Telescope advice?

NeilF

NeilF

NeilF

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Marlow
When I was young, I remember buying myself a small cheap refractor telescope and looking at the moon, the rings of saturn, jupiter and even the orion nebula. I'm contemplating buying a telescope just to look at these objects again, as well an allowing my son to get to grips with the fact we're really just on a lump of rock rushing/spinning through space...

Although I suspect the telescope wouldn't be used much, I'm willing to buy one to periodically view the night sky. So, I'm hoping for some advice from any astronomers here on a few questions?


Light polution
Where I lived when I was a kid it was in a fairly lit up area (near a main road and not far from a motorway/town - a mile or less), but none-the-less, in our back garden I could see Jupiter fairly well etc. Where I now live, there's probably slightly less light pollution, so I would hope to see the bands across Jupiter, its moons, and a fairly well defined smudge for the Orion nebula for example. Is that expecting too much? Will I be able to see that sort of detail from peoples experience with a low end (£150) telescope?

Is there any sort of simple rule of thumb for this? eg: If you can see X with the naked eye, then generally you're wasting your time with a telescope!


Portable
About 5 mins walk from my house are nice quiet fields. And it would be nice if the telescope could be walked and setup easily there.


Photography
I might be interested in attaching my D90 SLR, and taking some photos. I understand there's a couple of issues regarding how to attach/mount a camera to a telescope (eg: requiring a T-adapter & barlow) but wonder if this would also mean a motor might be required?

Would I be right in saying with a camera you can take numerous photos (eg: 20 photos each 1 second apart) and then using an application you can process them into a single more accurate/detailed photo? eg: Photographing Jupiter?


Keeping in view and Motors
I recall when I was a kid, on high magnification chasing Jupiter across my field of view... I assume these days with a modern telescope you just turn a dial to rotate/move the telescope in the equatorial plane to follow objects across the sky easily?

And I assume those telescopes with motors, they just do this movement for you? ie: Turn the dial at a slow constant rate?


Goto
Out of interest, I know some telescopes have "goto" computer control. Is this worth worrying about for the extra money? I assume this complicates the setting up/alignment of the telescope?


Model
Assuming I will be able to see enough objects well enough to justify a puchase, I'd be happy to spend around £100-200.

Any suggestions for something fitting the above requirements? eg:-
Skywatcher Skyhawk 1145P - 114mm - Approx £125
Celestron AstroMaster 130EQ-MD - 130mm motorised - Approx £150 (Although I've read some possible negatives about the tripod)

...and remember attaching an SLR and portability would be nice if possible?


Thanks in advance for any advice/help or personal experience(s).
 
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Saw a "the sky at night" episode a few days ago where they said that if you contact your local council you can get the street lights changed to the newer motion sense ones as the councils have an energy policy they must try and meet, so only using a streetlight when its needed works well for all parties.

As for the telescope, I can't advise on that I'm afraid :(
 
NickK said:
I'll come back to this later this evening :)
Click to expand...

Thanks... Any help would be appreciated!


I'm trying to read up and understand why telescopes seem to split into, aimed at planetary observation and aimed at deep-sky observation.

I don't quite get (yet) why a telescope can't be reasonable at both. ie: It's aimed at capturing as much light as possible and magnifying it. So I'm having trouble seeing why a telescope that is aimed at viewing Mars well, can't also look at a nebula well too? And when I say "look" I mean visually and photographically.

Simply put, why does increasing a telescope's focal length (and not changing its diameter) suddenly make it better for deep sky and worse for planetary?



If there's a unit I could buy for say £200-400 ideally with a motor so it could at least track for a while, or ideally even GOTO, and that could give reasonable results for planets and nebula etc, that would be great. (Worse case I could buy one of the units I originally listed for around £150 to suck it and see.)

I understand for £100 or so you could then get a webcam of some sort that you could then use for photography. But I'm unclear if this is then ideal for just planetary photography, or also nebula as well?


