Orion Starblast 4.5 first observation

shirox · Post by **shirox** » Sun Dec 26, 2010 11:46 pm

Hi guys,

I got this scope from Chris recently and was so excited to bring our my new toy today when i saw Jupiter on the west slowly dipping into the horizon.

A question. Asi'm a noob when it comes to scope and eyepieces, Chris gave me a 20mm meade eyepiece and a 6mm normal ones.

When i pointed at Jupiter using the 20 then switched to 6, i can see a globe but it was fuzzy and couldn't see it clearly.

Mai i check is it because of the cloudy weather? Or maybe i should get a better eyepiece?

Thanks for the help!

shirox · Post by **shirox** » Sun Dec 26, 2010 11:48 pm

should i use a barlow to increase the power?

andeelym · Post by **andeelym** » Mon Dec 27, 2010 12:02 am

Did you refocus after you changed the eyepiece?

A barlow on the 6mm will give you 152x out of a max mag of 225x for your aperture. In that case, yes, you should get a barlow.

shirox · Post by **shirox** » Mon Dec 27, 2010 12:51 am

yeah i focus it and it was still a small fuzzy globe. guess i will be looking for a barlow then. any suggestions to get a 2 x or 3 x?

andeelym · Post by **andeelym** » Mon Dec 27, 2010 3:03 am

If 2x on the 6mm, you are pushing past the limit at 304x out of max of 225x. And you will get views that you wouldn't like.

Well, in case you didn't know, max magnification is calculated by multiplying your scope's primary aperture, ie 4.5 inch in your case, by 50. And that is your max magnification for your scope (225x). Some of the veterans even recommending going lower like 40 or even 20-30 for your max magnification so that you are assured of getting good views when the seeing is good. Use this calculator: http://www.csgnetwork.com/telescopemagcalc.html and if you have an android phone, you can download an app I've done to calculate the values.

So with the max magnification in mind, you can plan your eyepiece/barlow purchase properly instead of buying everything available. Which is not a problem if you have the dough to spare. ;)

Gary · Post by **Gary** » Mon Dec 27, 2010 4:34 am

Hi Shirox. The best time to observe/image an object is when it is as high up in the sky as possible. Thus when you saw Jupiter setting into the west (I assume closer towards the horizon than zenith), it might not be the best view and best time to test the performances of your eyepieces and telescope which you may lead you to drawing the wrong conclusions and subsequently make a poor buying decision.

In your Backyard Astronomer book, if I remember correctly, there is a chapter on eyepieces and the suggested combos for various telescopes. Most of them are 2 eyepieces + barlow. So read that chapter again and take your time to plan your future eyepiece and barlow choices suitable for your current telescope and the scopes that you think you may be getting.

Try to attend starparties and sidewalk sessions with your scope to test the various types of eyepieces from the participants.

In Singapore skies, it is quite rare to have nights where one can push their scopes to their maximum useful magnifications. There is no perfect telescope - no scope can be extremely good in viewing planets AND extremely good in viewing widefield. Your scope's main strength is in the widefield section. So don't base your eyepiece buying decision just after observing one planet. Try also to observe more Messier objects with your scope and enjoy your telescope as it is designed and meant to be enjoyed.

I assume you didn't stay up for the third quarter moon which will look marvelous in your 6mm.

cloud_cover · Post by **cloud_cover** » Mon Dec 27, 2010 10:50 am

Andy - If I'm not wrong, the starblast is an f/4 scope for a focal length of 450mm
Hence a 6mm is 450/6=75x. A 2x Barlow will result in 150x, which is arguably doable with the starblast.

Shirox: The starblast is a reflector and hence needs to be collimated or else the views will not be sharp no matter what you do. Assuming Chris sold you servicable equipment (I'm sure he did), its unlikely the issue was with the eyepieces. Was Jupiter tack sharp with the 20mm or also a little fuzzy? If fuzzy then the 6mm will magnify this effect even more.

Do describe your fuzzy image a little more: Was it out of focus, mis-shappen or seems to be jumping/moving around?

rlow · Post by **rlow** » Mon Dec 27, 2010 11:08 am

I think you need to collimate your starblast.

My Starblast gave a sharp image of Jupiter at 152x using a 3mm eyepiece. This Starblast gave a better image (sharp, higher resolution) than a 80mm apo. It makes a great 2nd scope that can be a travel scope for overseas trip. Ironically I put it up for sale at a good price but no one grab it....

Gary · Post by **Gary** » Mon Dec 27, 2010 12:26 pm

@shirox: In your backyard astronomer's guide book, there are instructions on collimating a reflector. You may want to read up on laser collimators for reflectors.

@rlow: You may want to list your telescope sales separately instead of lumping them together. People (esp newcomers) are more likely to browse through the list at the main Buy and Sell subfrom before clicking on anything of interest.

Btw, I guess yours is no ordinary 3mm eyepiece.

From now on, you cannot sell any 80 APO higher then your Starblast price. LOL.

orly_andico · Post by **orly_andico** » Mon Dec 27, 2010 12:39 pm

I was looking at Jupiter myself last night with the 100mm ED I've been trying to sell.. there's a lot of haze close to the horizon (about 20* above at midnight) which definitely makes things fuzzy. Was using a 6mm Burgess/TMB giving 150X. Not too sharp, and still quite small. I've seen much better with this scope, so it must be the atmosphere.

SingAstro

Orion Starblast 4.5 first observation

Orion Starblast 4.5 first observation

Re: Orion Starblast 4.5 first observation