will however show you stars and other objects that are too dim to see with the naked eye.

You will be able to see the planets as disks, and even features on the planets, such as the bands on Jupiter, the rings of Saturn and the phases of Venus, and also moons around some planets. There are other objects that will show more detail when magnified, such as nebula. You will be able to see a lot of craters and other detail on the Moon.

Your problem is simply that you are not pointing the telescope at these objects. This seems to be one of those telescopes that "automatically" finds objects, but these so called "go to" scopes only do this when they are set up properly. I can't say what step(s) you have missed, but clearly even if the scope thinks it is pointed at the moon, if you can't see the moon, it is NOT pointed there. The Moon will fill the field of view even with the least powerful eyepiece. If you are seeing stars as points, then the eyepiece is focussed and working properly.

Jan 13, 2011 | Celestron NexStar 4 SE Telescope

1 Answer

I cant see anything through my telescope

New telescope users are taken by surprise at the difficulty of just pointing the telescope in the right direction to see anything. The field of view is quite limited, especially if you are using a high power eyepiece. The higher the power of eyepiece on a telescope, the dimmer the image, the more difficult to aim it at any chosen object, and the more difficult to focus. When the scope is not focussed, even if there are stars in the field of view, they will only be faint blurs.

It is best when you are starting out with a telescope to try it with the least powerful eyepiece (the one with the highest number) to begin with, until you become more familiar with how it works. Do NOT use the Barlow lens if one came with the scope.

The finder scope is meant to help you get the main scope lined up on the object you want to view, but it won't be any use in pointing the telescope until you adjust it to precisely line up with the main scope. Telescope manuals recommend that you do this in daylight, by pointing the scope at an object on the horizon and adjusting the finder to match (never point a telescope toward the Sun!). Once you have a tree or mountain peak in the center of the main scope's image, you can then adjust the screws around the finder scope to get the crosshairs (or red dot) centered on the same object. It is very difficult to do this job in the dark, especially as objects in the sky are constantly on the move.

You will find that there is a very wide range of movement in the focus mechanism, because different eyepieces focus at different points, but the actual focus range for any eyepiece will be a small part of the overall range afforded by the focusing mount. It is much easier to familiarise yourself with this in daylight.

At this point you will learn that astronomical telescopes usually show an upside down image. There is a good reason for this- erecting the image needs more bits of glass in the light path, which reduces the amount of light and increases aberrations. Even if this is only slight, astronomers prefer to avoid it, and they don't really care which way up the Moon or Jupiter appear. It is possible to fit an erecting prism or eyepiece to most astronomical telescopes, and some of them come with one, but one wouldn't bother to do this with the small finder scope.

Once you have done the above, you can try the scope at night, on an easy to find bright object like the Moon. Looking at random stars will probably be disappointing, as they don't look different under magnification. You will have to find planets, star clusters or nebula to see anything interesting. You will also find the the object you are looking at swims out of the viewing field, and you must continually move the scope to follow it. This will be more pronounced at higher magnifications. Again, use the least powerful eyepiece. Small scopes are often advertised as having unrealistic powers (300, 500) which can never be practically achieved. You just get dim blurs.

There is an excellent website for beginner telescope users at THIS LINK

Jan 07, 2011 | Meade 60AZ-M Jupiter Telescope 60mm...

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The images of deep sky objects (such as M31 M8 ...) I get with my LXD75 (SN 8") are faint. The images of the solar system (Moon, Jupiter...) are decent. Should I proceed to a collimation ?

NO- the objects are much dimmer than the planets and your camera must take a LONGER exposure to get an image.

Collimation makes stars and planets "sharper" but NOT BRIGHTER.

Many deep sky objects require 10-15 minute exposures!

Aug 08, 2010 | Meade LXD75 8.0"/203mm f/4.0 Telescope OTA...

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I"ve been an amateur astronomer for "over" forty years, started when i was eight. Stars aren't that impressive, most look the same....i spend my telescope time with a cheap $200 21/2 inch "Refractor" and have seen all planets except pluto, i had to use a 41/2 inch refractor just to be able to view Neptune and just barely saw it and yes it was Blue!! Refractors are best for planet viewing. Dont waste your time with viewing Mercury or Venus...not impresive! The best looking (but not in the next few years because of ring alignment) is Saturn...hurry up and you might still get a chance to see the rings a little before they go into what i call hibernation mode, they'll make a straight inclination though the planet which makes for not so impressive most impressive and one i view the most is Jupiter and its for moons Calisto, Ganymede Io, and will always see these in different orbits. But i just use a pair or Celestron Binoculars 15 x 70s..i use them to look at the Moon, Mars, Jupiter, Saturn, Comets, overhead comunication Satilites passing bye..and the most awsome of them all the "Orion nebula" colors are outstanding, and if your real good at knowing your constellations you can locate the Andromeda Galaxy. It'll look like a buffy cotton ball with binoculars..dont view the sky ever with a full makes for poor viewing,but this is where the Reflectors like a 4"Newtonion or lot bigger like at least an eight inch Cassigrain..these telescope are made to view whats called "faint fuzzies", Nebulas, Galaxies, star clusters etc. 40 years ago i cold look up in my local skys and not have to worry about light i go out to the deserts with just my binoculars...they are so convienient. Start to learn the sky with"ll be well worth it! The one Great thing about binocs is that everything you view is right side up as opposed to telecopes upsidedown. To locate planets they will track within 10 degrees in the path that the sun takes. If you look and see some really bright stars that dont twinkle, chances are that it will be Jupiter, Saturn or Venus..but you will only see Venus in the early mornings or late evenings..Mars is a little trickier, sometimes its small and red and every few years it can be as bright as Jupiter when its at it closest to the earth!
type in this link i think above i think you enjoy! later.

