lenses and filters for my 8se

[JasonBoyd]

Hi Everyone,
I just purchased my first scope! (celestron nexstar 8se) i love it
but i only have one lens the 25mm that came with it.
i don't no much, scratch that, ANYTHING about lens/filters and was thinking of buying the celestron lens and filter kit, i was just wondering if you guys thought that it would be a smart investment for a beginner like myself to purchase one of these kits.
Also could someone briefly explain to me what the sizing of the lenses mean? like is a 6mm smaller magnification than a 25mm?

Im new to this forum and astronomy all together, so any help would be greatly appreciated!

Thanks Everyone!:)

Yours Truly

Jason

[scagman]

Hi Jason,
:welcome: and congrates on the new scope.
The magnification goes up as the number on the EP goes does. The 25mm you have will give u about 81x mag. a 6mm will give you 336x. (prob to much as it depends on the "seeing" from what I understand anything more than about 200-250x and u will be pushing the bounds of the scope. I cant comment on the EP kit as I am very new to this as well and only have a couple of EP's that I purchased with my scope. Plenty of others will give u better advice re EP's than I could.

Have fun with the new toy.

[scagman]

I forgot to mention how I got the magnifcations I got. Focal lenght of telescope(2034 i think you have) /Focal lenght of EP. 2034/25 = 81.36 2034/6=336.

I hope these calcs are correct and hope they help.

[barx1963]

I'm not a big fan of these kits, you tend to get lots of EPs that are short focal length and you would be better off buying one or two good quality ones in lengths you actually are going to use.
As an example, when I bought my 12" i got 5 EPs with it, 32mm, 25mm, 15mm, 9mm and 6mm. Only ever used the 32 and 25 and once I had the 13mm Nag and 24 Pan, never used the kits ones again.
True good quality EPs will cost more, but they are a lifetime investment.
As you are just getting started, I would suggest getting a good shorter FL ep. say a 15mm Plossl. That will give you 2 magnifications 81x and 135x ahich will be enough to go on with. You really need perfect conditions to push an 8" scope much beyound 150x. That will cost you a lot less than the kit. Once you have a bit of experience under your belt, you will be able to make a choice on quality EPs down the track.
If you really want to get into planetary observing, a set of coloured filters is not a bad idea, but not necessary unless that is your prime interest. Bintel are doing coloured filters for $19 each, so you could get four of those, plus a 96 ND Filter and a 15mm Televue Plossl ($95) for under $200 and IMHO better value than nearly $300 for the kit.

Malcolm

[JasonBoyd]

Thanks so much john!
Thats great news i will definitely be going ahead with this lens/filter kit by celestron then, it seems a great buy it comes with a 2x barlow lens and a 6,8,13,17 and 32mm plossl plus 6 planetary filters and a moon filter

thanks again!

[Poita]

I'd consider a zoom eyepiece instead of the kit. The kit is overpriced and has a lot of very average eyepieces you will rarely use.
For less money you can get a single good quality zoom eyepiece, and when you get to know the sizes you use most, then you can shell out for some good quality individual eyepieces.

You simply twist the eyepiece to zoom in, from 8mm - 24mm or a similar range. It is great not to have to keep changing eyepieces as well.

They range from about $95 to over $400.
e.g.
http://www.myastroshop.com.au/products/details.asp?id=MAS-004S
I have the Vixen and am very happy with it:
http://www.myastroshop.com.au/products/details.asp?id=MAS-014J

They also hold their value much better than the celestron eyepiece kit will, so if you outgrow it, you can sell the zoom eyepiece without losing much money on it.

[Suzy]

Hi Jason,

I hope this link here (http://www.eaas.co.uk/cms/index.php?option=com_content&view=article&id=4:a-short-guide-to-choosing-eyepieces-by-neil-paterson&catid=5:learning-zone&Itemid=8) helps you to understand eye pieces a bit better- it explains just about everything you need to know.

