Eyepiece selection query for beginner telescopes

[Markstar]

Hi, yes - I've read that barlows/powermates are not great with EP's of under 10mm. I would only use one with lower mag's...saying that, the powermate is about £150 - which I could spend on 3 more BST Explorers if I get on well with the first one...can't believe I didn't think of that earlier!!!

Thanks for the reminder...

[Charic]

Markstar......... Ive just come in from testing Celestron 127. The 3xBarlow no good tonight  ( trying to view the Moon through the gaps in the fast moving clouds?) The 4mm  is no good. The 20mm correcting  lens ok, the 8mmBST much brighter and completely fills the viewfinder with the Moon. The telescope is the letdown here. If you need to buy a BST, either an 8mm or 12mm would be fine, but insert one of those into a 200P and you`ll smile. Nothing you buy to be honest will really improve the 127. The lenses  are brighter because of the build quality. And  the price of a barlow exceeds the BST lenses, and theres only 5 to get (not all at once) so maybe not need a Barlow ( unless you want a 2.5/4/6/5.5/9mm lenses) An 8mm will be ok for now, but better in the Skyliner 200P.

[Markstar]

Hi Charic...thanks again. I've already accepted that this scope will not bring many rewards. I'm still going to get 1 or 2 BST's tho, ready for when I upgrade. If nothing else this scope will at least train me in looking for objects and how to use an EQ mount...? Funny you should mention the Skywatcher 200p - this is probably what I will go for when I upgrade, based on all the reviews I've read. Best things come to those who wait (& save their pennies!)

Mark

[Charic]

Markstar......... Ive just ordered the 18mm BST today  and will order the 12mm & possibly 5mm later this week, ebay sales pending?   I also understand your acceptance of the equipment you have. Look back at some of my earlier threads and you`ll see I was all for getting some Tele Vue lenses   . I`m glad I didnt now, although nothing wrong with those lenses except the prices for me.  I like the 200P. They say its even better at a proper dark site, not long now, and better weather, I`ll get to confirm that.

[mdstuart]

One other thing to remember is there is a thriving second hand market for eyepieces on astro buy and sell etc.

So if you buy a BST eyepiece and then later want to upgrade you will be able to get a fair bit of money back towards the next eyepiece.

The other journey you will go on is field of view. You can go from the view looking like you are looking down a toilet roll to a view that is like looking out of a big plane window...The FOV is usually described in degrees and goes from around 45 to 100. The BSTs I think are about 60..

Enjoy

Mark

[Charic]

...... The BSTs I think are about 60..

Mark

 Mark...........Thats correct for the 8mm but the true field is only 0.4 when using an 8mm lens on my telescope (AFOV/MAG)  which is the angular size (in degrees) of the actual area of the sky that you can view through a particular telescope with a particular eyepiece. Still very good though.

[Markstar]

On the subject of FOV, have you guys tried the Meade 4000 UWA EP's? If so how would you rate those? (not that I intend to get one anytime soon...!)

[John]

The Powermates and Explore Scientific Focal Extenders are excellent but also pretty expensive (especially the Powermate). 

If you want to see what a barlow can do for you at a reasonable quality without major investment the Revelation 2.5x barlow that Telescope House sells for just £32 are pretty good:

http://www.telescopehouse.com/acatalog/Revelation_Astro_2_5x_Barlow_Lens.html

Remember though that the eyepiece focal length gets effectively shorter by the amplification factor of the barlow, eg: an 8mm eyepiece effectively becomes a 3.2mm with a 2.5x barlow so you can quite quickly reach magnifications that are more than the scope and / or viewing conditions can support.

Reeny makes some interesting points about the Revelation plossl eyepieces and they are quite decent - made by the GSO (Guang Sheng Optical) company I believe. There are other eyepieces with the Revelation branding on though, as well as their plossls. All made by GSO too. 

[NeuStar]

Ok - I guess I' m thinking a bit too far ahead when it comes to astrophotography...ha ha!

Regarding EP's tho, I've decided to go for 3 BST Explorers at 8mm, 18mm and 32mm. If I'm happy with the results I'll then invest in a decent barlow too...glad my other hobbies are less expensive!

Just been out looking at the moon with my current crappy EP's...hoping to see more than the moon soon tho!

Thanks for all your input...if anyone is horrified by my choice of EP's feel free to let me know!

Kind regards

mark

I just ordered a skywatcher 20mm Ultrawide EP.  Will be interesting to see what the sky looks like through that.  Even a spectacle lense as an EP would be an improvement over the Chinese made H things I have been peering through - laugh.  Happy hunting with your new EP selection you chose.

[Reeny]

.....................If you want to see what a barlow can do for you at a reasonable quality without major investment the Revelation 2.5x barlow that Telescope House sells for just £32 are pretty good:

That is the same Barlow I use, the multi-element 2.5x Revelation.

Someone on here has tested this model and found it to be an actual 2.1x magnification.

That makes sense with the sums and head scratching I have been doing.

Whatever the mag is, it's quality kit.

I want to use it again on the moon with the 12mm and 9mm Plossls (210x and 280x magnification)

The surface detail craters need more investigation.

If the image is good with the 12mm at 210x, I have permission to get an 11mm 82-degree Explore Scientific Eyepiece.

The Plossls 52degree FoV is restrictive.

I don't think the 60-degree BST will cut the mustard since I have been spoilt with the MaxVision 68's

[John]

On the subject of FOV, have you guys tried the Meade 4000 UWA EP's? If so how would you rate those? (not that I intend to get one anytime soon...!)

The Meade 4000 UWA's are a bit of a mixed bunch. The 14mm is considered a classic UWA eyepiece but the shorter focal length ones seem to have a more mixed reputation. I tried an 8.8mm once and found it quite nice although it was very fussy over eye positioning.

The 5000 series UWA's might be a better bet I reckon.

Remember though with UWA's, what you are paying for is the extra field of view and the more you pay, the better corrected it will be in a faster scope. A Baader Genuine ortho or similar will actually slightly outperform them on light transmission and light scatter control in the central area of the field of view.

[Markstar]

DOH!!! - Yes, I meant the 5000, not 4000. The Meade 5000 UWA ep's scored 91% in Sky At Night magazine. Still, I'm thinking too far ahead again...haha!!!

[John]

One other thing to remember is there is a thriving second hand market for eyepieces on astro buy and sell etc.

So if you buy a BST eyepiece and then later want to upgrade you will be able to get a fair bit of money back towards the next eyepiece.

This is great advice, especially where eyepieces are concerned. I've bought loads of used eyepieces over the years and, if and when I decided to part with them, I've been able to re-sell at little or no loss. With eyepiece choice being a somewhat personal thing, this the best way to find out what suits you.

And this is a great place to do it:

http://www.astrobuysell.com/uk/

[Markstar]

^{Thanks for all your advise guys - I had some great views of Venus last week with my new BST EP's...looking forward to testing them out on some DSO's soon...}

[bingevader]

Excellent! Congratulations.

Cheers