Ethos eyepiece: who else has ordered one?

Rodstar (Rod) · #1 23-11-2007, 07:00 AM

Just wondering what the take-up rate in Aust/NZ is for the new TV Ethos EP?

I placed an order with Bintel about a month ago. It seems that the world wide demand is vastly exceeding the rate at which TV can make them, because we may be waiting another 3 or 4 weeks till they arrive in Australia. I am OK with that....I am prepared to wait for this beauty, and I would rather TV keep production standards at premium levels, and not compromise.

Anyway....have you ordered one? If so, what magnification will it achieve with your gear? What objects do you think it will be suited to?

With the Mary Rose, it will produce an image at about 190x without paracorr, and 225x with paracorr. That may be a bit high on some occasions, but should be a nice medium level magnification EP most of the time. I expect it will be spectacular with globular clusters, and some galaxy clusters.

In particular, though, I am hoping I can treat myself to an Ethos view of 47 Tuc by Christmas this year!

PhilW · #2 23-11-2007, 09:36 AM

Rod, I got one in Bintel's original batch that came in September. I'm using it in a 35cm F/4.6 scope, and it immediately became my default eyepiece. For me it generates 123x with a 2.8mm exit pupil & 0.8 degree true field of view, which is perfect for viewing most deep-sky objects. The only time I feel the need to switch eyepieces is for objects that require higher magnification (smaller globulars & planetary nebulae), and for planets. I haven't tried it with a Paracorr, but haven't felt the need of it either.

Only issue I've had with it is that it required more in-travel on the focuser than I expected. I can only bring it to focus by taking out my 1.25" adapter & fitting it in the 2" barrel.

Phil

DaveM · #3 23-11-2007, 10:07 AM

Hi Rod,
I placed an order for an Ethos with Optcorp soon after it came out. I think mine turned up pretty quickly because a lot of people with pre-orders bailed out when they saw how much it was. Without wanting to take business away from local suppliers, it cost almost $100 less after postage that way, though postage does take longer of course.

With a 16" Lightbridge it gives ~140X (0.7 degrees actual field of view) without the Paracorr and ~160X with it.

Although it is an insane amout of money to pay for an EP, the views really are very nice (as they should be I suppose). I haven't been able to go galaxy hunting yet, but I have found globulars and open clusters to be great targets. 47 Tuc is a stunner with the Ethos.

Rodstar (Rod) · #4 23-11-2007, 04:57 PM

Phil, I guess two Ethoses for the binoscope would be outrageously extravagant? Perhaps they are too large, and have trouble with the in-focus issue? I am glad it is proving such a perfect combo with the 35cm scope. Do you notice much coma ( I would expect a fair bit at f/4.6).

David, sounds like a marriage made in heaven, at 140x and a 0.7 degree actual FOV. And from what I hear, the Ethos is pretty light for its size, and so you wouldn't have major balance issues? How do you find the coma issue?

Starkler (Geoff) · #5 23-11-2007, 06:41 PM

Quote:

Originally Posted by PhilW

I haven't tried it with a Paracorr, but haven't felt the need of it either.

Rod i had occasion to try out an ethos in my scope at the snake valley camp.
It has very good edge correction at f4.8 to the extent that I didn't feel any need to try it with my paracorr, which for me is a must with naglers.

ausastronomer (John Bambury) · #6 23-11-2007, 10:02 PM

Don't worry Rod. I am the proud part owner of the first ETHOS to land in Australia and I can't even get to use the damn thing. Mr Argo Navis has it in his possession and has gone on vacation for two weeks

Cheers,
John B

Stephen65 · #7 24-11-2007, 12:08 AM

I have one on order from Bintel, and its all Phil's fault. He lent me his for a few hours one night at Snake Valley and it was outstanding in my f/7 refractor - absolutely pinpoint to the edge and no focus difficulties. The last word I heard from Bintel is that they are expecting a shipment from TV but don't know if it will include Ethoses (Ethae?).

GTB_an_Owl (Geoff) · #8 24-11-2007, 12:14 AM

so will it be back in time for the next pony club John ?

i don't think Rod can wait to get his own

geoff

DaveM · #9 24-11-2007, 08:14 AM

Rod,
You are right, the Ethos is surprisingly light so balancing is not too much of an issue (any more than it normally is with a lightbridge anyway). I didn't really notice the coma. I have read reports that people feel the need to use a Paracorr, but it was not intrusive for me. I'm sure the Paracorr helps, but it's not a neccessity.

ausastronomer (John Bambury) · #10 24-11-2007, 09:03 AM

I don't think so Geoff. It will probably miss by a couple of days.

Rod,

I don't feel a need to use the paracorr with it at F4.5. With eyepieces under about 15mm focal length I don't use the Paracorr, 14mm Pentax XW excepted. The paracorr flattens the field a tad with the 14mm Pentax XW, hence I use the paracorr with it.

Cheers,
John B

Satchmo · #11 24-11-2007, 02:06 PM

Quote:

Originally Posted by Rodstar

Phil, I guess two Ethoses for the binoscope would be outrageously extravagant? Perhaps they are too large, and have trouble with the in-focus issue?

Rod , Theres plenty of experience of this on the CN Binoviewer group. Eye relief is no problem and as long as your IPD is more than 63.5mm . If I went to the expense I wouldn't hesitate to have a small flat machined on each to make IPD min 60mm.
These EP's have added one bit more to my `desert island "if only allowed one " fantasy scope..cost no object'...now a 16" F4 binocular with conical mirrors, Servocat cat and twin Ethos' with screw on non-amplifying Baader coma correctors and definately no steps required. Sigh...

Kal (Andrew) · #12 24-11-2007, 05:25 PM

I would have to view through one at a starparty (or IIS meetup) before commiting to a purchase

PhilW · #13 24-11-2007, 06:08 PM

Rod, I have indeed tried the Ethos in the binoscope (just one side to experiment in the first instance). Alas it wouldn't come to focus; not enough in-travel. My binewt is set up for Naglers & the truss poles are too long for the Ethos. As Mark says, they are being used successfully in binoviewers, provided your eyes are far enough apart. Just as a reference point, at Snake Valley I had folks using the bino whose interpupillary distance ranged from 59mm to around 68mm.

I don't notice the coma in the 35cm without a Paracorr. It is way off to the edge of the field, & not noticeable. As Stephen says, it was quite nonexistent in his WO triplet apo - quite an uncanny view. The stars were tiny points right to the edge.

My guess as to the plural is 'Ethoi' btw.

Phil