I agree with everything Malcom said.
The only thing that I'd like to throw in on top of what Malcom said is a 10mm wide view eyepiece. This will work very well on your 8" scope for many objects such as some planetary nebulas, galaxies, globular clusters and the planets. The reason I recommend a wide view for a 10mm is that at high magnification a wider field of view will show the entire object, where as the 50 deg plossls won't show the entire object if they're large- the Omega Centauri globular cluster is a good example. In the above link I've supplied, you will see some good examples of how high magnification can affect what you see thru different fields of view.
For dobsonian telescope owners, I also recommend the wideview eyepieces as they allow a longer drift time across the ep without having to nudge the scope so often.

I know it can all be so confusing at the start. Take it slow, and take Malcom's advice to build up your better quality eyepieces over time as you get to understand them better. That's exactly what I did myself. If you wear glasses while you're observing, you will need to look for eyepieces with a 20mm eye relief.

On my 10" dob, my most used eyepieces are a 10mm (high power), 15mm (medium power) and a 22mm (med/low power). My most used being the 15mm. The next most is the 22mm, and the next being the 10mm. Good quality eyepieces will help to pop in some of those really faint fuzzies into view as they have better contrast, therefore a bit more detail is available. They are truly a worthwhile investment.

Some info on filters here (http://www.lumicon.com/astronomy-accessories.php?cid=1&cn=Filters).
Personally I've found coloured filters a big waste of money, with the exception of the blue filter used at odd times on planets. In my opinion, to start up, my first filter of choice to recommend would be a UHC filter. It will enhance the views of many nebulas incl. planetary nebulas.

Here's some links to help you along with this hobby a bit more...

Sky & Telescope "How to start right in astronomy". (http://www.wwnorton.com/college/astronomy/astro21/sandt/startright.html)

Observing tips. (http://www.astro-tom.com/messier/messier_files/observing_tips.htm)

Top ten essential astronomy accessories.
(http://www.visualastronomy.com/2008/01/ten-essential-astronomy-accessories.html)
Timothy Ferris' how to videos
(http://www.pbs.org/seeinginthedark/explore-the-sky/how-to-videos.html)
Practical Astronomy written by fellow forum member, Baz. (http://www.asignobservatory.com/index.php?option=com_content&view=article&id=88&Itemid=65)

The 26 Brightest Stars (http://www.astro.wisc.edu/%7Edolan/constellations/extra/brightest.html). Learning these will help you to navigate the sky.

Maps made by fellow forum member Rob K. (http://sites.google.com/site/southernastronomer/)
(You can't go passed these brilliant maps- many of us use them. Print them off and pop them into plastic sleeves in a ring binder. Aside from being very easy to use, I love that these maps list under them a whole bunch of details on objects of interest.

And also, if you haven't already, download the free software called "Stellarium". It will help you immensely in navigating your way around the night sky.

Happy reading, it should keep you busy for a while. ;)
Enjoy! Astronomy is so much fun and so rewarding. :D

[Poita]

That is a great link Suzy, I also like this .gif from the Explore Scientific site
http://www.explorescientific.com/images/eyepieces_afov.gif
http://www.explorescientific.com/eyepieces/82_degree_series.html

After looking through an 82 degree eyepiece, I'd never want to look through a 50 degree plossl again, except maybe for planets.
I can't imagine a 100 degree AFOV, I think I'd be worried about falling in...

[Suzy]

Peter, that is a great animation! :D
Consider it nicked and bookmarked for future reference to send to others.:P:lol:

I would like to try those 85 deg Explore Scientifics one day, I hear good things about them. I too agree with what you about the 100 deg- I'm not quite there yet- 85deg is more than I can handle at the moment, with the 70deg being my preferred fov. I find that the fov is large enough that I don't have to work my eyeballs too much as it's just the right size to take it all in.

EDIT: Whoa! And I've just noticed they are back on sale- back down to $99 from $179!
Grrrrrrr i've just used up my allowance of astro purchases at Xmas. Hope that sale will stay for a while. I'd be interested in trying the 4.7mm.

[JasonBoyd]

Thanks Guys for all the help and advice, very much appreciated,
i will definitely give the celestron kit a miss, i gave the guys at bintel a call and they said they could put together a kit for me that came with a barlow, 12mm, 15mm, 20mm also 5 of the most common filters for $180
do you think i should go ahead with this?

Thanks again guys!

and suzy i can't thank you enough for all your info and links!

[Poita]

I didn't notice the sale either, dammit I am broke too.

Jason, you would be way, way better off picking up three of these eyepieces than the kit, and it would come to about the same money at these prices.

If you didn't like them, they would most likely sell at about the same price as you bought them!

An 11mm (184X magnification) or 14mm (145X magnification) would be a great adjunct to your existing 25mm (81X Magnification).

On a night of magnificent seeing, a 6.7mm will give great views of Saturn and Jupiter at 303X magnification, but those nights are rare where I live. 11mm tends to be the limit I find with the C8 on most nights, but I do use the 6mm occasionally and on those nights the view is spectacular.

[dj gravelrash]

I nominate Suzy to be inducted into IIS Hall of Fame. Leggggggggggend !!! lol. What quality info.:)

[astroron]

I second that.:D
Cheers :thumbsup:

[JasonBoyd]

Thanks peter, sounds like the way to go, what brands do you think i should look into?
also what do you guys think would be the best filters for looking at jupiter i really want to see the belts clearer and more defined but with out changing the natural colours of the the planet.
would you say the uhc filter suzy mentioned?

-Jason

[Poita]

I'd be more inclined to spend $120 and just grab an 11mm or 14mm ES eyepiece and then make a decision on more eyepieces at a later date. You will end up replacing those cheap eyepieces, and it will cost you more in the long run.
I don't think you will end up using the both 20 and the 25, so you could forget the 20, and I'd rather get a 14mm and a 6.7 or similar than have a 12mm and a 15mm.

I'd be going for bigger steps between mags, say your existing 25mm, plus a 14 or 11mm and then a 7mm or 6mm for the planets on those great nights of seeing.

A good eyepiece you will keep forever, and if you don't for some reason, you can resell it for close to what you paid for it.
Cheap eyepieces will go by the wayside, you will get less enjoyment and their resale value is mostly non-existent, it costs less even in the medium term to buy some reasonable quality eyepieces, and get the great views from day one!

[Poita]

To make Jupiter clearer, a better quality eyepiece, with greater contrast will help.
Honestly though, getting the scope really well collimated will help more, the difference between an OK collimation on a C8 and a really good collimation makes a huge difference on Jupiter. You are in Sydney, so it should be easy to find someone who can help. The money might be better spent on some Bobs Knobs to help with collimation than on a filter.

Many of the filters for viewing jupiter change the colour to bring out the contrast, but a good eyepiece and better collimation will most likely improve your views greatly. The view through a 14mm ES will blow the current view via the 25mm eyepiece you have away.
A cheap TMB planetary eyepiece (about $50?) at high magnification could be an option as well.

[JasonBoyd]

Thanks peter,
your advice is really clearing things up for me.
hmm, i've never heard of these bobs knobs before, what do they do exactly?

-Jason

[astroron]

Hi Jason,:hi:
As Celestron Ultima 8 20cm SCT for over twenty years:) I would suggest you forget about the kit and all those eyepiece combinations and filters .
Just follow Suzy's advice and you can't go wrong .
A 7mm eyepiece is the Maximum magnification I would go to in your scope, any more and you would need a perfect night to get any benefit out of the eyepiece.
I would choose a 30mm eye piece for finding things,and also doubles as a wide field for looking at nebulae and large clusters.
An eyepiece of around 14 to 17mm for medium magnification and maybe a 9-10 mm for fairly high mag.
Don't bother much about the colour filters for the moment as they will probably just finish up being a not very much used part of your kit.
Get some experience before parting with your money on them.
A UHC filter will be a prized possession and I can assure you you will get plenty of use out of it.
An O111 filter is the best for most planetary Nebula, but take a little bit of getting used too as they tend to block out the stars .
Keep your spending down to a reasonable level till you gain some experience.
There is a lot of good advice being offered here,so take your time and evaluate it before spending your hard earned dollars.
Cheers :thumbsup:

[Suzy]

Jason,

I'm with Peter- go for the 82deg Explore Scientific's- even tho I haven't tried them, I've heard many good things and lots of people on this forum have them. From what people are saying, I understand they are quality eyepieces. Only $99 on sale at the moment!!!
I've also tried the 7mm TMB- quite good also on planets.
If you have a quality ep, you will get better colours and contrast on those planets anyway without really needing to have to filter. Stay off white toned eps for planets (washes them out as my Meade UWA 5000 does) and head towards neutral and coffee toned for planetary viewing. I don't honestly know what tone the E.S. ones are, I just know the Pentax (which I own) are neutral & just beautiful on planets, and the Naglers have a slight coffee/warm tone which apparently is good too on planets I've read. When I tried the TMB 7mm, I was very happy with the tone- seemed neutral to me, brought up colours on Jupiter quite nicely, albeit out of focus as I had some issues with it and had to send it back (seems my scope just didn't like that ep, no one else seems to have had any problems).

The last time I've needed to use a filter on a planet was the last time Mars was in our skies (18mths ago? seems ages ago) and I popped in the blue filter to see the snow cap - was quite awesome!

The UHC filter is not for planetary- as mentioned in my post, they are for nebulas.

[JasonBoyd]

Thanks Ron!

Suzy, Thank you for your advice, do you think with my 8 inch the uhc filter would be a waste of time, as the only nebula i've found so far is orion would you say there's many others that are viewable through an 8inch telescope?
if so where should i purchase a uhc filter? any good brands ?

Thanks

-Jason

[astroron]

Jason A UHC is a great addition to your observing arsenal.
It enhances Most bright and Dark nebulae,also can be very good for some planetary nebula.

[Suzy]

Agreed & good advice! :thumbsup:
As also everything else Peter said in his posts here so far.
If you get a 2 x barlow, and keep those focal lengths in bigger steps, they will all barlow down nicely: 25mm to 12.5mm, 14mm down to 7mm (I use 7mm and the 10mm a lot for planets on my 10" dob), and then your 10mm down to 5mm (when the conditions are good). You won't go wrong. :D

The 12mm you were after initially, I think is too close to the 15mm. You really want something around 9mm-10mm to bring out those planets in my opinion. And! blow your mind when you throw a 10mm (WideView!!) on globular clusters ... wow!:eyepop:

My start up kit suggestion for you...
Eyepieces: 9/10mm, 14/15, 22/25mm
2 x Barlow
Filters: UHC for nebulas - good all rounder filter and will do most nebulas.
Blue filter for planets.
Bintel cleaner- a special solution they make up to clean your eyepieces
streak free. Buy it from Bintel.
Red light torch- a necessity to preserve your eyes dark adaptation.
A comfy chair
Rob's maps (as mentioned in previous post) or any other maps for that matter really (but his are good!)
Download Stellarium software (it's free)

And.. binoculars if you've already got them will come in very handy to help find things.



Re Filters....

Have a look here (http://starizona.com/acb/basics/equip_filters_lunar.aspx) what the difference a blue and red filter does to Mars. See how the blue filter brings out the ice caps? Mars is in our sky at the moment. :D

Have a look at this link here (http://alpo-astronomy.org/mars/articles/FILTERS1.HTM) for more info- I have posted some of it's contents below. If you read on, you will notice the blue filter is used the most.
My 2cents worth.. for now just get the blue and put the rest of the money that you would otherwise use on the rest of the filters into some good quality eyepieces that will show you good colours and contrast anyway. :question:

[Poita]

I can lend you an OIII and a UHC filter, so you can try them out before spending money on them.
Some people swear by them, others don't get much use out of them, it all depends on your viewing habits and where you are etc.

No need to dive in and get everything at once, grab one or two eyepieces, get to know the sky and your scope, get it collimated and enjoy the views.

I agree that a 6.7mm or 7mm would be as high powered as it makes sense to go, I've been using a C8 since the late 80s and have never had an opportunity to use anything more high powered than a 6.

Bobs knobs are just some bolts that replace the collimation hex bolts in the front of the celestron, they make collimation easier as you are not messing with an Hex key and can use your fingers instead.
Bintel sell them, you can view the instructions here:
http://www.bobsknobs.com/page3/assets/Instructions_English.pdf

[JasonBoyd]

Thank you! suzy once again great advice!
and peter i think i might take you up on that offer of borrowing your uhc filter!

Thanks every one! truly such a warm welcome to this forum!

yours truly

-Jason

[Suzy]

Have gone a very dark shade of beetroot after reading that. :lol:
Thanks Deno (& Ron!).
Just glad to be able to help and glad you're enjoying the informative links I've supplied. :2thumbs: It's rewarding and so worthwhile for me, when people enjoy and learn from what I post, as some of them do take up a bit of my time. :rolleyes::lol:

[Poita]

No problem, A Vixen 8-24mm Zoom eyepiece, 1.25" OIII filter and Meade 4000 series UHC 1.25" filter is in the post to you now.
Have a play and see what you can see.

I know there are a couple of IISers in your neighbourhood, you may want to make your suburb known and someone might be able to help you collimate your scope as well to eek the best out of it.

Good star hunting!

-Pete

[Suzy]

What a great guy! :2thumbs::jump:

[Poita]

Did you get a chance to try them out yet?

[JasonBoyd]

Hi Peter,
i did! about 4 nights ago we had perfect conditions, sadly there has been so much cloud cover throughout the last two weeks to really view anything at all, however like I said a few nights ago the sky was crystal clear and I used every minute of it.
The zoom is fantastic and super easy to use, i will definitely be purchasing one for myself! If you don't mind me asking where did you get yours from?

When it came to the filters I went straight to the orion nebula to have a look but strangely i found it easier to see without the filters,
i have to say i wasn't 100% sure what the filters were going to do, and still overly don't. All they seem to do is make whatever you look at green. I'm sure thats to help the mist contrast against the black, but i still could see a lot more of the nebula without any filters at all.
does anybody know of any other nebulae out at the moment that are viewable with an 8inch scope?

Thanks

- Jason
P.S Peter i will be sending your gear back as soon as i get one more look!
Thanks again for your generosity!

[barx1963]

The Orion neb (M42) is not a good test for filters as it is quite bright. Their main thing is increasing contrast so you can get the really faint ones.
Might have a try for the Flame nebula (NGC 2024) near Alnitak, but you will want pretty dark skies if only using 8"

[Poita]

No hurry on the return, get some use out of the
! I don't find the filters much use either, perhaps they work better in more light pollutes skies. I bought the zoom eyepieces 2nd hand, so can't help you there, but shop around, they vary a lot in price.

[JasonBoyd]

Hi guys,
I shall be buying my EP's very soon but I have one Last inquiry.
1.25 inch or 2 inch ? I still don't overly understand the difference does 2inch mean more light gathering or just a wider FOV?

Thanks guys!

-Jason

P.S Peter if you could PM me the address you would like me to post your gear back to that would be great, thanks again!

[Poita]

No point in 2" eyepieces with your 8SE, but have a read here for technical details
http://astrosurf.com/luxorion/reports-epsuggestions.htm
and here for a previous discussion
http://www.iceinspace.com.au/forum/showthread.php?t=77748