What to expect with my telescope?

[scottca]

Hi All,

Fairly new to astronomy so please bear with me...

I have had a telescope for quite a few years now, I didnt really fully understand it originally and kind of gave up... but since moving out house I uncovered my scope and set about actually learning how to use the equitorial mount!

I think I have this bit sussed.. although if I have problems im sure ill post the question!

I have a Helios Evostar (I think it could be the evostar 120, which is a 4.75 inch refractor) - The lenses vary and include a 2x barlow lens. They came with the kit and so are probably nothing special. Unfortunatly I dont have the exact lens information to hand but can get them if its relevent.

My Question is, what should I expect to be able to see with this scope and with what detail. Looking at the moon is amazing, however when I look at Saturn for instance, the best image I can get is a very very small yellow ish saturn, you can make out the ring around the plant but thats all.

Another forum a while ago posted pictures of how they could see saturn with a 120mm refractor and it was amazing, much larger with colour variations etc.

Will I be able to achieve that with my scope and is it purely a case of the lenses I have are not very good? - Just wondering what I should expect to see, Will i be able to see galaxies / nubulas etc?

Kind Regards,

Craig

EDIT:

I believe I have found the original specifications that were listed for my scope.. they are as follows:

Magnififcation Range: x36, x50, x100, x200

Objective Lens DIameter: 120mm

Focal Length: 1000mm (f/8.33)

Eyepieces Supplied (1.25"): 10mm & 20mm piossls

Eyepieces Supplied (2"/50.8mm) 28mm Kellner

2"/50.8mm Star Diagonal with 1.25" adaptor

x2 Deluxe Barlow Lens (1.25" / with Camera Adaptor)

6x30 Finderscope

EQ3-2 Equatorial Mount

Fully Multi-Coated optics

[crovax]

I am a total newb and I have reflector but I suspect the basic stuff is very similar. In reflector magnification is tube focal length/eypiece focal length. And the maximum magnification is main mirror diameter x 2. Again I repeat that those formulas are for reflector so they may be a little different for refractor. But anyway I am sure that even for refractor the smaller eyepiece you use, the higher magnification you get.

[crovax]

I know that I didn't answer your question afterall and sorry about that. I was just trying to tell that info about the eyepicies you have is rather important.

[Astro_Baby]

Well the camera may not lie but astro cameras certainly put some spin on the story

Imaging will produce much bigger, brighter and better images than yo will most likley ever see with your eye.

What would you see with a small scope ? Well with the right eyepieces and a good sky you would be able to see the Cassini Division in the rings. You'd be able to see cloudbelts on Jupiter and its moons. Some DSO objects would appear pretty well - M13, M42, M45 would all be pretty good in a small scope (M42 and M45 looks pretty good in binoculars to be honest).

A big part of observing though is 'learning' to see. Your eye will nevere see the objects the way cameras do but you can improve your eyeballs. Make sure your fully dark adjusted by staying away from white light - you need about 20 minutes to let your eyeballs adjust. Next you need to LOOK. You need to be looking at an object for 5 minutes or more to let your eyeball pick up the detail. You wont see much with a quick peek. Finally over time your eye gets better at seeing things in a telescope. I know that sounds weird but its true.

120 isn't actually that small a scope really - I'm a bit of a refelector nut so I dont know what the issues may be for a refreactor but I am sure someone on here can help who has the same or similar scope to you.

[ako]

hi craig, my main scope is a 127mm meade refractor and u should b able to gleam a lot of detail from saturn. i also hav a 3inch william optics refrator and on a good night i can make out the bands with the 3inch. for saturn u should b using the 10mm with the barlow to get a good mag. b careful while focusing as a little bit could make a big difference in the view

all the messiers are viewable as smudges with the 3inch from a dark site, there is some detail that can be gleamed with the 5inch. james omearas books are very good with sketches rather than pretty pictures. make sure u let the scope cool before using it, say half an hour. remember where the object is in the sky makes a big difference, the lower the more atmosphere.

i image quite a bit as initially i was disapointed at looking at these smudges of light, after kelling spring star party my visual observing has be re-ignited and ive started upgrading my eyepeice collection- my scopes has 3lens but eyepeices can hav 7 or 8, surely they do more or as much to the view as the lens collecting the light

matt

[ako]

oh and final tip- get yourself to a star party as soon as u can, or local astronomy society. ppl spend years bumbling about on their own in the dark at home, as soon as u get together with like minded ppl your knowledge comes along 10fold!

