Panoptic 27

[Dantooine]

Can anyone give me their experience on using a panoptic 27 with a 102 f7 refractor please. I’m thinking this would be a nice one for my lowest Magnification. 
 

Dale. 

[Louis D]

I've used my Panoptic 27mm in a variety of scopes for 21 years.  It is extremely sharp in the central 50%.  It remains very sharp in the remaining 50%, but slight astigmatism and field curvature starts to creep in.  It's very minor, but enough I switched over the the APM UFF 30mm over the last year or so.  The APM is also significantly more than 10% wider due to having much less edge of field magnification.  It is also usable with eyeglasses while the Panoptic is too tight on usable eye relief to use comfortably with eyeglasses.  I've also scratched eyeglasses on the Panoptic's exposed eye lens retaining ring.

[NGC 1502]

Hi Dale.  I’ve had a 27 Pan for 15 years, used in several telescopes -

8” f6 Newtonian, 10” f4.8 Newtonian, 16” f4.3 Newtonian.  Recommended in any similar scopes with the proviso that you will see issues caused by the scope not the eyepiece.   That’s why TeleVue make the Parracor to sort the coma inherent in the Newtonian design.   But without the Paracorr views are still great, however what’s ok for me may not suit another.

I realise you’re asking about performance with a 102 f7 refractor.  With my 70mm f6.8 Pronto the field curvature inherent  from the scope can be seen, but acceptable to me and recommended.

Eye relief is fine, but I don’t use glasses to observe.  I’ve not tried the TeleView Dioptrx but that’s a possibility you could research.

Ed.

[Dantooine]

6 hours ago, Louis D said:

I've used my Panoptic 27mm in a variety of scopes for 21 years.  It is extremely sharp in the central 50%.  It remains very sharp in the remaining 50%, but slight astigmatism and field curvature starts to creep in.  It's very minor, but enough I switched over the the APM UFF 30mm over the last year or so.  The APM is also significantly more than 10% wider due to having much less edge of field magnification.  It is also usable with eyeglasses while the Panoptic is too tight on usable eye relief to use comfortably with eyeglasses.  I've also scratched eyeglasses on the Panoptic's exposed eye lens retaining ring.

Thanks for your reply. I will maybe try one for 21 years then, must have been pretty good to “put up” with it for that long. I don’t observe with glasses so that’s a plus. 

Edited July 6, 2020 by Dantooine
Wrong word

[Dantooine]

25 minutes ago, NGC 1502 said:

Hi Dale.  I’ve had a 27 Pan for 15 years, used in several telescopes -

8” f6 Newtonian, 10” f4.8 Newtonian, 16” f4.3 Newtonian.  Recommended in any similar scopes with the proviso that you will see issues caused by the scope not the eyepiece.   That’s why TeleVue make the Parracor to sort the coma inherent in the Newtonian design.   But without the Paracorr views are still great, however what’s ok for me may not suit another.

I realise you’re asking about performance with a 102 f7 refractor.  With my 70mm f6.8 Pronto the field curvature inherent  from the scope can be seen, but acceptable to me and recommended.

Eye relief is fine, but I don’t use glasses to observe.  I’ve not tried the TeleView Dioptrx but that’s a possibility you could research.

Ed.

Second person to use one for over a decade! Must be nice to use. My 102 is an Ed so maybe it would be good in that. 

[Louis D]

I use a TSFLAT2 in my short refractors to flatten the inherent field curvature of them.  Even then, the slight field curvature relative to the APM is obvious.  The Panoptic is a fine eyepiece, and there weren't a lot of other options at that focal length at the time I bought it.  I now have a wide range of eyepieces between 26mm and 30mm; and the Panoptic sees very little scope time now, mostly owing to its lack of usable eye relief and fairly tight true field of view relative to its competitors.

[Graham Darke]

I used one with my f7 refractor and my Maksutovs and it was great. There was plenty of eye relief. I wear specs when observing and never had any issues. The eye relief on the 27mm Panoptic is 19mm. 

[Louis D]

I measured the usable eye relief of the Panoptic 27mm to be 14mm, which is about how it feels with my eyeglasses.  Remember, the design eye relief is measured from the center of the eye lens, and it is deeply concave on this eyepiece and slightly recessed.  The usable eye relief is measured from the top of the folded down eyecup.  So you've got about 1mm for the folded eyecup, 2mm for the eye lens edge recession from the metal lip the eyecup attaches to, and 2mm of eye lens concavity.  By comparison, the Pentax XLs and XWs advertise 20mm of eye relief and deliver 18mm of measured, usable eye relief, so much closer to advertised than the Panoptic.

Part of my problem wearing eyeglasses with eyepieces is the bridge of my nose is 14mm deep, so I need a few millimeters more than that to accommodate my eyeglasses.  I suppose I could try using a monocle. 🧐

[Dantooine]

Well you have to admit a monocle would fit the stereotype of astronomers. I understand what you are saying about actual eye relief though as I had some explore scientific eyepieces. They really overstated their eye relief and some lenses are very recessed.