Telescopes

[Dick Smith]

This is really a question for ali@ards, I suspect.

Earlier this week Julie asked me what I wanted for my birthday (a ritual we go through before saying 'nothing' and forgetting the whole business) and I thought of a telescope. Where we are in England the sky is never dark, and you are lucky to msee a full moon, but the skies in rural Normandy are magnificent. At the moment we use binoculars, but they are uncomfortable and wobbly.

Given that we are and are likely to remain rank amateurs and so don't want to spend a fortune, what should we be looking for? I'm after something that would let me see the rings of Saturn and the moon in detail, stand on a patio table, and if at all possible connect to a Nikon D70.

Am I asking for the moon?

[ali-cat]

Give me two minutes & I'll go & get Mark!! [:D]

[ali-cat]

Hi Dick

Other half of Ali@ards here.

First of all a reasonable question with a very unreasonable answer. Secondly you're on very dangerous ground here as astronomy has a habit of becoming a little addictive to the detriment of your bank balance and social life (although Ali would probably contest that I was never any great shakes on the social front in the first place).

There is a maxim in respect of telescopes that, ceteris paribus, aperture rules i.e the larger the scope the more you'll see. Ordinarily then I'd recommend buying the largest scope you can get for the money which is the Dobsonian type - a simple relector type on a basic alt/azimuth mount that you basically just ‘push’ to view. For example you can get a 6" scope - more than capable of seeing detail of Saturn’s rings plus many deep space objects for £160 (http://www.sherwoods-photo.com/sky_watcher/skywatcher_fs.html). Word of warning - you might be surprised how large this scope is.

You did mention the camera though so I assume you’d like to try some photography. With the Dobsonian type mount you could centre the object in the field of view and then take your shot before it drifts out of view but that sounds like a lot of work and really you need a scope with a mount that allows you to track objects as they move across the sky. In that case you’ll need a telescope with an equatorial mount and preferably one with at least a motorised polar axis drive.

As for scope type refractors are considered a good choice for planets as they provide good contrast (plus they look like a classic telescope) however unless you pay a lot for a high end refractor with exotic lenses they tend to suffer from false colour (usually a purple blue fringing) which can obscure detail and unfortunately shows up strongly on photographs.

Therefore if you end intend to take photos I’d recommend a reflector type scope on an equatorial mount. Interestingly the BBC Sky at Night magazine did a beginners scope test last year and their top choice was this type -the Skywatcher Skyhawk - 1145 - preferably with the optional motor drive (http://www.sherwoods-photo.com/sky_watcher/skywatcher_fs.html).

Unfortunately where this doesn’t meet your criteria is that the mount and tripod is much too large for a patio table. If you wanted to forego taking photos I would recommend the Orion Starblast (http://www.scsastro.co.uk/it040018.htm) as a starter scope that will sit on your patio table. Alternatively if your budget would stretch something like the Meade ETX 90 (http://www.sherwoods-photo.com/meade_scopes/meade_index_fs.htm) will both track objects, sit on the patio table and as an added bonus the built in computer will find tens of thousands of objects for you (in theory).

Bet you regret asking now - maybe a nice bottle of Scotch would be a better idea?

Cheers

Mark

[Dick Smith]

Mark

That is wonderful! Thank you very much. I love the Orion Starblast - sounds so Hitchhikers' Guide! It'll take me a few minutes to digest all of that, and I think I may forego the photography, but that is massively helpful - thanks again.

[ali-cat]

Glad to be of help Dick.

 

A few more links to help you decide.  The second is particularly comprehensive and witty.

http://www.souledout.org/rsl/telescope/choosingtelescope.html

http://www.findascope.com/

Regards

Mark

 

[Deimos]

I cannot add much experience as I’m a beginner but;

My parents visited last week and brought my scope out from the UK (an 8 inch SCT) and boxed-up it only just fitted in the back of a Ford Focus with the back seat flat.  Dick, I believe your car is larger than this but it is still a significant volume.

