Questions For A Skywatcher 127mm Maksutov Cassegrain with GOTO Mount Tripod

[Landy (Andrew Laynie)]

Hey Everyone,

I am very excited as last night I saw Jupiter and it's moons which was unbelievable! It may be old news for everyone but by golly it was breathtaking to see it for my own 2 eyes (well one eye through the telescope! Haha)

I purchased the Telescope I mentioned in the title and I have a few questions surrounding it.

I am a very new user to Telescopes (2 days) so please forgive my ignorance if I do not explain my issues correctly. I am looking for information around Eye pieces, the Spotting scope and Power for the GOTO Mounts.

Eyepieces
- I received 2 Eyepieces with this model which were a Super 25 Wide Angle Long Eye Relief and a 10mm. I used the 25 with no issues at all but when I tried to swap to the 10mm I could not get an image from it. I could see light when it was waved in front of the telescope (Mobile Phone light) but There was no image whatsoever it was just a blur. Do I need to re-adjust anything or have I just not focused it correctly?
- 2x Barlow lens: From what I can tell this lens increases the magnification for existing lens. The same problem as previously stated happened with this lens where there was no image, it just looked black (until light was infront). I had the thought that maybe I had misaligned the lens hence the no image but I wasn't sure as the 25 seemed to work fine without the barlow but with the barlow there was nothing.
-Difference between the Super 25 and the 10mm?? I can't seem to figure which one will get me the better/bigger picture. For example if I was looking at Jupiter (Which I did last night and it was awesome with the 25!)what would be a better choice of lens and when should I incorporate the barlow lens? Also the Super 25 doesn't state that it is a 25mm it just says Super 25. is it a 25mm?

Spotting Scope
- When I have lined the scope up with the Telescope it seems like it is still loose in the cradle. So if I were to move the Telescope or put it away it could potentially come out of alignment and I would have to re-adjust. Is this normal?

Power for the GOTO Mount
- This currently take 8 AA batteries in a pretty simple piggy back case that has a connector for the Telescope. I don't want to have to keep replacing the batteries so was hoping to see if any one had come up with an alternative for this. I have seen there was a car cigarette lighter power cord that you could purchase which I will more than likely do but I was thinking that maybe you might be able to use a RC Car Battery and just replace the connector. Has any one investigated a solutions for this?

Any help on these would be appreciated one these. I am hoping for a clear night tonight so I can check out more. Just as I finished setting it all up BOOM clouds everywhere... Stupid weather

Thanks Guys and Gals!

[julianh72 (Julian)]

It might help you to try using the telescope on a distant object in daylight (eg a tree or building on the horizon), as it is a LOT easier to work out how everything works with a nice bright terrestrial target. If it goes slightly out of focus, or changes alignment slightly, when you change eyepieces or add a Barlow (e.g. the different weight of the two eyepieces can make a difference to the exact aim of the telescope), you can generally make out some sort of image, and easily work out which way you need to refocus or realign for the new eyepiece.

The 25 mm eyepiece will give a lower magnification view, and the 10 mm eyepiece will give a higher magnification, somewhat dimmer view. Generally, both eyepieces should be roughly focussed at the same settings, but you generally need to do some refocussing when you change eyepieces. The Barlow will increase the magnification of any eyepiece, but will also reduce the brightness, and you may need to refocus quite a bit when you swap the Barlow in and out.

In general, the low power eyepiece is the easiest to use, so get fully familiar with that, and then experiment with the 10 mm, then try the 25 mm and the 10 mm with the Barlow.

I would guess that your target (Jupiter) was slightly out of view when you swapped to the higher power eyepiece (and possibly also out of focus). This is where experimenting in daylight can help - even if the image shifts a bit, you can easily work out what you are looking at; with a single small target, when it is out of view, and slightly out of focus, you may see nothing, and may not know which way you need to realign and / or adjust focus etc.

The Finder Scope should clamp reasonably firmly in the mounting bracket. Try making sure all three thumb screws are reasonably firmly tightened - but don't overdo it. But yes, some small finder-scopes may wobble a bit in the bracket.
(Note on terminology - the small "piggy-back" scope you use to aim your main telescope is the Finder Scope; a Spotting Scope generally refers to a small stand-alone telescope designed for terrestrial viewing.).

For batteries, try getting 8 x AA rechargeable NiMH batteries - they should get you though a couple of night's viewing pretty easily, and you just recharge them instead of throwing them away when they are flat. Yes, you can also power the mount using a cigarette lighter lead from your car, or from a car jump starter. You can use pretty much any 10 volt to 12 volt battery, but don't try to hook up anything with more than 12 volts, and make sure you get your battery polarity right - if you get the polarity wrong, you could fry the mount in an instant.