So what about a Skywatcher Explorer 130P SupaTrak AUTO, or with Goto for example? Would I be able to do reasonably effect viewing and photography of both planets and nebula etc?
 
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If you imagine a certain amount of light, or sand, in a circle then make smaller circle and then expand the light/sand to cover the original circle size then resulting circle is dimmer (or thinner layer of sand).

For visual you'll need lots of light for DSOs so a larger aperture the better.

For photography:
* webcam photopgraphy - this can be done at high FPS with a webcam on a dobson for example. Lots of frames (ie 3000) are then stacked to product an image. This works for moon, planets at a push - I wouldn't try this with DSOs unless they're very bright (ie can see with naked eye).
* DSLR - that needs a mount to track the object accurately so that the images don't blur. This is where is starts getting expensive (DSOs) - trust me on this ;).

In reality the basic starting points are: visual is about light capture, photography is about the mount accuracy.

Skywatcher are a good, solid brand to start with and a 150 would be exceptionally good. You can then do webcam first and then progress as you go.

Motorised tracking is useful, Goto is good for impatient kids. However tracking for AP requires more accuracy than visual.

Dobsonians are a good starting point too and will work for webcams. they're literally point and view light buckets! you can mount them later as they're just newtonians that sit on the ground.

Lastly for photography you really want an equatorial (EQ) mount rather than AZ as an EQ mount only needs to move one axis to track objects (less blurring).

Everyone wants a scope todo everything, unfortunately none exist :)

I use a 102mm aperture refractor that is 670mm focal length (f/6.38). This allows me to hunt DSOs, take photos of the moon and go after planets too (and solar with a filter). however my planets and smaller DSOs are small until I got a 2x barlow but it take four times as long to collect the same light with it attached! Can I use it visually - yes but the galaxies simple smudges compared to big light buckets as its designed for photography.
 
^^ That's all useful thanks!

If we consider say the SkyWatcher EXPLORER-150P + EQ3 PRO SynScan GOTO Newtonian, which is around £500! That's f/5 which I believe would be good for DSO? And I believe it should also give reasonable planetary views?

And wouldn't the SynScan allow me to take say 30-60 second exposures? So I lock onto to say a nebula, the Synscan tracks it. I tell my SLR (Nikon D90) to take say 10 photos, each say 30-60s exposures? These would then be stacked?

And even with planetary photography, either:-
- Take 50 photos and stack them.
- Take a LiveView and stack that output? Although the AVI is compressed, but is in 1280x720 resolution!?


So , one big question is, would that "EQ3 PRO SynScan GOTO" keep the tracking accurate enough for x minute exposures?
 
Hehe it's probably better to read further into it - Making Every Photon Count is a good starting book and I've met the guy who wrote it and he's knowledgeable..

Here's an image with a SW150P using two 2x barlows to increase magnification for photography: http://www.flickr.com/photos/64835179@N05/6160175848/
Or: http://www.northlincsastro.com/images.html

An EQ3 Pro would be ok for visual, others have used it for photography for webcam but unfortunately DSOs are where the cost starts creeping in.

You can try out the software using your camera during the day too :) Registax or DSS etc are all applications that can stack frames.

Note that DSOs do not visually look like their images!

A synscan controls the mount. The mount accuracy depends on it's payload (the less it's holding the more accurate they are) and the gearing (the HEQ5Pro and EQ6 have the right accuracy of gearing).

You'll find it has some coma, etc but AP is more of a journey than a buy one thing and you get perfect images.

I warn you now - AP is far far far more difficult than normal photography (I can see the debate ;)). You'll swear.. continuously.
 
Thanks again... You seem you're suggesting that SkyWatcher EXPLORER-150P + EQ3 PRO SynScan GOTO Newtonian might not be smooth or accurate enough for minute long exposures for example?

