60 replies to this topic

[TayM57]

See post #4

Yeah it wasn't clear if you had the older Barcon or the baradv. Reading the specs sheet of the baradv, it says it has 48mm threads. Which means it should be able to be threaded onto any 2" EP.

[Moravianus]

..

 

If you were to use a PowerMate, Tele Vue recommends PowerMate -> Paracorr -> Eyepiece. But doing that with an ES92 is going to make your focuser yelp.

 

[areyoukiddingme]

Yeah it wasn't clear if you had the older Barcon or the baradv. Reading the specs sheet of the baradv, it says it has 48mm threads. Which means it should be able to be threaded onto any 2" EP.

 

Baradv. It has two sets of threads, and the bottom set might fit, but you can't get them to connect because of the first set of threads stops them engaging.

[nkoiza]

Thanks- would appreciate that either via PM or email.

 

Reading Richard's links, it appears the baradv does have 48mm threads. It should be able to thread onto the ES92s. Really the only question is, if I want a 2x mag factor, I probably need a spacer for that. I think it's the older barcon that doesn't have the right threads.

Another thing. Before acquiring the AP BARCON, I imagined using the ES 92s in bottom only mode, i.e., in the way you are planning. However, on arrival I found the AP barlow to be compact enough and abandoned my initial plan.

 

Even with Paracorr, AP BARCON and ES 92 in the system, I still find this coupling convenient when using the BARCON drawtube.The fact of the matter is that the ES 92s and AP barlow work beautifully together like this. It's worth using a very high quality barlow like the AP given the ES 92s are worthy of its use.

[TayM57]

Another thing. Before acquiring the AP BARCON, I imagined using the ES 92s in bottom only mode, i.e., in the way you are planning. However, on arrival I found the AP barlow to be compact enough and abandoned my initial plan.

 

Even with Paracorr, AP BARCON and ES 92 in the system, I still find this coupling convenient when using the BARCON drawtube.The fact of the matter is that the ES 92s and AP barlow work beautifully together like this. It's worth using a very high quality barlow like the AP given the ES 92s are worthy of its use.

 

I've given that quite a bit of thought as well. I'd love to use the Siebert 2" 2x or 2.5x ultra telecentric, which is 9oz compared to the 2x TV PM's 24oz.

 

But yeah, the baradv looks small enough that it probably weighs considerably less than the 2x TV PM.  I think the 2x PM is excellent optically, it's just the weight is a problem with the ES92s. 

Edited by TayM57, 27 March 2025 - 08:59 PM.

[nkoiza]

The more I use the ES 92s, the more I love them!

 

Just got back inside after carrying out a comparison of 17 ES 92, 20 APM XWA, 16.5mm Pentax XW and 17.5mm Morpheus with P1 through my 16" F4.4.

 

I rate them in the following order on open clusters which were the only objects I studied tonight:

 

1) 17 ES 92

2) 16.5 XW

3) 17.5 Morpheus

4) 20 APM XWA

 

I think the 17 ES 92 has now retired my 16.5 XW  

[TayM57]

The more I use the ES 92s, the more I love them!

 

Just got back inside after carrying out a comparison of 17 ES 92, 20 APM XWA, 16.5mm Pentax XW and 17.5mm Morpheus with P1 through my 16" F4.4.

 

I rate them in the following order on open clusters which were the only objects I studied tonight:

 

1) 17 ES 92

2) 16.5 XW

3) 17.5 Morpheus

4) 20 APM XWA

 

I think the 17 ES 92 has now retired my 16.5 XW  

 

Goes to show what a shame it is that ES dropped what was, and continues to be, their best eyepiece line. Hopefully this is a design that gets copied and expanded upon by other companies at some point in the future.

 

I put in an order with Siebert for two of their 8oz telecentric barlows that I plan to use only with the ES92s.

 

 

[nkoiza]

Goes to show what a shame it is that ES dropped what was, and continues to be, their best eyepiece line. Hopefully this is a design that gets copied and expanded upon by other companies at some point in the future.

 

I put in an order with Siebert for two of their 8oz telecentric barlows that I plan to use only with the ES92s.

Couldn't agree more. Apparently, ES were working on designing an 8.8mm ES 92 and another even shorter focal length 92. Pity these got canned, especially as the design characteristics of 17 & 12 ES 92 are excellent as is their performance. Only trade offs are weight and size but that's a small price to pay for as close to perfect a wide field as you can get in my view.

 

Good luck with the Siebert telecentric. We are not the only ones to appreciate the ES 92s in this way - I know a few others who also invested in top quality barlows so their 92s can also be enjoyed at different focal lengths.  

Edited by nkoiza, 08 April 2025 - 09:20 AM.

[kklei940]

I've been using my ES 92's with the GSO 2" barlow screwed onto the bottom of the eyepieces. Please report back as to how these telecentrics end up working out for you. It looks like it might be a nice option.

[25585]

Goes to show what a shame it is that ES dropped what was, and continues to be, their best eyepiece line. Hopefully this is a design that gets copied and expanded upon by other companies at some point in the future.

