Which 40mm Eyepiece

[Littleguy80]

I’m thinking about getting an eyepiece in the region of 40mm to give maximum exit pupil in my 80mm refractor. The Vixen LVW 42mm is a contender. The 41mm Panoptic is a pricier and heavier option. Based on the specs I found the Panoptic is lighter than the ES82 30mm which I can use comfortably with the 80mm refractor. 

What experience do others have with these or any other eyepieces when used with a small frac? Particularly interested in contrast and transmission. I haven’t got anything in mind around AFOV at the moment. 

[Mr Spock]

I use a 42mm LVW with an 80ED. Excellent wide field views especially under dark skies. Contrast and transmission are very good as is sharpness - stars are tiny specks with plenty of colour.

[Piero]

The Vixen 42 LVW I had was probably good in a F9 or F10 telescope, but in my Tak f7.4 showed quite a lot of astigmatism in the last 20% of the fov. 

The Meade maxvision 40mm is another good eyepiece after removing its armour. 

In any case an eyepiece giving 7mm exit pupil is very specialised and requires deep skies. In my 'long focal length' journey the TV panoptic 35mm was much better than the above two eyepieces. It was replaced by the APM UFF 30mm which gave me a more useful exit pupil and its weight is closer to my other eyepieces.

[LDW1]

I have a 2” WO 40mm, 70° ep that I use for low power, wide field views in all my refractors from f6 to f11.4. It puts up some great views when skies are at their best ! I also have 2”, 30, 50, & 65 mm eps as well ! How can you tell I like low power wide views, lol !

[McNewt]

I have a 41mm Panoptic on its way from FLO and I already have an 80mm f/6 triplet APO.   If you haven't pulled the trigger on an eyepiece once I get to take it out for a spin I can check back with a first impressions report.   My main use case with this combination, plus an UHC filter, is to find nebulae.

The view with the APO and the Nagler 31 is very sharp throughout most of the field, but slightly less so closer to the edges due to field curvature.   The sky is very dark uncovering zillions of otherwise invisible stars.  Very impressive and addictive.  On first light I pointed the scope to Altair and panned toward Deneb.  In seconds the Dumbbell nebula came into view.  Seeing was so-so and under Bortle 5 skies other objects in the area were hard to detect.   I'm patiently waiting for the darker autumn and winter months as in the summer the sky doesn't get truly dark here.    Anyway, these wide field views are intriguing and makes me want to search and discover rather than fiddling with alignment and hand controllers.  

 

[Littleguy80]

1 hour ago, McNewt said:

I have a 41mm Panoptic on its way from FLO and I already have an 80mm f/6 triplet APO.   If you haven't pulled the trigger on an eyepiece once I get to take it out for a spin I can check back with a first impressions report.   My main use case with this combination, plus an UHC filter, is to find nebulae.

The view with the APO and the Nagler 31 is very sharp throughout most of the field, but slightly less so closer to the edges due to field curvature.   The sky is very dark uncovering zillions of otherwise invisible stars.  Very impressive and addictive.  On first light I pointed the scope to Altair and panned toward Deneb.  In seconds the Dumbbell nebula came into view.  Seeing was so-so and under Bortle 5 skies other objects in the area were hard to detect.   I'm patiently waiting for the darker autumn and winter months as in the summer the sky doesn't get truly dark here.    Anyway, these wide field views are intriguing and makes me want to search and discover rather than fiddling with alignment and hand controllers.  

 

Thank you. I have similar plans to use narrowband filters to hunt for nebulae. Look forward to hearing your impressions for the Panoptic  

[jetstream]

One limiting factor for f7ish refractors (or others) is the lack of Ethos quality hyperwide eyepieces in the 35mm-40mm range IMHO. There is a noticeable increase in contrast when using Ethos over Nagler/ES eyepieces, at least to my eyes. This is in respect to nebula.

