Pixies

Hi, I have a shorty Cheshire, which is fine for collimating the primary mirror. However, I am so short-sighted I have problems trying to use the crosshairs when adjusting the secondary. With my glasses off, my close-up vision is fine - but only up to about 20cm for a decent focus - so I can focus on the cross-hairs just great. I need my specs to be able to see the doughnut, but the closest I can focus with my specs is also 20cm, so I can't focus on the cross-hairs! I realise that a long Cheshire is probably still too short for a good focus on the cross-hairs, but it might be a little bit more easy to use. However, I'm not clear on the differences between the short and long style. Is there a functional difference? Is one more suited to a particular type of scope than the other? And a final question. Regarding FLO's "Premium Cheshire Collimating Eyepiece": It has a stepless barrel, so I assume this means you can vary the depth to which you insert it into the focuser? Does this help with anything? Cheers P

@Stargazer Joe - bringing it back to your original post. Have you had first-light with your scope yet? If not (or otherwise, anyway) a good starter DSO target is M57, the Ring Nebula. It's probably the easiest star-hop you can make and your 2 EPs will be perfect. Using Mk1 eyeballs, start with Vega (the brightest star in the Northern Hemisphere summer sky and the highest of the summer triangle) and then find Sheliak and Sulafat in the constellation Lyra. Then all you have to do is point the scope's finder half-way between the two: Now use your 28mm widefield eyepiece, and M57 should be in the view. It will appear as a small grey fuzzy star. Like it's out-of-focus. Once you find it, get it centred in the view and then to get a better view, swap in the 10mm EP. If you lose it with the higher-powered EP, you might have to go back to the 28mm EP or the finder and star again.

I do similar, but add them to an observation list in SkySafari I have created for things I want to try and observe at a later date. The Pro version does have the FOV stuff. It took me ages to work out how to find it, even after someone on SGL told me about it. Version6 plus and pro: Click on the 'Observe' eye icon. Click on 'equipment' Then 'add telescope' - and find yours on the list or add a custom one - 'add to my equipment'. Then again: 'observe' -> 'equipment' -> 'add eyepiece', and find it on the list, or more likely, create a custon (you'll need focal length and AFOV) You can also add bins, barlows, etc. Once it's all been added, goto: 'Observe' -> 'Scope display' Select 'add FOV indicator' and select whichever scope/EP combos you want to have available. Finally again goto 'Observe' -> 'Scope display' Select the FOV indicator you want to use. Also Telrad circles. Select 'Show even if not connected to telescope' Apologies to the OP for hijacking his thread.

Don't worry - you have the 5 points for that. I'm just going for the picture bonus. Numberwang!

SkySafari is great. There are various cost options. I use 'plus' which allows you to superimpose the FOV indicator to match your scope/EP combinations. Also, it has an 'observation' feature which allows you to have your own pre-planned observation lists, or use public ones (including many created by SGL). the observation feature is worth the cost alone. It is always being discounted, don't pay the full whack. Stellarium is a great free app for a laptop.

Yep. the barlow parts are indicated below. There is a nosepiece or similar stuck in the barlow ('x')

Isn't that the objective end of the finder? It has a rubber o-ring (albeit a little frayed) with objective in the box: and finder eyepiece: This is a great game!

If I tilt my head so the lines are horizontal - the 17 pops out. Also, if I remove my specs (very short sighted)

Oh - and probably some type of collimation tool.

A good guide to finding them would be a start. Such as "Turn Left at Orion" by Guy Consolmagno and Dan Davis. Your scope is perfect for deep sky objects. As a newbie myself, I would suggest you just start with what you have before jumping into the never-ending abyss of upgrades and additions. Find out what works and what you have trouble with and then look to make things easier for yourself. I would imagine your initial purchases will be either eyepieces or improvements to your finder(s) - but until you have a shot, you won't know what your priorities are. But just to get things started... what eyepieces do you have?

Yep - just try and centre it with the focuser tube a bit more. You want to make sure you can see the whole of the outside circumference of the primary (and the 3 clips should look equal). Sometime you have to fine-tune the rotation of the secondary slightly, too. Take your time, this is the really fiddly bit.

