Pentax and Delos 3.5mm eyepieces

[alan potts]

Pentax XW 3.5mm TeleVue Delos 3.5mm.

Well here we go again having just wiped 2000 words from Word by pressing a wrong button.

Pentax 3.5mm XW

This eyepiece is the shortest of the Pentax XW line up and like its fellow combatant is about the tallest of the range. The eyepiece comes in a rather nice screw fit bullet case and that fits neatly into a well made and padded box, no surprises there from what is a quality company marketing near to the top of the price scale. The 3.5mm tips the scales at a modest 365 grams according to my Argos specials in the kitchen, though this is of course subject to a tolerance of plus or minus half a kilogram. The eye-relief on all the models from the range is 20mm though the eye-lens is a little recessed but presents no problems for me when I put on my glasses and tried it out, this is something that I do not need to do normally.The field of view is a nice 70 degrees and one would expect it to be sharp. As a part of the same system there is a twist up eye-guard that can be deployed to help get the eye in the correct place for viewing, this is something that I took advantage of as although I can use Delos without the system raised I could not on the Pentax, this is due to the fact I am used to one and not the other and black-out or kidney-beaning is something we can do without.

TeleVue 3.5mm Delos.

This eyepiece has been on the market for about 18 months now and is one of the shortest from TeleVue, because of that it will not appeal to everyone as the magnification is going to be very high on all but the very shortest focal length scopes. However it is an eyepiece I can use on very good nights on a small selection of targets, mainly the Moon and Planets. Older TeleVue eyepiece just used to come in a study box with a thick plastic bag inside holding the goods along with some instruction and a little chrome and black sticker. Now the box seems to have been upgraded a little with a type of poly foam liner holding the eyepiece wrapped inside a plastic bag with the other bits as well. I have noticed this on all my Delos and Ethos eyepieces but others seem to be as they always were. The Delos is again about the largest in the line and weighs in at 460 grams, so it is a fair bit heavier than the Pentax but I do not believe is likely to trouble any Dobsonian uses, it must be the extra 2 degrees of field the Delos offers. Eye-relief is the same 20mm with a newer design lift up and twist lock eye-guard, of the two here my preferred choice and a massive improvement over the T4 Nagler and Radian systems.

Look no beans.

Scopes

Because of the focal length I am only going to use my shorter scopes. Total scope time for the test was 15 hours 20 minutes over a very long period due to inclement weather.

115mm APO, which is F7 and gives a magnification of X230.

190mm Maksutov/Newtonian from Sky-Watcher, this is F 5.26 and give a power of X 286

70mm ED refractor which is F 6 and gives a lower X120, this is still close to its maximum though.

Targets.

Moon

Saturn

Jupiter

Mars

Comet Panstarrs.

Apo 115mm, well cooled, power X230 used driven and undriven

The Moon.

I viewed the Moon with this scope on two nights when seeing was good but not the best ever, nonetheless it was allowing me to use X230. The Moon was 5 days old and later in the week just about exactly first quarter on the second night.

On the first night I was studying the craters Kant, Tacitus, Pitiscus and Hommel switching eyepieces at about 4 minute regularity, being very careful with focus. I was trying to see if there was any detail what so ever I could see in one that was not there in the other, it was a good job I was not holding my breath on the result. I changed location to craters Burg, Plana and Plana ‘C’ witch lie north of the Mare Serenitatis but the result was as far I could determine the same.

The next time the Moon had moved on a couple of days, it was now in about my favourite position half illuminated, up to this point I find the Moon an interesting object but much passed three-quarter phase leaves me a bit cold and no doubt annoys our astro-photography members no end. I was scrutinizing the area of Werner and Nonius ‘F’ and later taking in the area of Mons Hadley, part of the Apennins Mountains where Apollo 15 landed and made base. It is difficult to comprehend that men walked and bounced near or where I was looking and may even have played some golf, my they left it in a mess. I spent a long time on the Moon with both eyepieces and at no point could I see one was any better than the other, though there was a small amount of chromatic aberration from the very edge of the Pentax when you got the Moon in the right place that was not visible in the Delos, I struggle to believe it would be an issue with anyone though.

