New Joiner - SkyWatcher 130

[Littleguy80]

Hi. I was fortunate enough to get a telescope for Christmas. I've always been fascinated by space. The scope I have is a SkyWatcher 130/EQ2 mount with the normal SW 10mm and 25mm eyepieces, 2x Barlow  and a basic moon filter that came with scope. I've been really pleased it with the highlight so far being seeing Jupiter and 3 of it's moons. 

I've now reached the stage of looking at equipment upgrades. I'm trying to cover my bases for planets and DSO's whilst not spending a fortune. The wishlist I've compiled is below. I've put it priority order

Meade ND96 Filter 13% 

BST Explorer 8mm 

Revelation 2.5x Barlow 

Vixen NPL 30mm

SkyWatcher Light Pollution Filter 

SkyWatcher UHC Filter

SkyWatcher OIII Filter 

Baader T-thread to 1.25" Helical Focuser 

Any thoughts/suggestions on my selections     . The forums here have been a massive help with trying to piece together what to buy

[Daz69]

I'm a newbie too, and I swapped out the supplied EP's for some Celestron plossl's of similar size to what you say above (9mm and 32mm in my case), for my 130, and the difference was great. Personally I'd get the new EP's and just the UHC filter for now. Save your money for Turn left at Orion (book) and an illuminated finder, like a RACI or a little cheaper say a Telrad or Rigel. They are what has helped me the most so far.  

[ronin]

Meade ND96 Filter 13%

I have never yet bothered with a moon filter, more a case of personal preference, would 13% not be a bit too much blockage? Would have thought around 30% more useful but as I don't have one what do I know.

BST Explorer 8mm 

Good general use eyepiece

Revelation 2.5x Barlow 

2.5x seems too much, too much for the 10mm and the 8mm. On the 25mm that makes the combination a 10mm, which you have, and on the possible 30mm then 12.5mm. May be useful if you go imaging planets - is this the idea ?

Vixen NPL 30mm

Nice wide field. Will point out that a 25mm BST Starguider gives the same field.

SkyWatcher Light Pollution Filter 

Depends on the light pollution, if white then one may be of limited use.

SkyWatcher UHC Filter

Unsure of this one - looking at the Skywatcher site it appears to be in effect an OIII filter. THe transmission curve indicates it passes at the OIII wavelengths and not at the Ha. So you could end up with efffectively 2 OIII filters.

The Skywatcher site says:

The narrowband UHC filter, like the O-III filter, allows only the two doubly ionized oxygen lines (496 and 501nm) and the hydrogen-beta line (486nm) emissions through while blocking everything else,

SkyWatcher OIII Filter 

In terms of transmission I suspect this operates close to identical as the SW UHC.

Baader T-thread to 1.25" Helical Focuser 

No idea, what is it ?

[Littleguy80]

Thanks Daz. Hadn't considered an upgraded finder. The red dot finder that came with the scopes works well for planets though I had been wondering how best to approach finding DSO's with it. Something else to research

[Littleguy80]

Thanks Ronin. I'd been concerned about the 2.5x Barlow being too much. Perhaps something like the Orion Shorty 2x would be a better option? 

My very simple thinking has been the 8mm BST for planetary and the 30mm NPL for DSO's. I was thinking of then moving onto Baadar Classic Ortho 6mm for planetary and a 12 or 18mm BST for DSO's. 

Interesting comments on the UHC vs the OIII filters. As I understood it, they're each better for different Nebula? 

