Dilemma - advice needed

[Stargazer_00]

So long story short I've been doing Astronomy now since shortly after Stargazing Live series 1. Still at it, which is good, and still as keen (or keener) as ever.

The dilemma i'm having is I'm just not satisfied with my scopes I have and am not entirely sure what to do about it.

I originally puchased an Explorer 150, EQ3-2. Great starte scope but soon found myself wanting more detail, so I figured I needed more aperture. i sold the scope and bought a 10 inch dob which I still have. That was about July last year.

Since purchasing the dob I have also bought a number of binoculars and then a ST80 which I use on a camera tripod as my grab and go setup.

My problem is that I just don't ever get the Dob out, it sits in my shed under it's protective blanket and in my mind it's my main scope. It's there for when I get the urge to have a serious long session involving a schedule of things I want to look for. Getting it out and using it is a bit of a faff as I have to move it in two parts, its large and cumbersome to use, I have to be seated, I have to bend in odd ways to find targets, and I think the main reason I dont get it out much is I have to put it on wet grass and I, for some reason, don't like that idea. On the flip side I find myself usually getting the ST80 our on it's tripod. It's more complex to set up in terms of individual actions but its small and compact and easy to set up. It's light and portable, can move it around my garden to get different view nicely but it struggles to really show me much well beyond open clusters. I enjoy standing more than sitting, I like the fact that the scope is on a tripod, and I really like the tripod functionality, it has an height adjustment pillar which makes a LOT of difference to the ergonomics and convenience.

My observing habit is such that I will go out on clear nights between 7-11pm for probably 1-3 hours max with 1 hour/90 minutes being the usual. In that time I typically look at anywhere between 5-10 different objects. I enjoy DSO, and dont want to not be able to look at these, but planets probably get more of a look in and the moon if its up, as I can resolve good detail on that as well. open clusters are nice (particularily in the ST80) but Globs are probably my favorite of all targets.

I am starting to think I would like a GOTO setup which has a tour function on it, my memory can only store the star hopping locations for about 8-10 things. The tour would allow me to see a great deal more things and thus enrich my viewing with a wealth of targets I probably wouldnt have looked for before.

I recently purchased WO Binoviewers and want to use them (unbarlowed) all the time without modifying the scope. To this end I am thinking I need a Mak.

I have little to no interest in astrophotography, I am all about visual.

I am considering a few options and would like some advice:

MAIN SCOPE

Celestron CPC GPS XLT 925 or 800 - I think this scope would give a nice range of options. It'd show alot of the smaller DSO, I'd expect to be able to see M13 and both it's framing stars in the view. Great on planets and moon. Has GOTO, looks easy to set up, is on a tripod.

Mak 127 on a GOTO mount. As above really, just smaller aperture. Is the price difference worthwhile between these (usually sub £500) and the CPC series (£1500-£1800)

Maybe get a decent GOTO mount on it's own and then buy a 180 Mak and a 150 or 120 long F ratio frac?

GRAB AND GO

As much as I love the ST80 I'd ike the small scope to give more detail. I'd keep the ST80 as a "when I go on holiday" scope.

Upgrade the ST80 to a ST102 or ST120 to keep it at F5 with a nice widefield view (and use this on the above GOTO mount if I went for third option and wanted tracking on a widefield scope)

Upgrade the camera tripod to a AZ4 and find some form of height adjustable pillar option (does this exist?)

Is it odd that with a 10 inch dob in my shed I always go for an ST80 instead? :/

[foundaplanet]

As is said the best scope is the one you use the most.

It sounds like you may be best avoiding an EQ mount and may be better getting an alt/az if you want quick set up, if you want goto the 8SE maybe the one. I have never used one so I can not tell you about the set up time.

The other alternative maybe to put one on a Skytee alt/az mount..

[Nibor]

"Upgrade the ST80 to a ST102 or ST120 to keep it at F5 with a nice widefield view (and use this on the above GOTO mount if I went for third option and wanted tracking on a widefield scope)

Upgrade the camera tripod to a AZ4 and find some form of height adjustable pillar option (does this exist?)"

Stargazing00,

For a Grab and Go set up I have found the following tripod head very handy, largely because it allows for 360 degree slow motion controls.

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Ascension.asp?p=0_10_5_1_1_110

I currently use it on an old - but fairly sturdy, photo tripod - it is fine with my Opticstar AR80S however I am considering upgrading to the following Horizon Tripod:-

http://www.opticstar.com/Run/Nature/Nat-Supports.asp?p=0_13_4_10_70

I occasionally use my Mak 127 on the Skywatcher ALTAZ GOTO but I find it a bit marginal even with the tripod weighted down with a 5kg sand bag.

Like your Dob my 10" Newt doesn't seem to get out much!!

Hope this helps - I am sure others will chime in!!

[Dunkster]

If the Dob is too large and cumbersome to use, a CPC would be too. IIRC, even the 8" weighs in over 30kg!

For size and weight, the 8SE is hard to beat, but an 8" Dob, might come close. Either way, you're going to see less than with your current big Dob.