One thing I did notice was that whatever eyepiece I was using when I changed them over, thought that the next eyepiece had better contrast as the black looked, well blacker. I can only think this is something to do with the eye relaxing as it is taken away from the views of the bright surface into the darker conditions around me. Then the eye dilates again as it’s reintroduced to the surface of the Moon which must be may times bright than my surrounds.

Mars.

Mars has never been one of my favourite planets and I believe this is much to do with the power that you need to use to see it at any size, doing this we are fighting a battle with the seeing Gods, one we seem to loose most of the time. First night on Mars was April 9^th so it was very close to the opposition which we only see ever two years or so. I was seeing some detail on the surface that was triangular in shape and checking SGL the following day told me it was Syrtis major which to me looked a bit like Africa in the wrong place. There was also the white of the polar cap to be seen when seeing permitted which is never enough. Both eyepieces perform excellent on the first night and on this scope I again could not really drive a wedge between them. I would say that there was very slightly more peachy orange about the Delos rendition, the Pentax seemed paler but only just. I was getting a little flare from the XW from time to time that was there one moment then gone, I didn’t see the same with the Delos.

Second and third nights on the planet with this scope were a month apart and results were much the same though one of the nights I could see a bright area to the south of the disc which I am lead to understand is an area known as Hellas. The last night I could see Mars was not a bright as I could remember it was the month before though there was still a good deal of detail that could be weeded out from the view.

Saturn.

This planet takes magnification very well and the rings are wide open making a spectacular view, though unfortunately it is not best placed this year as it is low down in the sky for me and must be worse from England. I was rather astonished that I could see as much as I could as it was wobbling around in the turbulent air but Cassini was there and I could also make out a little of the polar region being darker than other parts of the disc. This was something to leave for a few weeks as I did not want to stay up all night. When I final got back to it the other night conditions were excellent and the air was nice and still for once, with the scope being one of three I was using in a scope juggling ( very dangerous art taught to me by a circus performer) routine, the X230 the APO delivered was close to optimum for the planet. Again Cassini was there but this time clear and shouting ‘look at me’, the polar shading was clear with a definite line there to be seen and I could make out what I think was 4 of the moons.

I believe it was John that said to me there could be a situation where one eyepiece would better the other on a target specific basis, for me this was true I did just prefer the Pentax on Saturn as the view seemed a bit more polished where as with a gun to my head I would have picked the Delos for Mars, now we have to have two eyepieces of same focal length costing a fair wedge just for planets, it sort of left me wondering if it varied for different scopes as well.

Jupiter.

The largest of the solar systems members is past its best now but it is still high in the sky for the first part of the night, though it will not be long before the twilight claims it. Always a joy to look at though any scope and for many X230 is prime power, though in my opinion it is a little too much, for me less is more and I prefer to view around the X170 mark regardless of telescope aperture. Of the two nights I viewed this target oddly the moons were all on one side but the belts were clear to see through both eyepieces and again I would not say one was better than the other. There was no detail as such that I could see in the equatorial belts though of course they stood out clearly and as usual the Great Red Spot was on its holidays, I was unable to see little in the way of clear polar region shading that was there with a lower power which always makes me wonder why people seem to over egg the pudding.

70mm ED refractor, let us not forget with Carbon fiber tube. Power X120.

Jupiter

This was viewed only the once with this scope as a part of the juggling act and I am always amazed just how much you can see with a small scope when X120 is getting close to its theoretical limit. All moons were clear to see albeit a bit unbalanced and the two equatorial belts stood out nicely. The chromatic aberration on the Pentax XW seemed a little worse with this scope and there was some visible using the Delos as well so the scope was having a hand in matters, it is fair to say it is not in the same class as the other one. There was no light scatter that I could see and both views were very alike but there was something that was telling me the Pentax was just a tad cleaner, it was just a feeling with no hard evidence.

Comet Panstarrs.

