Eyepieces for mak/newt?

[ofranzen]

Is there anything particular one should keep in mind when looking at eyepieces for mak/newts? I have the SW 190MN astrograph and the eyepieces I got when I bought it are all but rubbish.

I am looking at a bunch of different models ranging from about 5-25 mm and perhaps 60-85 degrees fov. So nothing too extreme.

More expensive EPs talk about "well corrected" but that is less of an issue with the mak/mewt, right?

Regards

/Ola

[John]

The 190MN is F/5.3 so you do still need reasonably well corrected eyepieces to avoid seeing astigmatism in the outer parts of the field of view. Astigmatism comes from eyepiece optics. Coma (which comes from from the scope optics) is quite a bit less in a mak-newt than a conventional newtonian.

Decent eyepieces range from £50 (eg: BST Starguiders) to, well many £hundreds for the really exotic ones.

Baader Morpheus are well thought of quality eyepieces with a 76 degree apparent field and a good range of focal lengths. There are many choices really, depending on the budget available.

[ofranzen]

Thanks for a quick reply. I'm leaning a bit towards the Hyperion zoom with its barlow. I really don't know what FL will be most useful to me yet so the zoom, or the Hyperion modular with the tuning rings could perhaps be a good start. The zoom is particularly of interest as it will come in handy basically forever when showing the telescope to family and friend as for some reason the first question is always "where is the zoom"

[RT65CB-SWL]

2 hours ago, ofranzen said:

Thanks for a quick reply. I'm leaning a bit towards the Hyperion zoom with its barlow. I really don't know what FL will be most useful to me yet so the zoom, or the Hyperion modular with the tuning rings could perhaps be a good start. The zoom is particularly of interest as it will come in handy basically forever when showing the telescope to family and friend as for some reason the first question is always "where is the zoom"

I think you have made a wise choice in going for the Baader zoom. It is not as heavy as it looks. I tried one a few weeks ago. Once you have found the sweet spot, then you can purchase an eyepiece of a fixed focal length to what you need. Also a plus for having a zoom for public out reach, (when we can get out and about again after curfews/lockdowns have been lifted), and if you have a lot of other astro accessories and want to travel light.

Edited March 26, 2020 by Philip R

[John]

I agree with Phillip - the Baader zoom would be a good workhorse and earn its keep !

 

[F15Rules]

+1 for the Baader Zoom, it's very good. And if funds allow you to also buy a Baader Hyperion 2.25x Barlow lens (often come up used, here or on UKABS for c £50), this will transform your 8-24mm zoom to a c 3.55-10.66mm high power zoom for moon, planets and tight doubles.

The 24mm setting is rather narrow, at 40 degrees, so you might want to add in a single wide angle low power  eyepiece of say 22-30mm.. if you could stretch to a used Vixen LVW 22mm (65 degrees), or Televue Panoptic 24mm (68 degrees), you might never need anything else😊.

Dave

Edited March 26, 2020 by F15Rules

[ofranzen]

Thanks for your input. The Zoom and its 2,25x barlow sells for £235 as a bundle so chances are big I'm ordering that soon.

Clear skies.

/Ola

[Owmuchonomy]

Personally, I struggled with the Baader zoom. The eye relief is very short and so I passed it on.  I enjoy much easier views with my Lunt zoom on a variety of targets. It was used predominantly with my 130 pds and an Altair Astro 102 triplet. For me, the ES 82’ range are unbeatable at their price point.

[Second Time Around]

15 minutes ago, Owmuchonomy said:

Personally, I struggled with the Baader zoom. The eye relief is very short and so I passed it on.  I enjoy much easier views with my Lunt zoom on a variety of targets. It was used predominantly with my 130 pds and an Altair Astro 102 triplet. For me, the ES 82’ range are unbeatable at their price point.

Another vote for the Baader zoom + Barlow.  

One of the many plusses for me is that it takes a Dioptrx to correct my astigmatism.

From what I've heard the Lunt is not as sharp as the Baader on fast scopes, but I can't speak from personal opinion.  However, extra eye relief sounds interesting and would be an advantage if you observe with glasses or a Dioptrx.

A couple of questions about the Lunt zoom: firstly, does a Dioptrx fit it? Secondly, does the eye lens rotate when zooming?