[mdstuart]

Buy the book turn left at Orion and that will give you a 100 items to work through which should be visible in your scope which is actually quite large for a refractor...

Try the ring M57 when its next clear..

Enjoy

Mark

Mark

[Astro_Baby]

ps - it might well be an Evostar 120. The specs are the same and Sky-Watcher used to be sold in the UK with the Helios name.

[scottca]

Hi All,

Thanks so much for all your replies! what a wonderful community here.. suddenly I dont feel as stupid for not knowing such basics!

Ive confirmed tonight its a Evostar 120.

On a good night, using the barlow and 10mm - I cant make out any detail on saturn at all, I know it sounds silly when I say its small.. but, how big shoudl an object like saturn be?

Ive tried to let my eyes get used to the dark before and have a special red light I use to read information with etc.

My viewing location is good, hardly any light pollution, even with saturn high in the sky, i cant seem to get a good viewing.

I must be doing something obvious wrong, or could it simply be my lenses are not that great? is a 10mm a 10mm, or do they vary considerably in quality?

Astro_Baby - When I look at jupiter, the best I can get is basically a bigger image of what i can only describe as an uninteresting ball of light, not very defined? Ill work on those viewing techniques though!

ako - 3 lenses? what eyepices do you use to get good views on saturn?

mdstuart - thank you, ill have a look for the book tomorrow!

Thanks again!

Craig

[Astro_Baby]

Hmmm - it could be the scope is 'hot' and hasnt cooled down enough. You may have been unlucky and the sky has not been very good. Vieiwing in the UK can be very variable, thermals, high level haze etc can all contribute to lousy viewing.

I dont know enough about the issues with refractors to advise you. Certainly the eyepieces supplied with the scope are not the greatest but they arent that bad either usually. EPs come in a variety of sizes and qualties. The cheapest can be had for around £10 - the most expensive around £500 so you can see its a big range. A good mid priced EP at around £70-120 would give you a good view but you really need to ask for advice as to what would work well in your scope. They'll all fit but some EPs work better in some scopes than others and of course personal taste comes into play. I like my Baader Hyperions - some people hate them. In matter of taste theres no dispute - you use what gives you personally the best view. Again I cant advise because I dont know the scope.

My 5.1" reflector could get Jupiter to show cloud bands ( though you'll only see these as faint grey lines and you'll only see two bands usually) it could make out the moons of Jupiter but pretty much only as points of light.

Saturn would show the rings and the Cassini Division but no banding. I have never seen banding on Saturn myself even on bigger scopes than mine.

If you go HERE and scoll about halfway doen the page you'll find some sketches I made of what the view through a 5" refelector looks like. I'm not sure how that would compare to your scope - yours has a longer focal ratio so should get better magnifaction but yours has a smaller light gathering capability - that shouldnt be a problem with planets I'd have thought.

Something to bear in mind is that with magnification less is often more. The more magnification you apply the dimmer the image and the more critical focusing becomes PLUS the planets will whizz across the field of view and the least movement in the scope will make the view jump about.

Thats an idea of whet the view is like anyway of planets for you to gauge against.

Hope its of some help.

[The Warthog]

If the stars are twinkling, it's a sign that seeing isn't terrific, and you may experience some wobble in your view of Saturn, or even of craaters on the Moon. If you should see a little colour fringe around objects, this is an inherent problem with achromaitc scopes (I have one, too) and can be mitigated by using a pale yellow filter, a 'minus violet' filter, or just ignoring it. The advantage of refractors is higher contrast in whaat you see, and with a 120mm refractor, you can really impress your neighbours as well. I find my 105mm refractor very, very sharp on the Moon, much sharper than my 150mm reflector. You have a good scope there.

OH, at 100x, Saturn will look a little bigger than a BB, but you can still get some detail out of it on a good night.

[Macavity]

See ALL above?