This little scope has a massive field of view with the right eyepiece and I used it to track down Comet Panstarrs which is just below Ursa Major or the Plough at the moment. I don’t know who gave the name of the Great Bear to this collection of stars but I would suggest they were into some strong narcotics at the time, the Plough I can see and live with. I fully understood this was going to be a difficult object in so smaller scope but I was able to locate it with a finder eyepiece and work up with other eyepieces until the 3.5mm’s  were selected for the breach. I will not lie, it didn’t look a great deal like a comet to me, more of a dim blob, I am sure without sky like mine it would have remained invisible. The thing though I did notice was the Pentax seemed to make a better job of point star sources in the area of the blob, again though I am being hyper-critical here and either one would out perform most it not all on the market. It has to be said that the night of this observation was my best sky so far this year, it was truly exceptional.

Sky-Watch 190mm Mac/Newt. F 5.26, cooled and collimation checked.

Saturn.

I viewed Saturn the other night in excellent condition and the extra aperture of this scope, which I think is under-rated as a visual instrument by some way, it always seemed to get labeled an astrograph, but extra size was there and telling. There is nothing like top conditions to bring out the best in a scope and make me look tired out all the next day but with the weather of late you have to make hay while the sun shines. This telescope was giving a rather large X286 and boy Saturn didn’t seem to mine one bit. Everything was there that was there before with the smaller scope and then some. With both oculars I was able to see not only a bold Cassini Division and polar belt but I could see a difference in colour between the A and B ring but no sign of the other elusive Encke gap, I think something much larger is called for. I believe I could see 5 moons as well but could not check as my outdoor laptop has finally given up the ghost. I spent over an hour on Saturn alone and this time I just feel the 3.5mm Delos was top of the class but Pentax was pulling the shirt tails rather hard. With the right scope and conditions these two are really sharp There is of course another explanation as well, that it is all in ones head and these two really are as good as each other. In some respects it is a shame that I cannot lay my hands on a Vixen LVW 3.5mm as then we would have just about every top line 3.5mm eyepiece I know offering such eye-relief albeit with a slightly smaller field of view.

The Moon,

Without going over the same ground I used the exact same craters on the same nights with the Mak/Newtonian and I have to say on this target even at a large magnification of X286 there was nothing in it what so ever, just sharp and contrasty views. It must be said that even on something short of top quality seeing the views these two eyepieces give of the Moon are worth the price tag alone, they are truthfully jaw-dropping. My Son Daniel wanted to look and rightly made the comment, “our house wouldn’t last long there look at all the meteorite damage,” since seeing the program on the Russian Meteor everything is meteorites and dinosaurs.

The optical illusion, for want of a better way of putting it, that I saw on the 115mm Apo was still in evidence here with regards to the perceived contrast difference, I would love to hear any thoughts from site as to what this is and has anyone else noticed.

Mars.

The good thing about this scope is quality of image and with the eyepieces both 3.5mm in focal length the power is right up there in the Mars power band at X286, with the right conditions the telescope is large enough and can handle this.

Firstly the disc was much larger but focusing between the two completely different focus points of first the Pentax and then the Delos was tedious, the tiniest bit out and all detail is gone. Again I was seeing a slightly more orange Mars with the Delos but it was so hard to pick up it could have been me. Details seemed a little more up front with the TeleVue and sort of looked like the glue lines you see on a tennis ball when looked at the right way, as well there was a complete lack of any aberration that I could see from one side of the field to the other. The Pentax was again showing this slight flare from time to time, nothing serious but it was there and the detail, whilst the same was just a touch more subtle.

Just as I was ready and willing to believe the flare I was seeing periodically in the Pentax was a fault in the XW, I saw the exact same thing with the Delos just for a fleeting moment, this just goes to prove that an eyepiece test needs to be done over a few nights as this was clearly variation in seeing conditions and nothing to do with the eyepieces.

Conclusion.

