16 replies to this topic

[Saxonjan]

Looking to push the magnification more than my Morpheus 6.5mm to split doubles and planetary viewing. I’m tossing up between Pentax xw 3.5mm, televue 3.5mm Delos or 3mm delites.  Happy to hear people’s thoughts/opinions or recommendations. My IPD is 67mm so wider eyepieces shouldn’t be a problem?

[jrazz]

I've found that for high magnification the lighter, narrower eyepieces are easier to handle. From your list I would pick the Delites (have been considering them for my BT-100).

 

Since you already have a Morpheus EP, why not consider the Morpheus 4.5mm? You'd get ~145x magnification with an exit pupil of ~0.85 which is great for doubles. I know magnification seems great but the image quality deteriorates very quickly. You don't gain resolution either. Star hopping and orientation would also be significantly easier.

 

One last option. I've been using and enjoying the BST Planetary range of eyepieces. The 3.2 mm is a fairly decent one. It doesn't hold a candle in quality as compared to the above options but they are far cheaper, easier to handle and work superbly for splitting close doubles. The FOV and edge sharpness are nothing to write home about and they do suffer from internal reflections but the center is excellent. I've been able to split 1.5" doubles with them conditions permitting. GRS on Jupiter is also wonderful though the Pentax 5mm seem to do slightly better on really bright objects (see internal reflections).

 

 

Whatever you choose, please let us know how it works! Us, high magnification BT users are far and few between. Most prefer wide views and prefer telescopes for high magnification. Glad to see I'm not the only crazy one out there  

[oldmanrick]

Saxonjan, I envy your 67mm IPD, mine is around 63mm, and quite restrictive as to which eyepieces I can use.

 

For my 100mm Lunt BT, I favor the Morpheus 4.5mm pair.  I have tried others down to 3.4mm, but I felt the FOV was too restrictive or the view too dim with restricted contrast.  In my 100, the 4.5 pair seem slightly better matched optically the BT than the 6.5mm pair.  I have a pair of 4.7mm Delites, but much prefer the 4.5 Morpheus pair, due to greater eye relief and overall greater viewing comfort.  I also like the Morpheus line of eyepieces due to their shaft design, which is more compatible with the collets in the focusers on my BT's.  They are also quite light compared to most other premium eyepieces, although somewhat bulky.

 

I realize that the 4.5's may not be enough different in magnification from your 6.5's to suit you, but I find that going above that in my 100 results in a pair of eyepieces that seldom get used. Of course your Obie may be different or better.  

 

I also have a pair of ES 3X focal extenders, but they add more complexity to the setup plus a lot more weight at the back of the BT, so they seldom see use.

 

Good luck with your venture into getting more magnification out of your BT, and keep us posted as to what ends up working for you vs what you have tried.

 

Rick

[aznuge]

I have had good luck with 5mm TV DeLites in the 127BT.  Although I have the 3-6 Nagler Zooms, I only use those for confirming image merge at 217x since the eye relief is not up to an eye glasses standard on those.  But I do like the Morpheus eyepieces and have used the 6.5mm version extensively in APM BT100s, and also in the 127s.  Rick's comments about the 4.5mm Morphs have gotten me interested in adding these as well for the 127s.  To go to the 3 to 3.5 mm range, I think I will wait for the OP's report

[Saxonjan]

Thanks jrazz it’s great to know you have some luck with the 3.2’s even though you say they are of a lesser quality, it’s reassuring considering I posed the same question directly to Kevin it OW, he recommends down to a 5mm Delos, it was interesting to know that he collimates the 127sd using 4mm tv radians.

[Saxonjan]

Old man Rick I organised to purchase a pair 4.5mm Morpheus but as I walked in the shop something made me thing the 6.5s might be a better first eyepiece purchase before going higher. It’s interesting that you think the 4.5s are more suited to your 100mm bt. How well do your focal extenders perform, do you feel they reduce the quality of image? I think the extra weight wouldn’t be noticed so much since the 127mm bt has roughly twice the weight.

[Saxonjan]

Aznuge I’m considering the 3-6mm Nagler zooms too, would you use them more if you didn’t wear glasses? Also how close is the quality of image compared to a fixed focal length in your opinion? I’m still not sure which way to go yet and to make it harder  to make a decision I start reading about the apm and Williams optics 100-110degree wide view eyepieces, but am not sure how they’d go IPDwise as they look huge. Maybe some other people can chime in. All in all I’m a bit more reassured knowing some others are having luck pushing the magnification a bit more than what Kevin recommends. I was leaning towards the Pentax xw3.5mm after reading a lot of comments here on cloudy nights but still the idea of a quality zoom still sounds great if I wouldn’t lose too much in image quality, even if the field of view is smaller.

