Newbie advice please.

[Xgaze]

Hi all,

I'm about to purchase a skywatcher Heritage 150 Dobsonian.

Looking for advice and tips please. 

I live near a dark skies reserve, Exmoor. Will be using it camping. Is finding a sturdy base an issue? Also, will dew be an issue?

Any help much appreciated! TIA!

 

[PEMS]

Just a couple of opinions, and one question or condition:

Is the scope bit f/8 ? Therefore having a 1200mm focal length. I assume it is. On that presumption it should be relatively easy as basically it is not a "fast" scope". You will not need overly many eyepieces. 3 or 4 reasonable ones will cover you. I do suggest that you drop any idea of the magnifications they often quote. One rather simple idea is expect a magnification equal to the diameter (150x therefore) if you get more out of it then be content. The quoted "maximum" is likely 300x, you will not get that. 150x is sufficent for Saturn and so covers Jupiter, Mars is a bit more questionable but Mars remains somewhat out of view until next year, and I believe the end of next year.

For eyepieces I would suggest say a 6mm, 8mm, 12mm and a 25mm in the now fairly common 60 degree field format = BST Starguiders are the obvious although they do not have a 6mm. Suggest that you do not get carried away thinking the 5mm will do, it might prove too much and get little use.

Sturdy base? They come as 2 parts - OTA and base, so a little puzzled. If you mean a base to sit the whole thing on when outside and so keep it off the ground I would say look up a "step stool". One of the rather simple basic folding flat platform ones, they come in small and high. Both are not exactly high. eBay sells them and at one stage Aldi did but likely one of the "here today gone tomorrow" items.

Look up a hopefully nearby or accessible club: http://www.astronomyclubs.co.uk/

Expect to need some time to get familiar with the way a dobsonian works. Have realistic expectations.

[Cornelius Varley]

3 minutes ago, PEMS said:

Is the scope bit f/8 ? Therefore having a 1200mm focal length. I assume it is.

The Heritage 150P is f5  (d=150, fl =750). The SW Skyliner is f8 (d=150 fl=1200)

Sky-Watcher Heritage-150P Flextube Dobsonian Telescope | First Light Optics

[Tiny Clanger]

2 hours ago, Xgaze said:

Hi all,

I'm about to purchase a skywatcher Heritage 150 Dobsonian.

Looking for advice and tips please. 

I live near a dark skies reserve, Exmoor. Will be using it camping. Is finding a sturdy base an issue? Also, will dew be an issue?

Any help much appreciated! TIA!

 

Good choice ! I love my 150 heritage, it has shown me a lot , even from my light polluted suburban back garden. From Exmoor ... well, all I can say is, it's a good job you are camping, because you may well be so stunned you need a lie down ... 🙂

It is indeed 150mm aperture, 750mm focal length therefore f5, although this has no bearing until  you start to think about new eyepieces (which you will, eventually), but don't worry about those yet, there are more important things to consider first.

I've not found dew to be a problem, however I have always used my little dob with a 'shroud' around the open part . The small secondary mirror is exposed to the cold air if you don't have a shroud , and I'm told that is the part which dews up. To start off, I used a bit of a cheap closed cell camping mat (the sort no one in their right mind buys to actually sleep on ... ) and just tied it on around the outside of the bars with some elastic . When the 'scope was to be closed down, I'd just take it off and wrap it round the main body for storage. I've subsequently bought some 3mm closed cell foam and made a far neater shroud which is thin enough to slide inside the main body when the 'scope is collapsed, so stores neatly away with no faffing, open the 'scope up, and out comes the shroud (I have gaffer taped it to the light shield opposite the eyepiece). I'll find a link to the online vendor I bought the foam from, it was about £10 for a 1 x 1m piece.