Apr 02, 2010 | Galileo (G118DX) Telescope

1 Answer

Hardin Optical Deep Space Hunter model DSH-6

your telescope appears to be a newtonian reflector on a dobsonian mount. This type of scope is basically a point and shoot design, simplicity itself and many experienced astronomers swear by them, for there ease of use, set-up time etc.
The number 6 in the model number denotes the aperture (size of mirror) in inches. This is a good starter scope (much better than these small scopes that boast 525 X magnification) and with it tou will be able to clearly see Jupiters four main moons and the planets cloud belts. You will be able to see Saturn and it's ring system. Many nebulae, star clusters etc will become visable, that were invisible before.
Getting started with this kind of scope is pretty easy even for an absolute beginner. Set up the scope on a flat even surface, putting it all together should be self-explanatory. Insert the lowest power eyepiece (Usually the one with the biggest lens, and the one with the biggest number i.e. 40mm) and begin by pointing the open end of the scope at a bright object in the sky. To get you going with a bit of a buzz, I suggest Jupiter. Jupiter rises in the SE at 20.50, and is due South at around half past midnight, Look for a bright star that doesn’t twinkle to the right of the moon at about midnight, and that’s Jupiter!
Whilst looking through the eyepiece, carefully move the scope back and forth, up and down in the general direction of the planet. Remember, you are only looking at a very small part of the sky, probably about the size of a full moon.
It is unlikely your scope will be in focus at this stage so what you will find will probably look like a doughnut. When you find this “doughnut” you will need to focus. Adjust the focus knob until you see a crisp image of a small disk. If you are in Europe, you will see three bright moons (two on one side and one on the other) the fourth is hard to see tonight, but if you are lucky, you may glimpse a view of the shadow of this moon (Europa) as it crosses the disk. On the East coast of the US, you will also see three moons clearly, the fourth, Ganymede. Is still in Jupiter’s shadow at half past midnight, but by 1pm, it will become visible as it moves out of the shadow.
Keep looking for Ganymede during this half hour, it makes interesting viewing, and gives a sense of realism and motion to the whole event.
Try using different eyepieces as you become more accustomed to your scope, everything you see is upside down and back to front. Using different eyepieces will require re-focusing, but with a bit of practice, it will become second nature.
Finally, adjusting your finder scope. You will notice that the finder is held in place with two (sometimes three) adjustable screws. It may be best to set the finder scope up in the daytime. First find a distant object in the main scope (the further the better) a chimney pot on a distant roof etc. Then using the adjusting screws, centre the same object in the finder. It’s a bit fiddly at first, but you will get the hang of it. Then when night time comes, finding celestial objects is much easier. First locate the object in the finder scope, centre it, and the object should be in view in the main scope.
Hope this helps to get you going.

Kind Regards….Dave

Jul 16, 2008 | Hardin Optical Deep Space Hunter 6 (240 x...

1 Answer


What eyepiece do you have in the scope when trying to view the sky? (in mm)
I recommend starting out looking at the moon with the largest eyepiece you have (25mm, 20mm etc.). It is an easy target and is very impressive. Stars tend to look pretty much like little points of light in a refractor such as this anyway. Pretty boring.
Try Jupiter after you've got the moon down. You can work your way to Saturn's rings after that.

Jul 04, 2008 | Optics

1 Answer

Poor viewing

You don't state if the collimation is a plain view through the back plate at the sky, or with an evepiece. The description that you gave suggests that that is a view through the telescope back without an eyepiece. The images in the Meade manual are at high power (200x) on either side of focus. What you want to see is circular rings around a star on either side of the best focus point. If the rings are not concentric, then the collimation is off. Other factors can affect the clairity of the image, such as dirt on the optics (need to be really bad to affect the image), or you may be using a poor quality eyepiece.

Jan 13, 2008 | Meade LX200GPS Telescope

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