The Next Steps for 2 Inch EP Viewing, What Are

[yanello]

I Prefer 2 inch EP Viewing  (Orion Xt8 Plus & 28mm 2in Deepview ep).

So, naturally, what follows is that I am eager to try more 2 inch ep, or 2 inch barlow, or 2 inch televue.

What should I try first? A Barlow, a televue, or another ep?

Televue powermate?
Televue barlow?
Celestron Luminous 2.5 barlow?
Orion 2 inch barlow?
Orion Q70  38 mm ep?

I am leaning toward a couple of things already, so sway me if you can in a better direction to suit my needs. For example, I would like to try the Orion Q70 38mm ep, and some sort of 2 inch barlow or televue. Price is an issue initially. Also, if I do get a 2 inch barlow, I'd give my 1.25 Orion barlow to my daughter who has a 70mm refractor. I like using wide view 2in ep to view the sky, then if I want magnification, like on jupiter, I want to barlow it or equivalent.

Thanks for your advice. May it bring clarity to me!!!

P.S. Bonus question (for my benefit of course). Should I get a telrad for star hopping?

I do not like the red dot pointer that came with the dob, because I cant seem to get the scope and the finder lined up properly on an object, its off a bit, sometimes a good bit (maybe because I have not yet collimated the scope mirrors, who knows, I am so new I dont know). So, if a put a telrad on it, with a 4 inch riser, would I have the same problem anyway since I didn't deal with the mirrors yet? Or, would a telrad be my obvious next step in adding pieces to this scope? Thanks  .

Also forgive any astro-spelling errors or astro-term bungling! Appreciated.

[Ricochet]

What is it about using the deepview that you particularly like? With an apparent field of view of 56 degrees the deepview only just about requires a 2" barrel and so any shorter eyepiece with the same afov will only require a 1.25" barrel. 

[Timebandit]

Hi . I am coming round to 2" viewing also even though I have a number of 1.25 eyepieces.  You just seem to get a wider more in depth view with a large wide field 2" eyepiece than 1.25, and I have them in the 20mm , 28mm and 55mm, the views is all I can describe it as is  just a more of a space walking experience . I have some 2" in  televue nagler which I find great for a space walk experience and closely followed by my William optics uwan 2" eyepiece. I am also looking looking into a  powermate(which I understand are very good) to assist with my new fondness for 2". I hope this is helpful. 

[John]

If you are intending to use a barlow-type device with a long focal length eyepiece (whether 2" or 1.25") it's worth lknowing that a barlow lens increases the eye relief (the distance you need to place your eye at). Longer focal length eyepieces tend to already have quite generous eye relief so you can find yourself needing to "hover" your eye some way off the top of the eyepiece when the barlow lens is in use. This can be awkward and uncomfortable when trying to observe at high powers as well as letting surrounding light onto the top lens of the eyepiece which reduces contrast and creates distracting reflections.

A Powermate, TeleXtender or Focal Extender does not have this effect on the eye relief so can be a better solution for increasing the power given by long focal length eyepieces.

Something else worth considering is that you don't actually need a 2" format eyepiece to get an ultra or even hyper wide view with eyepieces below around 14mm in focal length. Even the 100 degree Ethos eyepieces are actually 1.25" eyepieces despite, their 100 degree fields, in the focal lengths 13mm and shorter. They are however fitted with a 2" barrel as well as the 1.25" one because their weight and bulk makes them more secure in a 2" drawtube.

 

[rwilkey]

Hi there, I see no real need to get a 2" Barlow, esp. as they do not work successfully with low power ep's in my opinion, why would you want to Barlow a low power widefield anyway?  I only say this because I made the same mistake and later sold the Barlow.  You learn by your experiences (good or bad!)

[Louis D]

Be aware that if you barlow a wide field, two inch eyepiece, you will get vignetting unless you use either a telecentric barlow like a Powermate or use a TV Panoptic Barlow Interface with either a TV Big Barlow or a GSO ED barlow.  The TV PBI is only available used.