I think whilst I was doing the observations for this report on what must be two of the very best 3.5mm eyepieces that are currently on the market, I have been wondering what to say at this point, not that I am usually lost for words. After 15 hours and 20 minutes I think both are outstanding eyepieces from two of the finest producers. They are both sharp, full of contrast with little or no scatter. I always wonder what Pentax could have done if they had set out to design an astronomical eyepiece as opposed to a range for a finder scope. My one criticism is I feel there could have been more in the range, I feel the jump of 10mm, 7mm, 5mm and then the one we have here is a little lacking, however this is just my opinion. TeleVue’s Delos on the other hand has more in the range and were designed with the night sky in mind and I believe some of the range are the best on the market. I own the Delos and it is a superb eyepiece, I borrowed the Pentax from my friend in Sofia, Dani, and I thank him for that.

There were plus points on each side all the way through the test and very little I could say that was negative. However I think if spent my money again I believe I would buy the Pentax XW, 3.5mm as it really comes so close to orthoscopic quality no matter what you point it at and it will also be on it’s game in the daylight as well.

I hope you enjoyed reading it.

Alan  

[John]

I have read it Alan and I did enjoy it 

Thanks for going to the effort of posting this quality of report on the forum.

[YKSE]

Excellent job Alan, you're not making it easier for those who just want to pick one

[Dude_with_the_tube]

Very interesting report.Based on your report,it is really difficult to choose Pentax xw or Delos. both have pros and cons.Would love to try them both some time.

Appreciate your effort of making this review and comparison Alan.Superb as always!

[AlexB67]

Very interesting read Alan. I have yet to sample that Delos range.  Having looked through a couple of pentaxes though they are my favourites in the case as overall performers  considering  ease of use, wide FOV,eyerelief as well.   I can dig why RikM ended up with a set of them, I am not jealous ......Who am I kidding 

The  only downside of such eyepiece once you have looked through them is I want more of them, and they ain't cheap, but worth the money and saving for IMHO.  I don't every see myself ending up with the 3.5 anytime soon, but the 5mm some day perhaps if I am getting too lazy for my beloved  5mm BGO. 

Edited May 21, 2014 by AlexB67

[Dude_with_the_tube]

Very interesting read Alan. I have yet to sample that Delos range.  Having looked through a couple of pentaxes though they are my favourites in the case as overall performers  considering  ease of use, wide FOV,eyerelief as well.   I can dig why RikM ended up with a set of them, I am not jealous ......Who am I kidding 

The  only downside of such eyepiece once you have looked through them is I want more of them, and they ain't cheap, but worth the money and saving for IMHO.  I don't every see myself ending up with the 3.5 anytime soon, but the 5mm some day perhaps if I am getting too lazy for my beloved  5mm BGO. 

count me in for Delos too.never looked through one,but i will not give up orthos for planetary any time soon.thats why i have 2 sets of orthos

[michael.h.f.wilkinson]

great report as ever. It is slightly annoying that these to series are so far from parfocal with each other. I have a Delos 8 to fill the gap between the XW7 and XW10 I already had before the Delos line appeared. The amount of refocus needed is considerable. It almost wants me grab the XF8.5 instead (not quite as good as the Delos, however), Maybe I should see if I cannot make some parfocal rings for them. I do not fancy trading the XWs in for Delos equivalents (as there is no Delos 7).

[AlexB67]

count me in for Delos too.never looked through one,but i will not give up orthos for planetary any time soon.thats why i have 2 sets of orthos

I can see why I only have the 5mm BGO and love it, so even if I did have a pentax XW5 I would not sell the BGO, they are great on doubles too and I've been be using it for that too a lot lately, and in my 10 inch Dob the 5mm delivers 240x on saturn it is a marriage made in heaven, sharp contrast laden views, as crunchy as crisps.

I can dig the ortho experience after owning one and it is a very pleasant one even if the eye relief is tight and FOV small.  I can only imagine how good some of those real top end orthos must be like, but I am hapy with the BGO, I may even get a few more atsro hutechs or second hand BGO in time, since they are not that expensive. 

When I look through a pentax though it is the nearest thing that reminds me of an ortho in how it renders things, even if I haven't got one in the same focal length to compare that's the feeling I get looking through them, there is that next to no glass feeling when you look through them, yet pentaxes are full of glass.

sorry for the OT. 

