John

I use the Sky & Telescope Pocket Star Atlas at the scope. Despite it's name it goes quite deep and is a very useful tool. For more detailed reference I also use the Cambridge Double Star Atlas (it's not just double stars !) and the very detailed and comprehensive Interstellarium Deep Sky Atlas or Uranometria 2000. If you don't mind printing your own, these are free and very good: http://www.deepskywatch.com/deepsky-atlas.html

You can get many different types and focal lengths of eyepiece. The focal length of the eyepiece is expressed in mm (marked on the eyepiece) and that is what dictates the magnification that the eyepiece will deliver when used with a particular scope. The larger the figure in mm, the lower the magnification you will get. I think you get 2 eyepieces with the scope ? One useful addition is a barlow lens. This goes between the eyepiece and the scope and has the effect of multiplying the magnification that the eyepiece provides, most often by 2x. What eyepieces do you have at the moment ?

I have just managed to split this attractive pair with my Tak 100mm. The secondary star is right on the thin diffraction ring from the primary with the 100mm aperture. Split at 225x and a little easier at 300x. Uneven brightness adds to the challenge. Rather like Zeta Hercules in some ways but the PA is quite different and the separation is a little greater with Propus. Well worth the effort on a cold night

As above, with a bright moon anywhere in the sky, all DSO's are going to look far from their best and the fainter ones (eg: galaxies and nebulae) will be conspicuous by their invisibility ! Star clusters are a possibility under such conditions, provided that they are not anywhere near the moon in the sky. Even those will not be at their their sparkly best. Under dark skies a 6 inch scope is capable of seeing hundreds of DSO's though so it's a realistic project. I first spotted M81 and M82 with a mere 60mm refractor. Apart from M31, most other galaxies are quite a bit harder to spot though. Under darker skies, try this star hop route to M81 and M82 - it works well !

Thanks Mark - all the best to you and yours as well

The red giant star Propus (Eta Geminorum) is situated just over 5 degrees to the W of the full moon tonight. This is a close double star with the primary star having a magnitude of around 3.4 and the secondary 6.2. The separation is 1.7 arc seconds or thereabouts so a nice challenge. Bathed in the moonlight this pair looks lovely tonight at around 300x. The orange / pink colouration of the primary star seems particularly enhanced perhaps by the moonlight ?. The dimmer star looks greyish tonight. Very nice pairing. Looks like the forecast was correct though and a thin but annoying layer of cloud is now spreading across the sky from the NW so thats probably going to end this session. Very nice while it lasted though

The seeing must be decent here tonight. 32 Orionis is an easy split and 52 Orionis is splitting quite clearly as well, during the best periods of seeing.

Got my ED120 refractor out with a couple of hours clear skies forecast. Despite Mars dwindling size it actually looked rather nice tonight. Sharp and contrasty at 281x. Phase and southern hemisphere darker markings showing nicely. No south polar cap as far as I can see though. Last time I viewed it (Xmas eve) it was useless to use more than about 180x. Much better seeing tonight. Uranus pale grey green disk also nice and sharp at the same magnification. While waiting for Orion to rise up a bit more I'm going though some of the double stars in Pisces and Cetus. Some nice ones in that patch of sky. It's supposed to cloud over around 11:00 pm so I'd better make the most of it

An object at focus through a scope appears at it's smallest when it is at sharp focus. Mars will look very small currently. Just a tiny pink disk like this: If you can see the dark shape of the secondary mirror and it's supports against a larger disk of light, you are way out of focus.

I would try and get it working with the accessories that come with it before buying anything else. Use the lowest power eyepiece (20mm ?) while you get used to how it works. No barlow lens and no erecting lens. Just the angle prism and the 20mm eyepiece. It will perform better if you take it outside to observe. While the supplied accessories will be basic, they will work and they will enable the scope to show quite sharp views. If you start buying additional eyepieces etc, you will very soon have spent more than the scope cost so it is worth getting the thing to work first.

