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Newbie mistake?


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Hi,

Having rekindled a general childhood interest in astronomy and a fair bit of reading (no access to societies etc.), I was able to find a combination of HEQ5 mount and 200PDS with various bits and bobs on the second hand market. This was in May 2021. While AP seems to get a fair bit of comment, I'm more of a visual person. Plus my day job involves a fair bit of data processing so time away from computers is a bonus. I'm not saying no to AP, just not for now - there's enough to learn as it is. I daresay my thread title and kit purchase are raising a few smiles with some already. ;)

Not long after purchase I had a long bout of sciatica. Spaced out on painkillers combined with bad weather has meant the kit has not really had any significant time in use. Until yesterday. Still bad weather, but I was able to spend an amount of time practising assembly and positioning. It is now clear to me that this can't really be a general visual set of kit - the eyepiece is almost certainly going to be in the wrong orientation.  

So, what can I do to mitigate my errors?

1) I could get a different OTA. Visual interests do make a decent refractor appealing. I would have got one second hand if I could have found one at the right price & location. I'm not afraid to pay for quality, so a Takahashi (probably doublet) is not necessarily out of the question, but am I jumping in at the deep end? I realise eyepieces etc have to be allowed for and my eyesight is terrible (strong varifocals) so these elements and a diagonal could get pricey too. So is a cheaper, but larger, refractor more beneficial apart from mount limitations.

2) Build a Dobsonian mount for the 200PDS. Not impossible for me, but is this a reasonable solution? What have I missed in thinking about this route? Even if I do 1) I might still do this just because (and I can leave it elsewhere).

What else have I got wrong, not considered or other suggestions? I'm aware I don't yet know enough to be asking questions intelligently...

Let the comments begin. :D

Adrian

 

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You can, of course, rotate the optical tube in the tube rings until the focuser/eyepiece is in a more convenient orientation.  Folk *do* use Newtonians for visual all the time.

To make this a safer operation, you can have one additional tube ring clamped to the tube, but not the mount, which can act as a stop and rotate against one of the two rings fixed to the mount (and suitably loosened so that the tube can rotate.)

Tony

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Not sure what to answer here.

Yes, there are several possible routes for you to take.

1. Get different type of scope that you'll be using on HEQ5 - no need to go all Takahashi on that :D - scope like this will be excellent and cost effective choice: https://www.teleskop-express.de/shop/product_info.php/info/p10133_TS-Optics-Doublet-SD-APO-125mm-f-7-8---FPL-53---Lanthan-objective.html, or maybe this one: https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f12-m-lrs-classical-cassegrain-telescope-ota.html depending on your interests

2. Get another mount like SkyTee2 to use with 200PDS - or as you suggested, build a dob mount for it. If you want goto capability - maybe exchange HEQ5 for AZEQ5 or AZEQ6

3. Sell all that and simply get 8" F/6 dob

In order to give meaningful advice - you need to tell us more about your expectations, targets, way of observing (seated, standing, tracked, manual), portability issues, etc ...

 

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Just now, AKB said:

You can, of course, rotate the optical tube in the tube rings until the focuser/eyepiece is in a more convenient orientation.  Folk *do* use Newtonians for visual all the time.

To make this a safer operation, you can have one additional tube ring clamped to the tube, but not the mount, which can act as a stop and rotate against one of the two rings fixed to the mount (and suitably loosened so that the tube can rotate.)

Tony

Gotcha. I did move the tube in the rings a couple of times while focusing on various man made and natural objects in the distance. It just seemed like a lot of potential faff for looking at various objects in different directions, with risk of a disaster - good tip of a third ring. It did show that one of the rings was not squarely mounted which was fixed. Good to hear that Newtonians are used in the manner I think I intended.

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24 minutes ago, vlaiv said:

Not sure what to answer here.

Yes, there are several possible routes for you to take.

1. Get different type of scope that you'll be using on HEQ5 - no need to go all Takahashi on that :D - scope like this will be excellent and cost effective choice: https://www.teleskop-express.de/shop/product_info.php/info/p10133_TS-Optics-Doublet-SD-APO-125mm-f-7-8---FPL-53---Lanthan-objective.html, or maybe this one: https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f12-m-lrs-classical-cassegrain-telescope-ota.html depending on your interests

2. Get another mount like SkyTee2 to use with 200PDS - or as you suggested, build a dob mount for it. If you want goto capability - maybe exchange HEQ5 for AZEQ5 or AZEQ6

3. Sell all that and simply get 8" F/6 dob

In order to give meaningful advice - you need to tell us more about your expectations, targets, way of observing (seated, standing, tracked, manual), portability issues, etc ...

