New Here: All Objects are Small & Blurry!

[Adam Isa]

Hello all. New to the forum, just found it by chance when looking for a new telescope.

I'll tell a brief background. Always been interested in the skies and beyond and eventually got a telescope in 2007. It's a Skywatcher 150. Not really knowing much about telescopes back then and having very little patience, I only used it to look at a few stars and the moon a hand full of times and then I left it for almost three years!

About three weeks ago I was using Stellarium and I noticed a what appeared to be a VERY bright star. Turned out it was Jupiter. Instantly my interest peaked all over again. Decided to take out the old telescope, which by now, had rusted on the nuts and bolts. Not much worked on it, finderscope was non-existent and I had no eye pieces.

Ordered some cheap ones of eBay and prayed for clear skies! Was rewarded with them seven days later! I had a 10mm and a 3.6mm. After looking at Jupiter I would just about be able to get it viewable. Thought maybe it was the eye piece or something. I had no chance with the 3.6. Even focusing it as best I could, it would still appear blurry. I had been looking at new telescopes and eventually (after much deliberation) decided on a Skywatcher 300P Dobsonian.

Went and bought it yesterday. It came with a few upgrades and was in mint condition. Got back home, set it up at sunset and waited patiently. Eventually, Jupiter had risen enough for me to see. Looked through the eye piece and there it was. the problem was, it was EXACTLY the same as the worn out Skywatcher 150. Still blurry. I tried using a 25mm, and that was the same.

I look at pictures people take and YouTube videos, and people are able to see such crystal clear images of stars, planets, the moon and nebulae etc etc, but I can't even get Jupiter to focus properly!

What could the possible causes be? Collimation, street lights, eye pieces?

The only thing I have ever been able to look at with a decent amount of detail is the moon. I feel like I'm missing out on sooo much!

Sorry for the lengthy post, all help will be appreciated!

[Llamanaut]

sounds like collimation to me... when i travel with my 300p if i dont sort the collimation out i get the same views as you describe clearish on the moon but blurred with more distant targets, if your scope is collimated you should get a clear although small well defined disc with what looks like two faint intersecting brownish lines with jupiter, the 25mm should provide a decent view in the 300p the 3.6mm will be dim at best and depending on quality possibly blurry (it will pick up more on the atmospheric seeing conditions)

Lots of people swear by cheshire collimators which are fairly inexpensive, personally i wouldnt leave home without my hotech laser collimator (£98 though it aint cheap) I collimate every time prior to using my 300p, some people dont bother at all and seem to enjoy adequate views... A free way of doing a quick check is to carry out a star test with your scope which entails defocussing on a bright star and seeing if the rings of diffraction given off are concentric and even. If you get chance to go to a star party you could get someone to collimate for you (or pop down to Weymouth and i'll check yours for you)

Hope you get it sorted soon and welcome to the forum

[Doc]

Hello adam welcome to SGL.

It's strange that you say that this happens in both your scopes, so to me collimation might not be the issue, but from your description it may be as well.

As it happens in both, are you sure you are focusing it correctly, it's a fine line from being in focus and out of focus.

Also are you allowing enough cool down time, a 300p will need a good 1 hour even more to cool.

Finally how is your eyesight?

[Adrena1in]

A good way to check the collimation is to point at a star and take the scope completely out of focus. What you want to see is a blur that looks like a CD...a round disc with a black hole right in the centre. If the blur isn't round and the black hole isn't in the middle, your telescope needs collimating.

Also, these out of focus views of stars show heat turbulence in your telescope nicely...they'll shimmer and waver until your scope cools down.

Finally, bed seeing conditions can play a major role in planetary viewing. When Mars was at its closest recently, I'd just picked up a Celestron C11. First night out was appalling. Seemed collimated, had been outside for hours to cool down, but all I saw was a boiling red blob, and I was so disappointed. Few nights later though...WOW!!

Good luck.

[russ]

What sort of time are you observing Jupiter? At the moment anything before midnight will almost certainly give a very poor view of the planet due to its poor height above the horizon. Won't matter what scope you use, even the Palomar 200" wouldn't fair any better. Jupiter really starts to kick in around 1am and then just gets better and better as dawn approaches.

Collimation almost certainly is a factor too. If the 150 has never been collimated and the 300P got a rough ride from the courier, there's an extremely good chance both scopes are out.

[Capricorn]

The 300P has a focal length of 1500mm. Quite a few of the SW 150's have a focal length of 1200mm. Basically not a lot of difference in focal length (25%) so a 10mm eyepiece in the 150 would give a magnification of 120x and in the 300 would give 150x. So really not a great deal of difference in what you see.

What it should be is brighter.

This does depend on the old 150 being 1200mm FL.

Collimation will cause the image to be blurry.

The 300 is an F/5 so you may have to consider reasonable eyepieces.

How good/bad are the eyepieces that you have and that came with it? Usually posts here say that the 25 is acceptable, the 10mm is dead weight. The 25 will give 60x and although small it may actually be too bright to see detail, that's a big mirror. I am guessing that the 10mm is poor.

A 5mm is probably as small as you will ever need, that would give 300x mag, I don't advise one immediatly until you get more familiar with the scope.