I hate to say it, and others please do correct me as I’m just a beginner and so far have only read about the astrophotography aspects (here and books) – but these days quite a lot is actually done on your computer (dark frame removal and flat field adjustment).  I understand people tend to disable e.g. dark frame removal being done automatically in the camera as this can filter out small faint start (e.g. the dislike of the Nikon D50?).  Similarly, people often stack multiple frames to get decent pictures.  anyway, the point being that most of the software I have seen for this is PC based.  I’m sure there is some Mac stuff, just I’ve not yet seen it.  I’m so much of a beginner I have not yet got my digital camera.

However, it a telescope an excellent idea so do no be put off.  A forum that may also be able to offer advice is http://www.popastro.com/phpBB2/index.php – they are not all mega scopes and quite a few participants have reasonable and portable sized telescopes.

If you want to use the telescope for non-astronomical use then check which way up the image is.  Many will invert the image (which is not too important is looking at stars/planets but might throw one a bit if looking at terrestrial objects.

 

Ian

[Dick Smith]

I'm going to have to sleep on this!

Would the Skywatcher 1145/114M let me see the sort of things I want to?

[Deimos]

I would imaging peoples expectations are all different.  Before I selected my scope I used the galleries on the various manufacturers web sites to see what people had done with different telescopes.  Many manufacturers have “user galleries” which show what people using their telescopes have achieved.  Whilst optical quality will vary between models, it will give you some idea as to what can be achieved with different apertures/focal lengths/eyepieces.

 

e.g. http://www.celestron.com/c2/images.php

 

Ian

[Dick Smith]

Thanks to both of you. I think I may have settled on the Skywatcher 1450 (recommended by Sky at Night) with the optional motor mount, and leave the photography until later. Will I get a good view of the giant planets, though?

Admin - I think that Mark should modify his post a bit and put it up in Useful Links.

[Dick Smith]

And would a 2x Barlow lens be worth it?

[ali-cat]

[quote user="Dick Smith"]I'm going to have to sleep on this!
Would the Skywatcher 1145/114M let me see the sort of things I want to?
[/quote]

Hi Dick

I've attached links to scans of the relevant pages from the Sky at Night magazine which might answer this.

http://i42.photobucket.com/albums/e332/Livingstone_Mark/starblast.jpg

http://i42.photobucket.com/albums/e332/Livingstone_Mark/Skyhawk.jpg

http://i42.photobucket.com/albums/e332/Livingstone_Mark/Summary.jpg

Before parting with your cash you could also consider attending a local 'star party' where like minded socially challenged (mostly male) stargazers gather together to admire each others' scopes and occasionally look at the sky.  Joking aside they're a great opportunity to talk to experienced users,  try out a range of scopes and even just get an idea of the physical size of the various scopes and just how portable and usable you would find them.  Just to contradict myself I did say that aperture rules but another truism is that the best scope is the one you use most - which for many astronomers is often a small 'grab and go scope' which allows you to take advantage of the rare breaks in the weather we tend to get here in the UK.  A large scope is great when conditions allow it to perform to its best but if it takes an age to transport, set up, and cool down (the optics on a larger scope can take an hour or two to cool down to ambient temperature before the views stabilise) then it won't get used. 

Hope this clarifies rather than confuses further.

 

Mark

 

[ali-cat]

Apologies.  Don't know what happened to the links first time around.

 

http://i42.photobucket.com/albums/e332/Livingstone_Mark/starblast.jpg

 

http://i42.photobucket.com/albums/e332/Livingstone_Mark/Skyhawk.jpg

 

http://i42.photobucket.com/albums/e332/Livingstone_Mark/Summary.jpg

 

[Dick Smith]

Thanks again, Mark.

I think that space is not too much of a problem - we can build a small viewing platform in our back garden which has excellent skyscapes, ot use the patio (which is, bizarrely, in the front). Broken down, storage should be OK. I must admit that I hadn't thought about lens cooling - not too much of a problem in 35mm photography!

I should have said a 3x Barlow in my last post, as the 1145 has a 2x Barlow included, I believe. Would that give me better viewing?