[Louis D]

I really like my Celestron Regal and Olivon spotting scope eyepieces.  Once the eye cup is screwed off, there is plenty of eye relief for eyeglasses and the top does not rotate during zooming.  They vary from about 44 degrees at 24mm to 63 degrees at 8mm AFOV.  The field stop is sharpest toward the central part of the zoom range and gets a bit fuzzy at either end.  Edge correction is pretty decent.  It's included in my eyepiece field of view images at 8mm, 12mm, and 24mm.  The only tricky part is finding them since they are not sold individually anymore.  I watched ebay and the classifieds to pick up mine from spotting scope owners who didn't want them but wanted to recoup some of their investment.

[Second Time Around]

Many thanks, Louis!

Do these zooms take a Dioptrx? I see there's a photographic thread, is it between 41 and 44mm?  If it's the same as the M43 on my Baader zoom a Dioptrx will fit, although an O ring or elastic band on the thread will help.

[John]

57 minutes ago, Second Time Around said:

Many thanks, Louis!

Do these zooms take a Dioptrx? I see there's a photographic thread, is it between 41 and 44mm?  If it's the same as the M43 on my Baader zoom a Dioptrx will fit, although an O ring or elastic band on the thread will help.

These posts on the Cloudynights forum cover that. It looks like it is possible, with some care:

https://www.cloudynights.com/topic/573621-new-baader-mark-iv-8-24mm-zoom-eyepiece/?p=8816705

There are some photos from Don Pensack (Starman1) further down that thread.

 

 

 

[Second Time Around]

14 minutes ago, John said:

These posts on the Cloudynights forum cover that. It looks like it is possible, with some care:

https://www.cloudynights.com/topic/573621-new-baader-mark-iv-8-24mm-zoom-eyepiece/?p=8816705

There are some photos from Don Pensack (Starman1) further down that thread.

 

 

 

Thanks, John, but I obviously didn't explain myself well.  It was the Celestron and Olivons that Louis was referring to that I'm talking about.

I can confirm that a Dioptrx fits my Baader zoom, preferably with an O ring.

 

 

[John]

7 minutes ago, Second Time Around said:

Thanks, John, but I obviously didn't explain myself well.  It was the Celestron and Olivons that Louis was referring to that I'm talking about.

I can confirm that a Dioptrx fits my Baader zoom, preferably with an O ring.

 

 

Actually I didn't read your post carefully enough - you did say that of course

I think this is one of the eyepieces that Louis was referring to by the way:

https://www.ebay.co.uk/itm/Celestron-1-25-Regal-M2-8-24mm-eyepiece-with-case-Boxed-Fully-multi-coated/162688568329?hash=item25e0fe8c09:g:juIAAOSwzHNZy2gr

I've not used one myself by Louis is always positive about them.

[Second Time Around]

Many thanks, John.

Just bought that one!  It's from a retailer and 30 day returns are accepted.

[Louis D]

3 hours ago, Second Time Around said:

Many thanks, Louis!

Do these zooms take a Dioptrx? I see there's a photographic thread, is it between 41 and 44mm?  If it's the same as the M43 on my Baader zoom a Dioptrx will fit, although an O ring or elastic band on the thread will help.

You'll like it.  What's also really nice about them is the silky smooth zoom action.  There's no stiffness in it like so many other zooms.

Once the eye cup is completely removed by unscrewing it counterclockwise after the eyecup is all the way down (it retracts when rotating counterclockwise), a 37mm thread is revealed that is 6mm high with 2mm unthreaded above that.  I was able to thread a 37mm step ring onto it perfectly.  Thus, if you can locate a 43mm to 37mm step down ring, you should be able to attach a Dioptrx to it.

[Second Time Around]

Brilliant, Louis! Many thanks.

[Second Time Around]

I've found several step down rings of the right size but all will reduce the eye relief, that's already been reduced by the Dioptrx.

The eyepiece hasn't arrived yet, but if I decide to keep it I'll have an adaptor made that's simply a narrow ring with a 37mm inside diameter and a 43mm outside diameter.

However, that will probably have to wait until after the pandemic is over.

[Louis D]

On 30/03/2020 at 06:37, Second Time Around said:

I've found several step down rings of the right size but all will reduce the eye relief, that's already been reduced by the Dioptrx.

The eyepiece hasn't arrived yet, but if I decide to keep it I'll have an adaptor made that's simply a narrow ring with a 37mm inside diameter and a 43mm outside diameter.

However, that will probably have to wait until after the pandemic is over.