Sorry - the 3 outer screws. Just as you were doing before - now we're fine-tuning. You might have to make smaller and smaller adjustments to centre the primary image.

It's 2 we are interested in. You need to keep using the colination cap. The next step is to fine-tune the tilt of the secondary, so that the image of the primary mirror (the bright white circle) in the secondary is whole and centered. It looks like you need to tilt the secondary slightly away from the focuser, bringing the image of the primary mirror 'left' a bit in your second picture. The plan is to get the image of the primary concentric with the secondary and the focuser. You should be able to see all 3 of the clips holding the primary mirror.

Nope - keep the cap on. That looks great. Now for a pic with the paper inside the tube removed (careful not to touch the mirror)

That looks fine for now. Can you take a pic with the focuser racked half way out too. Then take out the paper and let's see how things look.

Nice - that's miles better! Now you can adjust the 'tilt' of the secondary, using the 3 outer screws. You want to 'lift' the mirror up in that picture, so that it is concentric with the inside of the focuser tube. Currently it's a bit low down (in the view). When you adjust with these 3 screws - again be gentle. Loosen one first (1/4 turn) then tighten another by 1/4 turn (or tighten the other 2 by 1/8 turn each). you don't want to leave them loose - but again, don't overtighten. You'll soon get the hang of it. At this stage, all 3 screws heads should be extending out by roughly the same amount.

OK - try to see if you can adjust the rotation of the secondary as I mentioned above. Be careful with the screws and don't use too much force. PM me if you have any problems

No - it's fine just now. Is it all the way in?

OK. The next step is to adjust the position and rotation of the secondary. We want to get it centered under the focuser and rotated so that it presents a concentric 'circle' to your view. Loosen the centre screw slightly, keeping the tube horizontal, so that nothing can fall down. Be gentle with these screws, don't any damage by using too much force. If the centre screw is stuck, loosen the other 3 outside ones VERY slightly When it is looser, you should be able to rotate the mirror around the tube's axis. Be careful not to touch the mirrored surface. Rotate it so that it appears circular in the collimation cap. Then tighten the screw gently, so it is held securely. Then post the pic

That is extremely out of alignment. Can you please double-check that the hole in you home-made collimation cap is as central as possible. The hole should be only 1.5 - 2mm in diameter. Like so:

Hi Rishabh. The manual for your scope is here: https://www.meade.com/pub/media/downloads/62/Polaris_EQ_Models_V003_En.pdf What you are seeing is described as a secondary misalignment (fig 15) If you follow the Astro baby guide (Collimation Step 2 – The Secondary Mirror / Focus Tube Alignment) and stop before you do any actual adjustments. Just take a photo of the view through the cap, and post it here.

Actually. I've just realised that your scope is a Bird-Jones type. This will make the alignment of you primary a little different from the guide. However, the secondary does look quite a way out. Collimation is a task that a newtonian owner needs to learn. I don't know if your seller would consider this a good reason to return. Where did you get it from?

If you follow the guide, the first step is to insert some coloured paper which removes a lot of the reflections which can be confusing to what you see. I think your secondary mirror is well out of alignment - that will need to be sorted before you can start trying to align anything else. Are you confident that the hole in your collimation cap is completely central?

You REALLY need to make sure your eye/camera is centred exactly in the focuser. You will need a collimation cap as a minimum - although you can make your own. Have a look at this guide: http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/ and here is a previous thread with someone trying to align their secondary (with some difficulty) using the above guide and a collimation cap. To make it clear - I think from your images that your secondary mirror is rotated out of alignment. From Asto Baby's guide, start at "Collimation Step 2 – The Secondary Mirror / Focus Tube Alignment" (using the coloured paper) to align your secondary under the focuser and rotated correctly. You need a collimation cap of some type to help you do this. Unless anyone can suggest a better way?

It does look like the rotation of the secondary mirror is a bit out. What collimation tools (if any) do you have?