[ali-cat]

A note to all wives who have partners reading this thread!!

Think carefully before allowing tham to buy a scope!!  If it rains - they sulk.  If it's clear - you will never see them.  During the day - they will be fiddling with their scopes to improve the quality of the optics (or so they believe [Www]). 

On the other hand if they complain about the TV programmes you like to watch in the evenings or the amount of time you spend on the phone - it's great!!  You can watch & phone whatever & whoever you want!! [:-))]

Ali.

[Dick Smith]

Ah, but Julie wants to be out there as well. We may have to get 2...

[ali-cat]

So did I - until it dropped below -4 degrees & my feet froze!!  But I'm a wimp!!

[Dick Smith]

I'm thinking balmy summer nights and the scent of bouganvillia. Or possibly cows.

[ali-cat]

[quote user="Dick Smith"]Thanks again, Mark.
I think that space is not too much of a problem - we can build a small viewing platform in our back garden which has excellent skyscapes, ot use the patio (which is, bizarrely, in the front). Broken down, storage should be OK. I must admit that I hadn't thought about lens cooling - not too much of a problem in 35mm photography!

I should have said a 3x Barlow in my last post, as the 1145 has a 2x Barlow included, I believe. Would that give me better viewing?
[/quote]

Hello again Dick

Now you're getting into the black arts and voodoo. 

The ad that I gave the link to states that the Skywatcher 1145 comes with 10 & 25mm fl eyepieces giving 50x and 20x magnification respectively (as I'm sure you know from your photography magnification is a function of the focal length of the telescope - in this case 500mm - and the eyepiece - e.g.10mm - 500/10 giving 50x magmification).  Its good to have a range of eyepiece focal lengths available to give you a range of possible magnifications to suit the target.  20x mag is good for 'sweeping' the sky - giving you a wide field of view at low magnification - and allowing you to capture all of an extended object such as the Great Orion Nebula; Pleaides, the Moon etc.  150 to 200x magnification yields the maximum detail on the gas giant planets.  200x mag is probably the upper limit for the scopes we're discussing and seeing conditions often place a similar limit regardless of the size of scope used.  An eyepiece giving a magnification of 80-100x is a useful medium power choice for certain objects and nights when conditions won't allow for high powers.

With a telescope focal length of 500mm -you would need a 2.5mm fl eyepiece to give 200x magnification.  However usually, once you go below a focal length of 6-7mm, 'eye relief' becomes a problem - you may find yourself having to press your eye against the eyepiece and squint - even worse if a you're a glasses wearer.  A Barlow lens can help you get around this problem plus,  if well chosen,  can effectively double the size of your eyepiece collection.  For example pairing the 10mm ep with a 3x barlow gives you 150x magnification while preserving the better eye relief of the 10mm eyepiece.  Unfortunately pairing the 25mm ep with a 3x Barlow won't give you much more (60x mag compared to the 50x mag provided by the 10mm ep) plus longer focal length eyepieces tend not to work too well with Barlows (vignetting of the image). Alternatively,  if the package does come with a 2x Barlow, you could pair this with a 6mm eyepiece (which you would have to buy) giving you 167 times magnification.  The 2x barlow would also give you a useful 100x mag paired with the 10mm eyepiece.

The table below sets out the possibilities with the eyepieces supplied plus suggested addtitonal eyepiece focal lengths :

Eyepiece	Magnification	Magnification with 2x Barlow	Magnification with 3x Barlow
25mm	20	40	60
10mm	50	100	150
8mm	62	125	188
6mm	83	167	249

After all this - don't be too concerned at this stage.  The 10mm and 25mm eyepieces supplied will allow you to see a lot to get you started and even at 50x magnification you'll be able to make out Saturn's rings and Jupiter's moons and some banding on the planet itself.