[OBERWERK]

... I posed the same question directly to Kevin it OW, he recommends down to a 5mm Delos...

I said 6mm Delos, TV doesn't make a 5mm Delos.  There's the 5mm DeLite, but I haven't tried that.   

[oldmanrick]

Old man Rick I organised to purchase a pair 4.5mm Morpheus but as I walked in the shop something made me thing the 6.5s might be a better first eyepiece purchase before going higher. It’s interesting that you think the 4.5s are more suited to your 100mm bt. How well do your focal extenders perform, do you feel they reduce the quality of image? I think the extra weight wouldn’t be noticed so much since the 127mm bt has roughly twice the weight.

Saxonjan, I think you were wise to purchase the 6.5mm's before the 4.5's.  As magnification bumps up ease of use becomes more difficult, especially when using the same eyepiece line.  As far as differences between the 6.5 and 4.5mm Morpheus, they are very subtle, other than the greater magnification and lesser FOV, as expected in the 4.5  Actually it's a  bit strange, but I prefer the 6.5 just very slightly in my big APM 150 BT over the 4.5, where it's just the opposite in the Lunt 100mm.  This was decided mostly when trying to split close double stars or see tiny almost invisible objects like Saturn's moons, or the E and F stars in the Trapezium.  It could easily be different with different seeing conditions or with a different target.  I have four of the Morpheus pairs of eyepieces, and consider them to be my favorites for most viewing situations.  I also like the Pentax XL and XW lines, but have nothing shorter than the 7mm in those.

 

Ii's not so much that the focal extenders reduce the image quality, it's just that their length and mounting system coupled with the high power, make them more difficult to attain a merged image, and more difficult to use overall.  Actually, if I keep the magnification down to a reasonable level, (not much more than the 4.5mm gives by itself), they do surprisingly well.  It is much easier to just use the 4.5's by themselves.

 

The extra weight of the power extenders isn't much of a problem for me.  The 150 BT is so heavy that I don't know the difference, and I use a geared photo mount for the 100 BT which is very rigid and stays where I put it even with the extra weight.

 

Cheers!

 

Rick

[Saxonjan]

I said 6mm Delos, TV doesn't make a 5mm Delos.  There's the 5mm DeLite, but I haven't tried that.   

My bad sorry

[aznuge]

Saxonjan,

Your question got me curious about the NZs, so I set up a side by side, daytime comparison of different eyepieces in the APM BT100s and the OB 127XL (both are SDs).  I first wanted to get a comparison of equivalent power, between the BTs.  I used 5mm DeLites in the APMs (110x) and 6.0mm NZs (108x) in the OBs.  Target was a desert ridge two miles away - boulders, Cacti, trees, against the background of a cloudy sky and wavy thermals crossing the FOV. So many caveats apply. Hard to say which one had the better clarity, I was going back and forth.  In a comparison in the 127s only, between 5mm DeLites and 5mm NZs, I couldn't tell much difference in the center detail.  Then going from 6 to 5 to 4 to 3 in the NZs, socketed in the OBs, it seemed like there was ever increasing central detail amid the fuzziness, with the least improvement between 4 and 3mm.  Not ready for any conclusions yet, but I am anxious to try out the NZs on some really tight double stars to see if increasing power leads to better definition and separation.

 

Edited by aznuge, 17 February 2023 - 05:05 PM.

[Saxonjan]

Saxonjan,

Your question got me curious about the NZs, so I set up a side by side, daytime comparison of different eyepieces in the APM BT100s and the OB 127XL (both are SDs).  I first wanted to get a comparison of equivalent power, between the BTs.  I used 5mm DeLites in the APMs (110x) and 6.0mm NZs (108x) in the OBs.  Target was a desert ridge two miles away - boulders, Cacti, trees, against the background of a cloudy sky and wavy thermals crossing the FOV. So many caveats apply. Hard to say which one had the better clarity, I was going back and forth.  In a comparison in the 127s only, between 5mm DeLites and 5mm NZs, I couldn't tell much difference in the center detail.  Then going from 6 to 5 to 4 to 3 in the NZs, socketed in the OBs, it seemed like there was ever increasing central detail amid the fuzziness, with the least improvement between 4 and 3mm.  Not ready for any conclusions yet, but I am anxious to try out the NZs on some really tight double stars to see if increasing power leads to better definition and separation.

