cautious Newbie with questions

[Brycepj]

G!day everyone,
I have been read all you post with interest and it has been very educational.
Awhile back I decided to buy a pair of binoculars primarily for star gazing so I waited for a sale and picked up Olympus 10 x 50 which reading forums was an excellent place to start. Really good advice as it's been great. Of course the next step was ok which telescope, after reading and reading and questioning and fortunately been able to look through a 8 inch dod and a 5" televue refractor on an eq mount which had go to capability which actually blew me away seeing saturn 's rings. My thoughts were ok I'll pick up a small refractor with Goto for about $900. Before I pushed the button I thought hang on $900 is a fair bit for first scope as eventually I will want some thing better as eventually astro photography would be great I had a rethink and thought well my 10 x 50 are great how about up the mag. and aperture to say 20x80 that should get me out there and they are still reasonably portable I.ve got a good tripod for my DSLR. Trying to find one has been tough on a budget of say $300. Then I picked up a copy of "Australian Sky & Telescope May/June and there is this guy talking about how good his spotting scope is the things he sees how portable etc.. I can pick up a Celestron Ultimate 80 for $300 maybe that's the way to go. So my question is this what's wrong with spotting scopes for star gazing 20- 60 x80 highly portable, vs 20 x 80 binoculars I have read good and bad about spotters is this reasonable or do I just keep saving for the whiz bang refractor for $2,000? What am I missing.?

[JonR356]

Advice from a fellow beginner:

I'd say you're missing out on buying a decent size dob, without the goto stuff.

Buy a book or a smartphone app and learn your way around the skies. You'll have the best of both worlds with your binoculars and dob - something small and convenient and something to let you see the fainter stuff you'll never see with the binoculars.

Forget photography for the time being, and buy kit for that when you need to. You'll still use what you already have for visual work

[brian nordstrom]

;) Jon , that is very good advise , mate , well said .
I could not agree more .

Brian.

[raymo]

Jon is right on the money, if you have a real interest in astronomy,
you'll soon want to see more than an 80mm can show you. An 8" dob
is nice and portable, nice and cheap, and you can do photography at an
introductory level further down the track. Best of all, you won't lose
much money when you sell it in order to buy a better scope.
raymo

[astro744]

You looked through a 5" Tele Vue? Wow! That's like $9k worth of view! Wide flat field with pin point stars to the edge and very high contrast. Wish I had one. Dreamin'!

[raymo]

The scope needs to be balanced slightly against the drive direction, to ensure the gears are kept firmly in mesh. If it is perfectly balanced, the scope will flutter back and forth a little due to the play in the gears, and
probably ruin your pics. It depends on how much backlash your gears have. It is obviously less important with belt drive mounts.
raymo

[Brycepj]

Thanks guys got the apps and books and happy to let photography slide. An 8" dob sounds cool what are the collapsible like?
Astro Yeah the televue was awesome the guys in Perth near the ocean so little pollution he had a Dob as well which I found hard to see through May be just me.
peter

[raymo]

The Skywatcher Flex Dobs as they are called, are simple to extend and
collapse,[ about 10-15 seconds.] They hold mirror collimation very well.
I had a 10" one for several years, and never had a problem.
raymo

[Marios]

Keep in mind the mount is the heart of your setup, you only want a EQ mount to do photography.

If photography is in your mind longer term get a entry level HEQ5 mount, and a scope in your price range. This mount will give you room to grow in the future as your needs change.

[Camelopardalis]

This was probably the eyepiece being used at the time... different eyepieces have different characteristics which can affect eye placement for best viewing which ultimately affects comfort. The Dob and the refractor just put the eyepiece in a different place for viewing due to their design.

[Brycepj]

Ok guys here is what I'm close to buying. decided to go a bit further and buy something that will lead to astro photography and also fairly portable.
I'm considering a Skywatcher Ed80 refractor on a EQ3 mount. Down the track I'll add goto capability and the bits for astro photography. Can get one for about $1300 . My question is about celestial polar alignment. As I live in melb. I know the lat. is 37' I also know that The declination angle from mag. north is 11' if I have my compass I can adjust to true North is it sufficient to set a new mount up in this manner. Does it have to be the southern celestial pole, why not North???
I know Marios mentioned a HE 5 but that pushes the budget a bit. Will the EQ3 do the the job?

[el_draco]

Hi cautious,
The ED 80 is a good scope for beginning astronomy but astro-photography is a different ball game altogether. There are plenty of threads here to help though.

