A match made in heaven...Genesis and 31mm Nagler

[Stu]

I’ve just finished an hour or so with my recently acquired 31mm Nagler and Televue Genesis, and think I might be in love all over again!

I had this same combination some years ago, and had some wonderful views from dark sites, normally whilst camping down in Dorset. It gives a 5 degree field of view at x16 with a 6.2mm exit pupil. I remember the field being very flat, stars sharp to the edges; no difference in focus point between centre and edges. Filtered views of the Veil and NAN with an OIII filter were wonderful.

Fast forward a few years and I’m on my third, and best Genesis. This one is a keeper, most definitely, but the 31mm Nagler had gone elsewhere. I did have a 30mm ES eyepiece for a while, but it wasn’t quite in the same league, and showed noticeable field curvature in my current Genesis, defeating the object of such a widefield. In fact, I had begun to doubt my memory of the views with the Big Nag.

Anyway, as said, I recently reacquired a very fine example of the 31mm, and I’m delighted to say my memory was not deceiving me. The views are wonderful even under my light polluted sky, with that lovely flat field just as I remember it.

I won’t  make the mistake of selling this one! I’m looking forward to trawling the Milky Way with it in the late summer.

[John]

Great pairing Stu

They are "meant to be together" I think 

 

[Stu]

4 minutes ago, John said:

Great pairing Stu

They are "meant to be together" I think 

 

I do think so. I almost felt like a bit of a gooseberry! 🤣

[Louis D]

3 hours ago, Stu said:

I did have a 30mm ES eyepiece for a while, but it wasn’t quite in the same league, and showed noticeable field curvature in my current Genesis, defeating the object of such a widefield.

Interesting.  I have one of the original mushroom top 30mm ES-82s, and it is dead flat of field to my presbyopic eyes.  What I can't stand about it is the CAEP that causes the ring of fire.  It also causes extended objects like planets to split into a red and blue copy slightly separated from one another near the edge.  If you simply concentrate on the center, it's hard to notice this, so it is good for sweeping rich star fields.

Enjoy your Terminagler/Genesis combination!

[Stu]

4 hours ago, Louis D said:

Interesting.  I have one of the original mushroom top 30mm ES-82s, and it is dead flat of field to my presbyopic eyes.  What I can't stand about it is the CAEP that causes the ring of fire.  It also causes extended objects like planets to split into a red and blue copy slightly separated from one another near the edge.  If you simply concentrate on the center, it's hard to notice this, so it is good for sweeping rich star fields.

Enjoy your Terminagler/Genesis combination!

Which scope is that in Louis? As I understand it, scopes and eyepieces have curvature, so the best results are where these cancel each other out. If they reinforce then results can be bad.

The Genesis is a Petzval, and well known for a flat field, so I assume the 31mm Nag has a flat field too. There is some discussion elsewhere about the longer focal length Pentax XWs. I’ve seen a number of reports of field curvature in them, but do wonder if that is because they are designed to counter FC in shorter focal length spotting scopes, so are less good in longer focal length scopes?

[PeterW]

Look forward to seeing what this combo can deliver!

Peter

[F15Rules]

8 hours ago, John said:

Great pairing Stu

They are "meant to be together" I think 

 

Agreed, John..as a great rock band once said "Never turn your back on a friend"..😁. 

The "friend" in this case being the Nagler 31mm!

Lovely combination Stu, I look forward to never seeing this in the classified ads!!😂😂

Dave

[Stu]

32 minutes ago, F15Rules said:

Lovely combination Stu, I look forward to never seeing this in the classified ads!!😂😂

Please stop me if I ever try Dave!! 😱😱

[Merlin66]

I’ve measured up the Genesis, it will fit in the same box as me!!!!

when I go, It goes with me!!!!!

[ollypenrice]

For years I used something very similar, a Mk1 'Pearl River' Genesis but with a 35mm Panoptic. It was the widefield observer's dream - Stock 2 framed with the Double Cluster, the Rosette, the entire Veil....  I made it a small box which, with diagonal removed, allowed it to travel as airline carry-on as well. My first view of the Rosette was had that way, in Spain before I moved to France to live. I can see it from here, too, but never managed it in the UK.  The nearest I have currently is a Pronto which is quite nice but lacks light by comparison.

Olly

Edited April 15, 2021 by ollypenrice
typo

[Stu]

7 minutes ago, Merlin66 said:

I’ve measured up the Genesis, it will fit in the same box as me!!!!

when I go, It goes with me!!!!!

I do love mine too! I had a couple before and they were great for low power, widefield use but struggled more at high power. They were collimated well so I just assumed this was part of being a fast achro, notwithstanding the Petzval design. The one I have now is excellent even at high power. It still has CA of course but optically otherwise seems excellent so it will stay will me.

I have a lovely 4” trio now of Genesis at f5, Tak FC100DC at f7.4 and Vixen FL102S at f8.8 all of which I hope to keep with me for the long term. I do enjoy the older scopes.

[John]

The nearest I get to this is the Nagler T5 with my Vixen ED102SS F/6.5 which is a 3.8 degree true field.

As well as being able to take in large targets, sweeping around with these low power / very wide fields of view shows up star patterns that you can otherwise overlook I think. I find the area of sky around the double cluster in Perseus very interesting in this respect - all sorts of strings of stars and asterisms around there. Almost any area of the sky is productive though.

