A few beginners questions

[ian h]

Hi For Christmas I received a Jessops 1100-102 telescope. Finally got to try it out this evening. First clear night since Christmas.

I think I located Jupiter with the help of the stellarium software recommended elsewhere on this forum.

I was a bit disappointed with the image. It was quite blurry at best.

With the 12.5mm with 3x barlow I think I managed to see the equatorial belts but cannot be sure.

Would I benefit from upgrading the eye pieces ? and do I really need to be using filters ? If so some suggestions would be appreciated.

[John]

I think you were trying to use too much magnification - I don't know your scope or it's spec but I'd try using the lowest magnification (just the 12.5mm eyepiece on it's own) and see how that goes. A small, sharp image is much better than a bigger, blurry one !.

[ian h]

I am not sure the size of image changed dramatically. Jupiter was visible as a image no more than 2 0r 3 mm . I don't really know what to expect to see.

With the 20mm on its own the image is to small to be able to distinguish any detail.

[John]

Well it's never really that big to be honest, even in my 10" scope at 250x.

If you can post the specs of your scope I'm sure we can suggest how you get the best out of it - my inclination would not be to throw too many £'s at it but use it to get used to how scopes work and see if you like the hobby.

[ian h]

jessops ta1100-102 reflecting telescope

102mm objective diameter.

1100mm Focal length

3x Barlow lens

6mm, 12.5mm & 20mm eyepieces

Are the only specs I can find. Is there anything else that would be helpful to know.

[ian h]

One thing I was wondering was that when you pull it out of focus the cross hairs become visible. Is this normal ?

[Ags]

Hi, welcome to the forum. I think the 6mm eyepiece on its own gives you the max magnification for your scope (1100 / 6 = 183x magnification). This will show a small image of jupiter, but enough to see the main bands and even the Great Red Spot if you are lucky.

the barlow is useless - at x3, it makes the 20mm into a 6.3mm, and you already have a 6mm EP! You would get 264x magnification with the 12.5mm EP barlowed, which is too much for your scope, which can handle a max magnification of around 200x. I also guess the barlow is not high quality and degrades your views considerably.

Yes the diagonal vanes come into focus when you focus on things much closer than infinity. THat's normal. You can't see them when looking at stars and planets.

[Ags]

Are the EPs marked H or SR - these are common types of cheap, not very good EPs.

[ian h]

Cheers for the advice I think it makes sense. Would it be worth buying a better barlow ? If so would a x2 be more appropriate ?

The EP's are marked

HR20mm

HR12.5mm

and HF6mm

Are these also worth upgrading ?

[John]

I agree with Ags, don't use the barlow lens - it's not going to help at all.

I'd concentrate on using just the 12.5mm and 20mm eyepieces - even the 6mm will be pushing things a bit I reckon.

[ian h]

Thanks for all the advice so far. It has been really useful, and I now have a better understanding of what to expect from the scope.

So would it be worth investing in some better quality EP's ?

If so would this standard of EP be a fair upgarde ? Celestron Omni 15mm Eyepiece 1.25" on eBay (end time 23-Jan-11 21:44:22 GMT)

Would I benefit from any filters ? I have noticed the moon filter included with the scope makes a massive difference when viewing. I was looking at these type as they are cheap. Gso Yellow Filter for Astronomical Telescopes on eBay (end time 16-Jan-11 16:32:23 GMT)

I get the x3 barlow is no use as it exceeds the max maginfication. Would a x2 barlow be of any use ?

Sorry for so many questions but I have a lot to learn

[John]

Hi Ian

No problem asking questions that's what we like

I think some better quality eyepieces will improve the views your scope is giving a bit. You would need to invest around £20 or so per eyepiece and the plossl type would be an improvement over the ones you have - the Celestron Omni is that design. You might be interested to know that First Light Optics sell them for £25 each so don't pay too much for used ones:

Celestron - Celestron Omni Plossl Eyepiece

Being honest with you, the scope you have does have it's limits though so please don't expect an dramatic improvement and I'd stick to around a 100x (ie: a 10mm eyepiece) as a maximum magnification to get satisfying views. Much astro viewing is done at much lower powers than that - especially on deep sky objects.