You do need to polar align any eq mount for it to work effectively but for visual use, the alignment does not have to be anywhere near as accurate as for photography. You align on a the South Celestial Pole from Aussie. The North Celstial Pole is marked by a star called Polaris and its invisible from here. Think about a globe of the earth and extend the earths axis into space. Polaris is "above" the North Pole. We have a star called Sigma Octanis but its only visible, without a scope, under dark skies, not a hope from Melb. You can get your polar alignment more accurate by learning "drift alignment" ... and there is sure to be a thread here on that topic.

If I were you, I would forget about trying to do photography to start with, except for the moon and perhaps wide field work with just an DSLR. The moon so bright its easy through a telescope, (very short exposures), and the very low magnification of a DSLR will make tracking errors quite easy to mask. for panoramic shots. The results, in both cases, can be amazing!

Pretty much anything else celestial requires a RIGID mount and precision tracking. An eq 3 will probably struggle.

It might help if you specify your budget and what precisely are your interests in astronomy are so people can point you in the right direction.

Rom

[Brycepj]

Thanks Rom, Budget is $1500 Being able to take the scope on travels is a " "must have" like to be able to see Nebulas Saturns rings,Star clusters such as jewel box cluster ( better than I can see in my 10x50 Bin) Etc. The long term goal is astro photography but that's a fair way down the track. I would like to start with a decent scope and have been recommended the Ed80 on a Eq5 with Goto capability but like the challenge finding stars clusters etc my self
The ED 80 being an Apo really appeals and it's a scope that I would keep for awhile. There is so much to choose from and take into account it is hard to know if I'm making the right choices. A refractor is my preferred option I have at least made that decision.

[el_draco]

Ok, There are a couple of things to consider:

- If imaging is way down the track then consider yourself a visual observer to start with. At a later stage, if the passion is there, you can join the upgrade train and build up to a scope that will do imaging well. (Thats code for "run away as fast as you can NOW")

- If you are a visual observer, then size matters, to a point. DSO's generally require a lot a of light gathering power. This suggests a reflector, particularly for the faint fuzzies.

- A refractor is compact but wont show very faint diffuse targets very well. Good for clusters, moon and stuff like Saturns rings, cloud belts on Jupiter and a bunch of "moons". One of my first scopes was a 60mm achromatic refractor and Saturn was unforgettable. If you want to resolve brighter globulars, you need 80+ mm aperture. A 10 inch Dob will do this really well. A 10"-12" reflector would leave an 80mm in the dust for both resolving power and light grasp.

- A travel scope can range from a backpack scope on a camera tripod through to a 10" -12" Dob in a car. Both options have advantages and drawbacks.

- The key is to get something that will encourage your interest but can be on-sold as your skill / interest develops. Since you've said you like the idea of star hopping, (Good fun), go for a simple mount and learn about the sky first. Alt-Az is easy to use.

- Not sure a refractor will meet all your needs and I suggest you explore the reflector option a bit more from the perspective of light grasp. You can upgarde many dobs to GOTO capability, for example, or perhaps experiment with an "equatorial platform" for short run imaging Equatorial mounts take time to setup for observing, alt-az is a more practical grab and go option

- As for the budget, you can buy new but the second hand gear in the classifieds is a VERY pragmatic way to increase the size of scope you get; most folks look after their stuff very well and you can end up with an essentially new scope for 75% or less of retail. If you go refractor, I'd try for a 100mm ED if you can stretch it; 50% more light grasp than a 80mm and more targets within reach.

Hope this helps a little

Rom

[Brycepj]

Rom thanks for you advice. so basically I should be looking at either a reflector or refractor on alt Az mount providing the refractor is 100mm.
I have discounted the reflector after read about collmination issues and is it true that the images are reverse/mirror images ? Should I still look at Apo refractors? What 2nd hand sites can you refer me to that are trustworthy and reasonable

[el_draco]

For simplicity,
- I'd go for a 10 to 12 inch Dob, with a low F ratio say F4 or F5. Size may be an issue with the 12"
- For a refractor, I'd try for a 100mm, (Just that bit bigger) on an alt-az. Later on, you can move this over to an equatorial.

Its true reflectors need to be re-aligned frequently compared to a refractor, but the process is pretty simple and there are lots of tutorials on how to do it.

In all astronomical scopes, the image is inverted but there is no up or down in space, so its irrelevant. You can get a gadget that will flip the image back but its just one more element that robs you of light. For a refractor, get an apo because it gives a better image than an achromatic lens, no / little false colour.

Generally, astro sites are pretty reliable but its a case of buyer beware. The classifieds on IIS are a great source of gear and I use the site often. This is another:

http://www.astrobuysell.com/au/

If you see something that appeals, ask other people their opinion. Most are quite honest and only to willing to help. Sellers often have an extended history of posts and you can get an idea of what they are like.