 

The TS options look OK to me, but I have some longer post-Brexit concerns re any large purchase and warranty returns. Possibly unfounded in this case - who knows. Had the UK not taken a running jump into the unknown, I'd not be so worried. Apart from Brexit concerns, I'm not really excluding anything, the 200PDS purchase was more opportunistic (fools rush in?) in a time of stock and ease of speaking/seeing kit limitations. FLO are a 20 minute walk from me and normally I think I'd have spent a fair bit of time there discussing options.

Expectations. Nothing set in stone, but tending towards recognisable, so likely planets and moon. Some of the galaxies maybe (I can stare at a poster of Andromeda for hours), but I realise that what I can see will not equal well processed images taken by Hubble! I don't yet know what is visually possible for a set of limitations which are themselves not yet understood by me - cost, size/weight, local light pollution (locally Bortle 5-6, but I'm not far from 3-4) etc.

I'm happy to sit or stand. I guess for long durations sitting preferred (like drinking beer ;) ). I've not yet set up tracking (yet to sort a laptop & cables), so currently prepared to control manually. Portability - well tripod/mount lives in shed. OTA indoors, but upstairs. A little bit of bulk hassle, but far lighter than my scuba gear! All goes easily in estate car when boxed, so no transportability issues.

SkyTee2 looks like a good plan, potentially the AZEQ5 or 6. I did see a AZEQ6 come up second hand locally, but I'd just started looking and did not know enough about options etc. to realise I'd been looking at a gift horse. :( :) . 

Edited by UKDiver
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24 minutes ago, AKB said:

You can, of course, rotate the optical tube in the tube rings until the focuser/eyepiece is in a more convenient orientation.  Folk *do* use Newtonians for visual all the time.

To make this a safer operation, you can have one additional tube ring clamped to the tube, but not the mount, which can act as a stop and rotate against one of the two rings fixed to the mount (and suitably loosened so that the tube can rotate.)

Tony

I've seen someone with a large jubilee clip around the tube to enable this.  I think they had a spot of thin foam underneath too, to prevent scratches.

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BTW - I use a 6" newtonian on an equatorial mount exclusively for visual without any issue.  With a rough alignment to north, it makes keeping objects in the eyepiece easy.  One of your slow motion controls will correct for the drift caused by the rotation of the Earth.  It is a bit of a faff to go from one half of the sky to the other, so I tend to plan my sessions around a couple of areas per night.  Now all we need are some clear skies!

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I was in a similar situation when I had a 203mm Newtonian on a EQ-5 manual mount.  I soon decided that the combination was horrible and I had great difficulty in getting it aimed at general targets that, in theory, I would be able to view with it.   My solution was to abandon it and buy a used Celestron C8 SE GoTo SCT outfit (same aperture) which proved infinitely more pleasant to use for visual use.  The GoTo works well and the whole thing can be carried out of doors in one lump. The eyepiece remains in an easily accessible position.

I eventually sold the Newtonian and converted the EQ5 to GoTo with the Synscan upgrade kit, for use in occasional imaging with a small refractor.

Should you choose to do likewise, I think you would find this a satisfactory solution. 

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2 hours ago, UKDiver said:

It is now clear to me that this can't really be a general visual set of kit - the eyepiece is almost certainly going to be in the wrong orientation. 

I gather that it's in the wrong orientation because being mounted on the HEQ5 the eyepiece can be at a very high level? Have you considered ditching the tripod and putting the mount on a short pier? If you make with the tape measure you could work out the ideal height of the pier and then build a todmorden type pier for a few pennies. If it doesn't work knock it down and all you have lost is a few hours, some cement and a couple of concrete blocks.

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8 minutes ago, M40 said:

I gather that it's in the wrong orientation because being mounted on the HEQ5 the eyepiece can be at a very high level? Have you considered ditching the tripod and putting the mount on a short pier? If you make with the tape measure you could work out the ideal height of the pier and then build a todmorden type pier for a few pennies. If it doesn't work knock it down and all you have lost is a few hours, some cement and a couple of concrete blocks.

Yes, can be high, but direction an issue too.

Domestic planning permission unlikely! :) More seriously, I think that would currently be a step too far while I'm in a position of learning what works best for me. I will however go and dig out my concrete and steel design notes* and speak to my planning colleagues :D

*composted a decade or two ago.

Edited by UKDiver
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is focus good? I also have the 200p, it is supplied with an extension tube. This must be used to get correct back focus on eye piece, removed all you get is blur.

Yes to rotating the OTA. a little odd after alignment but ok if careful.

