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Prestonian

Am i expecting too much??

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Hi

I have a 70/900mm refractor with 3 lenses ( 22mm, 12mm, 4mm) and a 2x Barlow Lens. I havent used the telescope yet in areas where light pollution is at a minimum. Ive only looked from my back garden.

Ive seen Mars and Saturn(last night with the rings in view) but they look tiny thru my telescope, so much so that they just appear as a small light circle. I cant see a chance in hell of me being able to see any detail of their surface features. To make things even more frustrating is that wne i move down a lens from 22 to 12 or even 22 to 22+Barlow the object in view becomes more of a darker blur, basically rendering my 4mm and 12+Barlow lenses redundant. Is this normal for the scope I have..... or do things look better when im in a darker environment?

Deep Sky Objects:- I have a book showing a list of object and their magnitude. Looking at my set up, what magnitude can I get a good look at with my scope?

I looked at Orion's nebula's last night and was pretty dissapointed. I looked in the region of the horse nebula but found nothing, then I moved on to M42/M43 region and found to what seem to be a tiny cloud, but thats all I could see, and when I tried to zoom in again, things became a fuzzy blur as per usual.

Am I doing something wrong, or am I just expecting too much with a scope of my calibre? Will I see MUCH more detail if I went into a rural area?

If I cant see Orion's deep sky objects what hope have I looking anywhere else because Orion's are the easiest to spot arent they?

Andy

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Andy,

you maybe expecting too much. That scope is really going to struggle on Mars. Mars is proving difficult even with big expensive scopes. And to make matters worse it's now shrinking by the day. Mars is well past it's best for 2008.

Saturn should be a little more impressive than you describe. I can push our 70/700 refractor to approx 90x and it shows Saturn quite well. No detail but quite a nice shape. But yes the image does dim once the magnification is applied.

The deepsky is a let down in our 70mm too. Not even M42 can impress. Our skies are heavily polluted. The 70 performed far better from my parents house when they borrowed it. But they have nice dark skies, make such a difference. Even my 50mm Tasco performed well from there in 1983.

I think you need to look for a cheap 6" Newtonian. It will transform the deepsky and also provide worthwhile planetary views.

Russ

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Hi Andy,

To be honest what you are seeing is about what you might expect from a 70mm aperture scope. To see detail on the disks of planets you really need a bit more aperture and power. Jupiter should be a bit more impressive than Saturn or Mars when it comes around (Mars has been dissapointing this time around even through big scopes as it did not come too close to Earth) with a clear disk, 2 main cloud bands and the 4 brightest moons possibly visable through your scope on a good night.

I'm afraid the Horsehead Nebula in Orion is only visible in bigger scopes (at least 200mm aperture) with special filters and even then is considered a very challenging object. M42 should look nice at low powers but won't compete with the lovely photo's you see in magazines. You should be able to see the main parts of the nebula plus the 4 stars of the Trapezium embedded in it.

A 70mm scope is always going to be limited with regard to DSO's as most nabulae and galaxies are faint and indistinct - very faint smudges of light in a 70mm when you know just where to look. Globular Clusters such as M13 and open clusters like the Double Cluster in Perseus are worthwhile however and I used to get nice views of those through my old 60mm refractor.

The moon will be excellent of course !!.

I think you may have been expecting a little too much but if you keep at it and learn what your scope can and can't do then you can still find it rewarding. Try this web link for some suggstions of objects for the smaller scope:

http://irwincur.tripod.com/ten_best_obj_-_small_telescope.htm

John

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cheers russ

Thats what I like to hear, a clear concise honest opinion! I was only thinking last night that this telescope is probably only good for viewing the moon and your comments seem to prove that theory....

So... realistically, what amount of £££ do I have to spend in order to see some decent eye candy when looking at deep sky objects???

Ive spent £100 on this one and all I can see is a tiny cloud which isnt what I expected to be honest.

Cheers

Andy

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A lot depends on what kind of eye-pieces you have. A cheap eye-piece (E.P) isn't going to show you a great deal of detail on even the best of scopes.

Saturn and Mars both appear small in my scope so this is normal. But with a decent ep I can make out details on both disc's.

The horsehead nebula is very difficult to see. In fact you really need long exposure photography to see this dark nebula. (This is a generalisation. I'm sure some-one will post that they,ve seen it real-time)

Deep space objects really need a light pollution free viewing site, the darker the better. Also the further they are away from the horizon the better.

What make of ep's do you have?

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So... realistically, what amount of £££ do I have to spend in order to see some decent eye candy when looking at deep sky objects???

If you want views that start to look like the photographs then you need a 12 inch or larger scope - £500 and upwards for that sort of thing and you would probably need to budget for a few nice eyepieces on top.

On the other hand an 8 inch dobsonian costs around £240 new and will show you a lot more than your 70mm will :D

John

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Boy, you Prestonians always expect more than you are given, don't you? :D (I was born in Preston, so I do, too.) :D

Your scope is an entry level scope, and you can see quite a lot with it. You will not be able to get much more than 100x out of it in your light and seeing conditions. Your eyepieces, if they are the ones that came with the scope, are probably not the best. They are probably marked H22, H12, and SR4. They may be marked K22, etc, but Kellners should perform better than your eps are.