[michael.h.f.wilkinson]

I can see why I only have the 5mm BGO and love it, so even if I did have a pentax XW5 I would not sell the BGO, they are great on doubles too and I've been be using it for that too a lot lately, and in my 10 inch Dob the 5mm delivers 240x on saturn it is a marriage made in heaven, sharp contrast laden views, as crunchy as crisps.

I can dig the ortho experience after owning one and it is a very pleasant one even if the eye relief is tight and FOV small.  I can only imagine how good some of those real top end orthos must be like, but I am hapy with the BGO, I may even get a few more atsro hutechs or second hand BGO in time, since they are not that expensive. 

When I look through a pentax though it is the nearest thing that reminds me of an ortho in how it renders things, even if I haven't got one in the same focal length to compare that's the feeling I get looking through them, there is that next to no glass feeling when you look through them, yet pentaxes are full of glass.

sorry for the OT. 

You should perhaps look into monocentrics. I will keep avoiding short orthos, and stick with the XW/Delos experience. 

[Dude_with_the_tube]

You should perhaps look into monocentrics. I will keep avoiding short orthos, and stick with the XW/Delos experience. 

at 470 euro a piece and 30 deg FOV you have to be very hard core planetary observer  to have them in your arsenal.I would take Delos,Ethos or Pentax or any other ortho over them any day.Saying that,if money was no object,i would love to have them in my Ep box.

i would be also interested to see observers views or reviews on lower mag Delos vs Pentax,lets say in 10 or 12-14mm range for DSO.

[michael.h.f.wilkinson]

at 470 euro a piece and 30 deg FOV you have to be very hard core planetary observer  to have them in your arsenal.I would take Delos,Ethos or Pentax or any other ortho over them any day.Saying that,if money was no object,i would love to have them in my Ep box.

i would be also interested to see observers views or reviews on lower mag Delos vs Pentax,lets say in 10 or 12-14mm range for DSO.

I have used my XW10 on planetary nebulae quite a bit (in my F/10 SCT, mainly). Works very nicely.

[AlexB67]

at 470 euro a piece and 30 deg FOV you have to be very hard core planetary observer  to have them in your arsenal.I would take Delos,Ethos or Pentax or any other ortho over them any day.Saying that,if money was no object,i would love to have them in my Ep box.

i would be also interested to see observers views or reviews on lower mag Delos vs Pentax,lets say in 10 or 12-14mm range for DSO.

Alan did a review of the 14mm pentax versus delos at one time if I recall, it is somewhere in this subforum, or perhaps it was a 10, not sure. 

One of the man criticisms of the longer focal length pentax range is field curvature in faster Newts getting quite noticeable, though the paracorr does a very good job of removing most of that from what I gather that it is hardly visible, which wil be added to my stable at some point anyway so not too worried. 

My next purchase is a 14mm and likely will be the Delos, but I've not decided a 100 percent. perhaps it may be a XW or if an older XL tuned up. Often the second pentaxes can be got a  bit cheaper too wich is another consideration for me as well.  I am firmly stuck into that second hand buying though for those premium eyepieces, as Michael said in another thread there are many happy  enough to shift stuff along on a frequent basis, and I'll happily grab a bargain and wait a bit for something to turn up 

Edited May 21, 2014 by AlexB67

[John]

at 470 euro a piece and 30 deg FOV you have to be very hard core planetary observer  to have them in your arsenal.I would take Delos,Ethos or Pentax or any other ortho over them any day.Saying that,if money was no object,i would love to have them in my Ep box.

i would be also interested to see observers views or reviews on lower mag Delos vs Pentax,lets say in 10 or 12-14mm range for DSO.

I've owned a TMB Supermoncentric 5mm and at the same time the Pentax XW and Baader GO 5 mm's. Under the best conditions the Supermono showed slightly better contrast and sharpness on the planets. It's only a "slightly" though and the conditions need to be towards the upper end of good to appreciate it. For me the narrow FoV, tiny eye lens and tight eye relief of the Supermono were not worth the slight optical advantage so I let it go.

