Tele Vue Nagler or LE Delos

[SimmoW (SIMON)]

Hi, I have narrowed down my first eyepiece choice to an approx 23mm (as my pending Tak E130D scope works best with no more than 23mm EPs.

I've seen a friend's Nagler, it's very impressive! But as I wear glasses and have an 8yo son, I'm wondering if a 72mm Delos might be better? Any opinions appreciated!

I am planning to get a set of 22, 10 and 5mm. At only 5mm, does one type have a strong advantage?

Thanks

Simon

[AG Hybrid (Adrian)]

The Delos longest focal length is 17.3mm. So not really around your 23mm range.

Other options? Vixen LVW 22mm and the Denkmeier 21mm. Both have 20mm of eye relief and both are 65 degree's FOV. Both are excellent.

When your moving down the focal range. i.e. 20mm and less. The Delos are superb. They are move favorite eyepieces range. Excellent field correction and contrast. A nice neutral color tone. Excellent light throughput.

Since you said 10mm and 5mm. Also consider the Pentax XW series. They are cheaper then the Delos line (just) but are fantastic eyepieces. The Pentax XW 10mm may just be the finest 10mm eyepiece ever made.

That being said if I was going to do it again all again I would have bought the Delox 10mm instead as I find the Delos line more comfortable to use. (The Pentax eye cup tickles my eyelash when I roll my head a bit to focus on objects towards the edge, where the Delos doesn't)

YMMV

I'm actually looking now to get either a Vixen LVW 22mm or Denkmeier 21mm. Initial reports indicate the Vixen LVW has better edge correction in a fast newtonian so I'll probably go with that.

[MortonH]

Agree with Adrian - Delos or XW are more comfortable to use. The only downside is they're bigger and heavier than most Naglers, but if you're using a NEQ6 mount I assume weight isn't a problem for you

[Allan]

The 5mm type 6 Nagler has only 12mm of eye relief, which is very tight if you observe with glasses on. In that respect alone the Delos is a clear winner with its 20mm of eye relief. But apart from that, the Delos is a better eyepiece in every way, except that it has a slightly smaller field of view than the Nagler.

Delos are available in the shorter focal lengths you want, but for the 22mm the type 4 Nagler has good eye relief also for eye glass wearers.

[barx1963 (Malcolm)]

Simmo
I am generally reluctant to recommend eyepieces without looking at the scope concerned. One big query, is this Tak E130D being used primarily as an imaging or a visual scope?
The reason is that looking at info I could find online it indicates that this is an astrograph with f3.3 and a big secondary.
I always like to think about exit pupil when thinking about eyepieces. An ideal exit pupil is around 4mm. According to Smith, Ceragioli and Berry in their book "Telecopes, Eyepieces and Astrographs" the best images are usually obtained with an exit pupil of 3-4mm. My own practical experience certainly bears that out.
For this scope that would indicate an EP of around 13mm.
But the question still remains, if this is an astrograph, it is possibly not going to be ideal for visual use?

Cheers

Malcolm

[Steffen]

Another one to consider is the TV 24mm Panoptic. I wear glasses and I find it comfortable to use. It is also one of my favourite eyepieces overall.

Cheers
Steffen.

[Don Pensack]

Originally Posted by SimmoW

Hi, I have narrowed down my first eyepiece choice to an approx 23mm (as my pending Tak E130D scope works best with no more than 23mm EPs.

I've seen a friend's Nagler, it's very impressive! But as I wear glasses and have an 8yo son, I'm wondering if a 72mm Delos might be better? Any opinions appreciated!

I am planning to get a set of 22, 10 and 5mm. At only 5mm, does one type have a strong advantage?

Thanks

Simon

At f/3.3, I would be reluctant to use eyepieces longer than 16-20mm.
To be honest, few observers' pupils open wide enough for anything longer.
That puts a TeleVue 17.3mm Delos as an excellent low power eyepiece.
With a 430mm focal length, that would yield 25X--already a quite low low power eyepiece.
You will need to use the scope with a coma corrector. Trying to use an un-corrected f/3.3 would be a little like looking at a field of stars that resembles the image on the flight deck of the Millenium Falcon as Han Solo, Luke Skywalker, Chewbacca, and Princess Leia went to light speed. :-)
So the actual magnification will depend on the magnification factor of the coma corrector. If using a TeleVue Paracorr, you'd have an effective focal length of 495mm and a magnification on the eyepiece of 29X, not appreciably different.
I would not try to use something longer in focal length. The exit pupil will be too large, and the shadow of the radically over-sized secondary (because the scope is optimized for astrophotography, not visual use) will be obtrusive--especially on the Moon.

[SimmoW (SIMON)]

Thanks everyone for your advice, after reading it and doing more googling, the general opinion is that the newer Delos is better, contrast wise, than the naglers.

Takahashi warned me not to exceed 23mm due to vignetting issues for this scope. So two days I splurged on a set of EPs to last me a lifetime- 3.5, 6 and 10 Delos, and a 24mm Panoptic.

I was only able to pick up the 3.5 and 6 in person in USA, for a little over $300 US, good deals. God they are true works of art, so well constructed. Great wide view.

I may end up doing more visual work thru a cheaper Bintel reflector, with this scope dedicated to photo work. So I may one day get the 41mm hand grenade!

Thanks again. Can't Wait for first light!

[SimmoW (SIMON)]

And thanks for the coma corrector tip Don! I'll wait for the scope to arrive before ordering, but as I say I may end up with another scope for purely visual use. Sheesh, the EPs and the parracor are almost as expensive as the OTA!