Ethos/Dioptrx First Light

[UniPol]

I received my long awaited Ethos EP and Dioptrx from Bintel yesterday afternoon and wouldn't you know it, the sound of thunder was heard just as I was opening the package. Needless to say the rest of the evening clouded over and it rained. Not to beaten I got up this morning to be greeted by rolling clouds and twilight but the waning gibbous moon looked to be ideal for initial testing. And so it was, with a simple turn of the Dioptrx the moon appeared crystal clear and no glasses! I suffer from astigmatism in both eyes and they both have to be corrected by 2.00 diopters, this is fortunate as I can use either eye for viewing.

The ED80 gave around 46X with the Ethos and at a guess the field of view looked to be about 2.5 to 3 degrees (using the moon as a gauge and too early in the morning to do proper calculations). The moon showed no colour and was sharp right to the edge. Of course you have to shift your eye to look at the edges as it can only take in about 30 degrees of clear vision. I also tried the Ethos with my 2.5X powermate and even though the set up looked unwieldy and large, it performed flawlessly at 115X albeit not as bright. There was still plenty of field left even with the moon still in centre.

I am ecstatic with my purchase even though it was pretty expensive, the EP cost a similar amount to the ED80 (OTA, finder, dovetail, rings, case etc.). Fortunately, with the recent price drop to $745, the EP and Dioptrx came to $895 which was not much more than the earlier price of the EP alone ($869). The Ethos would be totally lost on me if I had to wear glasses as the eye relief is not sufficient to take in the huge field. The only drawback I can see with the Dioptrx is that if you are viewing with other people then it would have to be removed unless they suffer from the same amount of astigmatism of course. I meant to add that the Dioptrx comes with its own rubber eyecup and cap so the ones that came with the EP can be stored away. At least the Dioptrx will keep dust and dirt of the eyelens.

I took some quick pics of the set up this morning which will give some idea of the EP's size. I primarily bought the Ethos to complement my G11/Tak TOA-130 which I hope to try out this evening if the weather is kind. I will certainly write up a more in depth article at some stage featuring this combination.

Thanks to the guys at Bintel for their usual great service but not to Australia post this time as the registered package containing the EP was crushed and split. Fortunately Bintel wrapped the the EP and Dioptrx in lots of bubble wrap and the Televue boxes and contents were undamaged.

Cheers,

Steve B

[Starkler]

Hi Steve. I find the eye relief on the ethos to be pretty tight for taking in all of the field. Is it possible to do so with the dioptrx in place?

[UniPol]

Hi Geoff,

To be blunt, yes and no. I found that I have to put my eye pretty close to the Dioptrx to take in all of the field and noticed eyelash marks on the surface later. The Dioptrx eyelens is larger than the EP eyelens and is placed very close to it. As it was pretty cold this morning the eye lens on the Dioptrx tended to fog up owing to the warmth of my face. I mentioned earlier that you have to move/roll your eye around the field to take it all in. In any case the benefit to me me by not wearing glasses has been enormous.

As an aside and for others who may be interested, I have a TV 15mm Panoptic which , if used with my TV 2.5X Powermate, doesn't require the use of glasses, it is perfectly sharp and clear. Apparently it all has to do with your exit pupil. Around 1 - 1.5mm is sufficient not to require glasses and astigmatism doesn't come into it. Of course, using the EP by itself, glasses need to be worn.

Hope this answers your question. I realise that it would be a costly outlay if the set up didn't work for you.

Cheers,

Steve

[iceman]

Wow Steve, it looks like a monster on the back of that ED80!

What a pair! Are you going to SPSP?

[UniPol]

Hi Mike,

Quite frankly, I didn't think the ED80's drawtube would hold the Ethos and Powermate especially since the moon was so high in the sky this morning. A little turn of the tensioning screw underneath the focuser fixed up the slipping. The set up definitely looks like it means business and does!

I usually go to the SPSP but unfortunately something else has come up. I hope the weather will be agreeable for the event, from what Don Whiteman said, there should be record numbers of star gazers attending this year.

Cheers,

Steve B

[iceman]

It looks like it'll be clear leading up to it - I hope it stays clear for it!

Shame you can't make it, would've been good to meet up!