At this time are you willing tp spend say £100 on a couple of reasonable eyepieces? I suspect that the scope needs collimatiing then the addition of some decent eyepieces.

Haven't looked but where roughly are you in the UK?

OK: BB1, Blackburn = cannot lend you an eyepiece or two.

[Adam Isa]

Thanks for all for the replies and my apologies for my late one.

... clear although small well defined disc with what looks like two faint intersecting brownish lines with jupiter...

Yep, this is exactly how it appears in both of the telescopes.

As it happens in both, are you sure you are focusing it correctly, it's a fine line from being in focus and out of focus.

I'm pretty certain I'm doing it right, but I may invest in a dual speed focuser just to be certain.

Also are you allowing enough cool down time, a 300p will need a good 1 hour even more to cool.

Oops! I don't even give it a minute, let alone an hour! I'll bear this in mind, but by 'cool down', do I literally just leave it alone to adjust to the ambient temperature?

Finally how is your eyesight?

I need to wear glasses to focus on things if it is important such as driving, but when I went to the opticians, I'm just above the acceptable level for driving (based on the 20.5m number plate reading test). However, when I wear glasses, the stars and planets seem so much more focused.

If the blur isn't round and the black hole isn't in the middle, your telescope needs collimating

When I try this, the circle appears in the middle, and the outer ring appears VERY wavy and the inner not as much, but certainly noticeable.

What sort of time are you observing Jupiter?

At the moment, I tend to view Jupiter any time between 23:00 and 02:00, but the image is constant, regardless of the time.

If the 150 has never been collimated...

Embarrassingly, I had never even heard of collimating until a week or so ago, so the 150P had never been adjusted.

... on the old 150 being 1200mm FL.

The Skywatcher had a focal length of 650mm. Just noticed as well, it wasn't a 150 (6"), it's a 5"! Just goes to show how impatient I was. Thankfully, I enjoy it, and take it a lot more seriously now.

How good/bad are the eyepieces that you have and that came with it? Usually posts here say that the 25 is acceptable, the 10mm is dead weight. The 25 will give 60x and although small it may actually be too bright to see detail, that's a big mirror. I am guessing that the 10mm is poor.

At the moment, I've got a 10mm and a 25mm which came with the 300P and I have a cheap 3.6mm (eBay) and another 10mm (scopes'n'skies) as well as a 3x Barlow. As for how good they are, I can't really tell, what should I be looking for? As the telescopes haven't even been collimated, I think this would affect the apperance and my view on the eyepieces.

At this time are you willing tp spend say £100 on a couple of reasonable eyepieces

Probably couldn't A) afford it right now and if the wife found out, I'd be a dead man. Perhaps in a month or so I could think about upgrading, but is there a big difference? Can they average person really notice? Thanks for even considering loaning me the eyepieces anyway!

A note that I will quickly add is that today, about 00:30, I took it to a place called Pendle Hill at Pendleton. No street lights what so ever and very high up. The moon wasn't out either. There wasn't much cloud so I pointed the 300P at Jupiter with the 25mm and it seemed so much more clearer, could just about make out the colours and could see three moons. Shortly after, cloud came followed by heavy fog and had to call it a day.

So with all this in mind, would you say that i need to A) Collimate, upgrade the eyepieces and C) try and get it into a location where light isn't going to be a problem?

[Llamanaut]

all of the above!

[Astro_Baby]

Collimation is possible as a cause but I suspect its a number of factors. Check collimation - your description of the outercircle of a defocused star being wavy suggests either a damaged mirror (unlikely I hope) or atmopsheric turbulence (very possible). You can check my guide for collimation here whcih gives some pics at the end of the articale as to various faults in the defocused star images Astro Babys Guide to Collimation

Jupiter does generally appear as a small disk with two faint lines - at the moment one of them is missing (its called the Southern Equatorial belt) and its vanished for a bit.

The pics you see from imagers show far more detail because they are time lapsed and stacked and processed in all sorts of ways to bring out fine detail which you wont ever see with your eyaballs even through very large scopes.

I have attached two pics taken with a cheapie camera and messed about with to give a rough idea of what Jupiter looks like to the eyeball in a telescope.

You need to bear in mind that when using a telescope you need to learn to see - that involves watching the object for some time and also that better quality eyepieces will make a difference. Generally speaking the 25mm and 10mm you get with the Skywatcher scopes are ok(ish) but nothing special. A decent eyepiece in the £100-£150 range will show a lot more but it still wont be like pictures.

[Capricorn]

The 3 steps you mention seem about right, as first the scope has to be collimated for it to operate at its best.

After that eyepieces and the performance comes into it, although I guess the 3.6mm eyepiece will not get much use. For one that size it would need to be good quality and everything else would have to be right.

When the time arrives and if you are looking for magnification I suggest something in the 7.5mm area to give 200x.

Both SCS Astro and Astronomica have ranges of eyepieces at around £50 a piece that should be OK. Been looking myself that is how I know of them and the options they have.

Darker skies are always good but often depend on ease of transporting scope and setting it up. One annoying point, the more you put it in a car drive to whereever and then take it out, set it up, then reverse the process, then the more often you may need to collimate it. Sounds like you should be good at collimation in a shot time.:evil6: