What telescope?

[Mancunian Lee]

Hi.

My Budget is £500 but i can stretch, it will also be my first telescope. Can i get something in budget that will let me see this kind of thing?

http://stargazerslounge.co.uk/index.php?topic=1643.msg19354#msg19354

Ideally i want something i can progress with as i learn more, is portable enough to fit in the car and generally good fun to use.

The only thing it needs to have is a way of hooking up some sort of digital camera or CCD. (items needed for this i can purchase at a later date)

Is something like the Meade ETX 105 going to be able to do this? it looks high spec and small for the price. Or would i be better going for something along the lines of the LightBright range?

Your thoughts please i can stretch my budget fairly far, but that means saving a little longer

[mark RD]

On a budget of £500 you should be able to get something that will give views of the moon planets and DSO that would blow your socks of.

If you planning to use it for to image then it would make sence to have the mount fitted with motors, A motor driven mount will track what ever you are looking at so you don't have to.

The Meade ETX 105 would be a safe bet Id also recommend a sky watcher 8inch reflector on a HEQ mount at around £585.00

Mark

[Greg]

I'd go for an 8" Skywatcher if you can push to the HEQ5 then great - if not the EQ5 mount will do the job (£379.00) and will leave you some money for eyepieces.

http://www.opticalvision.co.uk/prodtype.asp?PT_ID=20

I see that Optcal Vision have an offer on at the moment with an eyepiece set.

If you are going for imaging then the HEQ5 mount or higher would be advisable.

Anyway - some food for thought.

Greg

[Mancunian Lee]

phattire im not sure which your referring too sorry, is it this one - EXPLORER-200 (EQ5)

200mm (8") f/1000 Parabolic Newtonian Reflector

Mark RD, what is DSO please? i did look in the Glossary but couldnt see it

Thanks for the posts guys.

[Mancunian Lee]

Deep Space Objects?

[Greg]

Yes Lee - thats the one,

Quite a few of us on here have that OTA (Optical Tube Assembly) with various mounts.. I think I can say that we are all happy with the set up.

However - remember that a Newtonian will need regular collimation (Tweaking) and a degree of cool down time when you first take out on to the patio(Or where ever).

Greg

[Naz]

Lee you can get a filter that reduces the light pollution, screws into the ep (eye piece), so you can observe from your garden / patio. Some of the other members use them to great effect.

naz

[OXO]

Some great Advise there Lee, i personally would go for the 8" Skywatcher Reflector and HEQ5 mount this will track objects(After polar alignment) and is good for Astrophotography(Better than the Meade 105etx).

But the Meade Etx 105 has a computer on board and will show you around the sky this is called GOTO and if you know very little abou the night sky it's perfect for learning you but Astrophotography other than the Planets and Moon is a no no because the srives in the ETX105 are not up too it..

So if you want something to progress with and do all aspects of Astrophotography get the HEQ5 mount and 8" Skywatcher(Just over 500 quid). But if paitaince in seeing whats up there is a problem get the ETX105..

James

[OXO]

There's a secondhand ETX105 on here if your interested it's being sold by Steve one of the Moderators http://stargazerslounge.co.uk/index.php?topic=3463.0 Good price aswell!

James

[lunator]

Lee it's always worth checking the S/H market as most scopes are well looked after.

I have an Orion Optics 8" scope and it is fantastic. It is very similar to the skywatcher.

You won't go far wrong with an 8" Newt as a first/ all-purpose scope.

Cheers

Ian

[Kaptain Klevtsov]

Just for the sake of the discussion this http://www.gas.uk.net/pics/M42.jpg is from the Explorer 200 f/5 Skywatcher Newtonian. Bear in mind that I do not have the skills the others on here do with regard to the processing. It did please me a great deal to get this image so I thought that to chuck it in here could be usefull.

Having several toys on hand, my weapon of choice would be the Explorer Newtonian to point at M42. That said, the image that you linked to was not, I think, taken with a 'scope like mine.

Well, after starting off with good intention, I can see that the water is getting muddier, and I didn't help much.

Captain Chaos

[chuenmanc]

Hello

It might be worth pointing out that what you'll see through the eyepiece will not be as impressive as the photos that these guys have taken, except perhaps for the moon, and to a lesser extent the planets. These DSO photos are probably the result of lots of hard work taking long exposures with an attached camera or similar device, and then working some magic on them with photo editing software. What you'll actually see with just your eyes will probably be a grey smudge of some kind. For example for M42, it will be a roughly similar shape to what you see here, but nowhere near the detail or colour.

That's my (limited) experience anyway.

For telescope recommendations, I considered the ETX range, and would have loved the goto, and the ease of setup, but decided I wanted to get more aperture. I have the HEQ5 mount that is being recommended here and it's great, but will take more time to set up than the ETX, and is probably a lot heavier! My feeling is that the HEQ5+Newtonian is a longer term and more flexible answer than the ETX. The ETX wins on goto and portability/ease of setup.

You can add goto to the HEQ5 at a later date, but i think it costs £300 or £400.

Chuen

[MartinB]

Hi Lee. If you haven't already done so go to the learning zone section where you will find a number of primers which should help you further.

http://stargazerslounge.co.uk/index.php?board=41.0

The thing to bear in mind with the ETX 105 is that it has and Fnumber of 14. This is the ratio of focal length to aperture. It should therefore deliver very good high magnification views (good for planets) but will give a narrow field of view with poor light catching abiltiy than a shorter focal length scope. These problems can be got round to some extent using extra lenses call focal reducers. It is very portable and the goto is great. You are totally dependent on the electronics and you wont be able to use any other scope on the fork mounts.

The skywatcher 8" explorer has plenty of people singing it's praises on this site. Great light catching so really good for deep sky objects such as nebulae and galaxies. It is big and might not pass your portablity test. It has an F number of 5. so the opposite to the ETX. It isn't ideal for high magnification views of planets but I know some people have been thrilled with their views of Saturn.

Rather than thinking about a do it all telescope you may be better thinking about a good mount. An HEQ 5 will be very good for just about any type of scope you are likely to be looking at for the forseeable future. It has motors and you can add goto at a later date when you have the pennies. You could put an 8" reflector on it or if you wanted a more easily portable route an 80mm, wide field refractor (for deep skies) and a 127mm skywatcher mak (for planets). You can get what you can afford now and build up your system over time.

You can get some great second hand buys often with scopes still under guarantee. If you go down this route this can allow you to consider an "SCT" (see the primers!), all round abiltiy, jack of all trades, masters of none scopes and p0rtable.

Hope this helps more than it confuses!

[Mancunian Lee]

I already have a decent digital camera and laptop

Lets just for a second take things back to a very basic level just to make sure i understand telescopes.

Say we have an 8, 10 and 12 incher. Neither offer anymore magnification than the other, just the higher the number will mean the more light it can let in and the more it can pertentially see. The eye piece is where the magnification comes in, so if i was to get a 12" scope it isnt going to give me deep space unless its backed up by a quality eye piece?

I understand a lot of the DSO (see picking it up already ) wont be imediatley available to see and a longer exposure is required to see them. I know some exposures can be up to 16 hours long :shock:

Now the mount i dont know nothing about!! is the quality of the mount just going to mean the scope will be still and not move in the slightest? i assume for a long expsosures i need a motorised one, will these move with the rotation of the earth automatically - especially the one your reccomending as i cant find any info on it.

BTW is this the coolest simile ever?

[GordonCopestake]

I already have a decent digital camera and laptop

Lets just for a second take things back to a very basic level just to make sure i understand telescopes.

Say we have an 8, 10 and 12 incher. Neither offer anymore magnification than the other, just the higher the number will mean the more light it can let in and the more it can pertentially see. The eye piece is where the magnification comes in, so if i was to get a 12" scope it isnt going to give me deep space unless its backed up by a quality eye piece?

I understand a lot of the DSO (see picking it up already ) wont be imediatley available to see and a longer exposure is required to see them. I know some exposures can be up to 16 hours long :shock:

Now the mount i dont know nothing about!! is the quality of the mount just going to mean the scope will be still and not move in the slightest? i assume for a long expsosures i need a motorised one, will these move with the rotation of the earth automatically - especially the one your reccomending as i cant find any info on it.

BTW is this the coolest simile ever?

The aperture of a telescope has no bearing on the magnification of the telescope no, but it does usually affect what focal lengths are available and it is the focal length, along with the eyepieces used that determine the magnification.

Also the aperture determines the resolution of the image, and how much detail can be seen. ie, it's hard to see the cassini division of saturns rings in a 80mm telescope. But if a 80mm telescope has a long focal length of say 1000mm then with a 10mm eyepiece you could still get 100x magnification. but you STILL wouldn't see the cassini division. In contrast a 8" scope with a 1000mm focal length and a 10mm eyepiece would have the same 100x magnification but you could see the cassini division in all it's glory. This is more so for 10",12" and 14" telescopes.

Now it's technically feasible to make any aperture with any focal length, but as telescopes are usually mass produced they are only availabe with certain dimentions. ie, 80mm telescopes usually have a 400mm focal length or 900mm focal length. (im going on memory here, im sure someone will correct me).

The F number refers to the ratio of aperture to focal length, so a 1000mm focal length telescope with a 100mm aperture would be f10 and a 400mm focal length with an (imaginary) 200mm aperture would be f2. As a rule the higher the f number the larger the magnification but the smaller the field of view.

Concerning DSO's, you'de be suprised but you dont need very high magnifications to view them, in fact it can be a hinderance if you have too high a magnification. This is why lots of people who observe DSO's use low focal length scopes. 60-100x is probably more than enough for most DSO's.

The planets on the other hand, being quite bright, can take as much magnification as you can throw at them, and planetary scopes usually have very high focal lengths, 2000mm or in some cases 4000mm, this means they can achieve very high magnification but at the cost of field of view. As such the f ratio of such scopes is usually quite high, over 10 and even up to f20 in some cases (the OMC200 is a case in point).

It all comes down to what you want to do with your scope. For a good all rounder, i personally would choose an f5 scope or 6 or somewhere around there. Too low and you are limiting your views of the planets, too high and you wont get much DSO use out of it. Choose a good all rounder now, and later when you have found out what you are most interested in observing you can buy another scope and specialise. Lots of people have 2 or more scopes, one for planets and one for DSO's.

It's all down to personal choice.

[Mancunian Lee]

Thanks Gordon, would the ones reccomended above be a good all rounder then? How about the ETX range? ive seen sample images taken with an ETX 90 and they were cool. Seen nothing with the 105 though but i assume they would be better?

[OXO]

You won't get many DSO images with the ETX range, Planetry and Lunar/Sun there good at

[MartinB]

As a general rule you can magnify your image by 2 x the aperture in mm. You can use a 80mm scope at x300 mag but you will have a very poor image - better to stick with a limit of around 150. However beyond x300 you don't gain anything usually because the earths atomosphere is the limiting factor.

you're right about the mount. Do a decent polar alignment slew it to a star and using the right ascention slow motion control will keep it in the field of view. A motor will do it for you and essential for imaging.

[Kaptain Klevtsov]

Lets just for a second take things back to a very basic level just to make sure i understand telescopes.

Say we have an 8, 10 and 12 incher. Neither offer anymore magnification than the other, just the higher the number will mean the more light it can let in and the more it can pertentially see. The eye piece is where the magnification comes in, so if i was to get a 12" scope it isnt going to give me deep space unless its backed up by a quality eye piece?

Yes and no. If you are familiar with SLR cameras then i can easily enlighten you, if not I'll try anyway.

Relating 'scopes to SLR lenses:-

The focal length of 'scopes is not often quoted, rather they use the aperture size and f/ number. This is opposite to what you get with camera lenses but the maths is easy. If you are looking at an 80mm f/5 'scope, then that relates to a 400mm (80 times the (f/)5) camera lens, still at a maximum speed of f/5.

The skywatcher 200mm f/5 is therefore the same as a 1000mm f/5 telephoto lens. Very fast for taking 'photos with.

The ETX105 f/14 works out as a 1470mm telephoto but this time the "speed" is much reduced at f/14.

The difference is that the ETX will give bigger magnification with the same camera OR the same eyepiece, but the image will be much dimmer.

In camera terms the exposure will have to be 7.84 times as long with the ETX compared to the Skywatcher. (2.8 stops slower lens)

In non-camera terms:-

The magnification is calculated as the focal length of the 'scope divided by the focal length of the eyepiece. Now for more sums.

ETX105 - focal length is 1470mm, so a 10mm eyepiece will give you X147 magnification.

200 f/5 - focal length is 1000mm, so the same eyepiece will give X100 magnification.

If you want to compare by magnification, you will need to consider how much you think you will need.

If you want to look at very small things (angularly speaking, that is), then you should consider something with a long focal length. This will be a "folded up design" Maksutov or Schmidt Cassegrain in most circumstances. Small field of view is good for planets which will show details of rings, bands, red spots and the like. It is also good for looking at the moon so you want to get out your bucket and spade.

If you want to look at M42 and other larger things, you need better light gathering and less magnification. This is where the Newtonian comes into it's own.

If you have the cash, you can get a 12" Mak os SCT, but for the same amount of money you can get a 12" Newtonian and a car.

Next, after the focal length has been decided, this will narrow down the range of 'scopes within budget. Then you need to work out if the magnification you need will actually work. Because of the pedantic nature of physics, you will be unable to get magnifications much past double the aperture in mm. So the Skywatcher will go up to X400 (needing a 1000/400=2.5mm eyepiece), but the ETX will only go up to X230 (1470/230=6.4mm eyepiece).

Now that everybody is confused, I'll throw in imaging just for good measure.

The easy way is to get an adapter and plonk the (D)SLR in the eyepiece hole, job done. This, however, gives fixed magnification and, as above, relates the size of the camera's imaging area to an angular field of view. If you can relate to camera lenses, then you're there, if not take a look at http://www.gas.uk.net/FOV.xls where I have stuck an Excel spreadsheet giving the field of view related to APS sensor, 35mm and webcam image sizes. If you have planetarium software you can use the numbers to give yuo an idea of how much sky you will cover with which arrangement.

To complete this section, you can add a Barlow lens which, like a camera teleconverter, will double the magnification (usually, can get different ratios) as well as a focal reducer which does the opposite.

The mount is everything. Yes really.

If your setup wobbles, you will have trouble seeing anything. If its a pig to point it where you want it, ditto. If its not driven, you should consider at least slow motion controls, hand driven in the direction of apparent sky rotation.

You can go Alt-Az if you don't want to use high magnifications as these only very rarely come with drives (expensive or built in to the 'scope) so you will have big trouble finding stuff and staying on it. At high magnifications the stuff is just going too fast to hang onto.

Now that I've skived off work for half an hour it's time for a cup of coffee, then back to it.

Hope this helps, if not let us know why and the guys and gals here will put you straight. (they'll also jump in and correct the mistakes above)

Captain Chaos

[GordonCopestake]

Personally for a good all round telescope I would choose a 6" 1000mm APO refractor. Unfortunatly i've not paid off my mortgage yet so cannot afford one.

In the mean time I use a Celestron 8" SCT. This is cheap (ish) and has enough aperture for DSO's and enough focal length for planets. This is a personal preference and not a hard and fast rule, but the popularity of the 8" SCT over the last 20 years shows that it hits a lot of targets.

Alternativly take a look at a 6" f5 newts. The Orion Optics Europa range has excellent optics and engineering for a fairly low budget. I dislike newts though because of the large physical size. The best thing you can do is join your local club and acually get your hands on some scopes to get the feel. You wont know what you like or dislike until you've used a scope for a little while.

At the end of the day, the best telescope is the one you actually use.

[Mancunian Lee]

my head hurts

I think i get the basic picture thanks guys, i have the choice of either 2 scopes or a comprimise and get one!! Maybe i can save for longer and get two :insects1: Ill read this thread a couple of times and report back

Captain Chaos, your face looks familiar - are you pictured somewhere along side your telescope?

[russ]

Hi Lee,

The HEQ5 comes with dual axis (one for Right Accension and one for declination) built into the mount. It's also supplied with a factory fitted polar axis scope. The tripod is vastly superior, as is the overall build.

The EQ5 arrives bare, no drives, no polar scope and a wibbly wobbly aluminium tripod. The cost of adding the drives, polar scope and steel tripod is £200.

Now compare their original asking prices:

Explorer 200 on EQ5 - £349

Explorer 200 on HEQ5 - £549

You can see it was a false economy to buy the EQ5 equipped version as you'll end spending the same amount but still have an inferior mount. Unless of course you have no interest in photography, in which case drives and polar scope are not important.

The 8" Newtonian is the classic all round scope and there's no reason why it can't be scope for life.

The ETX has massive appeal. Superb on the Solar System objects. But limited on deepsky, while widefield is a no go. I think if you bought an ETX you quickly yern for a second scope (widefield refractor). Which would also mean a second mount. And the cost would be escalating all the time.

The ETX does have the appeal of GOTO and it's a very nifty feature. But you'll very quickly find the ETX and it's mount are limited should you wish to persue astrophotography

I would stick to the Explorer 200 now and then perhaps view an ETX later as a nice Grab & Go scope to compliment the Explorer.

Russ

[GazOC]

Russ,

I think all Skywatcher EQ5s ship with steel legs now, your still right though...get the HEQ5!

Gaz

[russ]

Lee,

do you mind if i throw one more scope/mount into the mix.

It's the Skywatcher ED80 refractor on the EQ5 mount.

This is why I think it qualifies for your short list:

light and compact

requires no maintenance or collimation

ultra quick cool down

as portable as the ETX

better focuser than the Explorer

light gathering power will be on a par with the ETX105

fantastic widefield views that niether the Explorer 200 or the ETX 105 could hope to match

really nice views of the planets - detailed and contrasty

jaw dropping views of the moon

capable on deepsky, more so than the ETX but no match for the Explorer 200

awesome scope for imaging, better than either the Explorer or the ETX

will put no strain on the EQ5 mount. The EQ5 will have capacity to spare.

£290 for the scope

£190 for the EQ5

£70 for the drive

Russ

[russ]

Russ,

I think all Skywatcher EQ5s ship with steel legs now, your still right though...get the HEQ5!

Gaz

I did wonder. But as you say the verdict is still the same.