What is the diameter of your eps? Measure across the bottom of the male end. They will be either a little less than an inch, or an inch-and-a-quarter. The 1 1/4" ones are better, as you will find it easier to replace them with better ones. If you have the smaller eps (.965") then you have a couple of options.

If the diagonal that you put your ep into has a reducing collar, see if you can remove it and put 1 1/4" eps in it. If not, you can obtain a diagonal that has a .965" male end and a 1 1/4" female end, then get some Plossl eps. I would suggest you get an 18mm, a 2x Barlow, and a 25mm, in that order. This will give you a nice selection of powers that will not overpower your scope.

Oh, one more thing, and please don't be insulted as this is a common mistake. Does the cap on the end of your scope have a small cap in the middle? If so, did you take the entire cap off, or just the small cap? The small cap is for lunar viewing, but with it on, you may get the effect you mentioned here.

Good luck, and clear skies.

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Or, as others have suggested, get a larger scope. I usually suggest at least 90mm for a refractor, and 5" for a reflector, although I think 100mm and 6" are a better start. Celestron makes a nice 100mm scope on a goto mount.

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Andy, I have an 80mm refractor and I can see loads of clusters. Try for M45 Pleiades (superb, and naked eye), M44 Beehive, a little more tricky to find but a really nice sight. The double cluster between Perseus and Cassiopeia is another beaut.

Saturn, when I pushed my scope up to 160x (about maximum as it's very short) was still very small. Not a chance of seeing any more than that though. In fact, I tend not to bother with the really high magnification anymore, it's just so much harder to look through, and stick to a middle length eyepiece. Saturn is much smaller, but I can still make out the rings, and see some moons. And even better, I get a window of longer than 20 seconds to look. (My scope is mounted on a camera tripod).

If I push my scope to the limits, I don't get much more out of M42 then a pale cloud like impression, but I can just about make out the stars at the middle and M43 nearby. Although to see the cloud, I find I have to look away slightly, as the edges of the eyes are better for low light environments.

Do you have Turn Left at Orion, a great book, with sketches of what you might see. Look for targets listed as good in binoculars or easy in a telescope.

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. They are probably marked H22, H12, and SR4. They may be marked K22, etc, but Kellners should perform better than your eps are.

What is the diameter of your eps? Measure across the bottom of the male end. They will be either a little less than an inch, or an inch-and-a-quarter. The 1 1/4" ones are better, as you will find it easier to replace them with better ones. If you have the smaller eps (.965") then you have a couple of options.

Oh, one more thing, and please don't be insulted as this is a common mistake. Does the cap on the end of your scope have a small cap in the middle? If so, did you take the entire cap off, or just the small cap? The small cap is for lunar viewing, but with it on, you may get the effect you mentioned here.

Good luck, and clear skies.

Hi,

thanks for the reply.

The EP's are marked RK20, K12 and SR4 so im not sure if they are decent or not??? Plus I have a 2x Barlow that came with the scope. The best viewing I seem to get is with the RK20 + Barlow as the object still seems fairly bright.

The cap is fully off too so no problems there, I also leave the scope and lens outside for a good while before I use them so they have cooled down a touch.

Looks like I need a new scope if I am going to get this astronomy lark off the ground. Ive got the phillips stargazer 2008 book along with other Phillips books and charts and there seems so much to see that I want to continue, but I just dont feel this scope is up for it. Im not happy with just looking at the moon, I want to see DSO's!! :D

Andy

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..The EP's are marked RK20, K12 and SR4 so im not sure if they are decent or not??? Plus I have a 2x Barlow that came with the scope.

Looks like I need a new scope if I am going to get this astronomy lark off the ground. Ive got the phillips stargazer 2008 book along with other Phillips books and charts and there seems so much to see that I want to continue, but I just dont feel this scope is up for it. Im not happy with just looking at the moon, I want to see DSO's!! :D

The RK20 and K12 eyepieces should be OK, not brilliant but OK. The SR4mm is not goint to perform well I'm afraid. The barlow lens should be OKif it's an achromatic glass one, ie: 2 lenses stuck together rather than a single lens and not made of plastic (some are :shock:).

At 70mm scope is not going to show you much in the way of DSO's I'm afraid - just some of the brightest ones as noted in previous posts and that link I posted earlier.

Yes, to get satisfying views of DSO's you will need a bigger (larger aperture) scope. As I said earlier, an 8 inch dobsonian would be a huge step up from what you have now in that respect. Somthing like this:

http://www.firstlightoptics.com/proddetail.php?prod=dobsky200

John

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The SR4mm is not goint to perform well I'm afraid.

I'm afraid I have to disagree with you on that one John. I have used the SR4, at sensible magnification, and found it quite usable. I used it alongside an orthoscopic on saturn and the FOV was slightly smaller, a bit more colourful, but nevertheless surprisingly sharp in the middle. In my experience the humble SR4 can give you a fantastic first (or second for that matter!) view of saturn which will not disappoint.

