Help! Looking for quality eyepiece for small newton

[omikron]

 

Hi, I read a lot on the forum but I couldn't find what I'm looking for.

I would like a good eyepiece for my 130 pds 650 skywatcher.

I wear glasses and i would like a focal that allows me to better observe the planets.

The small skywatcher has a cheap 25mm, the budget is from 200 to 300 euros (about 300 dollars)

thank you!

 

[omikron]

Help...

[Kyle Allen]

How about a BST StarGuider 5mm? It will provide 130x magnification in your 130PDS. That should be good for Jupiter and Saturn at their current low altitude. For Mars you might want a bit more magnification though. 

[RT65CB-SWL]

Hi @omikron and welcome to SGL. 

Not to sure where you are, but these...
https://www.firstlightoptics.com/bst-starguider-eyepieces.html
would be an improvement on the supplied e/p's.

...or you join the 'Green & Black' mob...

My 'one-to-many' TeleVue 13mm e/p's.

Edited July 4, 2020 by Philip R

[Ruud]

A 650 mm focal length f/5 telescope. Good eyepieces.

I'll go for really good:

Morpheus 6.5 mm will magnify  100 times (approx €250)
Morpheus 4.5 mm                      144 times (approx €250)
Morpheus 6.5 mm + 2x barlow  200 times (slightly over €300)
Delite 4mm                                 163 times (approx €290)

It's difficult. The Morpheus have a 76° field of view, the Delite 62°. Both lines are very good and certainly spectacle friendly. The Morpheus are on the big side and are bigger still combined with a Barlow. The Morpheus are better value. The Barlow can also convert your 25 mm into a 12.5 mm. 

The 6.5 mm + Barlow would give you a choice of two magnifications. A hundred times is fine for most nights, but the atmosphere doesn't allow for 200x every day.

With your budget I would choose a good Barlow and a Morpheus 6.5

There are many good Barlows around! You can certainly get a good one at around €60, but I don't know which is the best at that price.

By the way, we all have different ideas about what is good. It depends on how spoiled we are. Coming from kit eyepieces you will certainly find the BST Starguiders good. Compared to Delos, Delight, Pentax XW and Morpheus however the BSTs are no more than fair.

And then, if you consider that you can get 5 Starguiders for your budget ... but how are they when someone must wear glasses?

 

Edited July 4, 2020 by Ruud

[DeathWarpedUp]

Baader hyperion zoom mk4 is a good choice, and as its a zoom so you maybe able to remove your gasses and focus in.

[jonathan]

Depending on your reason for wearing glasses, have you tried taking them off to look in the eyepiece?  I have good close-up vision (only need glasses for distance) so looking in binoculars or an eyepiece does not require my glasses, simply removing them temporarily allows me to get my eye right up to the glass for the best view.

Personally I like the Explore Scientific eyepiece range, but if you want a really good high magnification eyepiece then how about the Pentax 3.5?  It is a large, heavy eyepiece though, check suitability before splurging the cash!

[omikron]

First of all thank you very much for the answers, you are helping me to find a way. I also have a 2x barlow televue and i tried Planetary ED (look like the same as bst) but found them not so good for me.

I would like to ask you for an opinion about the 9mm Takahashi mc abbe, do you think it could be a good choice on small fast telescope?

 

Philip R, i can't recognize the televue models you posted, what exactly are they? Would you recommend them for this little fast scope?

jonathan   IMHO Glasses are secondary to other aspects in my case, i can unweare it with go-to, but it is always an extra operation to do if I aim a planet only by eye, it sometimes becomes boring. I agree that once centered in the eyepiece the object is no longer a problem.

 

[Ruud]

Abbe orthos are a good design but they have little eye relief: 0.87 times the focal length.

A 9 mm Abbe Ortho has 7.8 mm eye relief. The field of view is around 43°.

Abbe was a revolutionary optician, but after a 140 years of subsequent developments his orthoscopic eyepiece is a bit outdated.

[pete_81]

Hi @omikron,

Just browsed your post here, and thought I'd offer my choices too. Like you, I wear glasses (prescription is for seeing distant objects) but I've upgraded my plossls in my setup (f/4.8, 1200FL) to a few (68deg,24mm, 82deg,6.7mm and x2) Explore Scientific objectives, and whilst I can now use these while wearing glasses, the views are many times better without! You just have to adjust focus (slightly) for each observer. The total I spent on the lenses was around the €300, with the x2 throwing out of your budget, but cheaper than the televues which may be too good for my setup.

I had also spent time looking at the Vixen SLV, but decided the FOV wasn't quite what I wanted, but they may be worth a mention?
I also note Jonathan above says the same. The ES range appears to be great and was recommended to me whilst in a similar position. I was slightly concerned about the eye-relief (use with specs) myself, but don't regret going to ES.

Hope this doesn't add more confusion to you

[pete_81]

Got it. This site is great for showing the view of an eyepiece with the specs you put in (or use dropdown). It helped me figure out the best angles and magnifications for what my interests are - have a look and see if it works for you.

http://astronomy.tools/calculators/field_of_view/
Biggest point I would say though is don't fret about spectacles. Also have a look at the post I mention above when I was looking for my upgrades, there was a lot in there that may help. Obviously there may be stuff to confuse too, but I was in the same place this time last year!

 

Best thing about this site is everyone wants to help everyone. Let us know how things go!

[RT65CB-SWL]

18 hours ago, omikron said:

First of all thank you very much for the answers, you are helping me to find a way. I also have a 2x barlow televue and i tried Planetary ED (look like the same as bst) but found them not so good for me.

I would like to ask you for an opinion about the 9mm Takahashi mc abbe, do you think it could be a good choice on small fast telescope?

 

Philip R, i can't recognize the televue models you posted, what exactly are they? Would you recommend them for this little fast scope?

jonathan   IMHO Glasses are secondary to other aspects in my case, i can unweare it with go-to, but it is always an extra operation to do if I aim a planet only by eye, it sometimes becomes boring. I agree that once centered in the eyepiece the object is no longer a problem.

 

Hi @omikron ref: my image... left: is a 13mm 'smoothside' Plossl - centre: is a 13mm Nagler type 1 -  right: is a 13mm Nagler type 6

note: the type 1 is a heavy e/p (weight: 690g / 1lb 8oz) and requires re-balancing of the OTA - gives 82deg. AFOV, (as does the type 6); but at a fraction of the weight: 182g / 6.4oz and no re-balancing.

Yes! ...I would recommend the TeleVue 13mm Nagler type 6 as I find it to be the sweet-spot of my eyepieces; (including the ones from other brands too). The only downside is the astronomically high / eye-watering price.

Edited July 6, 2020 by Philip R

[Louis D]

Most folks who need to wear eyeglasses at lower powers (larger exit pupils) due to astigmatism can get by without them at higher powers (smaller exit pupils) as this chart from Tele Vue's Dioptrx page shows:

[omikron]

Thanks for the help, I live near a big city, there is often a lot of humidity. following your advice I seemed to understand that it is not useful to exceed 200x on my newton. Am I right?

At this point I could take it
1: Mporpheus 6.5 + barlow that I already have
2: explore scientific (which model from 6.5 or less?)
3 Takahasi Abbe MC

Televues are beautiful but also super super expensive :)

[RT65CB-SWL]

Sounds about correct! 

The late Sir Patrick Moore 🧐 is often credited as to saying: "...50x per one inch of aperture..." or something similar, so about 200x is about the most useful. Anything >200x views become 'mush & yuck'. As you said: quote: "...I live near a big city, there is often a lot of humidity..." that too will not help much either with moisture plus other airborne contaminants and pollutants in the atmosphere, especially at a lower altitudes.

Edited July 9, 2020 by Philip R

[omikron]

Hello guys,

bad news, i purchased the morpheus 6.5 but it produces blackouts. Even without glasses and for this reason i find it not very comfortable to use: keeping your head at the right distance is difficult, as soon as i move it a few millimeters forwards or backwards there is a blackout.

I don't know what it depends on, i chose this eyepiece precisely because it guaranteed a good distance from the eye and a large field combined with the fast newton causes this.

I'm not satisfied. I hate blackouts, even on some binoculars.

What can i do?

 

thanks

Edited July 14, 2020 by omikron

[Ricochet]

If you purchased a new one there should be an additional spacer ring that can be fitted between the eye lens and eyecup. Have you tried this combination?

Also, what sort of blackouts are you seeing? Are parts of the view going black or is the whole view going black because you are not keeping your eye centred over the exit pupil of the eyepiece? If it is the second then I would try lowering the tripod so that you can sit to observe instead of standing. Sitting is more stable and will help you to hold your head in the correct position more easily.

[Ruud]

I don't wear glasses.

I use my M6.5 with the extension ring and the eye cup. That make eye placement is easy.  As the eye cup lightly touches my brow I have tactile feedback which helps me keep my head in the right spot without effort.
The risk of blackouts occurring is bigger at daytime because when the observer's pupil is small, but even with a daytime pupil I have no problems with this eyepiece.
Is this the first time that you use an eyepiece with a big eye relief? It may be that you just need to get used to it.

When you wear glasses there is no contact between brow and eye cup. I suppose that complicates eye placement somewhat.

 

 

[omikron]

I tried with the extension ring and it improves but reflex of eyelashes still there and distract me a lot, the same happened to me with a old binocular that I had to replace because I couldn't stand it anymore. This does not happen with a leica trinovid for example. I tried on Saturn last night, same problem: total blackout and eyelashes reflex. I think it also depends on the eyepiece exit pupil couse i have to always keep eye widly open, otherwise blackout and eyelashes back. Annoying. Ironically, the cheap ED clone does not have this problem  and it is very comfortable being not tiring.

 

Edited July 14, 2020 by omikron

[Ruud]

35 minutes ago, omikron said:

I tried with the extension ring and it improves but reflex of eyelashes still there and distract me a lot, the same happened to me with a old binocular that I had to replace because I couldn't stand it anymore. This does not happen with a leica trinovid for example. I tried on Saturn last night, same problem: total blackout and eyelashes reflex. I think it also depends on the eyepiece exit pupil couse i have to always keep eye widly open, otherwise blackout and eyelashes back. Annoying. Ironically, the cheap ED clone does not have this problem  and it is very comfortable being not tiring.

I'm not sure if I understand properly. Do you mean that you close your eye involuntarily?

With as much eye relief as this eyepiece has, your eyelashes should not come in contact with anything. Could it be that you are somehow way to close to the eye lens? For no glasses, the eye cup ring + extension ring (two rings in total) should make this impossible.

On your f/5 telescope, the exit pupil is  6.5 / 5 = 1.3 mm. It's a well defined exit pupil too. On my f/5 it gives me no daytime issues at all, even on bright days when exit pupil issues show most prominently. Anyway, exit pupil issues should not cause eyelid reflexes. 

I'm sorry I can't be of more help. Except eye placement I have no idea what could be going wrong. Please experiment a bit more. With your glasses use just the eye cup ring and the eye cup folded up or  down, without your glasses try both rings, again with the eye cup folded up or down.

[omikron]

thank's for replay Ruud.

I'm sorry but I'm lost in translation, and it's hard to explain what I feel.

Ok: with/without glasses i have blackouts, i have to force myself to keep the eye physically wide open to avoid blackouts, and I have to stay at a precise and perpendicular distance. I also have the feeling that the diameter of the outer glass of the eyepiece is too large and ruin the comfort. But I had the same problem with some binoculars.

Another example: with the eyepiece copy of the Planetary ED 25 I have no problem about blackouts even during the day, they are very relaxing even in long sessions, i can rest my eye and relax. Here no, i must always keep it wide open, as soon as I relax it for a second ... blackouts coming, that's why I thought of the eyepiece exit pupil. Maybe only pentaxes are similar to planetary ED as a solution?

 

Edited July 14, 2020 by omikron

[Shaun Sr]

Get televue delos

 

[AstroMuni]

On 04/07/2020 at 20:58, Ruud said:

With your budget I would choose a good Barlow and a Morpheus 6.5

I agree, go for a good Barlow and a 6mm eyepiece. I personally dont see an advantage in buying a 2" eyepiece at this low focal length. A 1.25" would be less expensive, too.

Edited July 14, 2020 by AstroMuni

[AstroMuni]

2 hours ago, omikron said:

Ok: with/without glasses i have blackouts, i have to force myself to keep the eye physically wide open to avoid blackouts, and I have to stay at a precise and perpendicular distance. I also have the feeling that the diameter of the outer glass of the eyepiece is too large and ruin the comfort. But I had the same problem with some binoculars.

You will need to be a bit more clear about what you mean by blackout - i.e. do you see a black area when you should be seeing a bright spot; does it happen only at higher magnifications?

Try and explain by putting more details on when this happens, etc. and then we can try to suggest workarounds 🙂

Here is my interepretation so far ... you need to keep your eye in exactly one spot to get an image, moving it even a little bit causes the image to vanish and you see black. Am I correct?

Edited July 14, 2020 by AstroMuni

[Moonshane]

Look through the eyepiece in your hand not the scope. This will get you used to the correct position to avoid blackouts. Then you can translate this to the in scope position.

As for eyepieces an often stated ideal for maximum magnification is the focal ratio should be about the same as the eyepiece in mm. Or the aperture in mm the same as the magnification (130x or 5mm in your case).

You can sometimes get more and sometimes substantially more but most often, the most stable views will conform with this and often with not much gained (and often something lost) if you go above this.

Never used a Morpheus but they are good I believe. One possible option is to unscrew the Barlow element from the housing and screw this onto the eyepiece. For a 2x Barlow this equates to around 1.5x so with a 6.5mm Morpheus this equates to about 4.3mm so 150x pretty much allowing you to test the scope, conditions and your collimation (!) at basically no cost.