Portable but powerful scopes

[swedonator]

Explorer-200 EQ5 is a hot choice too, not too expensive and I could get some good eyepieces and other things.

[swedonator]

I have been thinking a lot about how people navigate a dobson. How easy or difficult is it to follow objects when using a dob?

[Bart]

I have been thinking a lot about how people navigate a dobson. How easy or difficult is it to follow objects when using a dob?

Dead easy, I worried about this when I first had my 6" on a eq mount, but since going Dob I've never looked back. Speaking of back, mine is a lot less sore since going Dob, never liked contortionism!

Dead easy I can assure you, there's no mystery.

Barry

[swedonator]

please explain :-)

[Steep]

The Dob is the most basic mount possible, just push or pull the front end of the tube to follow your target. The only thing is everything is reversed so when you look through the eyepiece and push the scope to the right the target star seems to move right and vice versa. To make it easier on myself I think in terms of pushing or pulling the object I'm viewing not the scope.

There is an addon you can buy or build called an EQ Platform, this is a motorised base that will move the whole scope round following your object so that you don't have to touch the tube for quite a long time, this saves having to wait for vibration to settle each time and gives you much easier viewing.

[Bart]

Just noticed you are thinking of the Omni 150, that was my first scope

What I mean is, unless you're planning on AP I'm not sure there is much benefit in an EQ mount. When observing certain objects, the eyepiece ends up in some queer positions and you have to loosen the tube rings and gently rotate the OTA until the eyepiece/focuser is accessible again. With a Dob the eyepiece always stays in the same orientation, the whole scope/base rotates, it's much easier to use . Hence I took the OTA off and built a Dob base, see pic.

You might be better off going for the Dob equivalent, or maybe an 8" if you can. The 8" Dob is probably the same as the 6" EQ

costwise

Hath

Barry

Just noticed tappatalk can't load pics , I'll load one on the laptop later

[ollypenrice]

I will go for the Celestron Omni XLT 150 (link) or the SkyWatcher Explorer-150PL (link). They both have a good price and will do good for some astro-images I think. The Omni is much smaller when I thought and will probably not be to hard to transport. The SkyWatcher is a tall thing, but I think it will be good.

I do have some questions about these. The Omni will have a maximum magnification about 360x, and the SkyWatcher about 300x. Should it not be the opposit? I thought that a tall tube would increase the possible maximum magnification? Am I an idiot? :-O

Rough rule number one; you can magnify about 50x per inch of aperture at the most.

Rough rule number two; it is rarely worth going over 250x in any scope. Occasionally you can, more often 200x will be the useful maximum. (Double star enthusiasts go way over that to get the split but they don't care about the quality of the view.)

Rough rule number three; making small things look big is less interesting for most targets than making faint things look bright. It is not all about magnification.

Olly

[Bart]

Absolutey Olly

I own an omni 150 and you definitely won't be going over x200 very often, believe me. I don't go over x200 very often even with a 10" or a 16", but I do go over:-) :-) :-)

The dob is easier, unless you want to photogragh

Barry

[Moonshane]

The Dob is the most basic mount possible, just push or pull the front end of the tube to follow your target. The only thing is everything is reversed so when you look through the eyepiece and push the scope to the right the target star seems to move right and vice versa. To make it easier on myself I think in terms of pushing or pulling the object I'm viewing not the scope.

There is an addon you can buy or build called an EQ Platform, this is a motorised base that will move the whole scope round following your object so that you don't have to touch the tube for quite a long time, this saves having to wait for vibration to settle each time and gives you much easier viewing.

I prefer the view through newts as it's just upside down (i.e. up down reversed). if you are looking at a map then do the same with this and the view is the same. the left right reversal of refractors drives me insane when following maps and in honesty is one of the main reasons I don't get on with fracs.

[Dunkster]

please explain :-)

An EQ mount can often put the eyepiece in some physically awkward orientations, and so you might sometimes need to a. contort your body to look through it or b. rotate the scope in the rings to make it more comfortable.

Dobs are easy to move and put the eyepiece in more convenient locations for viewing standing up. Shorter tube scopes (SCTs, Maks, small refractors) on an alt/az mount have much less sweep - obviously, the eyepiece rotates about the vertical axis by 360 degrees, but the height the eyepiece is presented at doesn't change much and it's easy to use a chair.