I don't honestly think you can go wrong with either the Skywatcher scope of the Orion Starblast.  They both largely share the same highly regarded optics differing only in the mount with the Starblast more portable and suitable for patio table use. In fact the Starblast was orginally designed for kids** but serious amateur astronomers keep one on hand because of its excellent optics and 'grab and go' ease of use.  Even if you enjoy the hobby and move on to bigger and better scopes either of these scopes will still have a use - plus of course any eyepieces you have can be used on any other scope.

Phew!! - Must go pack now as were off to La Rochelle early tomorrow morning.  Happy to try to answer any other questions etc when we return.

Cheers

Mark

** Not Just For The Kid's!
See the review of the Orion StarBlast in the June issue of Sky & Telescope. Reviewer Joshua
Roth commented, "Orion is justifiably marketing the StaBlast as a kid's scope, and I wouldn't
hesitate to buy one for a reasonably mature child with a demonstrated interest in astronomy.
But even old-timers might find it an ideal second (or third, or ... ) scope for grab-and-go
stargazing, camping trips, or possibly even airline travel."

[Russethouse]

Mr Russethouse has got the Skywatcher (explorer 200, I think) its got an 8in lens, Deimos is right, its much bigger than we thought and reasonably heavy too.

Dick, if its a birthday gift I would check out delivery times, we were messed about uphill and down dale by some one who apparently is a fairly well known TV name, it took nearly 2 months to actually arrive. Worth phoning round or emailing for actual availability IMHO.

[Dick Smith]

Thanks for that, Gay. No rush, really, as we won't be out again until the end of July, but I'd want it for then!

Does Mr R do any photography with his? I was wondering about some terrestrial stuff, but I guess it isn't any too nimble...

[Russethouse]

 He hopes to be using it for pics but its a learning curve. It was a 'big birthday' (and he works very hard !)so he had the telescope and SLR Cannon camera that will allow him to take pics.Of course the camera will be useful for general photography too.

The 'bonus' for the rest of us is that we may never need buy him another shirt for Christmas or birthday, I'm sure he will be wanting one bit or the other to go either with the telescope or camera to keep us going for a bit...............

Actually the same thing happened with the camera, we decided, because of their reputation for customer service, to buy the camera from John Lewis, did they have one - no ! We had to wait for about 2 weeks, but they did deliver...........

[Deimos]

[quote user="Dick Smith"] No rush, really, as we won't be out again until the end of July, but I'd want it for then!
[/quote]

 

I don’t know about Skywatcher but when I selected the one I wanted (Celestron), I called the importer in the UK (UK prices were about £300 cheaper than France) to order it and, none in stock, none on next delivery in a month so at least two months but they had no idea if they would be in the subsequent delivery or not (and that is one of the “mainstream” manufacturers).  What I chose is one of the more common models (nothing weird or unusual).

Phoned round loads and loads of retailers and eventually found one who had the model in stock, got it delivered, parents brought it out and it did not work (and appeared probably 2^nd hand).

From my limited experience I would suggest start looking, selecting and buying a.s.a.p as the process could take some time.

Ian

[Dick Smith]

Many thanks to all of you, I ordered the Skywatcher today. I will probably get a 3x Barlow and the eyepiece special offer to go with it. They (Sherwoods) have them in stock, and I am impatient already!

[Russethouse]

Thats a result - I was telling Mr Russethouse about this thread and we were going over the time frame again - we ordered the telescope  just after Christmas, hoping it would come in time for his birthday mid January, it turned up just in time for my birthday - mid March !

If yours is on its way you have done really well !

[Dick Smith]

 They have assured me by email. So of course it will be allright. Obviously. Erm...

I've got until the end of July, so it should be here by then, and there's not really any point in trying to use it in suburban Surrey - just too much light pollution. It's like the North Pole, it never actually gets dark.

Sliding OT, that is one of the real attractions of rural France (and yes, I know it would be the same in rural England, but I can't afford that!). Have seen some good comets, and I love it when you can see the colours of the stars with the naked eye. I just want to feast my eyes on the Milky Way and see some gas giants. I've wanted to do that all my life, and now it is possible. And, actually, a lot cheaper than I expected.