Eyepieces for Improving Deep sky observation

[imc]

Hi All,

I am relatively new to astronomy and was hoping I might be able to get some advice on eye pieces to help improve my viewing experience.

I've looked through a number of informative posts regarding this but am still not 100% sure of my next step.

I have a sky watcher 150mm (750mm tube) with 10mm, 20mm and 2 x barlow (That all came with the scope).

I'm looking to purchase a new eyepiece on a budget (£30 - £60) and have an idea a plossl would be a good choice but I'm not sure what size to go for.

I've looked through a number of scopes and am sure I can get a better view when Observing for example the ring nebula.

With 10mm it was smaller than anticipated and with the barlow on top of that (I think the atmoshere seemed to be causing a lot of problems) I was seeing nothing.

Should my next eyepiece be something like a 4mm, a 7mm or a 14mm with a barlow?

Also, would a wider angle eyepiece improve viewing in this circumstance or is this more down to personal choice?

From experience does the barlow seem to degrade viewing quality by much?

Any advice on a good setup and future purchase options would be much appreciated. If you've had experience with this particular scope all the better.

Many Thanks

[russ]

Certainly a secondhand Televue 15mm Plossl would be a good workhorse for your scope. Giving 50x and a 1deg true field. You can barlow that too 100x for the smaller deepsky objects such as the Ring Nebula. Or for stunning views of the moon.

The Televue is a stunning quality eyepiece. Costs £75 new or £40-50 secondhand.

http://www.telescopehouse.com/acatalog/TeleVue_Plossls.html

Alternatively you could go for one of the BST Explorer 15mm eyepiece. Will still work very well in the F5 150 Explorer. Gives a larger true field for the same power compared to the Televue. And can be bought for £40.

http://www.skysthelimit.org.uk/telescope%20eyepieces.html

The 15mm sits nicely between your current 10mm and 25mm. And there is no overlap when using the 2x barlow.

Or you could try a 12mm. Gives a slightly higher power (62.5x) but with a widefield eyepiece you still get a 1deg true field. And will barlow as a nice medium power for smaller deepsky or planets.

There is a BST Explorer 12mm. Or you could look into the new Celestron X-Cel LX 12mm for £69:

http://www.firstlightoptics.com/celestron-eyepieces/celestron-x-cel-lx-eyepiece.html

[russ]

Just noticed there is a Televue Plossl 15mm for sale at the right price:

U.K. Astronomy Buy & Sell

[imc]

Thanks for the advice Russ.

I see the advantage of getting the larger size, but would you always use a larger piece with a barlow or would a smaller size (say 7mm) without barlow give a better image.

Much appreciated.

Ian

[EasyFlier]

Before getting my more expensive EP's, I've always enjoyed my Swan 15mm 72° (even on the Barlow as well). Sharp images on both planetary and deep sky without breaking the piggybank ;-)

[russ]

If we were talking about Planetary observing then there maybe a very small argument for not using a good barlow.But a good barlow will disappear into the system and not have any detrimental effect on the image quality.

Plus there are Pros to using a barlow, especially when considering a Plossl eyepiece. A 7mm Plossl will have poor eyerelief and not be that nice to use. While a barlowed 15mm Plossl retains the superior eyerelief of that eyepiece. And for Deepsky observing you will not see any difference in optical quality.

I would stick to the medium power and barlow it. Perhaps factor in a better barlow as well, such as the Tal 2x for £35. You could have the BST Explorer 12mm and the Tal 2x for £75.

[imc]

Great advice and much appreciated.

I now have a path forward in my observing.

Thanks for taking the time out to give some value advice.

[russ]

It's a pleasure to help.

I think you maybe mildly surprised what the 12mm by itself will show. It will give 62x and a true field of almost 1deg, making it a nice DSO eyepiece for your scope. And the BST Explorer is a great eyepiece, nothing better under £50.

Personally i would just buy the 12mm BST and try it out solo and with your current barlow. Keep an eye for a secondhand Tal 2x, they only go for £20 secondhand. That would keep things on budget (£60).

[acey]

I've looked through a number of scopes and am sure I can get a better view when Observing for example the ring nebula.

With 10mm it was smaller than anticipated and with the barlow on top of that (I think the atmoshere seemed to be causing a lot of problems) I was seeing nothing.

The Ring Nebula is a small object and will always look small. If you increase the magnification on any DSO then by making it larger you also make its surface brightness lower. As you found, if you make the image too large then it disappears altogether.

There can be advantages to using high power on DSOs, especially at a dark site, but with even moderate light pollution it tends to be the case that low rather than high powers works best on DSOs.

The Ring has an unusually high surface brightness (so do some other planetaries, e.g. Eskimo), hence suffers less than e.g. galaxies when magnified - but you found that it disappeared with 5mm focal length (i.e. the 10mm plus barlow), and it will likely do the same with any other 5mm eyepiece. It wasn't atmosphere that was the problem, it was a basic law of optics. To see a bigger image satisfactorily what you would really need is bigger aperture (since the lowest power of a bigger scope is higher than the lowest power of a small one).

Given your budget you could consider a TeleVue 8mm plossl, but that would really be for planets rather than DSOs. You'd get a lot more use from the 15mm.

[milkyjoe]

Read this also... http://stargazerslounge.com/beginners-help-advice/80772-eyepieces-very-least-you-need.html

[legoalan]

Hi, I was wondering if a pair of Vixen NPL 10mm and 25mm eyepieces for an upgrade would be good for a new scope?

[g0ibi]

I have the same scope as you and my best buy so far was a better quality 2xBarlow (from Skys the limit web site) also use a 40mm EP for general viewing.

[stick]

i cant knock the BST Explorer ed eps i have

good veiw, good rye relief and a good price

check out skys the limit website

hope this helps

[sulaco]

Hi, I upgraded from my SW standard EP to the Vixen Npl and found them to be excellent for the money, I would say that the 15mm is my favourite and was using it this morning combined with a Revelation 2.5X barlow on Jupiter, giving crystal viewing.

The 10mm is also very good but I'm toying with buying a 6mm Baader orthoscopic and selling the 10mm for the 12.5mm BO even though it's a good Ep I would like the range with the 12.5mm.

Hi, I was wondering if a pair of Vixen NPL 10mm and 25mm eyepieces for an upgrade would be good for a new scope?

[imc]

Russ and Others, many thanks for all your help. It's great to have such a friendly and experienced community out there to offer advice.

I think the choice is between the Televue 15mm Plossl and the Celestron X-Cel LX 12mm.

The Televue would fill a gap in my current range and sounds like a quality eyepiece, but the the Celestron might give me better enhanced views than my current 10mm.

Any opinions on what might be the more useful piece of kit for general deep sky viewing.

Will definitley look at upgrading my existing out of the box barlow to a talx2 in the near future.

Thanks once again.

[rwilkey]

General deep sky viewing I use either the Celestron Plossl 32mm or my Panaview 32mm, both highly recommended

[legoalan]

Hi, I upgraded from my SW standard EP to the Vixen Npl and found them to be excellent for the money, I would say that the 15mm is my favourite and was using it this morning combined with a Revelation 2.5X barlow on Jupiter, giving crystal viewing.

The 10mm is also very good but I'm toying with buying a 6mm Baader orthoscopic and selling the 10mm for the 12.5mm BO even though it's a good Ep I would like the range with the 12.5mm.

Thanks for the advice, but I'm not sure whether to get a 30mm or a 20mm eyepiece for finding DSOs first. Any suggestions? Thanks

[russ]

30mm approx eyepieces are great for finding most objects. I use a 2" eyepiece in this range for a finder eyepiece and for looking at large extended objects such as M31, the Veil, M45 etc.

But some objects are tiny (small planetary nebula such as M76) and they will simply be undetectable in the 30mm eyepiece. Which is why its good to have a workhorse eyepiece for DSO's, one that gives a medium power.