[billyharris72]

My take (for what it is worth):

• I'd tend to demote the ND and light pollution filters on this list - the former is nice to have but not essential while I find the latter of very limited use indeed (you may get more mileage if you have a lot of old style sodium lighting in your area). Even so, I'd put these behind eyepieces.
• If you do want a filter for lunar viewing etc consider an 80a (blue). Will kill glare and provide better view of the moon, Jupiter and Saturn than an ND (albeit in blue).
• Better eyepieces are a good investment. Plossls are good, as are the BSTs and Celestron X-Cel LXs. Note though that wider field eyepieces such as the BST are generally better for DSOs than planets. For planetary viewing specifically, I'd take budget Plossls (~£25) over the budget 60 degree eyepieces (£50-60) any day (based on performance, not price).
• For a Barlow, the ones that come with a scope are usually pretty cheap. Get a decent one and stick to 2x; I think 2.5x is maybe a bit high. Don't spend a fortune though - they are optically pretty simple and there is no benefit in getting a (more expensive) triplet Barlow over a doublet. More important is decent construction quality, coatings, internal blackening etc. I use a Celestron Omni Barlow and it's alright. Avoid the single lens ones, as these tend to introduce chromatic aberation.
• I'd bump the OIII filter down the list and stick with the UHC (joint OIII and H-beta) for now. I have this filter and get a lot of use out of it. It's a bit less aggressive than the OIII, which will tend to produce fairly dim images in a 130mm scope. I can't think of anything an OIII will do in that scope that a UHC won't do better.

Hope this is some help.

Billy.

[JOC]

My take also being a new astronomer who has been shopping myself

Meade ND96 Filter 13% - don't think I'd bother with this - I've got a variable polariser which may be more useful for a wider number of things (only guessing)

BST Explorer 8mm - I've bought similar myself - probably worth getting something around this size

Revelation 2.5x Barlow - I've recently tried a cheap x2 Barlow and been pleased with the result.  I'm guessing the x2 is as much as is useful

Vixen NPL 30mm - I like the look of the Vixen EP's, but I've got a Celestron Omni Plossl at 32mm which also seems fine as a cheaper option

SkyWatcher Light Pollution Filter - got one, haven't tried it yet

SkyWatcher UHC Filter - got one, haven't tried it yet

SkyWatcher OIII Filter - - got one, haven't tried it yet

Baader T-thread to 1.25" Helical Focuser - Do you mean something to attach a DSLR to your set-up?  I also wanted to this and bought a T-ring specific to my camera.

[Littleguy80]

Thanks Billy, that's all really helpful.

• My current moon filter gives a green tint which I'd prefer not to have which is why I was looking at the ND filter. The moon was enough to allow me to see some of the banding on Jupiter which is nice. Silly question but how blue would the 80a filter be?
• Interesting. I wonder whether to go right to the Baadar Classic Ortho 6mm for planetary then and get the 18mm BST for DSO's. 9mm Celestron Omni Plossl sounds like another good option in the cheaper Plossl range that you suggested
• Really good advice on Barlows. Looks like Revelation do a 2x Barlow. I was getting hung up on getting a triplet so glad you mentioned that!
• UHC it is

 

 

[Littleguy80]

Thanks JOC. I'd looked at polarisers but discounted them mostly because I thought it might be a bit fiddly to adjust but I do like the flexibility. I've seen a few people mention the 32mm Celestron Omni Plossl and it's a bit cheaper too. Not sure how much I gain from the NPL.

The helical focuser is an interesting one. It was mentioned on a post on here as a good option for my scope. It essentially allows you to more finally tune the focus. I planned to see how I got on with upgraded eye pieces before getting this

 

 

[JOC]

I thought the polarisers could be fiddly to adjust, but I've seen a three different options so far.  You can buy one in its own turret that then takes its own EP and lets you adjust it without touching the EP.  I've seen a YouTube video where the demonstrator splits his and sits the second half in his EP eye cup for easy manipulation (I think this looks a bit Heath Robinson, but clearly would work - in fact it does because I tried it :-D), I tried the third method last night - take apart the Barlow (the unscrew at all sorts of points), fit half the polarising filter into the Barlow, then put the other half on the EP and just twist the EP whilst it is in place <<< this last method seems to work quite well and is my current preference.  Just ideas :-D

[Littleguy80]

Sounds like some experimentation required. Thanks for the ideas

[ronin]

For the eyepieces I will give a list of the ones I use:

BST 5mm, 8mm, 12mm, 25mm and an Altair 6mm.

The 6mm is for when the 5mm is not useable. Also no 6mm in the BST line - otherwise I would have had that. With the above a barlow is going to be of little use, but I am one that prefers single eyepieces and not a barlow+eyepiece combination.

I do have other eyepieces, about 40 others - TV's, Antares, WO, TMB, Celestron but they are the ones's that seem to be in the bag. If I want a bit more weight to cart around then I simply take the full set of BST's and the 6mm.

Do you get along to the Norwich club ? Suppose if you are up at somewhere like Hellesdon then it could be a fair trip and with fairly dense traffic round Norwich and on the way out.

[ronin]

4 hours ago, Littleguy80 said:

Interesting comments on the UHC vs the OIII filters. As I understood it, they're each better for different Nebula? 

To my thinking an OIII filter is for that bit of the spectrum - 496 and 501 nm

A Ha filter is for the Hydrogen Alpha at 656 nm

From the assortment around there are some marked as UHC filters that transmits a window at 500nm and at 656 nm so that filter passes both OIII and Ha for visual. Problem is tracking down the filter curves. I see that the SW and I guess the Baader ones are

Bit strange but it looks like the Meade OIII filter actually passes both OIII and Ha, now that is odd. Why buy an OIII filter and in effect get it polluted by Ha ?

The Baader UHC-S filter appears to pass both.

Do not consider combining an OIII filter and a Ha filter as that give nothing. Each blocks the other.

[Littleguy80]

@ronin Not been to the Norwich club. There's a talk on at the end of the month which I'm hoping to go to. Sounds like the BST's are good all rounders. What sizes would you start with? I want a Barlow at the moment as it gives more options while I build up my eyepiece collection.

I think I was mixing up the UHC filter with Ha filter. UHC seems like the best choice for me as it will give more viewing options. 

[Dave Lloyd]

Hi there, welcome. Careful what you're after, this hobby can get expensive very quickly. I'd get a couple of BST starguiders or explorers though,  they're good value for money. 

 

 

[Littleguy80]

Cheers Dave. I'm trying to be smart about my choices to save remortgaging the house  BST's certainly seem to be a favourite. I read somewhere that 3-5 eye pieces should be enough to cover pretty much everything you'd want to see. After that it's just upgrading existing eyepieces 

[Alan64]

Hello,

Do get a variable-polariser of some sort, as they allow 2% up to 40% of the light of an object through to the eye...

http://www.rothervalleyoptics.co.uk/antares-variable-polarising-filter-125.html

That one is sold out here in the States...

http://agenaastro.com/antares-1-25-variable-transmission-polarizing-filter-2081.html

...therefore I expect it to be that good.  Such is helpful when viewing Jupiter and Venus, and when they appear as this...

When I dimmed Jupiter down one night with my polariser, I suddenly saw colour and details, festoons and whorls within an equatorial band, and instead of all-white as without the polariser. 

I have the Vixen NPL 30mm, and via the recommendation of one our members here...

It has an extendable/retractable eye-cup for comfort, and an enormous field-lens through which to view; most expansive and spacious for a 1.25" Plossl.

I don't know whether you have a 130mm f/5 or f/7(longer) Newtonian, but no matter.  You'll want to get the collimation spot-on, especially when ramping up the magnification...

https://www.firstlightoptics.com/other-collimation-tools/rigel-aline-collimation-cap.html

http://www.forumskylive.it/Public/data/serastrof/201281510358_Astro Babys Guide to Collimation.pdf

[Littleguy80]

Thanks Alan. I've added a polariser to the list! I certainly noticed the difference even with the basic moon filter I have.

My scope is a f/6 reflector. I'm glad you mentioned the collimation. It's something that I know I need to look into. I get the impression it's pretty straightforwards with the right tool.

What do you tend to use your Vixen for? I was looking at some star clusters last night with the basic SkyWatcher 25mm I have and thought the Vixen might have been a good choice for that? 

 

 

 

[Alan64]

You're welcome Guy.

Your Newtonian has a focal-length of 900mm.  The 30mm ocular will give you a power of...

900mm ÷ 30mm = 30x

That will be about the lowest power possible, and for your brightest and widest view of the night sky; the largest "window" into the night, for observing the larger objects, like the Pleiades and the galaxy in Andromeda during the fall and winter, and for scanning the rich star-fields of the Milky Way during the summer.  It will also aid your finderscope in finding smaller objects to observe, then to pop in an eyepiece of shorter focal-length, and higher power, and for a closer look.

I took the following snapshot of the Moon one night, with a smaller, faster 100mm f/4 Newtonian, and with the Vixen NPL 30mm...

It was warm, and the wind was blowing hard that night, this past January at that, and dark clouds galloped, raced, across the sky, and over the Moon, at times obscuring it...

I've used the eyepiece for that, at least, and the event was well worth the ocular's acquisition.

Your Newtonian, again, has a 900mm focal-length, so the magnification will be higher, and the view somewhat narrower.  I took that first photograph and created a mock-up of how the Moon should appear through the 30mm eyepiece with your telescope...

Now, the fun with your telescope will come when you begin to use the higher powers, and a 900mm focal-length is ideal for that.  Most objects in the sky are at their most beautiful and engaging when observed at the higher and highest powers.  Jupiter and Saturn will be quite the treat, along with many other objects.   Globular clusters, nebulae; great stuff, that is.

Your Newtonian may already be well collimated, but you'll want to verify that, with the collimation-cap as suggested, and to avoid disappointment when ramping up the power.  At the low-to-moderate powers, the collimation is not as critical.

With the cap inserted where the eyepiece normally goes, you aim the telescope at a bright, blank, illuminated surface, a wall or other, and position a small camera, or a phone-camera, over the pinhole of the cap, then zoom in to where the secondary scene fills the view, and snap a shot.  This a view of the scene of my 150mm f/5 Newtonian...

Here it is again, and with its parts described...

Circled in green, the main, primary mirror, located at the bottom of the tube

Circled in yellow, the secondary mirror, its silhouette or shadow

Circled in red, the reflective underside of the collimation-cap, with the center-spot of the primary mirror(or "doughnut") there in the center, and the pinhole of the cap in the center of that.  I can tell from that image that the telescope is well collimated.  

The camera was on the other side of the pinhole, snapping the shot at the time.  I suggest using a camera to inspect the scene, as the eye may have difficulty seeing the scene as clearly, especially at that focal-ratio(f/7).

Now, your scene will appear similar to that if it's well collimated, but here's a mock-up of the scene of a 114mm f/8, which may be even more similar as to what you should see...

Note the much smaller secondary-mirror shadow of the f/8, and compared to that of my f/5.

One major advantage with a 130mm f/7 Newtonian is that the secondary mirror is smaller, than that of a faster 130mm f/5 for example, and therefore a smaller obstruction, which should result in somewhat sharper and more contrasty images.

[Littleguy80]

Thank you so much for taking the time to write that post, Alan, including all the mock ups! A gold mine of great information and tips! I'll be ordering the collocation-cap as suggested. The Vixen NPL looks like a great buy too. Do you have a favourite eyepiece for planetary observations? I've more or less decided on a 6mm Baadar Classic Ortho as it seems to be very well regarded for planetary viewing despite the short eye relief. I'm also keen one or two of the BST Explorers. Probably an 18mm for something midrange that I can use a Barlow on. 

[Alan64]

You're most welcome Guy.

I have more planetary eyepieces than I know what to do with, actually.  At the time that I got the 30mm, I also got this Vixen NPL 6mm Plossl...

If you can tolerate the short eye-relief, the view through that one is like...   

I've compared it once with my Baader "Genuine" 6mm orthoscopic, on Polaris, and I couldn't tell the difference, but I've yet to compare the two on other objects.  Here's the BGO and Vixen side by side...

I even made a virtual sketch of the event...

The comparison was made with a Celestron C90, a 90mm Maksutov-Cassegrain; a rather dim and very slow telescope.

Incidentally, you can motorise your mount, and for automatic hands-free tracking of any object...

http://www.rothervalleyoptics.co.uk/skywatcher-ra-economy-drive-for-eq2.html

I had an EQ-2 mount once, and I wish I still had it.  I gave it and the 80mm f/11 refractor to a relative, and they don't use it.

But when I had it, I had a motor similar to that one attached, and observed Venus one morning while it was still dark, and all the way up until noon, and with the Sun shining brightly in the sky.  At that point, there in the sunlit sky, Venus appeared a pale sphere sprinkled with fine sand.  I have a larger EQ-3, and motorised, but I haven't used it yet.  

You'd have great fun with the EQ-2 motorised.  There's another motor-drive kit available, with a hand controller, too...

http://www.rothervalleyoptics.co.uk/skywatcher-ra-motor-drive-for-eq2-with-multi-speed-handset.html

With that one, you can substitute an AC adaptor in place of the battery pack, if you observe from home, but always use a surge-protected outlet between the AC power and the motor-drive.  There are also other more modern battery-packs that can be used as well; lithium-ion, for example.  

 

[Littleguy80]

Thanks again, Alan. There's so much choice when it comes to eyepieces, especially for planetary viewing. Whatever I get will be a significant improvement on what I have.

I've seen that you can get a motor for my mount. I can definitely see the benefits just from viewing Jupiter and seeing how quickly it moves at high magnifications. Definitely something I have on my list. I'll have to learn about polar alignment then

[Littleguy80]

Going to place my first order in the next week. After much deliberation, I'm looking to order:

Celestron X-Cel LX 7mm - It's currently £58 from FLO. Only works out £10 more than the 8mm BST Explorer. The Celestron seems to get the better reviews of the two.

BST Variable Polarising Filter 1.25-inch with Eyepiece Holder - £25 from Alan @ Sky's the limit. The eyepiece holder seems to give a nice simple solution to easily adjusting the amount of light being sent through. Similar idea to @JOC's suggestion with the Barlow.

I'm hoping this will give me a good planetary setup. Then I'll look to order something more DSO orientated

[kilix]

I only want to add some info to the Baader helical focuser - if you mean this type here

It's a great addition to a telescope, fine tuning the focus is really easy and makes a great addition, especially for the price (like 35€ here) and if you only have single speed focuser right now.

BUT

• you need to make sure, that you now have a male T2 thread on your current focuser - that is M42x0.75 thread (I don't think you have this on your current focuser, I don't know, I don't own SW130/900)
• for astrophotography it's absolutely useless, as it is a rotating type of helical focuser. IMHO you are better off with a 2-speed crayford focuser in that case and don't bother wasting money on this one, go directly for a 2-speed crayford.
• it also adds some length to your focuser, which may be a problem, if your focuser is -with some eyepieces- near the end of its inward travel.

[swamp thing]

On 3/15/2017 at 15:15, ronin said:

To my thinking an OIII filter is for that bit of the spectrum - 496 and 501 nm

A Ha filter is for the Hydrogen Alpha at 656 nm

From the assortment around there are some marked as UHC filters that transmits a window at 500nm and at 656 nm so that filter passes both OIII and Ha for visual. Problem is tracking down the filter curves. I see that the SW and I guess the Baader ones are

Bit strange but it looks like the Meade OIII filter actually passes both OIII and Ha, now that is odd. Why buy an OIII filter and in effect get it polluted by Ha ?

The Baader UHC-S filter appears to pass both.

Do not consider combining an OIII filter and a Ha filter as that give nothing. Each blocks the other.

You are not going to see H-alpha light in a nebula visually. It's far too dim in the available light from an emission nebula. So Ignore the H-aplha pass of any nebula filter for visual use. The difference between a UHC and an O-III filter is the UHC passes O-III & H-Beta lines (both of which we can see). The O-III filter obviously passes just the O-III lines.