Sky Watcher 70/900 how far you look from the eyepiece?

[robg]

Hi guys,

Newbie here and recently bought a telescope. I am still struggling in aligning the finder scope. Anyway, I noticed that when I look at the eyepiece (SkyWatcher 45 Degree 1.25" Erect Image Diagonal w/o magnification (http://www.ozscopes.com.au/skywatcher-45-degree-1-25-erect-image-diagonal.html)) I need to move far away in order to see the image clearly and if I look closer, things just gets blurry. When I put the 20mm eyepiece I can't see anything. Is that normal? I find it weird looking far away from eyepiece or I am doing it wrong? Hope someone can advise.

I am still doing the calibration and testing it on a tree few hundred meters away.

Thank you for your reply in advance.

Happy new year.

Regards,
robg

[mental4astro]

Hi Rob,

When the eyepiece is in place, have you adjusted the focus with the focus knob? It needs to be asked...

Looking through the scope without an eyepiece means nothing. Your eyes will struggle as the scope niw is just acting like a big magnifying glass.

Alex.

[brian nordstrom]

:) Hi as Alex says but also the part you describe is the Diagonal , not the eyepiece , I may be wrong ,,,,,, but have you put an eyepiece in the diagonal ?. Worst things have happened ;)
Brian.

[robg]

Hi Alex/Brian,

Sorry to confuse you guys, I thought the diagonal is considered eyepiece, note taken. :)
When I assemble the telescope I did put the eyepiece in the diagonal but can't see a thing. I searched online and found an article about calibration and making sure first that I see something on the other end of the scope. I removed the eyepiece and can now see something in the diagonal but I have to be inches away from the diagonal to see the image clearly. I thought I have to fix this first before putting the eyepiece.

I will try again with the eyepiece and let you guys know the outcome. I am probably wrong in assuming that the way I look/see in the diagonal should be the same with the eyepiece just more zoomed in.

Thank you so much for replying, I hope explained my issue clearer. :D

Rob

[AstralTraveller]

Rob,

Hello and welcome to the learning curve. It's all pretty easy once you get the hang of it.

First thing I would do is ditch the diagonal, it just complicates things at the moment. That means everything will be upside down and back to front but that doesn't matter. Use the eyepiece with the largest number (ie lowest magnification and widest field of view), which I think will be the 20mm (btw is it a H-20 ?). Now point the scope at something you can't miss and, with your eye about 10mm (give or take a bit) from the eyepiece, adjust the focus. If the object is too close you won't achieve focus but you should at least see that something is there. If you can use an object a few hundred metres away, or further, you should get focus. (I use the Illawarra escarpment which is about 1km from me)

Move the scope until it is centred on some distinctive point, such as a tree, tower, antenna etc (I use the TV tower on the escarpment) and lock it there. Now look through the finder. Adjust the focus and use the alignment-adjusting screws to move the finder until its cross-hairs also point to the object in the main scope. You are now ready for your first look at the moon!

Let us know how you get on.


Edit: Correction - I should have said to ditch the correct-image diagonal. Just use a 90 degree diagonal if you need the extra path length.

[doppler]

Seeing that you have a refractor, you should use the diagonal. My SkyWatcher refractor won't rack out far enough to get focus without the diagonal.

Definitely try it on terrestrial daylight stuff first to get used to the focus etc. You will have to wind the focuser out a fair way for closer objects and as said below use the lowest magnification ie. the eyepiece with the highest number. You can only "calibrate" the finder scope, centre some object in the main scope and then adjust the finder to match the main scope.

[robg]

Hi Guys,
:thanx: for all the inputs, I guess I was doing what I should not be doing looking at the diagonal. silly me. :rofl: I placed the 20mm eyepiece and voila I can see my target with my eye close to the eyepiece. Maybe when I put the eyepice before I did not know about the knobs. Thank you again!

Now I am back to aligning my finder scope, it is hard to centre the cross hair using the screws. If I use my fingers to focus on the target (without tighthening the screws yet) I can see the tip of the other end of the telescope. It is just the standard finder scope that came with this telescope (http://www.ozscopes.com.au/skywatcher-sw709-refractor-telescope.html)

Anyway if you have tips do let me know.

Can't wait to see the moon.

:D