And as some sage (author) once said. Planets are small and very far away. To get a feel for things, remember e.g. that the Moon is about 30' arc Minutes (Half a degree) in diameter. Jupiter is about 40" (arc seconds), Saturn (disk) about 20". Thus, to make them look (about!) tha same size as a naked eye Moon, you'd need 60x magnification. Think how much you can see on the Moon with the naked eye. HOWEVER (a big one) all the other things like atmospheric turbulence (poor seeing) are magnified too, the object much dimmer, the contrast smaller etc.

Be encouraged that the Lunar views are quite GOOD - As indeed (IMO) are Refractors of this general ilk. With my ST102/F5 which has less light gathering and shorter focal length, the moon look great, albeit with a little "Purple Haze" inherent to the achromat. Planetary perfomance is not THAT startling. Technical wibble: I have star tested the objective, and it shows a good diffraction pattern on one side of the focus... and "not a lot" on t'other! <G> But it's still pretty good for the price. A Baader "Fringe Killer" or "Contrast" filter will remove the violet fringing - should I (even) want to do so.

With a casual look (I seem to remember) I can see 2 greyish belts on Jupiter, I MIGHT be able to see the Cassini division and a white blob (with darker polar regions?) for Saturn. For the reasons cited above (greater aperture, larger focal ratio) your scope should do somewhat better, but we won't be talking orders of magnitude (As in factors of ten or even several)! But I still love my little refractor, for it's splendid views of the Moon, but most of all for wider angle, views of star fields, open clusters etc.

Thus I use my 5" MAK for (occasional) planets, and e.g. splitting CLOSE double stars! But again we're talking modest improvement, "swings and roundabouts" re. cooling times etc. Such is astronomy?

[scottca]

Wow thanks all, loads to take in and certinately a lot more reading is required! I will also investigate to see if there are any groups near me

I now cant wait to get out there again and start viewing! Im also glad to hear my scope isnt that bad... There was me preparing myself (and getting the justification ready for the mrs!) that I needed a new scope to achieve what I want, but, it seems, I can.. I just need a bit more knowledge!

Astro_Baby - Thank you for the images, thats actually pretty much what I see, so I dont think the scope is as bad as a thought, Im thinking its more me needing to learn how to look!

Im finding it very difficult to keep an object in view as when I track it, the scope wobbles as i dont have the most steady of hands! Would motorising the mount help? Its an EQ3-2 Mount and I beleive when I first got it, the chap said I could attach motors at a later date? Is this still posisble with it being an old scope?

Jumping the gun completely here... and I know im simply not ready but im curious, photography - am I right in thinking, with my scope, im not going to see any galaxies / nebulas? if I will, how will they appear? I presume to get the colours and detail I need to have a large exposure time on an image.

If I did want to go down that route, I know motorising the scope is a must to keep the object in focus at the correct position, but what cameras do you use? A family member has a digital SLR however im not sure what exposure time options it has? are we talking dedicated astro cameras?

Thanks again,

Craig

[Dr Dixon]

Ok this is a bit of a guess, but as a very rough example as i am doing from memory, but with my 80mm refractor the view of saturn that i would get is prob. similar in scale to the following image using a 12.5 mmm eyepiece. the planet and the rings when viewed by eye were a lot brighter though.

compare with http://stargazerslounge.com/imaging-planetary/80941-saturn-titan.html which is the view the webcam gets through the 80mm using a x2 barlow

[The Warthog]

Oh yes, you can see galaxies and nebulae. I would suggest M81/82 in Ursa Major if your skies are fairly dark. The Ring Nebula in Lyra and the Dumbbell in Cygnus are fairly easy targets. Lots of globular and open clusters will fall to your scope, and you should be able to split many double stars. Don't fret, it's a good scope you have there, and superior to any 'starter' scope.

[scottca]

Thanks Guys, The saturn I see appears in similar size to the picture Dr Dixon posted, thanks for that - really helpfull!

I never seem to be able to find galaxies and nebulae? - This is a very silly question, but.. how big do they appear in relation to what saturn is in the pic above?

I hope im not just missing them if there really small?

Will a 2x barlow degrade the quality of the object or is it best to say, just buy a 5mm lens instead of using a 10mm with barlow?

Thanks again all, sorry these questions are so basic!