A more robust setup, with a seemingly identical reflector might be a Celestron Omni XLT 150 with CG-4 German Equatorial Mount and Dual Axis Motor Drive for about £345+£91? That surely should be robust/accurate enough for 1 minute exposures? Although the lack of Goto is a shame :)



What I'm trying to do here is not spend a few hundred quid and find it's in the wrong direction. I'd rather spend a bit more, but wisely, to get something that lets me experiment and get reasonable results!?
 
Ignore GOTO, its not required and to be honest, most of the fun is trying to find what you are looking for! Head for GOTO territory only when you know your way around the sky, and are after specific targets night after night after night. I love star hopping, although it is frustrating at times!
 
I started with a Vixen A80Mf and a manual porta mount :) Then jumped directly to an EQ6 so I don't have confidence of the EQ3's ability to take photos. Also I'm very aware that I'm spoilt from a scope perspective by the Pentax as I picked it up secondhand for a good price.

I would have a chat with the folks at Stargazerslounge. I know other forums are frowned on but it will stop you from spending hard earned cash in the wrong place, be disappointed with expectations. :D

I star hop too, I have the synscan handset but now use the laptop to track the stars optically using a second camera whilst the main camera takes the photo.
 
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well i started with a cheap £50 refractor off the carboot, then move to a meade etx125pe, then for more portible solution i got a skywatcher evostar 80 ds pro apo f/7.5 focial 600m (aka black diamond ed80). now if you want more get and go telescope the 150p might not be ideal choice as it quite big and tube weight's 6kg then got to carry tripod and various bit & piece so it can get to the point you carrying over 10kg. as for astrophotography im still just getting my foot in the door but the reflectors are very good at this and 150p has a lot of good reviews. personally if i was going the reflector route i would go for 150p ds, has the ds serise as the much better 1.25/2" dual speed crayford control on it which in my opinion is far better at focusing. as for mount if you wish to save i suggest getting a motorize mount that can be upgrade at later point to goto as with those mount it a simple task of replaceing the handset. so look for a motor mount that give you that option. i would look at the eq5 mount it may cost more than the eq3 but it lot more soild that the eq3 so it won't move about as much in the wind plus eq5 can carry lot more weight so if you ever decide to upgrade your scope you simple have to look a buying ota tube instead of telescope and tripod package.

ps most if not all motorize non-goto mount have tracking ablie on them. only real advance of goto is that it allow you to hook up gps / connect to a laptop to remote control the telescope.
 
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pecnarf said:
well i started with a cheap £50 refractor off the carboot, then move to a meade etx125pe, then for more portible solution i got a skywatcher evostar 80 ds pro apo f/7.5 focial 600m (aka black diamond ed80). now if you want more get and go telescope the 150p might not be ideal choice as it quite big and tube weight's 6kg then got to carry tripod and various bit & piece so it can get to the point you carrying over 10kg. as for astrophotography im still just getting my foot in the door but the reflectors are very good at this and 150p has a lot of good reviews. personally if i was going the reflector route i would go for 150p ds, has the ds serise as the much better 1.25/2" dual speed crayford control on it which in my opinion is far better at focusing. as for mount if you wish to save i suggest getting a motorize mount that can be upgrade at later point to goto as with those mount it a simple task of replaceing the handset. so look for a motor mount that give you that option. i would look at the eq5 mount it may cost more than the eq3 but it lot more soild that the eq3 so it won't move about as much in the wind plus eq5 can carry lot more weight so if you ever decide to upgrade your scope you simple have to look a buying ota tube instead of telescope and tripod package.
Click to expand...

Your comments about the 150p's stand are interesting. I mentioned the Celestron Omni XLT 150 with CG-4 German Equatorial Mount above because I believe it's basically the same telescope (same company owns both Stargazers and Celestron??) but on a much more robust mount - http://www.celestron.com/astronomy/celestron-omni-xlt-150.html

A motor can then be fitted this for under £100.