[michael.h.f.wilkinson]

I used to have a TMB Paragon 40mm, and foolishly sold it.  Clones are now sold as TS Paragon or SkyWatcher Aero 40mm. Really excellent performance, and very comfortable. Quite light too. The LVW 42mm I have now is also good, but is a bit less comfortable and a bit more prone to kidney-beaning.

[Louis D]

I tend to prefer my Meade 5000 SWA 40mm (same as the Maxvision) to my 35mm OVL Aero ED and 30mm ES-82 for scanning wide swaths of the sky.  I also really like my Baader Scopos Extreme 35mm due to it being super sharp in the center 60% of the field (better than any of my other wide fields).  The downside is it only has a 39mm field stop compared to the 46mm Meade, 44mm Aero, and 42mm ES.  The 30mm Wide Scan clones (Agena UWA 80 below) are great in the center 50% and then have severe field curvature out to their 44mm field stop.  If your eye has loads of focus accommodation like a camera lens, it might be a cheap option bought used.

Here's my composite of wide field eyepieces I posted elsewhere:

[michael.h.f.wilkinson]

Apparently, the 40mm Paragon/Aero is a great deal better than the 35 and 30mm versions. My TMB Paragon was really excellent, and worked well in an F/6 scope

[John]

On 17/09/2019 at 15:29, michael.h.f.wilkinson said:

I used to have a TMB Paragon 40mm, and foolishly sold it.  Clones are now sold as TS Paragon or SkyWatcher Aero 40mm. Really excellent performance, and very comfortable. Quite light too. The LVW 42mm I have now is also good, but is a bit less comfortable and a bit more prone to kidney-beaning.

Bit late to this but I agree re the Paragon. I don't use 40mm 2 inch eyepieces that much so went for a 40mm Aero ED clone (which I believe is the same optically as the Paragon) and have been very pleasantly surprised but it's performance even in my F/5.3 12 inch dob. By far the best focal length in this series IMHO.

By the way, I paid £50 for my mint Aero ED clone which makes you think when the Panoptic 41 costs £400+ and the Vixen 42mm LVW at £240.

FWIW I'm not sure what the AFoV of the Vixen actually is - there has been some confusion on this.

[Louis D]

It boggles the mind that the 40mm Aero ED/Sky Rover is sold out everywhere and the Chinese factory isn't churning out any new ones.  Clearly there's a demand for it worldwide.

[michael.h.f.wilkinson]

6 hours ago, Louis D said:

It boggles the mind that the 40mm Aero ED/Sky Rover is sold out everywhere and the Chinese factory isn't churning out any new ones.  Clearly there's a demand for it worldwide.

Weird indeed. No surprise it is popular, it is an excellent EP for a very modest price. Robtics still lists it:

https://www.robtics.nl/product_info.php?cPath=28_44_854&products_id=5649&pID=5649&language=en&osCsid=fqkvs84mcpulqj18bq3ji14nv1

But they are not always accurate when it comes to listing the supplies they have (they still list the XW 40mm). TS also don't list their Paragon 40mm any more. Looks like that line is coming to an end. I would not be surprised if the rather poorer performance of the 35 and 30mm versions has impacted sales of the series in general. 

[Louis D]

From what I understand, these Chinese eyepiece factories will crank up production on whatever you want and label it however your want so long as you meet their prepaid minimum order standard which seems to be somewhere between 100 and 300 units.  So, until some vendor like FLO, TS, or Astronomics decides to place an order, there won't be any more produced.

[McNewt]

I received the 41 pan and the Astronomik UHC and Astronomik UHC-E filters from FLO Thursday.  The weather wasn't all that great so I had to wait until yesterday before trying them out.

I started out at 9pm.  Seeing was okay.  I live under a Bortle 5 sky bordering Bortle 4.  The Milky Way can clearly be seen only a few nights a year.  Yesterday I could make out the Milky Way after my eyes had dark adapted.   I have quite a few tall tree around my garden, but there are a few openings; one directly south and one directly east.  With some planning it works out fine for observational astronomy.  