I would go for the ES Maxvision 40mm eyepiece next to maximize your field of view at a reasonable exit pupil for your scope.  I have the Meade 5000 SWA version and love it.  It's sharp to the edge with a coma corrector at f5.

Next, I would recommend the 17mm Nagler T4.  It can be picked up used for a very reasonable amount as more people move to Ethos eyepieces.  It's also very sharp to the edge.

Below 17mm, I would recommend using 1.25" eyepieces.  The Delos are my favorites in this range.

[Louis D]

On ‎6‎/‎11‎/‎2016 at 11:56, yanello said:

I do not like the red dot pointer that came with the dob, because I cant seem to get the scope and the finder lined up properly on an object, its off a bit, sometimes a good bit (maybe because I have not yet collimated the scope mirrors, who knows, I am so new I dont know). So, if a put a telrad on it, with a 4 inch riser, would I have the same problem anyway since I didn't deal with the mirrors yet? Or, would a telrad be my obvious next step in adding pieces to this scope? Thanks  .

Look into mounting a green laser sight as described in this Cloudy Nights post.  I mounted one on each of my scopes and permanently aligned them since I never remove them.  It beats trying to crank my old neck around to point my scope.  Just watch out for aircraft before lighting it up and you'll be fine.

[yanello]

On ‎6‎/‎11‎/‎2016 at 13:32, Ricochet said:

What is it about using the deepview that you particularly like? With an apparent field of view of 56 degrees the deepview only just about requires a 2" barrel and so any shorter eyepiece with the same afov will only require a 1.25" barrel. 

Greetings Ricochet,

Being a babe in this (but old in years), I do not have enough experience to answer the question. Yet, I would like to get a 38mm 2in ep, and am also considering the Baader 8-22mm 2in Zoom ep, and its barlow that attaches specifically to it (as I read recently, that was the original use of a barlow, and not sure if it matters much anymore). Anyway, I just like the bigger 2in ep's, my limited experience with the 1.25 just seem to make the 2in easier for me to use, and keep objects in fov.  

 

[yanello]

On ‎6‎/‎11‎/‎2016 at 14:30, Timebandit said:

Hi . I am coming round to 2" viewing also even though I have a number of 1.25 eyepieces.  You just seem to get a wider more in depth view with a large wide field 2" eyepiece than 1.25, and I have them in the 20mm , 28mm and 55mm, the views is all I can describe it as is  just a more of a space walking experience . I have some 2" in  televue nagler which I find great for a space walk experience and closely followed by my William optics uwan 2" eyepiece. I am also looking looking into a  powermate(which I understand are very good) to assist with my new fondness for 2". I hope this is helpful. 

Good Evening Timebandit,

I agree, that its more of a figurative space walking experience, and a great escape from daily life! Just floating up there with the stars in my space ship, I mean in my mind! I now lean toward the Baader 2in ep 8-22mm Zoom, and its 2.5 barlow. I have not yet purchased anything, but I want a 38mm Q70 Orion or equiv, and the Baader Zoom. Have you considered the zoom or what is the drawback? Thanks for you Time. Pat

 

[MarkVIIIMarc]

I am the proud new owner of a Telrad and find it to be a great tool combined with my right angle finder on my dob.

I also own a relatively inexpensive Zhumell 2" barlow. For my inexperienced eyes it seems like a good purchase.  It effectively doubles the number of magnifications available to me. Eventually I may have twice the eyepiece collection, but not yet!

[yanello]

On ‎6‎/‎11‎/‎2016 at 17:28, John said:

If you are intending to use a barlow-type device with a long focal length eyepiece (whether 2" or 1.25") it's worth lknowing that a barlow lens increases the eye relief (the distance you need to place your eye at). Longer focal length eyepieces tend to already have quite generous eye relief so you can find yourself needing to "hover" your eye some way off the top of the eyepiece when the barlow lens is in use. This can be awkward and uncomfortable when trying to observe at high powers as well as letting surrounding light onto the top lens of the eyepiece which reduces contrast and creates distracting reflections.