Seeing a familiar deep sky object or a planet looking tiny within the context of an expansive star field can be lovely as well

 

 

 

Edited April 15, 2021 by John

[Stu]

8 minutes ago, ollypenrice said:

For years I used something very similar, a Mk1 'Pearl River' Genesis but with a 35mm Panoptic. It was the widefield observer's dream - Stock 2 framed with the Double Cluster, the Rosette, the entire Veil....  I made it a small box which, with diagonal removed, allowed it to travel as airline carry-on as well. My first view of the Rosette was had that way, in Spain before I moved to France to live. I can see it from here, too, but never managed it in the UK.  The nearest I have currently is a Pronto which is quite nice but lacks light by comparison.

Olly

I remember you talking of that one before Olly. This one too is a Pearl River original, nice to have found.

As you say, objects like the Veil are wonderful with it from a dark site, I must get back somewhere where I can view this. I have seen the Rosette from the U.K. a couple of times with a 106mm f6.5 triplet and OIII filter, but would expect the Genesis to be better for this. It is pretty tricky visually, particularly if you end up looking ‘through’ it, which is where the widest field helps as you well know.

[Chris]

A can sense the elation, very nice post, Stu  Hmm? Maybe ES doesn't give 90% the performance of TV at half the price after all!? This could be a very expensive thought 🤔😄

[Stu]

Just now, John said:

all sorts of strings of stars and asterisms around there. Almose any are of the sky is productive though.

Totally agree. I didn’t look at it last night, but that string of stars from the DC to Stock 2 that Olly mentioned is lovely, amongst many others!

There is also the lovely S sweeping between Mintaka and Alnilam.

[Stu]

9 minutes ago, Lockie said:

A can sense the elation, very nice post, Stu  Hmm? Maybe ES doesn't give 90% the performance of TV at half the price after all!? This could be a very expensive thought 🤔😄

In this instance I would say no. The ES missed the mark through its field curvature in this scope. I’m sure the performance varies depending on the FC specs of the particular scope so it’s quite a complex issue. All I can say is that these two work very well together, which I guess you would expect, both coming from Televue 😀👍

[Ken82]

Awesome I also use my 31mm nagler with my fsq 85 so very similar field of view. Interestingly I prefer the 31 nagler over my 21 ethos. Just a little bit more field of view. 

[Chris]

34 minutes ago, Stu said:

All I can say is that these two work very well together, which I guess you would expect, both coming from Televue 😀👍

Yeah your right Stu, I was thinking that in terms of edge performance, 500mm at f/5 was simply 500mm at f/5, but of course the Genesis is a 4 element Petzval design which was know doubt optimised using TV eyepieces like the Nag31 (if the Nag31 came first?).   

[Stu]

22 minutes ago, Lockie said:

Yeah your right Stu, I was thinking that in terms of edge performance, 500mm at f/5 was simply 500mm at f/5, but of course the Genesis is a 4 element Petzval design which was know doubt optimised using TV eyepieces like the Nag31 (if the Nag31 came first?).   

I think the Genesis came first Chris, they were produced between 1988 and 1993 I think. There is a nice history here:

http://www.company7.com/televue/telal.html

The Nag 31mm came along in 1999 apparently.

http://www.company7.com/televue/index.html

 

[Davey-T]

I remember drooling over the Genesis in ad's but never had anywhere near enough money to afford one, the 31mm Nagler OTH I've had pretty much since they first appeared and despite having the 21mm Ethos the Nag' is going nowhere.

Dave

[michael.h.f.wilkinson]

I can well imagine the wonderful views. Sounds very much like my APM 80 mm F/6 triplet with the Nagler 31T5 "Panzerfaust", 15.5x magnification and 5.3 deg FOV. I tend to use it with a 2" Amici Prism, giving wonderful correct image views. Really ideal for wide-field sweeping. M31 from a camp site near Olly's place was just astounding

[Arneb]

In my early teens I used to dream of owning a Genesis SDF. I must have sent countless stamped self-addressed envelopes out to the astronomy retailers of the day to receive the various brochures and advertisements they held for the scope manufacturers of the time. I seem to remember a TeleVue advert with a photo of the Renaissance and Genesis (and possibly a Pronto) on Gibraltar mounts together. They looked stunning to my eyes.

Well the marketing, kind of, worked as almost 30 years later I acquired an NP101. It was worth the wait. Those low power, wide field views were exactly as described by Mr Nagler in the literature I had poured over.

How awesome it will be to get the NP101 under some dark skies again. And perhaps I should send off for the 31mm Nagler brochure 😉...

Edited April 15, 2021 by Arneb
Clarity

[Stu]

@Arneb, you know it makes sense to grab a 31mm Nag for your lovely NP101 🤣. That seems to be what these scopes are all about, beautiful widefield views which the Nag excels at. I bet the NP is fab, with the much better colour correction it has over my old Genesis.

[Littleguy80]

Great combo, Stu and fab report. I debated more than once on the big Nagler. Originally I plumped for an ES82 30mm which I did really like. It was quite a big heavy beast though. Recently I sold the ES and got an APM UFF 30mm. It’s really nice and light and gives a 4.2 degree FOV with my 80mm refractor. I think the lightness of the APM makes it a better match to the little frac. One thing that helped with my decision to sacrifice some FOV was the AERO ED 40mm I have. Again, very light weight for a 40mm eyepiece. It gives a nearly 5.5 degree FOV with the refractor. Both of these are great for sweeping across star fields or observing big objects like the Veil.

Long story short, I completely agree that the wide field views from these eyepiece and little fracs are something to be treasured  

[Captain Scarlet]

The closest I can come to that is my Kowa TSN-883 (88mm/510mm) for which I got Kowa’s astro-eyepiece adapter. The adapter can only do 1.25” eyepieces so my Pan24 is as wide as I can go. That combination gives me 21x, 3.2 degree FoV and 4.1mm exit pupil. Still quite nice though.

I too do hanker after a Nagler 31 though...

M