Here are photos of the finders on my 12 inch dobsonian and of my Sky & Telescope Pocket Sky Atlas along with another very useful tool. Hope that helps

Hi and welcome to the forum. Unless the collimation is massively out, you should at least be able to get the scope to focus. You can fine tune the collimation once you have cracked that. Orion Optics scopes usually need an extension tube of around 50mm to get eyepieces to focus - do you have one of those fitted ?

I think the Telrad would work OK but would be a large addition to the WO 73. Here is a Telrad on an ST80 refractor:

Hi and welcome to the forum. We need to know more about the scope (eg: the specifications) that you are going to put on the mount, whether you have a budget in mind and whether you are interested in imaging, visual observing or both

This website does actually sell parts of scopes including the top piece you pictured and more besides: https://www.astroboot.co.uk/AstroBoot They are based in Europe though and I've no idea if they will ship to the USA. You would need to work out what suited your purpose and how to actually make the modifications to your scope - the supplier would not take any responsibility for that.

Travel for me. Got all the kit and more that I'll ever need Can I have 6 months please if it's just my other half and I ?

If you get the settings right, the depiction of the size of the field of view will be accurate but as for the visibility or other wise of the object itself, I would take that with a very large pinch of salt. Observing conditions, observer experience and equipment make a really big difference to what is actually seen "at the eyepiece". I've just looked at Stellarium and zoomed in on Orion using the parameters of one of my scopes and eyepieces. It shows a couple of nebulae there (the Flame Nebula and the Horsehead Nebula) rather clearly but the reality is that these objects are really, really difficult to see even for experienced observers under dark skies with big scopes. So the size of the view can be accurate but not necessarily it's contents !

I use a Skywatcher 6x30 RACI finder on my FC100-DL. It fits neatly into the Takahashi 30mm finder clamp. The trick is to find a finder mount that will fit your finder and also can be fitted to the 2 holes on the Takahashi FC100. This is the Takahashi 50mm finder mount, it might fit your 50mm Orion guide scope ?: https://www.rothervalleyoptics.co.uk/takahashi-finderscope-bracket-for-7-x-50-finder.html

I use a Skytee II and a Giro Ercole for my 100mm - 120mm refractors. My 130mm refractor needs something more stable again to get the best from it. I managed to get a T-Rex for that which has a similar capacity to the Rowan AZ100 but is out of production now. The Ercole and the Skytee II are around the same capability but the Ercole is a better made and finished product. The Skytee II has slow motion controls though which can be very useful. Difficult to knock the capability of the Skytee II for what it costs. The dovetail clamps do need to be upgraded though which should be factored into the price.

This is a 12 inch. It's an Orion Optics tube and the whole thing weighs about as much as a Skywatcher 10 inch dob. I did have a Meade Lightbridge 12 inch dob and that was much heavier so didn't get anywhere near so much use. Best scope I've ever owned in terms of what it has shown me

It's a good combination for planets as well:

If it is a .965 inch diagonal your choices will be very limited I fear. Check that first. If the scope uses 1.25 inch then your choices are very wide indeed. Presumably the scope was purchased used then ?

That top pic looks OK to me. Stop worrying about it and get on and use the scope

The finder arrangements mentioned in other posts, ie: 9x50 RACI optical finder AND a 1x illuminated reticule finder (Rigel Quikfinder in my case) have worked wonders for my deep sky observing over the past few years Added to the above, I have found having a good hard copy star atlas has been a huge help. In my case I found the Sky & Telescope Pocket Sky Atlas really effective. Using that and the finders mentioned I've had nights with my 12 inch dobsonian when I've found literally dozens of deep sky objects that I've not seen before.

If the scope focuses sharply without the diagonal in place and the diagonal is the only change between that and not being able to get sharp focus, even after adjusting the focus, then the prime suspect becomes the diagonal. It is possible that the mirror of the diagonal is out of position, ie: not at exactly 90 degrees to the light coming down the scope ? If you bought the scope new, you should really take it up with the vendor and see if they will supply a replacement diagonal. If the scope was bought used and the diagonal is faulty, you can buy replacements. I assume that this is your scope ?: The mirror diagonal with these is pretty basic so it is quite possible that the mirror has come loose.