Lenses

[Inkswitch]

Hi everyone,

I bought a Celestron 114powerseeker reflecter scope and it came with a K20, SR4 and a cheap looking barlow lens.

What should lenses would you recommend to buy/use ?

Which lenses do i use for looking at DSI's & planets.

Another stupid question, at the top end of the OTA is a plastic cap that covers the tube that has a small dust cap in it - am i suppossed to just remove the small, about 2" dust cap all the whole plastic cap covering the OTA.

Tip No1. - Don't buy a scope when you live in Cairns in the middle of the wet season unless you are a very patient person :)

Much thanks

[[1ponders]]

G'day Inkswitch, welcome to the site. Can't help you much with eyepieces but you need to remove the whole plastic cap from the end.

Incase you aren't aware on how to set up your scope, raise the axis closest to the tripod top to the latitude of Cairns (15 deg? :shrug:) and then point that axis towards the south pole. 'scuse me if you are already aware of this. ;)

[Lester]

Hi,

Sounds like the end of the telescope has a aperture reducer built into the end cap. Remove the whole thing for night viewing, you may want to try the 2" opening for viewing the moon if its too bright, otherwise use full aperture, all the time.

You can spend from $50 to many hundreds on eyepieces. The K20 may be okay for a start on Deep Sky stuff. Don't know what the focal length is to work out magnification, but you will need 100 x and 200x max for planetary viewing.

Is the scope on equatorial mount?

Welcome to IIS, its great.

[asimov]

The smaller hole is used to view the moon to cut down on the brightness I thought: could be wrong here though..

WELCOME to the forum!! :)

[asimov]

Oops! Lester has already mention that bit....Smart lad that Lester guy! :)

[Inkswitch]

Thanks for the quick replies.

Its on a EQ mount. 114mm aperture, 900mm focal length, f/8 if this helps in recommending lenses.

Thanks

[Lester]

Hi again,

to work out your magnification divide the size eyepiece in mm into the focal length of the telescope. eg=900mmfl divided by 20mm eyepiece=45 x magnification. This would be okay as I said for a start for deep sky objects. For planets a 10mm will give 90x and add a 2x barlow to double that to 180x. But get a good barlow otherwise image will not be very sharp and clear. Or get a 5mm eyepiece instead of barlow and that will give you 180x magnification also. The SR4 would give you 225 x magnification, try that first before getting 5mm. If image is not sharp, or the mount not steady enough for good viewing at that magnification then get the 5mm.

Hope I explained it okay for you.

[mickoking]

G,day Inkswitch, welcome to the community :)

First good quality eyepiece? Thats a very personal question. We all have our interests and observing requirements. Something like a 25mm-16mm plossl would be ideal particually for deep sky observing (which is my interest) A high quality one from Televue or an LV from Vixen wont let you down. A lot of people on this forum will offer you lots of advice, most of it good :P so be patient and tread carefully.

Cheers, Mick