A Powermate, TeleXtender or Focal Extender does not have this effect on the eye relief so can be a better solution for increasing the power given by long focal length eyepieces.

Something else worth considering is that you don't actually need a 2" format eyepiece to get an ultra or even hyper wide view with eyepieces below around 14mm in focal length. Even the 100 degree Ethos eyepieces are actually 1.25" eyepieces despite, their 100 degree fields, in the focal lengths 13mm and shorter. They are however fitted with a 2" barrel as well as the 1.25" one because their weight and bulk makes them more secure in a 2" drawtube.

 

Good evening John,

Excellent details. I appreciate it. Do you think I can achieve a great so called 2 inch viewing experience with the following: a 38mm 2in ep or equiv, and also a Baader 8-22 Zoom 2in ep (and its barlow, I heard some say that  DSO's are good to barlow). I just truly like the idea of having a so called walk around lens, the lens I would use the most, as that zoom I listed. Do you have a zoom, and is it 2 or 1.25, or why don't you have one? I look forward to your answer on this.

[yanello]

13 hours ago, rwilkey said:

Hi there, I see no real need to get a 2" Barlow, esp. as they do not work successfully with low power ep's in my opinion, why would you want to Barlow a low power widefield anyway?  I only say this because I made the same mistake and later sold the Barlow.  You learn by your experiences (good or bad!)

Good evening White Dwarf,

Well, I too agree that barlowing a low power ep does not seem fitting. Yet, two things prod me on the path I am on, though a babe I am indeed. One, I do not like 1.25 ep very much at all (yet, I have only one 2 in ep in my collection). Two, I heard that barlowing DSO in general can be desirable. And so, why not barlow with a 2 in ep, my preferred giant way of looking at things? Maybe I am just too inexperienced to heed your advice. What say ye? Thanks, Pat 

[yanello]

3 hours ago, Louis D said:

Be aware that if you barlow a wide field, two inch eyepiece, you will get vignetting unless you use either a telecentric barlow like a Powermate or use a TV Panoptic Barlow Interface with either a TV Big Barlow or a GSO ED barlow.  The TV PBI is only available used.

I would go for the ES Maxvision 40mm eyepiece next to maximize your field of view at a reasonable exit pupil for your scope.  I have the Meade 5000 SWA version and love it.  It's sharp to the edge with a coma corrector at f5.

Next, I would recommend the 17mm Nagler T4.  It can be picked up used for a very reasonable amount as more people move to Ethos eyepieces.  It's also very sharp to the edge.

Below 17mm, I would recommend using 1.25" eyepieces.  The Delos are my favorites in this range.

Good evening Star Forming,

I just checked out the Maxvision. With your recommendation of not using a 2 in ep below 17mm, would you then discourage me from using the Baader 8-22m Zoom 2in ep, along with its 2.5 barlow that attaches right to the ep, like they did it of old, or originally? 

Any firm direction one way or the other will be appreciated. Thanks, Pat

 

[yanello]

2 hours ago, Louis D said:

Look into mounting a green laser sight as described in this Cloudy Nights post.  I mounted one on each of my scopes and permanently aligned them since I never remove them.  It beats trying to crank my old neck around to point my scope.  Just watch out for aircraft before lighting it up and you'll be fine.

Sounds like a great tip. I shall look at that post now. Thanks, Pat

[yanello]

19 minutes ago, MarkVIIIMarc said:

I am the proud new owner of a Telrad and find it to be a great tool combined with my right angle finder on my dob.

I also own a relatively inexpensive Zhumell 2" barlow. For my inexperienced eyes it seems like a good purchase.  It effectively doubles the number of magnifications available to me. Eventually I may have twice the eyepiece collection, but not yet!