Yes, weight is a concern, but unfortunately it seems weight and image quality/capture sort of go hand in hand! :(
 
the thing with the cg-4 mount is that it much better than the eq3 mount in terms of design, build quality and robust. but it still in the eq3 class in terms of what weight it can carry, upgrading will only allow for dual axis steping motor with basic handset control but no goto handset can be installed on it so that mean no gps / computer hookup / autoguilder etc, if you ever got into astrophotography or stargrazing the cg4 mount would limit what you could do so you would have to upgrade to a eq5 or better mount. Celestron CG4 Omni Dual Axis Motor Drive upgrade kit is current at £120 to buy. also i suspect that the 150 will be close to the weight limit of the cg4 so when you go to connect you d60 to it, it might put a strain on the stepping gears or create a inbalance. if it does create an inbalance it can be solve by adding counter weight and adjusting their placement but again this will add more weight and but a strain on the gears.

ps philips spc900nc is web camera that can be mod by yourself quite easily to be used as a colour vga ccd imagier. for under £50
 
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^^ I've looked on the Celesteron and Skywatcher sites at the mounts, and I can't seem to see what their weight limits are? ie: Could I fit a 150mm telescope, the dual drive kit, and a 1kg (D90) camera on?
 
now i check various forum of on the payload of the cg-4 from people who are using it. they are mainly using it with 80mm to 120mm reflactor which weight at 2-4kg then with eyepiece at 0.4kg plus dslr @ 1kg they say it little shaky at times. as for using the 150p or simiar telescope on it they say it pushing it but ok for visual but not ok for AP as once you start adding the weight for the adpater and camera it becames unstable.

now celestron say the max payload that the cg-4 mount can carry it 20lbs (9.1kg) this mean that it is the absolute max it can carry. but in fact it a lot less if you want to use it safely and correctly with out any problem.

150p tube = 5.7kg
D90 = 1kg
eyepiece = 0.2-0.8kg
barlow = 0.5-1kg
extension tube = 0.1-0.4kg
 
NeilFawcett said:
Eyepieces and barlows can weigh 1kg???
Click to expand...
the eyepiece's can weight anything between 0.3kg - 0.8kg but depends on the type and build for example Baader Hyperion weights 0.4kg (400g)

barlow len 0.2kg - 0.9kg but depends on the type and build

now thier cheap one that weight next to nothing then their excellent ones then weight a lot but that because they triple glass apo eyepiece, barlow come the same but sometime heavy cause their 3x-5x in mag so more glass used. now when viewing you can use 2 or more barlow stack then the eyepiece.

2x barlow len 0.5kg x2 > eyepiece 0.4kg = 1.4kg
if you do eyepiece projection where camera is attach to the eyepiece and not the telescope body (which called "prime") then it be
2x barlow len 0.5kg x2 > eyepiece 0.4kg > connector 0.03kg -0.1kg> dslr 0.9kg-1kg = 2.33kg - 2.5kg

it soon adds up.
 
OK... So we're talking about:-
SkyWatcher NEQ5 PRO GOTO SynScan Mount for about £412. And that would even take a 200P telescope, yet alone a 150P!

What's interesting is if you then add on the 150P separately, that will take it to about £600, but for £700 you can buy the SkyWatcher Explorer 200PDS/1000 EQ5 PRO GoTo.


Anyway, the important bit! So with the EQ5 mount, you'd then suggest it could keep a nebula or something lined up for ten or twenty minutes for exposures?
 
if you talking about the SkyWatcher NEQ5 PRO GOTO SynScan Mount rather than the eq5 then yes as the neq5 is design for ap in mind hence why it was a guild port on it plus it can hold lot more weight compared to the eq5. in terms of weight people mount their c9 -c11 cas/mak on the neq5 with 80mm reflactor mounted on top of the c9-c11 scope then add camera and it still operate well within normal.

eq5 with 150p as long as it align correctly and has some sort of guild scope then yes it could keep track dso for 10-12 minute's maybe more. but please bear in mind that the neq5 is design primary for ap use and is much more suited to ap than the eq5 is, but the eq5 can be used for ap.
 
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