Another item to bear in mind is tracking. Motorised tracking is not included with all scopes, but once setup is pretty easy to achieve on an EQ mounted scope since you only have to move in one axis (RA). With manual alt/az mounts, you will need to move the mount in both axes to keep the object in view. Dobsonians are the same, although the Dob Mob refer to it as 'nudging'. GOTO scopes, on any mount, do the tracking for you (once the scope has been 'aligned'). This is especially useful when using higher magnifications. However, GOTO scopes cost more than the equivalent aperture manual scope because you have to pay for electronics and motors, etc.

[swedonator]

Curios on the small expensive refractors too. For example a Skywatcher 80 ED is expensive, only the tube. What mount should you use for that if you want to do astrophoto? how much would a setup cost exclusive camera. You need eyepieces and such things, because they only sell the tube OTA.

[swedonator]

I have made my decision. It will be the Celestron C6 or C8. It will be well over my budget, but I have room for that. Bad or good choice?

[swedonator]

The tube has a Vixen dovtail, does that mean that any mount with a vixen dovtail may be used? do you have examples of good mounts that are not goto?

[michael.h.f.wilkinson]

I have made my decision. It will be the Celestron C6 or C8. It will be well over my budget, but I have room for that. Bad or good choice?

I have had my C8 for 17.5 years now, so I would call that a good choice.

The tube has a Vixen dovtail, does that mean that any mount with a vixen dovtail may be used? do you have examples of good mounts that are not goto?

I mount my C8 on a non-goto EQ mount (Vixen Great Polaris). Any sturdy mount with a Vixen dovetail will do. A non-goto EQ5 should work, as would any alt-az mount with a loading capacity of 6-7kg or more (a bit of a margin is preferable)

[D_Mike]

Yes the TS scopes are basically the same as the Orion ED80T minus the carbon fibre. They are well reviewed, however I have read a couple of concerning reports on quality assurance and customer service. As with any company if you really look hard you'll find a bad report - but this put me off completely:

http://stargazerslou...service return

I have no direct experience of the company, but lots of general experience of Germany... I am perfectly happy buying stuff from Germany but I'd say that British and German expectations of quality customer service are somewhat different. As long as people are aware of that at the start of their transaction, then fair enough.

[swedonator]

I have never ordered a tube and a mount seperate before, so it is a little bit difficult to choose :-) I do not wanna have to return it if it do not fit :-P

[Dunkster]

Depending on the price you pay, the SE mount that comes with the 6SE or 8SE is a decent enough mount for the price - about £200 or so over the price of the ota alone in the UK. You can always detach it and stick it on any other compatible mount you acquire.

[swedonator]

But if I have understand right, big apperture is great for observing double stars? even if you live in light pollution.

[michael.h.f.wilkinson]

But if I have understand right, big apperture is great for observing double stars? even if you live in light pollution.

All things being equal, the larger the aperture, the better the resolving power. Note however that optical design also plays a role. An 8" apochromatic refractor will be better at separating doubles than an 8" SCT, due to the central obstruction of the latter. A very slow Newtonian (F/11, e.g.) will have such a small obstruction that it will rival the refractor. Neither of the latter designs are anywhere near as compact as the SCT. Splitting doubles does not depend much on light pollution.

[swedonator]

They are also more expensive, apochromatic refractors :-P

[michael.h.f.wilkinson]

They are also more expensive, apochromatic refractors :-P

Not quite. They are far more expensive

[swedonator]

Hehe :-P I am not going for more then what I need if I go for the C6/C8? I want to see double stars and everything else there are to see when I am out in the country, but most the solar system I think.

[michael.h.f.wilkinson]

A C8 is a wonderful all-round visual instrument in a compact package. It does double stars and planets very nicely and is my main DSO hunting tool.

[swedonator]

It's so difficult to see how big something are IRL. I have watched videos at YouTube on the C8, and it does not look so big and heavy. It should weight about 25kg I did read. I could store it in a heated garage or in my room, the tube and mount dissconected from each other.

I think the garage would be best, because from there I have only about 1 1/2 meter to a door that goes out to my observation place, about 2 meters from the door :-P

[michael.h.f.wilkinson]

The C8 is light: 4.7kg for the OTA, the mount can weigh a lot more, but I can handle my GP mount easily. If possible, store it in a cool, dry place. I store it in a garage heated just enough to prevent frost. The only reason I keep the temperature above freezing is that the water supply of the washing machine must not freeze. The closer the temperature is to the outside temperature, the better.