[acropolite]

Interesting to hear more feedback on the Ethos, I've been thinking of buying one myself, 13mm is a good useable F/L in my Lx90 (gives around 150x) and it would also be brilliant in the ED80. Geoffs comment on the tight eye relief has convinced me to take a look through one before buying.

[Starkler]

Always a good idea to see for yourself buying laying out the cash.
It seems that my eyes are different to other peoples. I find the coma/astig in type 4 naglers to be horrible, and in some others including the ethos I cant take in all the field without getting close enough to the eye lens to cause blackout. For this reason i sold my 26 nagler to PhilW who is very happy with it :shrug:

If I'm paying for a huge fov, I want to be able to see all of it at once.

[gb_astro]

Just another opinion, as I had a look at an Ethos at Bintel today
and for me:

Black-out was minimal, seemed a lot less than my T12.

Could only see the total field by looking dead centre,
using peripheral vision, having the eye guard down and
being very close to the glass.

But then again field of view is only one of this eyepiece's claim to fame.

Steve B, I see you are using the Bintel Alt/Az tripod/mount.
What's your opinion of it?

gb.

[UniPol]

Hi GB,

I think you articulated my thoughts on the Ethos very well. Looking dead centre and close to the eye lens certainly describes the visual feeling and yes, there is certainly more than looking for the edge of the field. For me, with the addition of the Dioptrx, no more glasses!

The mount I am using is the Vixen Porta mount. I am not familiar with the one Bintel sells however I imagine that it is similar in construction. The Porta mount is the best investment I ever made and is the most used piece of astronomical equipment I have ever owned. In tandem with the right angle dovetail mounting plate, just about any small scope and binoculars can be attached easily. I regularly attach my PST, Solarmax40, ED80, Tak Sky-90, Tak FS-60C, WO Z66, 20 X 80 binoculars and various cameras. It is so quick and simple to use and is light yet sturdy. With the addition of flexible cables for Alt/Az it is much improved. The second best investment I made was the viewing chair from Bintel. This and the Porta mount make life so much more pleasurable and that is what amateur astronomy is all about.

Cheers,

Steve B

[acropolite]

I have a porta mount and totally agree with what Steve says. FWIW a mate of mine is using the bintel mount with a Tak FS102 and found it to be too wobbly. The culprit was the lengthy arm that the OTA ounts on (the vixen one is shorter and more rigid). He replaced the cast aluminium part with steel and reports a huge improvement. I suspect that the bintel mount would be OK with an ED80 though.

[gb_astro]

Phil, thanks for the info.

Doing a bit of searching I see they are different,
apart from both being white.

Steve, agree with you about the Stellar Seat.

gb.

[wavelandscott]

I have an ED80 that I place on the Bintel/GSO vixen porta mount clone and with the slow motion controls it works a treat. I use it primarily with Denk (Big Easy) binoviewers attached to view the moon and/or solar viewing (with proper filter)...for these uses it is nice and stable.

[UniPol]

I had a chance last night to try out the Ethos on my Tak SKY-90 which has a focal length of 500mm, this equates to approximately 38X. The viewing was about 9/10, very steady and cool. As I was observing undercover on my top deck it was only possible to view north so the obvious choices were Orion, Saturn and M44. M42 looked spectacular as expected in the Ethos and even at this low power, the trapezium was very sharp and clear. The field of view appears to be a little under 3 degrees. Orion's belt i.e. Mintaka, Alnilam and Alnitak is about 2 3/4 degrees and the EP would just encompass them. M44 (Beehive cluster) from memory is around 1 1/2 degrees and it is certainly great at this power as well. I used the TV 2.5X Powermate to look at Saturn and no loss of quality was noted. The planet was sharp and crisp and in such a large field simply looked stunning.

This eyepiece looks like a keeper, I have no trouble with blackout, kidney beaning or anything untowards. The Dioptrx is just brilliant to use and does what it claims, at least for me.

I have attached a couple of pics showing its huge size in comparison to the SKY-90. The scope has no trouble in coping with the weight and focuses perfectly with or without the Powermate. I still have to try it out on the TOA-130 which has exactly twice the focal length of the SKY-90 (1000mm). This equates to 77X which should be pretty useful for most objects.

Cheers,

Steve B