3.5mm Delos vs Vixen HR 2.5mm for planets?

[GTom]

I have to admit I am lagging behind following the advancement in eyepiece-tech. Which would you prefer for planetary work with a 105/735 APO refractor and a c5?

Delos 3.5mm or Vixen hr 2.5mm, or something else? The Delos would already yield a 200+magnification, I don't think it's too much use to stretch it further. 

 

Did anyone has/had a chance to compare these two?

[mikeDnight]

X210 with the delos 3.5 would be good on a steady night, but the 2.4mm Vixen HR giving X306 would give you a significant boost in image scale which would be great for lunar in particular. It may need an exceptional night to see any advantage in planetary performance in your 105 Apo. Though I've not yet used either eyepiece, i regularly use a superlative 3.5mm XW on my own refractor and its a great focal length eyepiece. I've also had terrific views of the moon and Venus at X474 while using a Vixen 2.5mm LV and a Tak extender Q, so can say with certainty that the 2.4 HR on your refractor is not asking too much from your scope due to the scopes sharp optics. You may find both eyepieces to be pushing it on your C5.

Mike

[John]

I'd probably want both focal lengths in my eyepiece case to be honest, though the 3.5 Delos would get used more often.

I have a 3.5 Pentax XW that gets plenty of use in my Tak 100 F/9 and sometimes the Nagler 2-4mm zoom gets in the action if I'm trying to tease apart really close doubles.

With the C5 though I think the 3.5mm would be quite a lot more than is useful. So you are buying for your refractor here rather than for the SCT I feel.

[Timebandit]

Hello. I to have a Pentax 3.5xw and a very good eyepiece it is to(70d field of view with sharp Ortho type of great optical quality and 20mm eye relief) . This eyepiece I use for splitting stars mostly and lunar('had some very sharp high power views of the lunar craters with this eyepiece) in my refractor with good seeing conditions. probably in theory the most powerful eyepiece that I should think about buying. But I  have also  been interested in the vixen 2.5 HR to which initially I had great concerns if this eyepiece of such a power would produce worth while views. But if I remember correctly a chap called Bill paolini (I am not sure I have spelt the gents name correctly) did a test/review of the vixen HR and if I remember correctly he got extremely sharp crisp views through it using a sensible size quality refractor. And if I remember correctly he compared it to, and ranked it in the same sort of league as the legendary ZAO to which to me is extremely high praise indeed. So I would think this would be an excellent eyepiece to use for very high power use using a refractor when seeing conditions allow   

So to answer your question IMO you will probably get more use out of a 3.5mm , but when the rare seeing conditions allow the vixen HR from what I have read will provide extremely sharp high power views. The refractor will be able to be used with both. I suspect to much for the c5

Hope the above is of some help☺

[Paz]

I've just landed a 2.5mm SLV second hand and a 3.5mm Delos and 4.5mm Delos are the last two eyepieces on my list to track down.

I had a brief go with the 2.5mm SLV in my 120mm f5 refractor last night - the SLV gives a 0.5mm exit pupil and 240x which is as far as the scope should go in theory. The image was very good clarity-wise, better than I was expecting but last night was relatively good seeing and I wonder if it was good luck that the conditions allowed it. The dimmer image from the higher magnification is noticeable and there's certainly no need for a moon filter.

The other thing the SLV threw up was that 240x is a lot of magnification for an AZ3 mount to handle!! Tracking manually with an alt/az was more work than I'm used to and time to settle down from vibrations after focusing etc was noticeable when it is't something I notice at lower magnifications. I need to give it a go mounted on the EQ5 - I think that will solve tracking and vibes.

I don't have anything of a similar focal length to directly compare it to but all things considered it seems good - I also need to give it a go in a smaller 70mm travel scope where it will provide a useful 160x.

[GTom]

Thanks for all the replies! One more candidate enters the scene: Barlow + Delos 3.5, for those nights with extraordinary seeing. Honestly I am reluctant to buy two eyepieces for planetary but a good Barlow could be used all around. 

 

And yes, i am more buying this eyepice for my refractor, especially that a second one, a 90/600 triplet is on the way, that's going to br my travel scope.

[John]

On 12/11/2016 at 00:24, GTom said:

Thanks for all the replies! One more candidate enters the scene: Barlow + Delos 3.5, for those nights with extraordinary seeing. Honestly I am reluctant to buy two eyepieces for planetary but a good Barlow could be used all around. 

 

And yes, i am more buying this eyepice for my refractor, especially that a second one, a 90/600 triplet is on the way, that's going to br my travel scope.

If you do consider that route I'd recommend a Powermate, Tele Extender or Focal Extender rather than a barlow. The Delos already has 20mm of eye relief and the barlow will extend that further which canl make eye placement rather difficult. The 3 former devices either remove or much reduce this effect.

 

[GTom]

9 hours ago, John said:

If you do consider that route I'd recommend a Powermate, Tele Extender or Focal Extender rather than a barlow. The Delos already has 20mm of eye relief and the barlow will extend that further which canl make eye placement rather difficult. The 3 former devices either remove or much reduce this effect.

 

Good point! I'll see that first hand, because I have an old Zeiss Barlow in stock which is worth of a replacement.