Advice for my sons Xmas present

[Carolinechampion]

Hi guys hope you can help me,my boy is 15 and into astronomy in a big way and now wants a decent telescope.from reading on here already I have seen that a lot of people recommend the sky watcher explorer,I've had a look on FLO and there is 3 different models.the explorer 150P the explorer 150pl and the explorer 150p-ds. In your opinion cauld you tell me which model would suite him best,any advice would be gratefully received thankyou X X

[ronin]

The PDS varient is for imaging so I would leave that one out of consideration, even if he wants to try imaging the scope costs more and the area of astro imaging is generally costly.

I would guess the 150P comes on an equitorial mount, probably EQ2.

That mount is not the best but does get anyone familiar with an EQ mount, if he carries on then at some time he will meet one, so now or later.

The 150PL is often on a dobsonian mount, you push, pull, nudge, kick the scope at the object. As you are holding on and so in contact it is something that has to be learnt but is not overly impossible.

The PL varient is "easier", the longer focal length will mean less collimation and eyepieces are easier - although here you would get recommended the same upgrade for the PL or the P varient, namely BST Starguiders.

I would suggest the 150PL on the dobsonian, as the 150P if on an equitorial mount is still manual and you are a bit more removed from the scope. If you were to go for an EQ mount then I suggest one with motors to track a target.

Which bit of Essex? There are clubs around that may be worth visiting.

Just in case P = Parabolic (mirror shape) and PL = Parabolic and Long, as in parabolic mirror and a longer focal length. Not sure what the DS bit stands for in PDS, the P is still parabolic.

[ronin]

If you are near High St/Station Road in Burnham-on-Crouch

There is: http://www.essexastro.com

Just remembered about them and I had a book mark.

May be worth dropping in, they say they have a shop/showroom - look under the "About Us" bit.

[Carolinechampion]

Thanks for advice we are in clacton on sea,but can travel we will keep Essex Astro in mind X

[Floater]

... on a dobsonian mount, you push, pull, nudge, KICK [my capitals] the scope at the object.

Moderators! I wish to report this abuse of equipment!

Caroline, apologies for crashing your topic. The advice above is spot on, of course, and I would second the 150 Dobsonian - just not the kicking bit!

[Carolinechampion]

Thankyou Floater lol X X

[Alien 13]

If there is even the slightest chance that he will want to put a camera anywhere near a scope then it has to be the PDS version.

Alan

[ronin]

OK, remove Kick, replace with "reorientate with your knee". :grin:

You'll be telling me next that Dobfest is not a bonfire of dobsonians and roasting of potato's while having a sing along. :eek:

Caroline, mounts are a difficult area.

A manual EQ is not always easy, as you have to have your eye at the eyepiece, and the sky rotates in relation to us so objects drift out of view. With the dobsonian you tend to be stood with it and looking through so you perform small nudges to keep the object in view.

Works OK for one person but handing the scope over to someone else means they alos need to have worked out how to use the scope.

I suspect that something like a goto EQ3-2 is not a consideration, equally that means learning the dark art of setting up a goto and a equitorial from scratch, likely a worse introduction, but there will be people to answer questions.

So far everything is assuming visual only.

[Dave Lloyd]

Hi Caroline, welcome. Get your son to ask as many questions as he likes on here. He'll get all the help he needs.

[Carolinechampion]

Thankyou Dave X

[BritAngler]

The PDS varient is for imaging so I would leave that one out of consideration, even if he wants to try imaging the scope costs more and the area of astro imaging is generally costly.

Why is the PDS variant for imaging only? the P stands for Parabolic, the DS stands for Double Speed focusing (which means there are two focusing knobs, one to roughly get the image in focus, the other to fine-tune).

[happy-kat]

You don't mention budget but I would get the 150p but on the AZ4, like this:

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-az4-mount.html

Same 150p that you mention in your first post but on a very easy to setup and use tripod.

[pipnina]

To anyone starting out in astronomy I can honestly say that one of these three scopes are the ones you should start with:

Whichever one of these suits your budget best... Which you didn't state but I will hazard a guess at around £175 since you were looking at the 150p dob.

The thing with astronomy... aperture (size of the large mirror/lens) is key. More aperture = higher chance of seeing that target you took interest in. generally speaking (huge targets can prove an exception, but there aren't many targets that are larger than 1.5 degrees AND in reach of the majority of amateur astronomers) On the scale of 130 to 200 on this scale, the 200p skyliner would be best if it's in your budget.

If there were any reason I would NOT recommend the 150p it's that the focal ratio is too high, making high exit pupils difficult for deep sky observing you want to easily reach 5mm of exit pupil (exit pupil is the size of the circle of light that leaves the eyepiece, too big and it'll waste aperture (doesn't go in your eye) too small and the image will be dark, 5mm is a safe bet for a maximum exit pupil but young people (and some older people) can go up to 7mm)

the 150p dob has a focal ratio of 7.84... That's kinda high if you want to reach 5mm exit pupil you will need a 40mm eyepiece (which, if neither you nor your son wear glasses, could provide a floating eye relief, where the ideal place to put your eye above the eyepiece is so far out it becomes hard to find the middle and you have to "float" above the EP) Whereas the 130p flextube manages it with the stock eyepieces and the 200p dob manages it with a 32mm (and has 4.0mm with the stock ep).

My personal choice would be either the 200p skyliner or the 130p heritage, long story short...

    ~pip

[Carolinechampion]

Thankyou everyone for your advice X X