[The Warthog]

I don't find that any but the cheapest Barlow noticeably degrade the view. Galaxies are mostly dim, greyish smudges and are best looked for at medium-low magnifications. Try M81/82, which are nicely defined in a dark sky, and actually appear bluish to me.

Using a Barlow has the advantage that it retains the eye relief of the longer ep, and if you are bumping up to a magnification that you won't use often because of seeing conditions, you don't have an ep sitting in your case for very occasional use. A Barlow can also be ussed to fill in gaps in your ep kit. However, you can do without a Barlow. See my article on a basic ep kit: http://stargazerslounge.com/beginners-help-advice/80772-eyepieces-very-least-you-need.html

[scottca]

Thanks

Reading the forum more, Ive read about the Skywatcher OIII Filters for viewing nebulae - although some have seem to say you need a very large scope for them to do anything. I know im not at the position to look at nebulae - but looking forward to it already!

Thanks again,

Craig

[The Warthog]

Why aren't you? You don't need a certificate! Go out and look for the Ring, already!

[Astro_Baby]

The EQ3-2 can be motorised easy enough and even, if you want, given a full GoTo upgrade. Single drive (RA only) is about £70, dual drive (RA & DEC) is about £90 the full GoTo kit is about £300. Worth giving Stsve at FLO a ring though to check availability.

[RichieP]

Thanks

Reading the forum more, Ive read about the Skywatcher OIII Filters for viewing nebulae - although some have seem to say you need a very large scope for them to do anything. I know im not at the position to look at nebulae - but looking forward to it already!

Thanks again,

Craig

Rather than an OIII filter (which cuts out so much light the images can be unacceptable dim in smaller scopes) I would recommend an UHC fillter for viewing nebulae.

Skywatcher, Baader and Lumicon all do readily available filters.

Also I would recommend motorising the EQ3-2. When you don't have to worry about keeping the object in view yourself, you can concentrate on actually looking at it. It's when you do this that you start to see detail coming out.

Richard

[sxinias]

<<I never seem to be able to find galaxies and nebulae? >>

I have a Meade 2090 (90mm) refractor and can see many galaxies, nebulae, and star clusters with it. Your much larger refractor should do a lot better than mine. I must admit that I also have a goto mount that helps out considerably.

Galaxies, most nebulae, and star clusters are easily missed by inexperienced observers who are expecting to see something resembling the photos they have seen in magazines, etc. Whay you will see is a faint grey smear of light that is easily overlooked.

At first you will see absolutly no details at all, One trick is to take a pencil and paper and sketch what you see. Also use adverted vision. Soon you will see some details in the gray smears of light; however, you will never, even in much larger scopes, see details anything like photographs.

If you are thinking about changing your mount, you may want to consider the new Skywatcher AZ GOTO mount.

Joe

Meade 2090AT

Meade 2045 LX3 SCT

Celestron C6S SCT

[Vega]

I've managed to take the magnification to 333x on Saturn with my 120mm evostar (using a 6mm EP and 2x barlow) which is past the recommended maximum of 240x. Admittadly the seeing has to be good otherwise the planet shimmers all over the place at such magnification. However on the right night the view is fantastic through this scope. the best deep sky acheievement I got out of this scope was seeing the Leo Triplet galaxies (all three). and a very very faint Whirlpool galaxy (no spiral arms visible though).

Cheers

Matt

[mdstuart]

Next clear night you really must try the M57 ring. Find the bright star about half way up to the NE, this is VEGA. Then look below it and you will find a square of stars. In the middle of the bottom two is the ring. It is small but obvious as it looks nothing like a star, then put a high power eyepeice in and you have a grey ring about half the size of Saturn....

Let us know if you find your first nebula...Also I have a UIII filter and It only helps a bit in a few cases on nebula and I have a 10 inch....

Mark

[scottca]

Sorry for tha lack of replies all - Have been away!

Thank you so much for all the replies, its much appreciated. I am currently looking at motorising the mount, but have to wait for Payday!

Ive looked around online for the cheapest shops, does anyone have any suggestions on a good vendor to buy it from?

We have been getting some clear nights so now im back im hoping to get out there and do some spotting

Thanks again,

craig