Rom

[astro744]

Any odd number of reflections will cause reversed images, i.e. View will not match star char. An even number of reflections will produce an upside down image but not reversed and the view will match a star chart.

A Newtonian reflector has two mirrors so produces an upside down image with no reversal.

A refractor with star diagonal has one mirror and produces an upright image with left/right reversal.

An SCT has three mirrors with star diagonal and also produces a reversed image.

Upside down does not really matter with astro objects but reversed does if trying to compare with charts. It is only really an issue with wide fields when trying to find something.

[Amaranthus]

I got the SW120 achro for widefield visual, and it's terrific for that purpose. $ for $, it's hard to beat! On planets you get some CA, but it's not too bad, especially with filters. It's a good low-cost way to get into refractors, with a decent light grasp for the DSOs, especially if your skies are dark.

[The_Cat]

Cannot add too much to this discussion.

1. Here is a very nice piece of gear. It may be a bit out of the price range but it is very nice:

http://www.myastroshop.com.au/products/details.asp?id=MAS-041J

Upgrading these from a standard to goto model gets expensive it is cheaper to get the goto model straight away. don't worry about collimation it is easy to learn and do!

2. For use with the binoculars / smaller telescope recommend getting the

Bright Star Atlas 2000.0
By
Wil Tirion and Brian Skiff

This atlas has lists of objects on each page. You will also get used to the co-ordinate system ... RA / dec .

3. One of the classic books for the amateur astronomer:

Norton's STAR ATLAS
and Reference Handbook

EDITED BY IAN RIDPATH.

Clear skies,

Jeremy

[el_draco]

This is amazing value FREE :eyepop:
http://www.deepskywatch.com/deepsky-atlas.html

[The_Cat]

Excellent stuff. Passed this link on to some of my mates.

Jeremy.

[Brycepj]

been surfing around the net found bintel have a 12 inch for around $850. Have anyone had experience with these? (well within budget) or an I better off with a collapsible 10 " skywatcher for $1030 or the same but Saxon for $1000. Hey I now get it more bang for your buck with a do band I'll get to see more. Bit chunky for transporting but if I can get great images then I can live with that (40kg all up is a work out)

[Brycepj]

hey Jeremy do these cover Southern Hemisphere.. thinking may take these to office works and get them laminated in a3. got a few iPhone apps that work well
Thanks
peter

[The_Cat]

Hello Peter,

I have a 250mm Skywatcher goto dob. This is my "grab and go" 'scope. It is very easy to setup and use. Main thing is that it does need collimation after a trip over corrugated roads. it is a very nice scope and I use it for public viewing nights where I would not want to take my imaging stuff for people to play around with.

I transport it on the back seat of the Holden Colorado it takes a bit to get it in through the back door. I would not want the scope to be any bigger. putting this unit in the tray will need some shock mounting as there is not enough weight in the back to get a smooth ride.

I made the mistake of buying the simple version ( no GoTo ) and a year or so later I bought the GoTo upgrade .... Bad mistake as this was the very expensive thing to do. the upgrade consists of a new base and all the electronics etc. and almost costs as much a the goto unit on its own!!

Jeremy.

[Brycepj]

Jeremy
you and Rom have been great help. tell me the difference between the the 10" (250mm) and the 8" (200mm) skywatcher collapsible Goto scopes is the extra $320 justified. As a newbie would I pick the difference if they are side by side?
How collapsible is collapsible. ? Do I still need a laser guide to collminate?
I'm leaning towards the 8" as it just a bit easier to transport it will need to fit in a Sv6 Commodore, no kids so back seat is free.

Rom what's your opinion. tomorrow could be the big day
thanks peter:):thanx:

[el_draco]

I wouldn't hesitate going for the 10" . It has a bit over 50% higher light grasp compared to the 8" (Square the radius 25 V 16). OTA will be a bit over a 1m long I reckon. Laser collimator is okay but you can eyeball pretty good alignment.

However, if you still asking questions, wait a bit until you have them answered before buying and don't forget the classifieds. These scope come up regularly and a lot cheaper than buying new.

Also, its winter and somewhat chilly atm

Rom

[The_Cat]

Logical answer to:

1) Is the added $320.00, for the 250mm , cf. 200mm, good Value?

Well the ratio of diameters is : 1: 1.25

The 250mm has an area of 1.56 greater. (Almost 60% collection area)
The volume is 1.95 times greater. (Almost 2x bigger, heavier , more stable)

The 250mm is a substantially bigger telescope. On this argument, for an extra $320.00, BUY IT !!

