#1  
Old 29-06-2018, 06:31 AM
Adam101 (Adam)
Registered User

Adam101 is offline
 
Join Date: Jun 2018
Location: United States
Posts: 6
Question Help with my telescope

Hello, I bought a reflector telescope and I cannot get it focus on anything other than the moon. I thought it wasn’t culminated but after buying a laser culminator I still can’t focus on other planets like mars or Jupiter, they come out like a fuzzy ball. The only thing I could think of is that there is a flood light at the end of my house but I don’t stand in the light I stand in the dark. Does anyone have any suggestions on what I may be doing wrong. Thanks
Reply With Quote
  #2  
Old 29-06-2018, 07:20 AM
N1 (Mirko)
Registered User

N1 is offline
 
Join Date: Oct 2013
Location: Dunners Nu Zulland
Posts: 1,661
Hi Adam, welcome to IIS. If by focusing on the moon you mean being able to see detail with some clarity (such as the craters), then you absolutely should be able to get it to focus on planets too. The 3 most likely causes of not doing so are:

- scope is out of collimation (disregard if you were satisfied that this was achieved when you bought, and hopefully used, the laser collimator)
- scope was not pointed at the right target (a star will never show any detail but may appear fuzzy when out of focus or magnified too much)
- poor seeing conditions (atmospheric disturbance over your observing site can dramatically reduce the amount of detail you see)

Most reflectors show a black disk inside a bright one when defocussed so in order to focus, ensure this is not the case)

Light pollution can be ignored for what you are trying to achieve.

Hope that helps
Reply With Quote
  #3  
Old 29-06-2018, 07:23 AM
OneCosmos's Avatar
OneCosmos (Chris)
Registered User

OneCosmos is offline
 
Join Date: Apr 2010
Location: Brisbane
Posts: 537
Hi Adam,

Firstly congratulations on the new telescope. Secondly, in the interests of helping the device you purchased is actually a collimator and thus your scope is collimated

It might be useful to know what make and size the telescope is, but that wouldn't fundamentally affect its ability to focus - or shouldn't.

If you couldn't get it to focus at all that would be a simpler problem that would have an easy enough fix (your scope probably requires some extension tubes in front of the eyepiece. If it focusing on the moon, however, it should be reach focus on other objects too.

What eyepiece are you using and what else have you pointed the scope at? If the eyepiece is providing too high a magnification for perhaps a small scope you may just be not seeing a very large field of view and the view may be very dim.

Provide more details please and I'm sure help can be provided.
Reply With Quote
  #4  
Old 29-06-2018, 07:34 AM
Allan_L's Avatar
Allan_L (Allan)
Member > 10year club

Allan_L is offline
 
Join Date: Mar 2008
Location: Central Coast NSW
Posts: 3,336
Hi Adam.
Welcome to IceInSpace

If the scope you have is a Skywatcher, (and this happens regularly with these) please make sure you do not have Both the 1.25" adapter AND the 2" adapter in the focuser together.


If that's not the problem, then a bit more info is needed.
Scope type and size.
Eyepiece being used.
Target being viewed.
Anything else in the focus train (eg barlow, filter,)

Generally, the planets will actually look like fuzz balls if you try to magnify them too much, especially if low in the sky, and/or atmospheric conditions are messy.

Hope we can help
Reply With Quote
  #5  
Old 29-06-2018, 11:41 AM
Adam101 (Adam)
Registered User

Adam101 is offline
 
Join Date: Jun 2018
Location: United States
Posts: 6
Thanks for the replies my telescope is a 6 inch twin star and I was using a 6mm lense on mars and Jupiter both were fuzzy but the moon was clear. I bought a laser culminator and used that but they were still blurry even though the skies were clear that night.
Reply With Quote
  #6  
Old 29-06-2018, 11:57 AM
mental4astro's Avatar
mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
If the Moon was clear and sharp, it is odd that Mars and Jupiter would be just a fuzzy blob, regardless of collimation.

Surrounding flood lights wouldn't be the issue either.

Would be more the case of poor seeing affecting the image. "Seeing" is the thermal currents in the atmosphere, and if these are very active, then the more magnification that you use the more the image degrades, and yes, then Mars and Jupiter can appear as fuzzy blobs. Especially using a 6mm eyepiece. Because the Moon is a really big object, more of it will "focus" than a small little blob that is a planet.

When you looked at the Moon, did you notice the image shimmering? This shimmering is the tell-tale sign of poor seeing. With good seeing conditions, the image is tack sharp and does not shimmer or go in and out of focus.