Hope this helps!

[rustigsmed (Russell)]

good advice below already,
also the planets are very particular about the seeing and sometimes "zooming in" too much if the conditions aren't good ends in blurry planets. i would try using the 25mm on the moon then the 10mm (or barlow) as its nice and bright and you'll be able to tell more easily if focus is reached or if it is due to atmospheric disturbances.

[sharptrack2 (Kevin)]

Hi Landy,

Welcome!

Julianh72 and rustigsmed offer some great advice, another way to look at it is when you put the lower number eye piece in the focuser, you are increasing magnification by reducing what is called the Apparent Field of View (commonly referred to as AFoV). So if the object is not exactly in the center of 25mm eye piece, it will most likely be out of view when you put in the 10mm eye piece. And as mentioned, it will also be much dimmer because you have reduced the amount of light coming to your eye.

Re: the barlow, most factory supplied barlows physically move the eye piece away from the focus point you may originally set, towards you as you look at it. To get back into focus, you will need to adjust the focuser in, toward the body of the telescope.

Hope that helps! Good luck!

[Landy (Andrew Laynie)]

Thank you so much guys this is amazing help!

I will try to align the finder scope and also try the 10mm when I get home with a bit of light. The barlow I will try to do some testing with at a later time. Also thank you for the explanation Sharp I have seen this mentioned a few times but didn't quite get it until now!

I think I must have picked up "Spotting Scope" from being at the rifle range. From when I was playing around last night I only saw 2 adjustment screws for the Finder Scope and then a third spring loaded connector that I think is for quick release. The quick release may screw in as well though so I will check that out tonight.

The power I might investigate a little more before I go plugging things in to the GOTO mount. My original thought was to make some sort of rechargeable battery packs that I could have a few ready to go so if I went on a camping trip I could take a few without the worry of recharging. I will keep you guys posted on this!

Thanks again for your help you guys are awesome!

See you in the stars!

BTW rustigsmed, I had a snoop on your flicker page and wow those shots are amazing! Keep them up!!

[julianh72 (Julian)]

Originally Posted by Landy

The power I might investigate a little more before I go plugging things in to the GOTO mount. My original thought was to make some sort of rechargeable battery packs that I could have a few ready to go so if I went on a camping trip I could take a few without the worry of recharging. I will keep you guys posted on this!

One very common power pack is to just buy a cheap car jump-starter from Super-Cheap Auto, K-Mart, etc. They pretty well all have 12 volt cigarette lighter sockets, so you can use a suitable cable to power the mount. Many of them also have utilty lights, USB sockets, air compressors, etc, so can be handy for all sorts of applications. (And they're also handy to jump start the car if you need it!)

A typical jump starter should be able to power a mount of this sort for many, many hours, depending on the amp-hour rating. (Note: It is the amp-hour rating that matters, not the maximum amps!) How long can you get on a single charge? It's hard to say - your mount's user guide will probably quote a power demand of perhaps 1 to 2 amps - but this is typically the peak demand when the telescope is panning at maximum speed (eg when moving to a new GoTo target). It will draw a lot less current when it is in tracking mode - maybe 250 mA to 500 mA or so. If you have a 17 amp-hour power pack, say, you should be able to get well over 24 hours of continuous use on a single charge.

Another option is to buy a 12-volt Sealed-Lead-Acid battery (SLA) from JayCar or similar, but you would need to buy a suitable charger as well, if you don't already have one.

[raymo]

The spring loaded one is just that; The finderscope will only be as secure as the strength of the spring dictates. It's always a good thing to quickly check
the finder alignment before observing, and it only takes a second or two
to adjust it.
raymo

[Landy (Andrew Laynie)]

Thank you everyone for you responses! I wanted to update where I am now at with everything

Eyepieces
I was able to focus the eyepieces through the day as mentioned. It seemed I was just completely out of focus.
After using the given eyepieces, I have now purchased a Plossol eyepiece kit which includes 6mm, 8mm, 13mm, 17mm and 32mm + filters (Which I have no idea about yet lol but will put another post together about that) I now have been trialing all eyepieces and seem to have the hang of it now!

Finder Scope
I think I have it pretty much almost set to perfect. May need the slightest adjustment but can pretty much find most things reasonably quickly. It is still a little loose though but I guess that's normal.

Power for the GOTO
I ended up going through the Jaycar option and purchased a SLA battery. I soldered up a connection for it and it is working great! Thanks for the advice on that one Julianh72!

From that it has been awesome so far getting used to everything. I am going to make another post shortly but thank you again for everyone's help on this it has been a massive help!

To the stars!!!