Second thing you will need is some plumbers PFTE tape to improve the focuser, both this and the light shroud are shown really well in this video

https://stargazerslounge.com/topic/359669-semi-permanent-light-shroud-and-focuser-mod-for-heritage-150p/

A sturdy base for the tabletop dob is something you will perhaps be able to improvise while camping , I have made mine a small but very sturdy triangular 3 legged table from scrap wood to raise it about 25cm off the ground, maybe you have something like a 'really useful' plastic crate as part of your camping kit ? An 18L crate is big enough, altho' the plastic of the lid does flex a bit , so turn it over and use the crate base, or ideally  have a bit of wood to use to stiffen it as a platform. The 3 feet on the dob base are 34cm apart (that is to the outside of the foot) to give you an idea of the sort of size of platform you need. If you can find a suitably placed fixed wooden picnic table, or even a handy lump of granite with a fairly level top, that would be good .

Using the dob on the ground is not impossible , although you would be limited to quite high in the sky targets , and while a small child would be abble to use the 'scope that way, an adult would probably want to be sitting down , a  low camping chair might work well, but maybe sit on the ground. As the dob base is MDF type board, I'd definitely want to keep it safe from any damp vegetation, so would always use a tarp or binbag or similar under it.

Heather

[Tiny Clanger]

You can see my dob with shroud and supporting table in the background in some photos on the thread I made to show off the observing chair I made (from the same left over Ikea sofa frame bits as the dob table ) here https://stargazerslounge.com/topic/376543-£355-scope-chair/

The foam I bought was black 3mm sheet from here (yes I did the extra m for £3.71, who wouldn't ?!) https://www.efoam.co.uk/closed-cell-polyethylene-foam.php  I bought online during lockdown, but I've read since that folk have sourced A3 foam sheet from craft shops, which may be handier for you.

There are a few other things I'd suggest you must have handy. Either a traditional planisphere (star wheel) or a book with star maps, or device with an electronic version of those, stellarium is the one I use, but many are available, either as downloadable programs (stellarium is one, open source and free for windows) or apps, or (possibly no use while camping ...) online .

If you don't already have a huge amount of knowledge and experience of stargazing , and like a dead-tree type book to refer to 'Turn Left at Orion' is a great, practical book . It's full of information and diagrams about how to find easy targets as well as what they are,  and is large format, printed on heavy paper. Not cheap (£20 ish) but worth a look. https://www.firstlightoptics.com/books/turn-left-at-orion-book.html

A red light torch is a good idea to preserve your dark adapted vision when you need more light  for a task (or have dropped an eyepiece ...) , and while the red dot finder on my  dob has lasted fine for the year since I bought the 'scope, including the odd 24 hour accidental leaving it switched on drain, it would be absolutely typical if you got out camping miles from  the nearest pound shop , and the battery died, so check what it is (mine is a CR2032) and get a just-in-case spare. You'll probably not need it for years but ....

Heather

 

[Xgaze]

2 hours ago, Tiny Clanger said:

You can see my dob with shroud and supporting table in the background in some photos on the thread I made to show off the observing chair I made (from the same left over Ikea sofa frame bits as the dob table ) here https://stargazerslounge.com/topic/376543-£355-scope-chair/

The foam I bought was black 3mm sheet from here (yes I did the extra m for £3.71, who wouldn't ?!) https://www.efoam.co.uk/closed-cell-polyethylene-foam.php  I bought online during lockdown, but I've read since that folk have sourced A3 foam sheet from craft shops, which may be handier for you.

There are a few other things I'd suggest you must have handy. Either a traditional planisphere (star wheel) or a book with star maps, or device with an electronic version of those, stellarium is the one I use, but many are available, either as downloadable programs (stellarium is one, open source and free for windows) or apps, or (possibly no use while camping ...) online .