If seeing conditions are poor, the only thing you can do is drop the magnification. If you really want to up the magnification, you will just need to wait for a few hours in the hope that things improve, or try again another night. Seeing can change very quickly, one moment being brilliant, and then it's gone to crap in an instant. And seeing can be different in different directions of the sky too - it isn't necessarily uniform as air currents can also travel in bands, not as one blanket.

Collimation, while important, won't change your ability to get the scope to focus. If the scope is out of collimation, you will see a distortion in the image, like it is smeared in one direction, but one part of the image will still be sharp, and not a uniform blob. By all means, take your time to learn to collimate your scope, but there is a whole lot more to viewing through a scope than collimation.

Seeing conditions also don't give a damn about how big your scope is or its quality. Seeing is the one Universal limiter of how much magnification you can use on a given night. Actually, the larger the aperture, the more susceptible it is to the effects of seeing.

Oh, and be patient! The image the planets throw up is low in contrast, so you will need to let your eyes adjust and re-learn how to view under these astro conditions. If you are impatient, then yes things can appear as a featureless blob. Jupiter demands patience to see more than the two equatorial bands, and the Great Red Spot too needs a patient eye, and it needs to be visible too as you won't see it if is behind the planet. Martian features are really difficult to spot. Rush things with Mars and you won't see anything.

BE PATIENT!

Also, Mars right now is experiencing a global dust storm! The whole planet surface is totally featureless right now!!! This is VERY important to be made aware of, and I'm sure a lot of people will be viewing Mars right now and be really, REALLY disappointed as they have no idea that Mars is stuffed right now. But that's what happens every now and then on Mars. NASA is actually very concerned for one of its rovers as this dust storm may deposit so much dust on the solar panels to make it inoperative.

Alex.

Last edited by mental4astro; 29-06-2018 at 12:08 PM.
Reply With Quote
  #7  
Old 29-06-2018, 12:06 PM
Allan_L's Avatar
Allan_L (Allan)
Member > 10year club

Allan_L is offline
 
Join Date: Mar 2008
Location: Central Coast NSW
Posts: 3,336
is this it? (see photo)
If so its specs are:
150mm (6 inch) objective mirror, 1400mm overall focal length
Short tube design yields maximum 400x magnification
25mm & 10mm Plossl 1.25" Diameter Eyepieces Included

At 1400mm focal length, a 6mm eyepiece would yield 233 magnification.
That's probably a little too much magnification under suburban skies.
That would look fuzzy.
A 10mm eyepiece would probably produce a more pleasing result. (being 140 magnification)

I know the specs say upto 400 magnification, but they lie.
Attached Thumbnails
Click for full-size image (twinstar 150.jpg)
28.0 KB25 views
Reply With Quote
  #8  
Old 29-06-2018, 11:09 PM
Adam101 (Adam)
Registered User

Adam101 is offline
 
Join Date: Jun 2018
Location: United States
Posts: 6
Yes that is it thanks guys for the help and I live in the country. Also where do I look to see for seeing conditions because that makes sense that the farther it is away the better seeing conditions are needed.
Reply With Quote
  #9  
Old 30-06-2018, 01:06 AM
Malcolm
Registered User

Malcolm is offline
 
Join Date: May 2015
Location: Lismore NSW Australia
Posts: 242
Is the focus tube actually moving? Some focus racks have a locking screw on the rack, but you are still able to turn the focus knobs.
Reply With Quote
  #10  
Old 30-06-2018, 07:23 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 5,990
Hi Adam,
Did you buy the scope from a reputable telescope shop as new ?
If so,they should assist you with your problems as it should be under a 1 year warranty ( most reputable telescope shops in Australia look after your initial problems - both beginner and higher level users )

Good luck !
Reply With Quote
  #11  
Old 30-06-2018, 01:35 PM
mental4astro's Avatar
mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
Quote:
Originally Posted by Adam101 View Post
makes sense that the farther it is away the better seeing conditions are needed.
At first it may seem that the relative distance of objects is a factor with respect to seeing conditions. Reality is it makes no difference at all. Doesn't matter if it's the Moon or the furthest quasar, focus wise they are all at infinity. And they are affected by seeing conditions in the same way.

The main difference is only the relative size in the eyepiece of each that things MAY appear different. But if you look at a crater that's the same angular size as say Jupiter, the details of each will be affect n exactly the same way and amount. Contrast is another way things may appear as a reason for differences, with the Moon a stark black and white and surface features of the planets much less stark, but seeing affects everything the same way.

Alex.
Reply With Quote
  #12  
Old 30-06-2018, 09:54 PM
Adam101 (Adam)
Registered User

Adam101 is offline
 
Join Date: Jun 2018
Location: United States
Posts: 6
Thanks Alex I’ll look for a day when the conditions should be good and try it out and see and I’ll let you know. Thanks again for the help.
Reply With Quote
  #13  
Old 01-07-2018, 04:00 PM
mental4astro's Avatar
mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
Adam, a couple more pointers to help you with seeing.