2) Will it fit in the SV6 Commodore ?
You be the judge based on:

Refer to the attached picture of the 250mm instrument :

Collapsed: Height of the OTA is 800mm
Diameter of the OTA is 350mm
With protrusions one needs 400mm to house it comfortably.

Fully extended the OTA is 1125mm long

Height of stand is 800mm
Base diameter is 520mm

Jeremy.

[raymo]

My 10" Flex Dob fits easily into my Corolla hatch, and visually definitely
a step up from my 8" EQ Newt.
raymo

[Brycepj]

Rom you are correct I still have questions for you Jeremy (Anyone else ).
Let's start with eye pieces. The unit comes with 10mm & 25 mm So to be a bit techno should get magnification of 120x and 48x (Focal length scope/ focal length eye piece?? )
Is that enough ? there is a celestron kit for $100 the has 6mm and 15 mm plus a 2x "Barlow" and a few filters. Doesn't sound like a bad deal.
But I await your opinions.
Next question is powering the syn scan can you use 240v using the correct adapter. What about batteries for remote locations?
Don't have anything else to question think that's about it please let me know if I have anything else to consider.
To recap Skywatcher 10" Goto Dob is what I will look at getting bit over budget but what the hell.

[The_Cat]

Here is a little write up as to how you may select a range of magnifications and eyepieces for a start. after this we could talk about the actual eyepieces.
Over budget eh? Peter. Well you only live once.

About powering the Synscan outfit. I use a 12v, 20ah gel battery - lasts about 10 hours per charge ... I have not run it down yet

The thing to watch out here is that if the battery is large, like mine, and cannot ride on the turn table you have to keep an eye on the cable. A point can be reached when the mount is slewing in azimuth when the cable will be stretched and pull out of the connector or worse damage the connector.

Eyepieces? Do Not go over board.

Stick with the supplied eyepieces but attend a viewing night organised by the local astronomy club or society and test everyone else's eyepieces on your 'scope before making a decision! Selecting eyepieces can be daunting and the cost can be very high.

How to select an eyepiece range:

Firstly look at a range of magnifications that you may require, say from x40 to x400
Ie. a range of 10 : 1 and how many steps (eyepieces) you may require. Say you require 5 eyepieces to cover the range. To make a range of eyepiece focal lengths use the following, choose any two points (A and B) and calculate the middle point as being the geometric mean ie. SquareRoot( A.B)

1) Choose the end points , x 40 and x 400, and obtain the magnification for the centre of the range as follows :

Magnification at the middle: SquareRoot (40 x 400) = 126.49

2) Calculate the next lower magnification : SquareRoot(40. X 126.49) = 71.13

3) Calculate the next higher magnification: SquareRoot (400 x 126.49) = 224.94

So we have a range of magnifications:

x40 x71 x126.5. x225 x400

Note how each magnification may be obtained by multiplying the previous magnification by 1.77 or say 1.8.
That is why we have a commonly available Barlow Lens of x 1.8

Now calculate the eyepiece focal lengths:

30 mm , 17mm, 9.5mm, 5.3mm, 3mm

Select a "good" x1.8 Barlow Lens and Voila, You have a 10 speed telescope with good transition between speeds.

Interestingly the range of resistors follows this rule and so does the ratio of gears in a manual 4WD

Notice the eyepiece range of Televue , Vixen, Takahashi etc. correspond to the rule above.

We can talk about types of eyepieces next if you like.

Jeremy

[astro744]

Sounds good in theory but in the field you will find the gap between 126x and 225x too much and will want to observe at between 150x to 180x more often than not as seeing permits. Also 400x is for rare occasions and a better high power eyepiece may be something that gives 250x to 270x maybe 300x.

There are also many options at the low power end depending on whether you want 2" eyepieces and what apparent field you are after.

Note too 1.8x Barlows were available some time ago but they are not that common now and even. Tele Vue have dropped the 1.8x and 2.5x Barlows from their line-up in favour of 2x and 3x Barlows. (2.5x available as Powermate).

[The_Cat]

Points Taken.

I chose magnifications just for example. What eyepieces and magnifications visual astronomers use is really upto them to make the judgements based on the optics etc. as for Barlows I do not use them as my imaging does not include planetary stuff.

Jeremy.