[Capricorn]

Either way, you're going to see less than with your current big Dob.

If he is not using the Dobsonian then whatever he uses, even the 80mm, he will actually be seeing more.

He has the potential to see more with the dobsonian only if it is used

[rowan46]

I would agree that the 8se is a good choice for what you want it's got enough apparture to be pretty good on globular clusters it's pretty good on planets and very good on the moon. it has a tour function and is fairly portable it's a lot more portable than the cpc series not as good as your dob visually but at least you don't have to be afraid to put it on a wet lawn

[ollypenrice]

If I were you I'd address the infrastructure around your observing sessions. I think this is more the issue than the scopes themselves. There is no reason why, once organized, the Dob need be any more hassle to set up than the 80. It might even be less.

One trick is to make a dedicated little palette for the Dob (very easy) and buy a hand truck (very cheap) to roll out the Dob-on-palette to a slightly raised concrete pad in the garden. (Sometimes wives have to be over--ruled. ) The Dob never leaves the palette. I used this system with a 10 inch SCT while in the UK. It works very well.

Olly

[Stargazer_00]

Thanks for the replies.

RE: CPC. The weight isn't really the issue with the dob. I think it's the general manner in which you use a dob I dont really like. I have to sit down and straddle it. I want something on a tripod and something that's GOTO and shows good detail. The questions i have with this scope are is it worth that much more than a GOTO127 mak. I dont mind saving if it is. the 8SE might be something I will consider too, now. Can you use binoviewers, unbarlowed, in a 127 mak, even a cpc 800? I assume the 925 wouldnt be aproblem as the focal length is huge.

Using the WO Binoviewers unbarlowed is incredibly important to my choice. I want to use both eyes all the time.

I can't get unbarlowed focus with the binoviewers in the dob, I think this was the first point I realised I wanted something else. that's the type of experience i want when looking through a scope, 1 eye just doesnt cut it after that.

[Dunkster]

If he is not using the Dobsonian then whatever he uses, even the 80mm, he will actually be seeing more.

He has the potential to see more with the dobsonian only if it is used

Very true . I stand corrected

[Naemeth]

If I were you I'd address the infrastructure around your observing sessions. I think this is more the issue than the scopes themselves. There is no reason why, once organized, the Dob need be any more hassle to set up than the 80. It might even be less.

One trick is to make a dedicated little palette for the Dob (very easy) and buy a hand truck (very cheap) to roll out the Dob-on-palette to a slightly raised concrete pad in the garden. (Sometimes wives have to be over--ruled. ) The Dob never leaves the palette. I used this system with a 10 inch SCT while in the UK. It works very well.

Olly

Good advice from Olly, as always

The Dob would probably get a lot more use if it was easy to get out .

[Stargazer_00]

Good advice from Olly, as always

The Dob would probably get a lot more use if it was easy to get out .

The dob sits in the shed, probably 10 feet from where i want to set it up. It's pretty quick to get out if im honest, I just dont think i enjoy the way you have to use it. I like to stand up.

Wife has given me provisional planning permission for a dedicated circular patio thing (you know those things Homebase / B&Q sell that come in a package) for my astronomy. I have a big enough garden that it wouldnt take up much space on the lawn. I just need to get the relevant paper work completed and back infor approval.

EDIT: Further to this she even said, if I wanted, I could put a dedicated shed in the garden with a roll off roof. So that would lend itself nicely to a nice tripod mounted set up. But useless for a dob given its mounted so low to the ground.

[Dunkster]

Globs are what gave me aperture fever I find that the 8SE gives nice views of M13,92 and friends, but bigger is better

Also, given their new prices, the CPC is a much more stable platform than the SE for the extra.

Putting your Dob on a trolley could save you a lot of money though!

[JamesF]

I'm inclined to agree with Dunkster about the weight of the CPC.

I have to admit that I don't have a problem with the height of my 10" dob when I'm using it nor with straddling the base if required, but different folks etc. (and in fact I built my own base which is smaller than the standard one I think). I'd be very tempted to do something along the lines of Olly's suggestion. If you can't make a raised pad in the garden, perhaps some sort of wheeled box that it could sit on permanently would do the job. You can probably make a much smaller base for it too, which might help with comfort whilst viewing. That could mean a single trip to get the entire scope out and a more comfortable viewing position. It might even be possible to use some sort of steel frame so you'd be able to put your feet underneath it rather than straddle.

Before I finished building the dob I mainly used an ST120 on an AZ3 for wide field viewing. It's a little undermounted if truth be told, but only just and with a carefully-fitted counterweight would probably be fine. It's perhaps just about portable enough for "grab and go", but barely. A lighter weight scope would be much easier. The ST102, perhaps. It's considerably smaller.

James

[rowan46]

A 127 mak is ok under dark skies but an 8" tube will show a lot more. as you know deep space objects require apparture the sct has a slightly shorter focal length so globs will fill the eyepiece better and because of the increased apparture they will be a bit brighter under magnification

[Stargazer_00]

Has anyone been to the widescreen centre in London? I think it's the closest astro shop with a showroom near me. I think alot of my decision will be made by physically looking at the various choices.