Andrew

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The SR4mm is not goint to perform well I'm afraid.

I'm afraid I have to disagree with you on that one John. I have used the SR4, at sensible magnification, and found it quite usable. I used it alongside an orthoscopic on saturn and the FOV was slightly smaller, a bit more colourful, but nevertheless surprisingly sharp in the middle. In my experience the humble SR4 can give you a fantastic first (or second for that matter!) view of saturn which will not disappoint.

Andrew

Fair point Andrew - the 2 I've tried must have been from a bad batch - they were awful !.

John

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The SR4mm is not goint to perform well I'm afraid.

I'm afraid I have to disagree with you on that one John. I have used the SR4, at sensible magnification, and found it quite usable. I used it alongside an orthoscopic on saturn and the FOV was slightly smaller, a bit more colourful, but nevertheless surprisingly sharp in the middle. In my experience the humble SR4 can give you a fantastic first (or second for that matter!) view of saturn which will not disappoint.

Andrew

Fair point Andrew - the 2 I've tried must have been from a bad batch - they were awful !.

John

That being said, the SR4 will considerably overpower this telescope, and is only included with these scopes because it is cheap to manufacture, and technically gives you the f/l claimed. It really isn't a good design.

The RK (Reverse Kellner) and the Kellner that came with the scope shouldn't be too bad. I used Kellners for years. They are sometimes sold under the name MA or SMA ((Super) Modified Achromat) and are as good as Plossls except for a more restricted FOV. Still, a couple of Plossls will improve things, and can be carried on to the next scope.

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I know how you feel, i just got myself an 8" LX 90 and to be honest i haven't seen as much as i would like. Its a £1500 scope. That being said i haven't had it out other than my in garden, where the light isnt the best. I can JUST make out M31, tried to look at the horse head but got nothing :D. I'm hoping when i take it to dark skys i will be able to see alot more. :D

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Its not worth trying for the Horsehead, its pretty much impossible to see. It's one for the imaging guys.

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I know how you feel, i just got myself an 8" LX 90 and to be honest i haven't seen as much as i would like. Its a £1500 scope. That being said i haven't had it out other than my in garden, where the light isnt the best. I can JUST make out M31, tried to look at the horse head but got nothing :D. I'm hoping when i take it to dark skys i will be able to see alot more. :D

I think this is an important issue with the hobby that its easy to overlook - there are many factors that will have a signficant impact on what you can see - the scope is just one of them. Light pollution, the seeing conditions (which can vary hourly or even more rapidly), eyepiece quality, the acuity of your eye and the observers experience will all make a big difference.

In truth, if it was just a case of shelling out the cash and then "reeling in" all these fascinating objects the much of the appeal and challenge of visual astronomy would dissapear for many IMHO.

John

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Indeed John. For the vast majority of us M31 is only ever going to be an oval smudge unless you've got a HUGE scope, quality eyepieces and perfect seeing conditions. Even then you'll only see the faintest of details, nothing like what you see in long-exposure images.

Tony..

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Well, I got myself a Bresser Messier R90 refractor two or three weeks ago and have had a couple of decent nights out recently. Saturn was amazing, but then I've done a little research and didn't expect to see a huge image, but still saw a very clear image and managed to even see the darkness between the inside of the ring and the planet itself. I think that this is incredible, something so far away suddenly appears through the scope.

I've got myself a couple of books which help, but there is a big learning curve. I think when you start to read about what it is that you're looking at and you read a little background info, you suddenly begin to realise just how rewarding it is to see even the faintest blur in the sky.

The moon is breathtaking.

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Unfortunately the human eye is not up to reproducing the sort of images you might see in the magazines so first views can seem a little disappointing (even in the larger scopes you won't see the vivid colours - even on the brightest DSOs like M42). Whether you can get hold of better eyepieces or not, the thing to do is make the best of the instrument you've got by preparing your viewing before hand....plan to view the objects most visible from your location at that particular time, if possible go to somewhere with dark(er) skies and decent seeing, put the scope out to cool and ready your night vision. Doing these will help you get the most out of your scope (and time at the eyepiece) .

With the 70mm aperture your scope has you should probably stick to a maximum 80-100x viewing under good conditions - pushing it much beyond those magnifications will start to cause the blurred viewing you've been experiencing. Also, a smaller, more defined image is far better than a bigger, blurred one. At the end of the day you have a scope with a relatively small aperture but under the right conditions it should still be able to provide you with some decent viewing at lower magnification!

It does sound like you've got the bug though so maybe an upgrade is on the cards to improve the experience....Skywatcher, Celestron etc do some excellent 'upgrade' scopes with mounts at reasonable prices. There are good retailers out there who should be able to advise you on any potential upgrade (some post regularly on here!).

Also, unless you plan to view the moon, avoid nights when the moon is shining bright in the sky....this causes natural light pollution and drowns out the DSOs!

Andrew

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