If you don't already have a huge amount of knowledge and experience of stargazing , and like a dead-tree type book to refer to 'Turn Left at Orion' is a great, practical book . It's full of information and diagrams about how to find easy targets as well as what they are,  and is large format, printed on heavy paper. Not cheap (£20 ish) but worth a look. https://www.firstlightoptics.com/books/turn-left-at-orion-book.html

A red light torch is a good idea to preserve your dark adapted vision when you need more light  for a task (or have dropped an eyepiece ...) , and while the red dot finder on my  dob has lasted fine for the year since I bought the 'scope, including the odd 24 hour accidental leaving it switched on drain, it would be absolutely typical if you got out camping miles from  the nearest pound shop , and the battery died, so check what it is (mine is a CR2032) and get a just-in-case spare. You'll probably not need it for years but ....

Heather

 

Thank you so much Heather!!

Some excellent advice there, very much appreciated!!

I saw Chris's video RE the two mods. Will surely be doing this. 

Your DIY setup looks fantastic! Thanks for sharing again. It's exactly what I was thinking. I enjoy making things like this from whatevers available might even have a go at a scope one day!

The 'turn left at Orion' book looks to be a good recommendation, there's some cheap second hand ones on eBay.

Spare batteries! Great shout!

Hoping it's collimated still when it arrives, do you find you need to adjust yours often? I guess it depends on how much it's moved around a d temperature changes?

It's being delivered tomorrow, so excited!! Like a kid again!😂

Thanks again for such a detailed response!

Tony

[Tiny Clanger]

Hi Tony,

I may be a beginner and a relatively underfunded one at that, but if I can save those even more beginner-y a bit of research, frustration and annoyance with the specifics of the little dob , that's my good deed for the decade sorted.

I've found the dob holds collimation really well, I've even had the whole primary mirror assembly off twice (first time to line the solid tube with black flocking material , which cuts down any internal reflections, and the second time to drill some holes for an extra finder shoe - nerve wracking ! ) and it's only needed a tiny tweak once back together. Mind you, I'm just carrying it outdoors and putting it down , not driving it around and having country roads shake it ...  What wasn't mentioned when I bought mine, was that the cap that blanks off the eyepiece holder has a hole in the centre and a reflective inner surface , making it a collimation cap , which is very handy. If yours doesn't come with one, there are plenty of guides to making your own online.

Collimation seems to be a great fear for some, and there are plenty of confusing, poorly explained online guides , I  like this guy's clear simple approach :

https://garyseronik.com/a-beginners-guide-to-collimation/

The one thing to avoid is going in all gung-ho and turning screws of knobs too much, caution and tiny steps is the way to go.

You are right to be excited, just think what is out there for you to see !    Clouds might keep you waiting a while (if the weather here is anything to go by ) but even at this time of year, with short, bright nights , there will be things to see . Jupiter and Saturn are rising in the east in the early morning ( 2.30 am ish) and are quite low at the moment, but Saturn with its rings was my first sight with the heritage dob,

That was on the evening of the day  I got it, almost exactly a year ago, and I'd carried the box (which is pretty big) upstairs to dump in the spare room after unpacking and putting the 'scope together. As I did so, I happened to catch sight of Saturn through the window, I was too tired to take the 'scope outside , so took it up, balanced it precariously on its own box, and with the stock eyepieces , (no collimation check, no shroud or any other tweaks or accessories ) through a grubby double glazed window, saw the rings for the first time ever, Saturn looking like a tiny, perfect, Christmas tree ornament.

I was enchanted.

Still am !

Heather

Edited June 28, 2021 by Tiny Clanger
typo

[Astro_Dad]

Interested reading your posts - Huge fan of my Heritage 150p - it’s been with me on a recent trip to Scotland. Perfect for travel ! I’ve just received an AZ GOTO mount for mine that I’m looking forward to trying later tonight hopefully. 
One question I have is that I’ve noticed 
the underside (outside facing, bottom of scope) of the primary mirror has unevenness/ patchiness in the frosted glass that I hadn’t noticed before. Is this something you see on yours ? I don’t think it would impact performance at all but curious. This would be a general newt query rather than a question for this thread specifically but worth a go! 

Clear Skies  

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