As it is I will have to save for a number of months to get anything else so for the time being I'll see what I can do with the dob. It's going to have to have a primay mirror adjustment so I can use the binoviewers, thats my only concern.

I dont think i'll get rid of the dob altogether. It is a nice scope and I feel bad for not using it so much. I dont want to put it on the ground thats my problem.

[Dunkster]

Well if you're going to build an obsy.... a big SCT on a pier or a big Dob and a ladder

Btw, can your finance director come round to speak to mine?

[JamesF]

As it is I will have to save for a number of months to get anything else so for the time being I'll see what I can do with the dob. It's going to have to have a primay mirror adjustment so I can use the binoviewers, thats my only concern.

I dont think i'll get rid of the dob altogether. It is a nice scope and I feel bad for not using it so much. I dont want to put it on the ground thats my problem.

If you need to move the focal point outwards for your binoviewers then you may just be able to get some longer bolts for the mirror cell. I know someone used to sell bolts for one of the larger Skywatcher dobs for that purpose, but bolts are bolts...

I made the base board for my dob with adjustable feet for levelling which means the base board actually sits about 3" off the ground and doesn't get wet or muddy.

I really think it's worth putting some time into thinking about how you might use it more effectively so you get more enjoyment out of it.

James

[stevetynant]

I agree with James and Olly - you already have a fantastic scope- I'd put my energies into optimizing your experience. Hopefully your already using a stool of some kind to obesreve - it makes it so much easier, raise the Dob by creating a platform of some kind. Start your patio in the spring to get off the grass then you've got all of next year to look forward to. Get a setting circle and wixey sorted - push to for your dob you'll see a lot more if your getting frustrated with the star hopping.

It sounds like you've kinda made up your mind you want something else to me but whatever you go with good luck.

[Stargazer_00]

I did find a thread on here about modding the scope

http://stargazerslou...primary-mirror/

to which I also a replied and got a good reply. Until I take the primary mirror off of the dob though I just cant visualise how all this goes together. I'm sure it's straightfoward once I see it, I just want to replicate whats already inside it but with much longer bolts to push the mirror up the tube.

Is taking the mirror out of the scope easy? Can much go wrong? Collimation is a non issue as I actually enjoy doing that.

I assume once I take the mirror out of the scope I can just go down to B&Q with £20 and get all the parts I need?

How much do I need to push the mirror up the scope? I wanted to replace the focuser for a 10:1 dual speed.

It was all this potential faff that got me thinking if I shouldnt just get a scope thats designed for the binoviewers. I guess this is a much cheaper option.

Would putting the dob on a water butt base work? Does it raise the COG too much to make it a topple risk?

On a side note I still want a GOTO scope. Can someone give me a run down of what a 127 Mak can show? Im not expecting galaxies or nebulas really, just planets, the moon, sun (with filter) and globs, definitey need to be able to see globs well. splitting doubles would be nice. Can binoviewers come to focus in a 127 mak without barlow? I think they have a 1500mm focal length.

[JamesF]

I can't answer all of those questions, but the mirror cell is easy to remove from the OTA -- it's just held in with the six(?) screws at the bottom end of the tube.

If your water butt base is large enough I don't see why it should fall over, but you could always add some clips of some sort to hold it in place.

The Mak is good for lunar, solar and planetary observing. I'd expect it to be fairly good for splitting doubles, too. I've never tried it on globs. I'd expect binoviewers to come to focus with the Mak because it focuses by moving the focal plane rather than the eyepiece(s). I can get eyepieces and webcams to come to focus with or without a diagonal, and my 450D will focus with or without a 50mm extension.

James

[Stargazer_00]

In terms of how far up the scope should I push the mirror. How would I work this part out, is it a general guess or what? I'm guessing it needs to go up the tube equal to the amount of focal length the binoviewers add to the light path. I have no idea how much that is for the BVs though, it isn't a stated attribute on them.

Would it be wise to change the focuser first?

[JamesF]

Would it be wise to change the focuser first?

I'd have thought so, otherwise you may find that you may need to move the mirror more, or you may not need to move it at all. I'd be tempted to drop an email to the binoviewer manufacturer and ask what the length of the light path is, too. Has to be easier than estimating it.

James

[Stargazer_00]

Good idea. Thanks

[KenG]

As you can see, I've got a 200mm Newt and an ETX125. The reflector is a super instrument for DSO's and is comprehensively equipped, however, lugging it around now, some sixteen years after I bought it, isn't the easy task it once was and I recently decided to get something lighter and more "instant" for quick observing sessions. After a week spent reading reviews and specifications it seemed to me that the ETX was ideal for my needs, and so it has proved. I can easily carry the telescope fully assembled on it's tripod - which incidentally, is very steady - and it only takes a few minutes to set up and align. Usually I don't bother with the go-to, but when I do use it, it's excellent, as are the optics and the tracking.

I have no intention of ever parting with my Newtonian, but now I save it for settled weather when there's no chance of cloud rolling in just after it's set up.