 

I put in an order with Siebert for two of their 8oz telecentric barlows that I plan to use only with the ES92s.

What magnifications are you getting? I have the ES 2x & 3x 2" fit B/extrs and a 4x Powermate.

[TayM57]

What magnifications are you getting? I have the ES 2x & 3x 2" fit B/extrs and a 4x Powermate.

1.2x 2" and 2.4x 2". This will give me a focal length spread of 5, 7, 10, 12, 14, and 17 with the ES92s. The appeal of the STB is their weights- 8oz compared to the 24oz of the 2x 2" PM.

 

 

I've been using my ES 92's with the GSO 2" barlow screwed onto the bottom of the eyepieces. Please report back as to how these telecentrics end up working out for you. It looks like it might be a nice option.

Yeah once I get the STBs in, I'll likely create a new thread with my review of the entire system.

Edited by TayM57, 08 April 2025 - 09:12 PM.

[25585]

Ordinary i.e. non-telecentric will be lighter, and will give a bit more eye relief in use. My lowest power is an Antares 1.6x, then an Astro Physics 2x and a Celestron Luminos 2.5x, none are too heavy.

 

One thing I wonder is why TV only does 2x & 4x in 2" Powermates & Barlows (Big Barlow is 2x).

[TayM57]

Ordinary i.e. non-telecentric will be lighter, and will give a bit more eye relief in use. My lowest power is an Antares 1.6x, then an Astro Physics 2x and a Celestron Luminos 2.5x, none are too heavy.

 

One thing I wonder is why TV only does 2x & 4x in 2" Powermates & Barlows (Big Barlow is 2x).

Yeah I know. I did consider the fact that a traditional barlow will increase ER. However, these ES92's already have the ER I need, and I didn't want to make any optical compromises when barlowing, and I wanted precise focal lengths from 5mm to 17mm.

 

The two STB's I got cost a pretty penny, nearly $700. However, $700 is reasonable when you consider I just added the equivalent of four ES92's- the 5, 7, 10, and 14.

 

I never considered the TV 2x PM because of the weight. These STB's are only 8oz.

 

I think TV made a business decision with regards to their PM magnifications- having too many magnifications might result in slow sales for some magnifications. Not sure, but that would be my guess.

 

Which is why I went with custom barlows from Siebert.

[nkoiza]

The two STB's I got cost a pretty penny, nearly $700. However, $700 is reasonable when you consider I just added the equivalent of four ES92's- the 5, 7, 10, and 14.

 

I never considered the TV 2x PM because of the weight. These STB's are only 8oz.

 

That's a really good spread of equivalent focal lengths to accompany 17 and 12. Given the light weight and the fact that these are likely to cover most of the ranges needed for DSO observing, it strikes me as though the two STBs were a great choice (assuming optical performance)!   

[TayM57]

That's a really good spread of equivalent focal lengths to accompany 17 and 12. Given the light weight and the fact that these are likely to cover most of the ranges needed for DSO observing, it strikes me as though the two STBs were a great choice (assuming optical performance)!

Everything I've read indicates the STB's are the equivalent to the powermates. Here's to that!


I'm a bit apprehensive about the gap between the short focal lengths. I would have liked a 6mm and 8mm but the way I set it up, gives me the biggest range.

Who knows I may get another STB down the road to get that 6 and 8mm focal lengths.

[DRodrigues]

Likely not, as it's 1.25" and the ES92's are 2". 

...

For using the 2.25x Baader Hyperion barlow with 2" eps, you just need a 2" to T2 ring adapter - the Barlow comes with 1.25" and T2 adapters. In my case, I wanted to use it on 1.25" mode so used also aT2 to 1.25" male adapter (beware  that it must be one with all interior with 1.25" filter female thread), and got a 5mm ES92 to use with spotting scopes!

Still didn't tested this solution with the ES92_17.

Edited by DRodrigues, 11 April 2025 - 01:09 PM.

[Ac2aj]

The ES 12 mm 92 is definitely my favorite Ep. I have the ES 2x focal extender but the weight is a lot. These days I only use it for the 12mm view. Glad I bought way back then for 499.00 January sale now it's 799 if they are not sold out.

[nkoiza]

The ES 12 mm 92 is definitely my favorite Ep. 

Same here, together with the 17mm ES 92 - despite having used most premium widefield eyepieces from all leading manufacturers except Nikon.

 

Nowadays, my deep sky viewing is carried out almost exclusively with 17mm and 12mm ES 92s and an AstroPhysics BARCON and 4x TV Powermate!

 

I own most of the Pentax XWs and some Baader Morpheus and APM XWAs, but these tend to stay in my eyepiece case except for occasional use of my 16.5mm Pentax XW and more regular use of a 30mm Pentax XW as a finder.  I have settled on this arrangement for quite a while now, as this set up has proven to work for me.

 

Planetary observing is a different story though, where I call upon my Pentax XOs and TMB Supermonocentrics and TMB ED 1.8x Barlow almost exclusively.