Did you get the zoom eyepiece yet?  Have you tried out a step-down ring on it for a Dioptrx?

[Second Time Around]

1 hour ago, Louis D said:

Did you get the zoom eyepiece yet?  Have you tried out a step-down ring on it for a Dioptrx?

The eyepiece has arrived and I've just taken it out of quarantine.  It's forecast to be clear tomorrow night so I plan to try it out then.

If I like it I'll be getting an adaptor made as I mentioned earlier.  One disadvantage though is that it doesn't have a filter thread.

Not having the eye lens turning when zooming will be handy with a Dioptrx, especially as I plan to get a binoviewer before long.

 

[Louis D]

2 hours ago, Second Time Around said:

The eyepiece has arrived and I've just taken it out of quarantine.  It's forecast to be clear tomorrow night so I plan to try it out then.

If I like it I'll be getting an adaptor made as I mentioned earlier.  One disadvantage though is that it doesn't have a filter thread.

Not having the eye lens turning when zooming will be handy with a Dioptrx, especially as I plan to get a binoviewer before long.

 

Yeah, I forgot about the thread business.  To keep the barrel short for spotting scope usage, they engineered it to put the bottom elements right at the end of the lower barrel leaving no room for threads.  You could put them on the front of the diagonal.

[Second Time Around]

16 hours ago, Louis D said:

Yeah, I forgot about the thread business.  To keep the barrel short for spotting scope usage, they engineered it to put the bottom elements right at the end of the lower barrel leaving no room for threads.  You could put them on the front of the diagonal.

I'm using it on my Dob so no diagonal.  However I can put 2 inch filters on my coma corrector, although it won't fit in the focusser of the 8 inch f/6 at the moment as the drawtube is flocked.  My 10 inch f/4.8 is being rebuilt, including fitting a Baader Diamond Steeltrack focusser.  Once I've finished this I'll probably put the same Baader focusser on the 8 inch.

I'm looking forward to testing the Celestron against my Baader zoom.  It'll be tomorrow night at the earliest now though, as this evening we've doing an online pub quiz with the family.

[Louis D]

3 hours ago, Second Time Around said:

I'm looking forward to testing the Celestron against my Baader zoom.

That should be interesting.  I've only looked through BHZs at star parties.  While decent, I thought that the eye relief was a bit tight with eyeglasses.  I always unscrew and remove the eye cup on the Celestron when observing with it to maximize eye relief.  I don't know if the same work-around is possible with the BHZ.

[Second Time Around]

Yes, you can screw the eyecap off with the Baader, Louis, although I use it with a Dioptrx.

I've now tried the Celestron and, although it was wasn't far behind the Baader, it had 2 disadvantages besides the FOV being smaller.  Firstly, as already mentioned, it didn't have a filter thread.  I realised that without that I couldn't use my 2.25x Baader Barlow as this screws into the filter thread.  Secondly, it's nowhere near as parfocal as the Baader, which would make it not so good with a binoviewer (that I wanted to use it for in the future), as both eyepieces would need refocusing.

For these reasons I've had to return it.  The seller, Northern Optics, was very fast at refunding me and I can thoroughly recommend them.

That said, I was very pleasantly surprised at the quality for the price. 

P.S. Thanks again to John and Louis.

Edited April 21, 2020 by Second Time Around

[Louis D]

1 hour ago, Second Time Around said:

Yes, you can screw the eyecap off with the Baader, Louis, although I use it with a Dioptrx.

I've now tried the Celestron and, although it was wasn't far behind the Baader, it had 2 disadvantages besides the FOV being smaller.  Firstly, as already mentioned, it didn't have a filter thread.  I realised that without that I couldn't use my 2.25x Baader Barlow as this screws into the filter thread.  Secondly, it's nowhere near as parfocal as the Baader, which would make it not so good with a binoviewer (that I wanted to use it for in the future), as both eyepieces would need refocusing.

For these reasons I've had to return it.  The seller, Northern Optics, was very fast at refunding me and I can thoroughly recommend them.

That said, I was very pleasantly surprised at the quality for the price. 

P.S. Thanks again to John and Louis.

Sorry it didn't work out.  From my frame of reference having used the Speers-Waler 5-8mm zoom for years, the Celestron Regal seems almost perfectly parfocal in comparison.  If a BHZ ever comes up for under $200, I might look at getting one for comparison sake.