Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

First telescope - 114mm x 500mm reflector


Recommended Posts

Ok, so i purchased this Tasco 302911 last week, second hand, £50. Thought it would be a good way to start off in astronomy. Aligned it during the day, great views so thinking it was collimated good, tried it that night, but a bit disappointed with the results.

After much looking online, found that Tasco is a brand much maligned by many. Undeterred, i also found some who thought the scope was decent enough, but the eyepieces are rather abysmal.

Now what i'd like to know is, if i purchased a decent 17mm plossl, would it make a great deal of difference to what i already have(20mm, 4mm, 3x barlow)?

And have also found the telscope accepts .925 ep's, though the holder does screw out, would i be able to fit the 1.25 into this or is it more cash to invest in a hybrid diagonal?

Would like to explore this baby to the fullest before i sell on/throw in the bin.

Thanks! :D

post-25871-1338775972_thumb.jpg

post-25871-133877597207_thumb.jpg

Link to comment
Share on other sites

Magnification is calculated by dividing the focal length (500mm) by the focal length of the eyepiece. So you already have got an eyepiece 20mm that gives you x25 magnification and a 4mm which will generate x125 magnification. I would not see any point in buying a 17mm eyepiece to give you x29 magnification. Forget the barlow, as its likely to be poor quality if it came with the scope and in fact it will make your viewing worse. The .925 eyepiece will be difficult to find and were more common in the past on older japanese scopes. A diagonal is something that you would attach to a refractor or a Cassegrain type scope and is used to provide an easier viewing position and does not contribute to the magnification.

To help you put the scope into perspective, if you're looking at Saturn for example, you will probably want a magnification of somewhere around x160 - x180 to obtain a meaningful image. Yes you can view Saturn in a pair of binoculars but you're unlikely to be rushing in doors telling the rest of the family what you've just seen. Now coming back to your scope, to get that kind of magnification you would need an eyepiece that has a smaller focal length than the 4mm that you have - that would be pushing the scope too far. The truth is, this scope is designed for very wide views of the night sky (low magnification) and the tubes length won't give you any useful magnification for looking at planets. The moon will be fine but I'm not sure how long your interest will be sustained if that is really your only subject matter.

I don't want to be negative but my personal view would be to enjoy the scope as it is and the views it offers but not to spend any money on it. I would put any future funds into a scope like a 200P dobsonian which will provide really great views, give you a wider range of objects to look at and that will accept 1.25" eyepeices which you can pick up fairly inexpensively.

Clear skies

James

p.s Looking at the first picture, your scope is set up incorrectly as the latitude axis appears nearly horizontal. Have a look at AstroBaby's set up instructions to see how the mount should look.

Link to comment
Share on other sites

Hi

The first scope I bought was a Tasco :D.

It never dampened my enthusiasm for astronomy.

The .965 eyepieces are truly shocking but I must say I just put up with them for a couple of years.

That said mine did come with a better selection 40mm, 20mm, 12.5mm and 6mm.

The 6mm and the Barlow rapidly were on coarse for the skip (utter rubbish).

You will probably find the 4mm and the Barlow utterly useless. Not to worry what you have is a rich field scope best used for star fields and the Milky way.:)

Used with the 20mm eyepiece it should provide a usable fun scope.

As a planetary scope this will always disappoint.

I would urge caution before spending any money on it, best to save it towards another better scope in a couple of years time.

Regards Steve

Link to comment
Share on other sites

Could do much worse for a first scope. Mine wasn't even branded and under performed compared to a Skywatcher of the same aperture and almost the same focal length. It still very good fun to just aim for anything in the sky and I certainly did not mind the 'unbrandedness' at all. Just make sure you have good seeing conditions and you should have a blast. Have fun =D

Link to comment
Share on other sites

I assume that you mean a hybrid focusser not diagonal? Scope looks to be a reflector and they don't normally use diagonals.

If you can get a cheap, as in inexpensive not junk, focusser for it then it opens up a lot more eyepiece options. Not sure if there is an inexpensive conversion.

For the cost it seems a little pointless splashing out on anything pricy, but it would benefit from say an 7mm and a 10mm giving 70x and 50x, a 20mm or 25mm for wider views would complete it in my view. You already have a 20mm.

For 0.925 eyepieces I can only suggest the web, or a few visits to car boot sales, bet someone will have a few sat on a table one day. Just when that day occurs I have no idea. A wanted ad on SGL (when enough posts) or Astro Buy/Sell may be productive.

Minor hiccup is 2 eyepieces (new) will exceed the cost of the scope.

Link to comment
Share on other sites

as others have said, tend to think you would be wasting money on more ep`s, as if you get a new scope you wont be able to use them with it, i see in the pic you have it set up pointing to a window, thats a bad way to use a scope as thermal currants distort image, just use it as a wide field scope for star fields then sell it at a later date when you want a bigger scope

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.