I brought out my TS Optics Photoline 80mm f/6 triplet APO, a Telrad, the Pan and the filters and I aimed at studing M27 since I know what it usually looks like.  Under dark skies you would be able to see the Milky Way and quite a lot of nebulosity in the Summer Triangle area.  For example the North America nebula.  In my backyard with an 80mm these are invisible.  I also planned to look at M31, without filters just trying the eyepiece, since it would be in the east at this time.

The 41 Pan is quite a hefty eyepiece, but compared to the 31 Nagler I would say it is lighter and somewhat smaller and by no means a mismatch for a small scope.  I did not have any problems balancing the setup on my small Skywatcher alt-az mount.  The 31 Nagler is a different story.

Using the Telrad I put the scope in the rough location of M27.  Basically the forth corner of a paralellogram drawn from Sadr, Gienah, Albireo and the location of M27.   Checking the eyepiece M27 was in view at first try.  It should be.  The outermost circle of the Telrad is 4 degrees and the FOV of the 41 Pan and a 480mm focal length scope is 5.5 degrees.   

M27 was faint.  I had to look at it with averted vision.  Other nights I could look at it straight on, but not now.  Perhaps seeing wasn't the best.

I decided to try out the filters.  I popped in the UHC-E and yes, contrast was noticeable better.  It made the sky a lot darker.  Stars still clearly visible although given a bluegreen tint.  The zillions of fainter stars were lost however, BUT I could now study M27 straight on.  Wow!   I proceeded switching to the narrower UHC filter.  It made the stars quite faint and clearly bluegreen.  Unfortunately it also made M27 a bit too faint to look at straight on.  My best guess is that under a darker sky and better seeing the UHC filter would make an improvement still.

I continued the session by pointing the scope to Deneb keeping the UHC filter in.   When panning around a bit closed to Deneb I could clearly see a lot of nebulosity.  Quite faint, but the filter provided the contrast needed to see it AND I could make out the North America nebula.  My first!  It was not a spectacular view.  I could clearly see the shape.   Exhilarated by the experience I decided to pop in the UHC-E filter since it brought out M27 so well.  Nah.  All nebulosity disappeared.   I switched back to the UHC for a while and then removed the filter to view the area without.   As expected the sky was washed out, but not too bad. 

I then relocated the scope to have a look at M31.  At this point in time it is located straight above Mirach so it is very easy to find.  On getting my eyes on it; GASP!  Wow.  The core was well defined and so were the arms.  I could see most of the extent of M31.   I kept studying it and I didn't want to stop.   For the sake of it I tried the UHC-E filter not expecting much and no, only the core was visible.

I did not notice any field curvature as I've done with my 31 Nagler and this scope.  However, yesterday I was well rested and it was fairly early in the evening on a weekend which do make a difference.  Eyes tired by a full day in front of a screen is a pain.  TL;DR; stars were sharp to the edge.  I've read quite a few threads were people complain about a fuzzy field stop in the 41 Pan.  I'm not sure about that.  I didn't see it.  At least, it was nothing that bothered me and this was something that I came to think about after I had brought in my equipment.  I did notice some pincushioning.   Nothing bothersome.  At least not to me.  Overall it is a very nice eyepiece that I found to be very comfortable to use.  I did also bought the TeleVue eyeguard extender in case I would have problems with eyepositioning.  I don't need it.

To sum it up; The 41 Pan with an UHC filter in a short focal length refractor does works great.  It allowed me to see the North America nebula under a Bortle 5 (/4) sky which has never been possible before.  Not even during late Nordic winter nights and roughly double the aperture.    The downsides; It doesn't replace a truly dark sky. 