Back on the topic of the Pentax XW's, I've seen the the views through them described a number of times as orthoscopic-like and have used the term myself to describe the views through my 5mm and 3.5mm XW's. I'm sure the Delos matches that too. FWIW I feel the Ethos gets pretty close to that as well which figures as the Delos was derived from the Ethos design.

[alan potts]

Well that seems to have got people talking. The 3.5mm Xw is not only up there with the best it also has a 70 degree FOV and 20mm of eye-relief. Taking John's point about the Supermono, I am sure that what he says is absolutely bang on but what good it an eyepiece like that if you have to wear glasses as quite a few on site seem to, this is why I do the reading glasses test to try and help them.

I fully believe no matter what you choose XW or Delos , it is not going to be a bad choice and I am sure anyone will be delighted with either but those last two lines hurt me a bit.  I've done 5mm XW and 4.5mm Delos and liked the Pentax more and now this, I am beginning to wonder why I didn't listern to John in the first place, he told me they were this good about 18 months ago.

A bad case of black and green fever.

I am going to do 6mm Ethos Delos.

Alan

[John]

...I am beginning to wonder why I didn't listern to John in the first place, he told me they were this good about 18 months ago....

And I should have listened to Steve from FLO and Rik several years back when they were singing the praises of the XW's before the Ethos and Delos were a black and green glint in their designers eye !

[Dude_with_the_tube]

to be honest,i dont think either of you have done something wrong by choosing lets say Ethos over Pentax or Delos over Pentax.All 3 eye pieces are great and apart of FOV i really doubt there will be any visual difference.This is the same talk we are going back about orthoscopic eye pieces.you can have a BGO on Circle T orthos and visual difference will be so small that in majority of times you will not notice it,unless you are in the best spot in the world where you have 365 clear nights and you can go well beyond 500 magnification.But not in UK viewing conditions.Price wise there is not a major difference between Delos and Pentax range.Ethos obviously is more costly but thats what you pay for 100 deg FOV isnt?

Again difference in ergonomics of the way how eye guard is built will open the can of discussions :meade 5000 UWA vs ES 82 deg range.where again optically there where no difference and it was individuals choice between them.Same about Pentax`s eye guard vs Delos.

Blue vs black, black vs green.endless story and endless arguments

I go for the one who can give me best views depending on what i am observing .i like ultra wide views for DSo and narrow 40 degs for planetary.but thats again me personally.

And once again, i appreciate all the effort Alan has done for this comparison,it did make me think about Pentax or Delos and I will deffo get one of these Ep`s my self.

[Luke]

Thanks for all your work doing this fantastic review, Alan, it was a good read. I have got the feeling from many comments on the two ranges that they probably run each other pretty close but can't recall having seen a big shoot out like this.

Hmmm, I think I may go for a 3.5mm Delos, just to be boring and stick with Delos as I have a few of those and am very happy with them. I could do with something shorter than my 5mm Radian to go with my 85mm refractor. I used a 2.5x Powermate and 8mm Delos on the Moon with it the other night, and it looked cracking despite the Moon being so low. I think that worked out equivalent to about a 3.2mm eyepiece.

There's a slight temptation to go for a cheaper eyepiece like a BST, TS HR Planetary or go half way-ish with a 3mm Radian. Hmmm, I feel the pull to the Delos, though might have to wait for Autumn to pull the trigger. Very tempting to pay the extra bucks to try and squeeze a fraction more out of my 85mm frac on planets.

Edited May 21, 2014 by Luke

[Pig]

Great report Alan thank you for taking the time out to write it.

It has been to long since your last review and as always a very interesting detailed read (and some of the Mr Potts humour)

[avtaram]

A very thorough and comprehensive report Alan.

Looking forward to the 6mm Delos, Ethos report as a 6mm eyepiece is on my shopping list.

Avtar

[A McEwan]

.you can have a BGO on Circle T orthos and visual difference will be so small that in majority of times you will not notice it,unless you are in the best spot in the world where you have 365 clear nights and you can go well beyond 500 magnification.But not in UK viewing conditions.