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Hi make some Wilcox rings I have them on my VX8L buy a jubilee kit off e bay and some plastic electrical trunking , now balance the telescope then wrap the top part of the trunking upside down around the tube next to the ring then cut a length of jubilee kit to make the jubilee clip up .Now fit inside the trunking as it's upside down it holds the jubilee nicely so you can tighten it up , make a second one  and do the same this now lets you have the main scope rings loose and not lose the balance of the telescope but it lets you rotate the OTA so eyepiece is always in the best position 

http://www.andysshotglass.com/wilcox_rotating_rings.html

Edited by Neil H
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49 minutes ago, Neil H said:

Hi make some Wilcox rings I have them on my VX8L buy a jubilee kit off e bay and some plastic electrical trunking , now balance the telescope then wrap the top part of the trunking upside down around the tube next to the ring then cut a length of jubilee kit to make the jubilee clip up .Now fit inside the trunking as it's upside down it holds the jubilee nicely so you can tighten it up , make a second one  and do the same this now lets you have the main scope rings loose and not lose the balance of the telescope but it lets you rotate the OTA so eyepiece is always in the best position 

http://www.andysshotglass.com/wilcox_rotating_rings.html

Now that's an approach that I can handle. It's actually very similar in terms of tubing (usually garden hose) and jubilee clips used for stage rigging dive cylinders! Some serious consideration to be applied.

Edited by UKDiver
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1 hour ago, spikkyboy said:

is focus good? I also have the 200p, it is supplied with an extension tube. This must be used to get correct back focus on eye piece, removed all you get is blur.

Yes to rotating the OTA. a little odd after alignment but ok if careful.

Yes, no issues with focusing, at least land based!

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7 hours ago, UKDiver said:

The TS options look OK to me, but I have some longer post-Brexit concerns re any large purchase and warranty returns. Possibly unfounded in this case - who knows. Had the UK not taken a running jump into the unknown, I'd not be so worried. Apart from Brexit concerns, I'm not really excluding anything, the 200PDS purchase was more opportunistic (fools rush in?) in a time of stock and ease of speaking/seeing kit limitations. FLO are a 20 minute walk from me and normally I think I'd have spent a fair bit of time there discussing options.

Expectations. Nothing set in stone, but tending towards recognisable, so likely planets and moon. Some of the galaxies maybe (I can stare at a poster of Andromeda for hours), but I realise that what I can see will not equal well processed images taken by Hubble! I don't yet know what is visually possible for a set of limitations which are themselves not yet understood by me - cost, size/weight, local light pollution (locally Bortle 5-6, but I'm not far from 3-4) etc.

I'm happy to sit or stand. I guess for long durations sitting preferred (like drinking beer ;) ). I've not yet set up tracking (yet to sort a laptop & cables), so currently prepared to control manually. Portability - well tripod/mount lives in shed. OTA indoors, but upstairs. A little bit of bulk hassle, but far lighter than my scuba gear! All goes easily in estate car when boxed, so no transportability issues.

SkyTee2 looks like a good plan, potentially the AZEQ5 or 6. I did see a AZEQ6 come up second hand locally, but I'd just started looking and did not know enough about options etc. to realise I'd been looking at a gift horse. :( :) . 

That TS scope is just branded by TS. It is also available in other brands like Altair Astro.

https://www.altairastro.com/altair-wave-series-125-edf-f78-apo-binoviewer-ready-37-inch-rp-focuser-454-p.asp

If you intend to observe mostly seated - then newtonian type scope is feasible only on dobsonian mount.

Targets like M31 - Andromeda galaxy are wide field targets and are best observed with short focal length - up to say 600-700mm. Planets on the other hand like aperture and also focal length.

You'll really have to choose between refractor and folded design like SCT or Cassegrain. Maksutovs probably won't suit you.

Compact scopes like SCT or Cass will have more aperture and be better at planetary - but won't allow you to get wide field views. Refractors will be good on planets - but less aperture for DSOs. Will allow for wider field of view.

Maybe @johninderby can help here because he owns two of mentioned scopes - 125mm frac and also 8" Classical Cassegrain.

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For the 125 would recommend buying from Astrograph. Rupert, the owner, is a real expert and can give proper advice and technical backup. Great service. Lots of high end equipment to drool over on their site.. 🙂

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGTEC125F78

The 8” CC is a great lunar / planetary scope. Mine is the TS but identical to the Stellalyra. Very sharp on axis and having a fixed primary  no mirror flop and a crayford focuser although I upgraded the focuser to a Baader Steeltrack. Fast cooldown and dewing isn’t a problem. Had a C8 SCT and a Skymax180 and find the CC better fits my needs. Not that the C8 and 180 aren’t good scopes but I simply prefer the CC. Just a matter of personal choice.

BTW on FLOs site the CC has the incorrect photo of the front of the scope. They have used the RC photo which has a bigger central obstruction.

 

8C70BFE9-3173-4E9A-B987-5D75EC5C1988.jpeg

4B6E7A1E-FCCE-496B-B841-9FEA8F7552B4.jpeg

Edited by johninderby
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On 02/09/2021 at 18:21, UKDiver said:

Yes, can be high, but direction an issue too.

Not sure if a right angled eyepiece adapter would help in this instance? Perhaps someone who has used one can comment.

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