Good evening MarkVIIIMarc,

I am glad to hear this about your Telrad. I did not yet, purchase one, but am leaning toward it, for two reasons. One, I do not like that chincy looking red dot that came with my dob. Two, the Telrad may help me grow in my use of the stars, with that circles, field degrees, or what ever one is suppose to call it, regarding its help in star hoping. Have a good night! Thanks, Pat 

[Louis D]

On 6/13/2016 at 19:51, yanello said:

would you then discourage me from using the Baader 8-22m Zoom 2in ep

Not at all.  That is natively a 1.25" eyepiece with a removable 2" barrel.  To my knowledge, the only 2"-only eyepieces below 17mm are the 5.5mm, 9mm and 14mm ES-100, 12mm ES-92, and 9mm ES-120 eyepieces (and possibly some other hyper-wide field eyepieces of similar build).  Pretty much all of them could probably just fit their field lenses in a 1.25" barrel, but it would be tight.  Certainly, the 5.5mm and 9mm ES-100 don't need to be since the similarly sized Ethos are not.  The most probably reason they are 2" only is because of their sheer weight.  The bigger barrel provides better support.

[yanello]

23 hours ago, Louis D said:

Not at all.  That is natively a 1.25" eyepiece with a removable 2" barrel.  To my knowledge, the only 2"-only eyepieces below 17mm are the 5.5mm, 9mm and 14mm ES-100, 12mm ES-92, and 9mm ES-120 eyepieces (and possibly some other hyper-wide field eyepieces of similar build).  Pretty much all of them could probably just fit their field lenses in a 1.25" barrel, but it would be tight.  Certainly, the 5.5mm and 9mm ES-100 don't need to be since the similarly sized Ethos are not.  The most probably reason they are 2" only is because of their sheer weight.  The bigger barrel provides better support.

Louis,

So, the baader 2 inch zoom (8mm-22) is essentially a 1.25 lens in a bigger casing? Hmm, interesting. So, I suppose this would only serve one purpose, that is the zoom can be okay for ease of use only, less lens taking out and putting another in (in that 8-22 range). So, it does not provide a wider fov since it is essentially a 1.25 lens in a 2 inch barrel? I can get similar fov or wider fov in certain 1.25 ep? I will have to think about whether or not I would actually use the zoom (in that range) or if I would only use the 2 inch 28mm, then switch to 1.25 10mm with our without my 1.25 barlow. The only other benefit of using the baader zoom may be that, barlowed with its 2.5 magnificatiom attachment, it would give much higher detail, if possible, considering the atmosphere and other factors. Good evening, Pat 

[Dave In Vermont]

The Baader Mark III Hyperion 8 - 24mm Zoom can be used as either a 1.25" or 2" - with removing and swapping around a few adapters that it comes with. The optics, as zoom's go, are a cut above many others. But like all 8 - 24mm zooms, the F.O.V. is rather narrow when compared to other eyepieces available in this range of focal-lengths. Zooms are convienent for such as a 'grab & go' eyepiece, as well as community outreach events in one's local park or top-of-building viewings in the city.

In 1.25" format:

 

And in it's 2" format:

Have fun -

Dave

[Paul73]

If you like the "spacewalk" views, don't buy the zoom. It is one eyepiece trying to be many! Something has to give. In this case, as mentioned above, it is the field of view which is positively claustrophobic. The quality of view is fine for the price and the convenience for a "grab & go" is undisputed. But, for imersive wide field viewing. No.

Hope that this helps.

Paul

[John]

7 hours ago, yanello said:

 

..... The only other benefit of using the baader zoom may be that, barlowed with its 2.5 magnificatiom attachment, it would give much higher detail, if possible, considering the atmosphere and other factors. Good evening, Pat 

One other benefit of a zoom is that you can quickly change the magnification "on the fly" to find what works best on the target that you are observing and under the seeing conditions that prevail.