The good thing about getting some improved eyepieces is that you can use them with any scope you may move onto once you have exhausted the possibilities of the Jessops one - which might be quite soon, if the bug bites

[KenG]

Forget about barlows and put your supplied eyepieces in a box. Invest in one 20mm eyepiece with around 70 degrees field of view and decent eye relief, buy a good introductory book about the night sky and how to observe it, and start observing. That's enough to keep anyone occupied for a couple of years. You'll get to know the constellations, you'll see lots of wonderful things, you'll learn how to use your scope, how to get the best out of an eyepiece, and you won't get frustrated.

I would suggest something like an Antares W70 19mm for an eyepiece - at around sixty pounds it won't break the bank, and perhaps Alan MacRobert's book "Star-hopping for backyard astronomers".

[jleach29]

I agree with what everyone has said so far, I have never really been that impressed with viewing Jupiter, it was the first planet I ever saw through my first scope and was happy to have found it, stay up late or wake up early and check out Saturn, it will blow your mind through just about any scope!

[matchew]

i have purchased exactly the same scope and have already shopped around for a quality lense and tossing up wich one to get,12.5 or the 20,after listening to keng i will now go gor the 20mm,i am actually over the moon with at ive seen with my jessops 1100x102,i have seen the darker shaded bands and clearly the moons with the 12.5 ep and barlow,the moon is like watching HD.but will most deffinately upgrade in the middle of the year,celestron has taken my fancy

[Tim]

Some nights the conditions in the atmosphere are just plain bad for viewing as well. You might find on another night that things have improved somewhat.

Also, have a go at the moon, see how you get on exploring the terminator, or the edge of is which is part shadow/part illuminated. You will see how the turbulence in the air mucks up the image to varying degrees.

Cheers

Tim

[matchew]

this may seem a silly question but wats the terminator

[jwallis]

The terminator is the line between the dark area of the moon which you cannot see, and the part that you can see. You get to see some great sites along that line. Hope this helps.

[brantuk]

The terminator is the line down the middle where light meets dark. You get to see shadows in the craters so you get to see some depth. Also - look for a line of peaks just in the dark next to the terminator where they are only just iluminated by light. Sometimes it looks like the moon is stitched together in two halves lol

[matchew]

well my dad has a 80/800 telescope and when i got mine he said the best time to look is when its not a full moon,he is always looking on the line,he sais he never gets bored because he always spots something different,i can now tell him this is commonly known as the terminator,

thanx boys it did help,was looking tonight as it goes and your right it does look stitched together,

thanx again matt

[ian h]

Just a bit of feedback from the advice you gave.

I bought a couple of new eye pieces and the improvement was quite dramatic. I have come to the conclusion that the ones supplied are not really worth having.

Just need a few more clear nights now. It just seems to be never ending cloud .

[brantuk]

Well Ian - I guess you just learned the first lesson we all discovered as starters - the supplied ep's allways leave something to be desired.

As a suggestion - see if you can find M42 (Orion Nebula) it's very obvious in the sky and can be seen naked eye. The lowest power ep will probably give you best views. Also the Pliedes (M45) is a nice open cluster and easy to target - and google Messier to understand the "M" numbers

Good Luck!

[ian h]

I viewed M42 two nights ago. Am I supposed to be able to see any red colouring like seen in pictures elsewhere ?

I don't think it was a good night to view as the moon was giving off so much light. Would this effect things ?

Cheers for the advice to google messier. Makes more sense now.

[sixela]

I viewed M42 two nights ago. Am I supposed to be able to see any red colouring like seen in pictures elsewhere ?

Not unless you have a 400mm telescope (if you have young eyes) or 500mm telescope (if you have older eyes) and observe from a very dark site with a very long focal length eyepiece. There, the inside of the nebula can appear subtly more salmon and less green than the rest. Otherwise, all you are going to see is green (at low power and from a dark site). But hey, green is colour! The fainter DSOs are all going to appear grey, because they won't trigger your retina's cones, only the night vision rods.

I don't think it was a good night to view as the moon was giving off so much light. Would this effect things ?

Yes. Big time.

[KenG]

You won't see any colours in nebulae as they (the colours) are too faint to register in a human eye. It's only in long exposure photographs that the colour becomes apparent.