Don't quite agree with this as I had a full set of the Circle T volcano top Ortho's before I started collecting the BGO's. The Circle T's were very good, for sure, but when compared to BGO's back to back in same focal lengths there were quite noticeable differences, especially in the light scatter department. The BGO's had considerably less scatter.

I've had several Pentax XL's and found them too to be superb eyepieces on all targets. What I found great about them, and it is obviously the same with the XW range too, is that I never had to swap them out, like going from a "wide field eyepiece" to a "planetary eyepiece" - they simply did it all with no fuss.

I do miss them and would have them again if I could justify the purchases against what I have in my eyepiece case these days.

Interesting comparison with the Delos. I've never even seen a Delos yet, so it will be interesting to maybe one night try one. It sounds like it will take me back to my Pentax days, maybe...

Ant

[alan potts]

Great report Alan thank you for taking the time out to write it.

It has been to long since your last review and as always a very interesting detailed read (and some of the Mr Potts humour)

Shaun,

I wrote a longish review only about two weeks back on a TBM 2.5mm and Radian 3mm, I think you must have missed it. I am working on one at the moment with 12mm Nagler and 12mm Delos as many ask which is best, I am going to try and help answer that question, the problem is the weather. As I write this it's just past 6 in the morning and we have a thunderstorm, it terrible, with the best will in the world I can't write reviews without observations.

Alan

[alan potts]

Avtar,

There is a review of the 6mm Delos and a 6mm BGO amd I believe 6mm setting on the Nagler zoom on site by me from last year..

Alan

[Dude_with_the_tube]

Don't quite agree with this as I had a full set of the Circle T volcano top Ortho's before I started collecting the BGO's. The Circle T's were very good, for sure, but when compared to BGO's back to back in same focal lengths there were quite noticeable differences, especially in the light scatter department. The BGO's had considerably less scatter.

I've had several Pentax XL's and found them too to be superb eyepieces on all targets. What I found great about them, and it is obviously the same with the XW range too, is that I never had to swap them out, like going from a "wide field eyepiece" to a "planetary eyepiece" - they simply did it all with no fuss.

I do miss them and would have them again if I could justify the purchases against what I have in my eyepiece case these days.

Interesting comparison with the Delos. I've never even seen a Delos yet, so it will be interesting to maybe one night try one. It sounds like it will take me back to my Pentax days, maybe...

Ant

My bad Anthony i picked the wrong ortho.meant to be BGO vs UO HD. i agree there will be noticeable difference between BGO and Circle T.

[Mark at Beaufort]

Alan you do produced some very enjoyable and detailed reviews. I bought a 10mm Delos to sit between my 8mm and 13mm Ethos and I have been so pleased with the quality and eye relief. At the moment to gain higher magnification I simply use a barlow but I am grateful to know that if I purchase a higher mag EP then the quality of the Delos is still the one to go for especially if it is close to an Ortho. I could try a Pentax but because they are so close and considering the focusing situation its best to stay IMHO with Televue.

In the Spring I had the chance to use some Hutech Orthos (thanks to FLO and John) and they were very sharp but in the end I did like the very tight eye relief and the shorter FOV.

Thanks again Alan it will help on future decisions on buying a higher mag EP.

Hope the sky conditions improve in Bulgaria.

[alan potts]

Mark,

Last night was superb before this mornings early call for all, only trouble was I concreted in front of where all my scopes are and could get them out.

Michael made a point of it in his first post about the amount of difference in focus there is between these two, it really can be a pain to mix them, which I have with the 5mm in between 6mm D and 4.5mm D.

I have one of the Hutech orthos (12.5mm) that I got from FLO, who were very kind and put one aside for me as they knew I was coming from afar, I would like to get a 5mm for those top draw nights and I would love a 4mm as well but maybe that is too short on ER, it's one to try before buy.

The 10mm is a gem and I would love another, sold mine to Stu as i had got the 10mm Ethos, I find the massive field a bit too much sometimes for planetary on the LX where 10mm is giving X304, a good Mars power.

Alan.