 

 

Addendum;  I was worried that I would not have enough inward focus travel with the 41 Pan.  With the 31 Nagler it is a close call.  Only 1 1/4 rev on the fine focus knob before end of travel.  To my surprise I had to move the focuser quite a bit out before reaching focus.   

 

Edited September 22, 2019 by McNewt

[Littleguy80]

Excellent report! Thanks for sharing. The 41 Pan sounds like a good match for short refractors. 

[jetstream]

I just read the the Panoptic was designed for fast newts (newts in general) and for use with a Paracorr. There may be field curvature issues in some scope types ie fast refractors but not all seem to notice it.

I'm looking at the 27mm Pan for my 24" with a Paracorr II.

Obviously the 41mm Pan might be different as it seems this fl suits refractors and SCT's.

Edited September 22, 2019 by jetstream

[jetstream]

3 hours ago, Littleguy80 said:

Excellent report! Thanks for sharing. The 41 Pan sounds like a good match for short refractors. 

The 41 Pan is most likely better than the 42 LVW IMHO.

[McNewt]

I had my worries when I ordered the eyepiece.  One was the inward focus travel and the other FC given that I do experience some FC with the 31 Nagler in the same scope.  Luckily it works great.  A different designed scope may give a different result though.   I do have an f/5 newt as well.   At the next session I hope to get both scopes and both the long focal length eyepices out for a comparison.    

 

[John]

Great report on the big Panoptic

I have the (by comparison, miniscule) Panoptic 24mm and enjoy it a lot.

Most of my low power viewing with my 12 inch dob is done with my Ethos 21mm and, less often, with the Nagler 31. I find that the 21mm gives a darker background sky because I have a little light pollution here to contend with. Thats why I don't use a 40mm often so the Aero ED 40mm will do fine and I doubt that I could justfiy the additional cost of the 41mm Panoptic given the amount of use that it would get

[McNewt]

2 minutes ago, John said:

I have the (by comparison, miniscule) Panoptic 24mm and enjoy it a lot.

And one would think an eyepiece design from the early 90s would be old and dated technology.   

3 minutes ago, John said:

Most of my low power viewing with my 12 inch dob is done with my Ethos 21mm and, less often, with the Nagler 31. I find that the 21mm gives a darker background sky because I have a little light pollution here to contend with. Thats why I don't use a 40mm often so the Aero ED 40mm will do fine and I doubt that I could justfiy the additional cost of the 41mm Panoptic given the amount of use that it would get

If you already have an eyepiece of same focal length that does the job I see no reason why buy another one.   If it wasn't for the larger exit pupil needed to compensate for losses by the filters I wouldn't have considered a longer focal length eyepiece at all.  I did some research and was about to pull the trigger on the 40mm ES Maxvision.  It seems to perform well, but it also seems to be absolutely massive in size.  I hesitated and a few weeks passed.   As I was shopping around for a new tripod the Pan ended up in the shopping cart just to see where the totals would land.  Agony.  I reasoned that if it didn't work well for me I could send it back, but if it did it could be a keeper for life.   I didn't remove it from the shopping cart.

[Littleguy80]

Since starting this thread, each of these eyepieces has become available secondhand. The Panatopic sold for £300 and was too expensive for me. The Vixen LVW went at a bargain price of £100 and I was simply beaten to it by another lucky member. This week, I picked up a 40mm Aero for a total price of £49. I was encouraged by Michael and John's words of praise for this eyepiece. It arrived today and skies were clear so it got a quick first light run out. Report here for those that are interested:

 

 

[McNewt]

Oh yes.  Report please!   It is raining and all miserable here so I'm relegated indoors for some armchair astronomy.    £49 is a great price.  

 

[Littleguy80]

28 minutes ago, McNewt said:

Oh yes.  Report please!   It is raining and all miserable here so I'm relegated indoors for some armchair astronomy.    £49 is a great price.  

 

Boo to the rain. Link to the report in the post above  

[McNewt]

Ahaa!   *LOL*   I must be tired.  I didn't see it.