[TayM57]

The ES 12 mm 92 is definitely my favorite Ep. I have the ES 2x focal extender but the weight is a lot. These days I only use it for the 12mm view. Glad I bought way back then for 499.00 January sale now it's 799 if they are not sold out.

They are indeed out of stock at most places. In my search for the 12ES92, I came across an astronomy site that still had 1, maybe 2, in stock for $799.

 

Same here, together with the 17mm ES 92 - despite having used most premium widefield eyepieces from all leading manufacturers except Nikon.

 

Nowadays, my deep sky viewing is carried out almost exclusively with 17mm and 12mm ES 92s and an AstroPhysics BARCON and 4x TV Powermate!

 

I own most of the Pentax XWs and some Baader Morpheus and APM XWAs, but these tend to stay in my eyepiece case except for occasional use of my 16.5mm Pentax XW and more regular use of a 30mm Pentax XW as a finder.  I have settled on this arrangement for quite a while now, as this set up has proven to work for me.

 

Planetary observing is a different story though, where I call upon my Pentax XOs and TMB Supermonocentrics and TMB ED 1.8x Barlow almost exclusively.

I expect to do the same, Delites/Delos for Planetary. But for Lunar, I do like the wide field views that the ES92's afford. Plus, for some nights, 5mm isn't quite short enough.

 

The STB's come in 2 weeks. Hopefully before May, I'll have them in hand. I'll post a write up on how the ES92's do with the STBs after I get a chance to use them on Luna, open clusters, and some DSOs before I do a write up.

 

Particularly important would be how the STBs + ES92s do on open clusters before I do a write up, as any optical abberations would show up easily on open clusters. 

Edited by TayM57, 11 April 2025 - 06:00 PM.

[nkoiza]

The STB's come in 2 weeks. Hopefully before May, I'll have them in hand. I'll post a write up on how the ES92's do with the STBs after I get a chance to use them on Luna, open clusters, and some DSOs before I do a write up.

 

Particularly important would be how the STBs + ES92s do on open clusters before I do a write up, as any optical abberations would show up easily on open clusters. 

Really looking forward to reading your write up 

[HfxObserver]

I've been on a similar path and finally had the opportunity to try out the ES 92's and GSO 2x in the 7-inch TMB Achro. Please ignore the 22 Nagler in the diagonal, I just had it in there when I started up.

 

Last night I had a chance to try out the barlow threaded onto the APM prism diagonal, later with the the Lumicon MFS 99%. Last week I tried it inserted into the diagonal and inserted in front of the diagonal.

 

Optically this works well, it is all quality glass. Mechanically though, unless I was trying to do something pretty specific, I couldn't imagine introducing any of these combinations. The primary issue is the required back focus necessitating an extension tube. It's just a lot of messing around to get to the desired powers.

 

Edit: while placing the barlow in the diagonal doesn't require an extension tube it is raising an already large eyepiece and just felt like something I might wish to do regularly.

 

So I'm not inclined to say you get a 17mm, 12mm and with 2x 8.5mm and 6mm, in practice it's like pick one for your setup that night. My Moonlight focuser is rated for ~10lbs so it doesn't feel sketchy or anything, but just putting this together feels like a mini project. On smaller scopes they would easily be overwhelmed and I don't know how one might manage balance.

 

I'm eager to learn how the OP finds the Siebert Telecentrics, they seem like the best way to get the most out of these eyepieces since these are focal extenders and shouldn't require an extension tube plus and the light weight will help mitigate any balance issues.

 

Additionally I'd read a prism will make CA worse in an achromat and theoretically a barlow might improve it but any additional false colour over a regular diagonal is something I couldn't really notice as there's lots of colour in my scope anyway. I do really like the aesthetic of the stars with the prism better since the stars seem to sparkle more.

 

Chris

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Edited by HfxObserver, 26 April 2025 - 03:43 PM.

[TayM57]

All of my scopes have Moonlite focusers, but the 8" and 10" may have a tough time owing to tube flexure. The 17.5" and 24" will have no issues with the weight or balance.

 

I should have the Siebert Telecentric Barlows within a week hopefully.

[HfxObserver]

Looking forward to your report.

 

We use these 92-degree eyepieces in a 12-inch scope using a Type II Paracorr and they are phenomenal but the focuser is barely up to the task. In your larger scopes they must be amazing. 

 

Like you, I wish ES had created the shorter focal lengths.

 

Chris

[25585]

My best focuser for heavy loads is on my APM LZOS, which has the APM 3.7" focuser. I can use a 4x Powermate, or ES Barlow-extender 3x with my 92s with ease. Next size down Is Takahashi 2.7".

Edited by 25585, 27 April 2025 - 04:11 PM.

[TayM57]

24" has a 2.5" Moonlite so pretty beefy. It'll handle the ES92's + STBs.

 

I ended the night last night with the 12ES92 in the focuser. Really wish I had these STBs in hand, as I find the ultrawide AFOV of the ES92s pleasing.

 

If ES had released just one more focal length, a 7mm, that might actually be a pretty good line up for a lot of people. The 12ES92 for me, is just not enough power for a lot of targets.