Try to avoid viewing objects close to the horizon if you can avoid it. This is where the greatest amount of atmosphere is that light needs to travel through, and closest to the warm Earth. Not always is seeing poor at the horizon, but more consistently so than elsewhere.

Summer normally has worse seeing conditions than the cooler months.

Early evening is warmer than later at night, so better to be patient for the end of twilight for things to cool off.

Of course, much of this has the caveat "it depends...". You have to be practical about things too. Some objects are horizon grazers, sometimes they are only visible early evening (many comets), other times you have no choice for other reasons. And sometimes the atmosphere just doesn't want to play nice... for months on end...

Alex.
Reply With Quote
  #14  
Old 01-07-2018, 06:39 PM
RyanJones
Registered User

RyanJones is offline
 
Join Date: Jun 2018
Location: Melbourne,Australia
Posts: 1,439
Hi Adam,

I am also a relitive newbie to this dark art but I'll pop in my 2c for what it's worth. I have a 4" scope with a similar focal length. When I first started viewing the planets, I experienced a similar problem. I was looking through a 6mm neagler lense lent to me by a friend. The moon was incredible with great crater detail and beautiful shadows cast at the terminator, alas, any other solar object was an undefined ball and were extremely temprimental to focus. I ended up getting a set of eyepieces that included a 5mm 13mm and 21mm. I used the 13mm and although the planets were smaller, they focused well and gave me 10 times the detail. I packaged that with a 2x Barlow and hey presto, bigger planets and same detail. The 5mm is amazing on the moon but impossible to focus on planets. I guess what I'm getting at or that I figured out at the end of this experimenting is that once the eyepiece gets close to your scopes limit the image falls off the proverbial cliff

Only extra that I would add is that there is also a huge difference in seeing ability once the planet gets about 45 degrees above the horizon due the the massively reduced amount of atmosphere you're looking through before getting to the black stuff !
Reply With Quote
  #15  
Old 01-07-2018, 07:35 PM
raymo
Registered User

raymo is offline
 
Join Date: Sep 2011
Location: margaret river, western australia
Posts: 6,070
The maximum magnification generally recommended is around 50x per
inch of scope diameter, so 200x for a 4" scope; a bit more when seeing is excellent, a bit less when seeing is below par.
raymo
Reply With Quote
  #16  
Old 03-07-2018, 12:13 PM
sil's Avatar
sil (Steve)
Not even a speck of dust

sil is offline
 
Join Date: Jun 2012
Location: Canberra
Posts: 1,474
A general rule of telescope packages is that the eyepieces are generally cheap quality and not able to bring out the most of what the Optical Tube Assembly is capable of. so many newcomers get disappointed with astronomy as a result. the best eyepiece that are included are often the 10mm and 20mm sizes (the smaller the number the more magnified the image gets and the more magnified the blurriness gets too). Most people rarely use 8mm or smaller unless the seeing conditions are superb. If you switch to a larger number Jupiter should be much crisper but it WILL be small in the eyepiece, it always is. publicity photos give a false representation of the eyepiece experience.

The eyepieces really need to be good quality, they are a series of optical lense elements and cheaper ones tend to be poorly made with poor grade glass (or worse plastic) that introduces distortions. The dont give great contrast which is important for planet surface details. I'd say you'll be well served looking at the Baader eyepieces. Their Hyperion range may still be available affordably, but they were replaced by the morpheus range. If you grabbed say a 32 or 24mm for a nice wide field view that'll help you get around the sky and a 8, 10 or 12mm eyepiece from baader you'll suddenly find your view bursting with stars as the contrast is increased. I think currentl you are losing a ton of stars you arent aware should be there right now. You'll also get less chromatic aberations (colour fringing around high contrast edges, edge of the moon shows it strongly, these are caused by the eyepieces you have and not the OTA. You'll also get better "eye relief" making the good eyepiece easier to use and more comfortable over time.
Reply With Quote
  #17  
Old 07-07-2018, 10:16 PM
Rkonrad's Avatar
Rkonrad (Richard)
Registered User

Rkonrad is offline
 
Join Date: Feb 2018
Location: Johannesburg
Posts: 103
Judging by the focal length of 1400 and the length of the OTA the scope is a Bird Jones type with a corrector lens in the focus tube , this type of telescope is more difficult to collimate ,one needs to center dot the primary and remove the corrective lens before using a laser collimator.

If you can see the moon clearly the its in focus for planets , so you are either using too much magnification (on the moon its fine but not for planets) or in your attempt to collimate it its badly out

Oh and welcome to the forum
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 11:17 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement