Eyepiece set for Celstron Nexstar 8 SE

[Mack Truck]

I started with a Baader Hyperion 8-24 zoom but I can't say it was love at first sight. So I started a set with a Nagler Type 6 9mm. I ordered a 2" diagonal so I was thinking about getting 2 more: 17mm Ethos and 41 Panoptic (that's what Televue recommends for 8" SCT). However they are not cheap, and I was wondering about alternatives. Any suggestions ?

[Dunkster]

How dark is the sky where you observe? Is there any light pollution?

[Mack Truck]

How dark is the sky where you observe? Is there any light pollution?

A bit of light pollution indeed in my yard. But there is a much better site about 10 minutes on a hill with not much around.

[Dunkster]

The reason I ask is that the 41 Pan will give around 50x magnification and with light pollution it will show plenty of sky glow. If its really dark where you observe, it'd give a nice wide view

If you really must have TeleVue, the Ethos 17 and Nagler 31 are perfect partners if you believe TV the latter showing twice the sky of the former. However, if I were to do it all again, it would probably be a 13mm Ethos or Nagler as that's a great focal length for globular clusters with the 8SE, good even for a first planetary look before ramping up the magnification if the seeing permits. I don't feel that 17mm is as useful a focal length, it's a nether region for the scope.

You might also want to consider a Nagler 11mm for better nights, or something like a Delos 10mm or Pentax XW 10mm... both are supposed to be excellent. I have the XW following recommendations here but haven't had a chance to use it yet because of the weather

If you're interested in less expensive options (such as ES, Meade, SW...) then there are some other good options around too. I occasionally use my ES82 30mm with my 8SE, but it's a bit of a handful!

[Mack Truck]

From my beginner point of view I don't understand the difference between the ethos 13 and 17mm, besides the 17mm being more expensive-and I assume there might be a reason for that I heard a a lot of good things about them ethos but I am not sure if the added value-compared to something more affordable-let's say a Nagler-is worth the price.

Regarding light pollution, do you think a filer might help ?

[John]

I love Tele Vue eyepieces but with an F/10 scope you will get pretty much the same performance from the lower cost Explore Scientific equivalents. They do eyepieces that compete well with the Nagler and Ethos ranges.

The 17mm Ethos is a larger eyepiece so more glass and other materials and precision machining is required to manufacture them. The 21mm, even more so.

[Mack Truck]

The reason I ask is that the 41 Pan will give around 50x magnification and with light pollution it will show plenty of sky glow. If its really dark where you observe, it'd give a nice wide view

Would you rather consider a 35 Pan ? The 41 was recommenced by Tele Vue but some users with 8" SCT seem to be better off with the 35.

[Dunkster]

OK, from a beginner's point of view... the different focal lengths of the eyepieces (13mm, 17mm, 35mm, etc) dictate the magnification you will get from your scope, calculated by...

Magnification = Focal length of telescope / Focal length of eyepiece

The focal length of your telescope is 2032mm. So for a 13mm eyepiece, the magnification is 2032 / 13 = 156x . For a 17mm, 2032 /17 = 120x. For a 35mm eyepiece, 2032 / 35 = 58x .... I'm sure you get the idea

Personally I find some eyepiece focal lengths more useful than others, part from experience and part from discussions with folk here The objects you are interested in seeing will determine what eyepiece focal lengths would be useful. For example, for the widest possible FOV for looking at the Orion Nebula, or one for looking at planets or the Moon.

A wide field of view can be achieved by using longer focal length eyepieces and/or wider apparent FOV eyepieces. The Ethos range present a 100 degree apparent FOV, so when you look through the lens it's not obvious where the edges are. The Naglers present an 82 degree FOV, the Panoptics 68, and the good old plossl 50 degrees aFOV. In each case, the appearance of the view becomes narrower from Ethos to Naglers to Panoptics, and the effect is in the experience. The Naglers were were the first to give the "spacewalk" experience, where the eye is immersed in stars, whereas with Panoptics and narrower you can easily see the edge as dictated by the eyepiece design. The larger aFOV incidentally, as John mentioned above, are more complex to make and require special glass, etc, and command a higher price tag. The Naglers and Panoptics less so. Note that the aFOV is not connected to the quality of the view, only how wide it appears. Different people prefer different experiences and aFOV, which is why all these types exist and remain for sale. It's really something you can only decide upon once you experience it for yourself.

As John says, the focal ratio of the 8SE telescope makes it less demanding on quality eyepieces than other telescope designs. Therefore some eyepieces made by other companies present an experience that becomes indistinguishable from that provided by TeleVue but at a reduced cost. For example, for the 82 degree aFOV eyepieces, models from Explore Scientific, Meade (UWA), Skywatcher (Nirvana and Sky Panorama)... I must have missed some...all provide a similar experience at a fraction of the cost of a Nagler.

Regarding the 35mm Panoptic... I don't know the reasoning of others, but this is possibly popular with 8" SCT owners because the physical parameters of the eyepiece match the limitations of certain specifications of the telescope...notably, the diameter of the baffle tube and the curvature of the mirror(s). The 35 is also a bit lighter than the 41 Pan and 31mm Nagler.

Given the cost of the Panoptics and my experience with other eyepieces, I bought the 30mm 82 degree model from ES... but if money were no object, the Nagler might have been a nice treat Personally I prefer the 82 degree experience for the wide views, but it's not to everyone's taste and only you can decide what your preference is by research, trial and error.

[Mack Truck]

Thanks for the info. Regarding the difference what I mean is "when would you use 17mm rather than 13mm ?" Or more generally speaking: what would you consider buying besides the Nagler T6 9mm I already have ? I had a Baader Hyperion 24-8 but did not quite like it.

[Dunkster]

The 17 would give a wider FOV, less magnification. I have the 17 and have only used it once with my 8SE, it gets a lot more use in the C11 which is a longer focal length scope, where it gives about 164x, good for globular clusters. I find if I want to really wide, I'll go for the 30mm. More often than not, I'll use neither - they're both big and heavy - and I'll use a 20mm Nagler instead.

A 9mm in this scope, at 225x magnification, will be for better than average conditions, at least in the UK you may get more use out of it where you are, if the conditions are often better. I often find my 11mm is about as good as it gets, my 8.8 usually just shows a bigger, more blurry image...but not always... and that's why it's useful to have a collection

What is it about the Hyperion Zoom you don't like? It's useful to understand that going forwards. Everyone is different and an eyepiece can be great for one person but not for another for whatever reason.

Also, I'm sure there are other members with opinions different from mine, there are a number of us with C8/8SE

[michael.h.f.wilkinson]

I had a TMB Paragon 40mm in my C8 for quite a while. Very good performer. The SW Aero is a clone, I am told. Much cheaper than the (no doubt outstanding) Panoptic 41mm. I now use the 31mm Nagler as my standard wide angle view EP. The ES 30mm would be a very good replacement. Both give a FOV a bit smaller than the 40/41mm, but at a higher magnification.

I personally prefer the Type 4 Naglers with their increased eye relief (the 31T5 has plenty as well). The the 22, 17 and 12mm are great EPs. As you have a 9mm, a pair of Naglers or ES 82 deg EPs of 17 and 31, or 16 and 30mm would be very good indeed.

[Mack Truck]

What about those Baader Hyperions ? Any good feedback on those ? I was told there won't be much of a difference with those and the Tele Vue for my 8" SCT.

[Naemeth]

At F/10, there will probably be not much separating a Hyperion and a Panoptic (both have the same apparent field of view), it's only when you increase the focal ratio to about F/5 where the Hyperion becomes mushy at the edges (I've heard many commentators saying this) and the Panoptic stays just as good .

[Mack Truck]

At F/10, there will probably be not much separating a Hyperion and a Panoptic (both have the same apparent field of view), it's only when you increase the focal ratio to about F/5 where the Hyperion becomes mushy at the edges (I've heard many commentators saying this) and the Panoptic stays just as good .

So I guess there won't be no benefits buying one of those Panoptics or Ethos for my 8" ?

[John]

So I guess there won't be no benefits buying one of those Panoptics or Ethos for my 8" ?

The benefits will be lessened rather than non-existent.

If you are looking for a 100 degree eyepiece the Explore Scientific 100 degree eyepieces will be very close indeed, if not exactly the same as the Ethos in your F/10 scope and cost quite a bit less.

As Michael says, the Tele Vue eyepieces really come into their own with fast scopes - ie: F/6, F/5, F/4 etc. Normally it's difficult to make wide and ultra wide angle eyepieces that work really well with fast scopes but Tele Vue are the masters of it - for a price !

[michael.h.f.wilkinson]

One other thing which has not been raised is that EPs are a very personal matter. If you have a chance, go to a star party or local astronomy club, and see if you can try some EPs (preferably in your own scope) before buying them.

[Dunkster]

What about those Baader Hyperions ? Any good feedback on those ? I was told there won't be much of a difference with those and the Tele Vue for my 8" SCT.

Given that you're not keen on the Hyperion Zoom, I'm not sure you'd be any happier with the fixed focal length Hyperion eyepieces. If you get along with them however, it presents another option for the longer focal length end...the Hyperion Aspheric are available in 31 and 36mm with a 72 degree FOV, and for less than a Panoptic Anyone got any experience of these?

[michael.h.f.wilkinson]

I have looked through a Hyperion Aspheric 36 mm in a 16" F/8 RC. Really nice EP, but I feel the original TMB Paragon 40 mm had the edge, especially in terms of ease of use.