[Brycepj]

thanks guys
it sounds like eye pieces and barrows are another science which I understand where you are comming from. Quite happy to revisit this once I have the scope home and tried a it out. Your advice about local astro society is a good one.
Jeremy just to get this right in my head your talking about a battery similar to those used in golf carts. Interested to see how the power system is actually laid out. What are the connections. is it a 240v with a DC Adapter? or or a 12 v system.? I do have a 12v 240v inverter all I need is a deep cell battery for remote locations.
You also mentioned earlier about driving on rough roads and recollimating. how do you do this are you using a whizzy laser thing that plugs into your eye piece.? or is there another way.?
This is all good stuff and really helping confidence in knowing I'm getting the right thing. BTW has anyone attached wheels to the base to move short distances? Thinking of wheeling it in and out of tool shed.
thanks peter

[Brycepj]

About to head off to Bintell in melb to buy a Orion SkyQuest XT10G.
Solid tube rather than collapsible. As it turned out there are only 2 Skywatcher Flex tubes left and delivery is 3 weeks but some issues with supplier. So I found the orion. Decided to go all out and buy A few extra bits but will wait till I talk with Bintell They are just so helpful.
The Sky quest is also a go to scopes with similar specs as the Skywatcher.
It only really comes with one eye piece 28mm so Question is do I buyTelevue Plossl 8mm 15mm.And a Barlow ( 2x or 3x) or do I buy the Bintel box ? Which has 32,20,15,& 12. My friend who has the 5 " Televue recommends 8,13'21 in the Ethos range but that is well past my budget.

[raymo]

Hi Peter, If you really wanted a Flex Dob, you could have got one elsewhere.
raymo

[Brycepj]

true yes could have however was able to save $ by getting it myself also found that the solid tube was cheaper than the flex tube which allowed me to pick up some extra eye pieces. If I was to do the same then would have been over a $2,000 which was well over the budget. It's always a compromise between what's affordable what result is achievable. As it turns out no problem fitting in the car
I have just finished setting it up and now wait for a clear night.
to everyone who gave there advice and guidance a big thank you if I have any other issues I will check back in:):D
thanks guys
regards
Peter

[raymo]

Welcome to the fold, and happy viewing.
raymo

[el_draco]

Well, that's another life we've managed to screw up...:thumbsup:
Doing well aren't we? ..... :D
Mwah ha ahhhhhh :eyepop:
There's NO escape, resistance is puerile.... :lol:

[Brycepj]

Romy
I don't see it as screwed up I see it "enlightened".
Can you tell me about filters understand looking at the moon (which I will need to get a moon filter) but why else.?
regards peter

[raymo]

Hi Peter, I've been observing for 67 years, and have never had or wanted a moon filter. Just put your eye about 6" from the eyepiece so you can see the moon, and move your eye slowly up to the eyepiece over about
10 seconds or so. Your eye will adjust to the brightness surprisingly
quickly. After the adjustment is complete you can look at a full moon
without discomfort.
Various filters are useful for enhancing features on the planets, and certain nebulae. Go to the Astro Shop website and
download their comprehensive list of filters and their specific uses.
cheers raymo

[el_draco]

teasing mate....;)

Colour filters will bring out detail in some objects but are not entirely necessary. In relation to the moon, its really bright but best viewed when its a crescent as the shadows across the landscape at the terminator makes detail easier to see. I don't bother with the full moon. You can get a variable polarising filter which can be very useful. I needed one for my big scope, but not so important on most scopes.

If / when you go that way, you'll need to remember there is a difference between visual and photographic filters, apart from $$. CCD filters have a higher level of precision in their manufacture.

[Brycepj]

thanks Rom for that advice
had first night with it last night lots to learn and it helps reading the Goto manual first.
Did get to view Mars which was great for first night.
then the clouds rolled in so that was it
Thanks all will be asking more soon
peter

[Brycepj]

two Questons:
1) has any body used or are using the Nexus-s wifey gizmo to run there Goto using iPad running the Stellarium app.? Is it easy to set up is it worth the $250
2) reading the latest astro mag there is an article on itelescope.net which is rent a scope and take pix on line. Seems an interesting concept if not a bit exe.
I was thinking it might not be bad to try like putting a foot in the water when considering astro photography. Me I think I'd still prefer to set it up myself as that's part of the fun.
When it's cloudy and you can't get your scope out it's an alternative.

here are some links
http://www.astrodevices.com
http://www.itelescope.net

regards
Peter:thanx:

[mental4astro]

The Nexus wifi system works very, very well. A good mate of mine has it on his dob connected to his smart phone (sorry, don't know if it's i or a), and it is very easy to use and accurate.

[Willow127mm]

Look in accessories classifieds you will see Cathy she sells great Bluetooth modules
I can vouch for the service price and quality
she should be able to help
cheers Brad

[Brycepj]

Thanks brad I'll check it out