There are zooms that deliver wider fields of view than the Baader, for example  the Speers-WALER zooms and the much praised Leica ASPH zoom. The former can be hard to source though and the latter bear a high price tag. Neither of these are actually 2" format eyepieces either although the Leica can be fitted with a 2" barrel instead of a 1.25" one.

[Dave In Vermont]

Last I read, John, the Speer-Waler (wide-area-long-eye-relief) Zoom was discontinued. At least so says Antares. So a hunt in the 'Used' astro-markets might be efficacious in finding one.

Dave - with an original 10mm Speer-Waler EP!

[AlentejoSkies]

A definite yes vote for the Telrad. I wouldn't be without one. Big and clunky for no obviouos reason, but a joy to use.

[Louis D]

I have the SW 5-8mm zoom, first edition from the late 90s.  It isn't a true zoom, more of a varifocal design to cop terms from photography.  As you extend the barrel, you increase the built-in, barlow-like smythe lens separation from the upper elements that form the actual image.  As anyone who has ever done this with an eyepiece and barlow can tell you, you need to keep refocusing inward more and more as you increase the separation/power.  The design actually works quite well.  The apparent field of view remains constant at about 78 to 80 degrees throughout the range.  It is nearly as sharp to the edge as my Pentax XL/XW eyepieces and is basically flat of field, so no refocusing of the edge is required.  It's just a bit short on eye relief compared to the Pentax designs, but that shouldn't be an issue for most people, even with astigmatism, at those exit pupils.  I just get a kick out of zooming in on objects like I'm traveling closer to it.  It's sort of a rush if you manage the simultaneous focusing properly.

[Ricochet]

On 6/14/2016 at 01:33, yanello said:

Greetings Ricochet,

Being a babe in this (but old in years), I do not have enough experience to answer the question. Yet, I would like to get a 38mm 2in ep, and am also considering the Baader 8-22mm 2in Zoom ep, and its barlow that attaches specifically to it (as I read recently, that was the original use of a barlow, and not sure if it matters much anymore). Anyway, I just like the bigger 2in ep's, my limited experience with the 1.25 just seem to make the 2in easier for me to use, and keep objects in fov.  

 

If the ease of keeping things in view is important then you should understand that this is related to the real field of view (RFoV) provided by a telescope/eyepiece combination which is the apparent field of view (AFoV) of the eyepiece divided by the magnification and not strictly related to the barrel diameter.

RFoV = AFoV / magnification

as magnification is the focal length of the telescope (Flt) divided by the focal length of the eyepiece (Fle) then

RFoV = AFov * Fle / FLt

so you can see that a wide RFoV can be achieved by using an eyepiece with either a large AFoV or a long focal length (or both). In the case of your deepview eyepiece the long focal length is the major factor. If you were to simply put it into a barlow then you would effectively lose that factor and the RFoV will be no better than in any 1.25" 56 degree eyepiece of the equivalent focal length. If you wish to increase the RFoV at shorter focal lengths then you should look at buying eyepieces with wider AFoV's to (partially) compensate for the shorter focal lengths.  That said, over time your ability to nudge your Dob the required amount should improve and you will then find keeping objects in view much easier.

[yanello]

On ‎6‎/‎16‎/‎2016 at 01:02, Dave In Vermont said:

The Baader Mark III Hyperion 8 - 24mm Zoom can be used as either a 1.25" or 2" - with removing and swapping around a few adapters that it comes with. The optics, as zoom's go, are a cut above many others. But like all 8 - 24mm zooms, the F.O.V. is rather narrow when compared to other eyepieces available in this range of focal-lengths. Zooms are convienent for such as a 'grab & go' eyepiece, as well as community outreach events in one's local park or top-of-building viewings in the city.

In 1.25" format:

 

And in it's 2" format:

Have fun -

Dave

Dave, Now I see the light on this, its really a 1.25 after all, just in a bigger housing. I still like this ep. Yet, I should carefully consider a 5.5 mm 1.25 ep wide fov, since my 1200 8in dob might be mag maxed out best with it or a 6mm. Good night, Pat