Leica ASPH beaten - but by what?

[Highburymark]

Have been enjoying an Indian Summer in London - just had the warmest September day for a century. Excellent seeing and lovely solar sessions with my Lunt LS50DS. And an opportunity to compare a range of higher magnification 10-12mm eyepieces which I find get most use when the atmosphere is behaving itself: Delos 10mm, Meade 4000 plossl 12.4mm, Leica ASPH zoom, Pentax XF zoom, and a new addition, TV plossl 11mm. Fripperies like field of view don't really influence solar astronomy - at least as far as I'm concerned. So I was simply trying to establish which EP gave the brightest, sharpest, most contrastful view, and which picked up most detail.

Fifth by some distance was the Meade plossl. Not a bad eyepiece by any means, but outgunned here. Particularly on transmission, which is more of a concern when observing a slight dimmer sun with a double stack filter.

Fourth was the Delos. Super sharp and impressive at night, I find the Delos range (and some other wide field TVs) underwhelms for HA solar, mainly because of the long eye relief, sensitivity of eye placement and exposure to stray light. I know some forum members swear by them. For me they stay in my night case.

Now comes the trickier bit: splitting the other three. I've droned on at great length about the Pentax XF zoom over the past couple of years on SGL. It's a wonderful solar eyepiece - sharp, lightweight, great value (if you shop around) and offers a user-friendly range from 6.5mm to 19.5mm - so much so that mine rarely leaves the Lunt diagonal. But in this company it (marginally) belongs in third place. 

The recent purchase of a low profile adapter gave me the opportunity to match the Leica zoom with the Lunt. This is my favourite and most used eyepiece. Ortho quality views with the advantage of a wide fov and the flexibility of a zoom. And it has an excellent reputation as a solar EP. But remarkably, this week it was beaten by the 11mm TV. I know the laws of physics favour a simple plossl design over the complex glass of the Leica when observing the sun, but I wasn't expecting the TV to be quite as good as it quite clearly showed itself to be. Over three days, under different conditions, observing the full range of features on the solar surface, the TV outperformed the Leica - giving me the most stunning and absorbing views of the sun I have ever had. There wasn't a huge amount in it - all of the top three EPs are top performers. But the 11mm TV plossl - its 15mm bigger brother is no slouch either - was a revelation. 

(With thanks to jabeoo, who first recommended TV plossls for the Lunt 50.)

 

[Roy Challen]

It's not that surprising really, it's a great eyepiece and has provided me with my best ever view of Jupiter.

[Stu]

Interesting findings Mark. The 11mm TV Plossl was always my preferred choice when I had my PST40, having tried many alternatives. I'm not sure I ever had both Leica and PST at the same time though so did not compare them but I suspect I would agree with you. I definitely preferred the Plossl to other more exotic widefield options such as Delos or Pentax XW and generally the 11mm was also nicer than a 12.5mm Ortho but that may have been a magnification or fov thing.

The Quark I had afterwards obviously needs longer f/l eps but plossls still work best.

Interestingly I have found white light solar to be different. The Leica, barlowed with a Baader VIP was better than any other option I tried in my Wedge, sharper than Orthos or plossls, and better for planetary too I thought.

I now exclusively binoview for WL solar, better than anything else I've tried, never done it for Ha though so not sure what results it would give.

 

[YKSE]

Very extensive and interesting comparison, Mark.

3 hours ago, Stu said:

Interesting findings Mark. The 11mm TV Plossl was always my preferred choice when I had my PST40, having tried many alternatives. I'm not sure I ever had both Leica and PST at the same time though so did not compare them but I suspect I would agree with you. I definitely preferred the Plossl to other more exotic widefield options such as Delos or Pentax XW and generally the 11mm was also nicer than a 12.5mm Ortho but that may have been a magnification or fov thing.

The Quark I had afterwards obviously needs longer f/l eps but plossls still work best.

Interestingly I have found white light solar to be different. The Leica, barlowed with a Baader VIP was better than any other option I tried in my Wedge, sharper than Orthos or plossls, and better for planetary too I thought.

I now exclusively binoview for WL solar, better than anything else I've tried, never done it for Ha though so not sure what results it would give.

 

Leica zoom doesn't reach focus in PST, Stu. it might do with VIP barlow, I've not tried it though.

I agree with you about Leica zoom in white light, it's just superb with VIP.

Same as you, I'm only binoviewing WL nowadays, no single ocular beats the comfort and perceived constrast seen with two eyes.

[Highburymark]

Thanks all for the replies - a wedge (and a dual alt az mount) is definitely on the acquisition list. Look forward to using the Leica in white light. But am loving the 11mm plossl.

[Moonshane]

I agree completely that the TV plossls are really excellent for solar. I do like my 17.3mm Delos though in Ha but prefer my Delites in truth. 

That said, I am considering moving to BVs for solar and suspect a 20mm or more likely a 15mm plossl will form the pairings for both white light and Ha.

[Highburymark]

Sounds good Shane - I haven't had a chance to experience a Delite yet, but can imagine they are superb for binoviewing and solar. 

I'd also be moving to binoviewers for ha if I hadn't been so tight when buying the scope and opting for the narrowest (bf400) diagonal/blocking filter. However I do have a binoviewer, a continuum filter and a pair of 15mm TV plossls, so am looking forward to trying them out on my Equinox 80 when I get a Lunt wedge.

Best of all, we moved house today (only half a mile down the road so no need to change the 'highbury' in my SGL name) - and I now have a garden with much better and more expansive views of the sky, so will be great for observing, whatever the target. 

 

[Moonshane]

I have a 5mm blocking filter in my pst mod (1000mm focal length) as does Peter Drew in his 150mm version and I have every intention of using binoviewers in mine after seeing the view at about 150-200x in Peter's.  why do you think you can't use them in your scope?

[Highburymark]

1 hour ago, Moonshane said:

I have a 5mm blocking filter in my pst mod (1000mm focal length) as does Peter Drew in his 150mm version and I have every intention of using binoviewers in mine after seeing the view at about 150-200x in Peter's.  why do you think you can't use them in your scope?

Just what I've picked up online - particularly on Cloudy Nights. Reports that Lunt advice has been that the narrowest blocking filter is not designed for binoviewers - but maybe there is hope?

[Moonshane]

Try it! You won't get full disk I suspect but who cares when you are looking at high res views of proms! 

[Highburymark]

Thanks - I definitely will!