 

Thanks viking1 that’s really appreciated, I can’t wait to hear about how you go with the doubles and other night observations, there’s really not much of that kind of info to find in comparing different eyepieces etc in the 127sd.  Was the fuzziness due more to conditions, eyepiece quality of image towards the edges or degradation due to its inherit limits being a BT? Looking forward to more comparisons. I’m still new to the game so the idea of of zooms giving quality views would be really good to my budget and having the finance minister/treasurer approve of more purchases lol

[Saxonjan]

I’d love to hear about people experiences using the Nikon zooms too if anyone is using them in BT’s, I’ve read good things about them too.

[aznuge]

Thanks viking1 that’s really appreciated, I can’t wait to hear about how you go with the doubles and other night observations, there’s really not much of that kind of info to find in comparing different eyepieces etc in the 127sd.  Was the fuzziness due more to conditions, eyepiece quality of image towards the edges or degradation due to its inherit limits being a BT? Looking forward to more comparisons. I’m still new to the game so the idea of of zooms giving quality views would be really good to my budget and having the finance minister/treasurer approve of more purchases lol

Fuzziness could have been a little of both.  Seeing conditions can have a huge affect at high mag and the daytime conditions were poor.  Anyway, got a break in the clouds tonight toward Canis Major.  I put the BT127s on Sirius with the NZs.  Seeing was not great, with cloudiness and haziness in the mix.  For what its worth, at 6mm I could see Sirius B.  This double is not a challenge from the separation point of view (11.2"), but from the delta mag point of view, which is ~9.5 orders, it is! At 5mm then 4mm the 8th mag companion star was still visible and slightly improved. Vibration and settling worsened since I was viewing from my back deck.  At 3mm I could not see Sirius B.  It seemed that the primary just overwhelmed the 2nd.  At this power I began to see diffraction rings from the brightness of A, and could not see B.  This was with the Nagler Zooms.  I also tried the 5mm TV DeLites during a later opening in the clouds and could see Sirius B with those EPs too. 

 

^^ another data point.  It will be an ongoing experiment to determine where the mag effectiveness diminishes in the 127s for me.  Meanwhile I pulled the trigger on a pair of  4.5mm Morphs, and may consider the 3.5mm Pentax XWs depending on results with the NZs on much tighter, but less contrasted doubles.  Even with poor eye relief, the NZs are turning out to be valuable tool for comparing power in the 127.

[Saxonjan]

Fuzziness could have been a little of both.  Seeing conditions can have a huge affect at high mag and the daytime conditions were poor.  Anyway, got a break in the clouds tonight toward Canis Major.  I put the BT127s on Sirius with the NZs.  Seeing was not great, with cloudiness and haziness in the mix.  For what its worth, at 6mm I could see Sirius B.  This double is not a challenge from the separation point of view (11.2"), but from the delta mag point of view, which is ~9.5 orders, it is! At 5mm then 4mm the 8th mag companion star was still visible and slightly improved. Vibration and settling worsened since I was viewing from my back deck.  At 3mm I could not see Sirius B.  It seemed that the primary just overwhelmed the 2nd.  At this power I began to see diffraction rings from the brightness of A, and could not see B.  This was with the Nagler Zooms.  I also tried the 5mm TV DeLites during a later opening in the clouds and could see Sirius B with those EPs too. 

 

^^ another data point.  It will be an ongoing experiment to determine where the mag effectiveness diminishes in the 127s for me.  Meanwhile I pulled the trigger on a pair of  4.5mm Morphs, and may consider the 3.5mm Pentax XWs depending on results with the NZs on much tighter, but less contrasted doubles.  Even with poor eye relief, the NZs are turning out to be valuable tool for comparing power in the 127.

That sounds great, looking forward to your ongoing results. The 3.5mm xo keeps coming up with great feedback everywhere. I’ve been considering the skywatcher 3.5 xwa too as cheaper alternative to the ethos, it seems they’re the same rebranded eyepieces from apm and a few others. I’m going to have to bite the bullet and lighten my wallet a bit soon. Unfortunately there’s only supplier of nz’s here in Australia who is out of stock. The 2nd hand quality eyepiece market here is very limited so I might have to exercise patience and order from the states. Can you recommend any good suppliers there who might ship here? Prices on eBay and Amazon here are asking a fair bit more. 

[pcctex]

You might try B&H Photo on the Web.  I have purchased all my Pentax XWs (4 pairs, so far) from them.  Not sure if they will ship to OZ, but it would be worth contacting them.

 

Best of Luck

[aznuge]

Dittos on B&H.  I believe they have international shipping, check this.