82° vs 100° dilemma on 16" - thanks!

[Rig3l]

Hello forum,

I'm here asking for some advices, because I'm going to buy a new eyepiece for my dobson sw 16"  (f 4.5)

This is the fact: I use a 8-24mm baader zoom, and I recently sold my william optics swan 33mm 72 degrees, which I didn't like so much because on my 16" it gives me back a 7.3 exit pupil! (I purchased it years ago, when I had the 10" sw).

Now I'd like to try an 82 or 100 degrees eyepiece on my scope but I don't have the opportunity, so I'm reading forums, tests and reviews to find out which is the best choise for me.

 

I'm not sure about a 20mm- 100°, or a 24mm -82° , or something different (staying in this range, 19-24mm.. I'd like to keep at least 1° true field of view)

- - - - - - - - - -

These are some models I was reading about in these days:

-Expolore Scientific 24mm 82°
-Luminos Celestron 19mm 82°
-Meade 5000 UWA 20mm 82 °

Explore Scientific Maxvision 24mm 82° (very cheap! but it should be the same as meade 5000, right?)

For a 100°, I could pick one in the "second hand"market, because of the price. For example:

Explore scientific 20mm 100°

 

I know about coma problem, but is it so evident? Could I manage coma in the future with a coma corrector?

- - - - - - - - - -

Thanks a lot!!   (and sorry for mistakes, I'm not English)

[Peter Drew]

Hello Rig3l.  I have a Baader zoom and a 19mm Luminos. The Baader zoom is best at F6 and longer, F4.5 is a bit tight for it. I use the 19mm in a 20" F3.5 and it gives an excellent image right across the field in conjunction with a Paracorr and pretty good without it. I also find that 82 degrees apparent field is already beyond what I can use without scrolling my eye round. You are correct to bear in mind the exit pupil size to avoid the waste of aperture if it's too large for your eye.

[Rig3l]

Hi Peter, thanks for your opinion.

In fact I notice a not-so-dark background sky, using the 33mm. Even when I am under a good sky, with no light pollution. I ascribe this effect to the exit pupil of the 33mm eyepiece. That's why I want to change it!

Do you use a Paracorr type I or type II?

[jetstream]

The immersive views that the 100 deg eyepieces give is hard to beat for low power use but some don't like it. I love it personally. The Luminos series is not well liked by some it seems and resale will be very low, mine work well however.

The ES 82/100 have very good coatings/glass and provide excellent performance, do you have an OIII filter?

[Rig3l]

No I don't. I used and recently re-sold an uhc and a light pollution filter, since I don't like filters so much. I tried them but I don't know.. I was not very impressed. Now I have just a variable polarizing one for the moon, and in the future maybe I could pick the OIII 2" (which is expensive and selective, but it could worth the price.. However I wish I could try before buying it)

Just now, I'm in a negotiation for a used ES 100 ° 20mm, which is sold new for 479 euro from the Explore Scientific official site, and I'm trying to buy it used for 310 euro (shipping cost included). It seems a good deal to me, and I feel this is my "dream eyepiece", despite the coma I'll have on my f 4.5 scope.. Don't know why. It's just a feeling, reading about  the "100° - wow -effect" on several forums.

But I'm waiting for the seller: if he does not agree my offer, I'll probably pick  a less expensive one, like an 82°.

[jetstream]

Great choice!

Very good plan you have, both the 24mm ES 82 and 20mm ES 100 are VG eyepieces, I own the 30mm ES82 and the 18mm ES 82 excellent stuff. I mentioned the OIII because if you pick the right one it will work great with your 20mm-24mm EP in the f4.5 dob... the Veil neb will blow your socks off looking thru the OIII/20mm...

Down the road consider an OIII...IMHO.

I also use a single polarizer , but I use mine for viewing Jupiter before darkness, just as it becomes visible.

Yes the "wow" factor of the 100 deg... if your anything like me you will like the feeling of having your face glued to the "porthole" in a spaceship looking outside lol! Seriously though, they are great and espc on the great nebs like M42, the Veil,Flame, Flaming Star and so many others.  And then there are the starfields....

Yup, I'm hooked on 100's.

[Rig3l]

I like to hear somebody so satisfied by the 82°/100° ES  like you! It encourages me a lot  ! Frankly, I'm really hoping to succeed in this transaction for the used 100°eyepiece.. But I know the 82° would be a good option too.  I'll keep you updated!

[swamp thing]

The 100˚ 20mm ES is very good indeed. The one I tried performed very much like a 100˚ Nagler.
The 82˚ ES I have mixed feelings about. One I tried was very sub-standard whilst the others have been very good. I would try before I put money down as far as this range is concerned.

[John]

I've used many 82 and 100 degree eyepieces. For me, the 100 degree ranges seem to be the the best quality items that the brands can produce. They seem to put their very best efforts into them and the quality shows

 

[estwing]

I agree.... the massive 100* view is just so immersive...I don't want the view framing, I want to be "there"!!

[Piero]

9 hours ago, jetstream said:

Yes the "wow" factor of the 100 deg... if your anything like me you will like the feeling of having your face glued to the "porthole" in a spaceship looking outside lol!

You know Gerry, I haven't looked through a 100 or read many reviews about these, but your words give a straight forward idea of what one could expect! This is the first time I believe I understood why people get so excited about their 20mm 100deg.

I suppose it is due to the combination of 100deg, 2 inches and large-ish eye relief. I say this because Ive never got a feeling like that on my naglers T6.

[Bart]

Have a look at the Bresser or FLO websites, they should have it for less than you're talking. Also consider the SKywatcher 100*  version, called the Myriad. 

[John]

1 hour ago, Bart said:

Have a look at the Bresser or FLO websites, they should have it for less than you're talking. Also consider the SKywatcher 100*  version, called the Myriad. 

The Myriad's are pretty good 100 degree eyepieces. I reviewed them for the forum here:

 

 

[Rig3l]

I never heard about these "Myriad's" before. I'll consider them if the seller will not accept my offer for the ES. Thanks for all your opinions!

[John]

7 minutes ago, Rig3l said:

I never heard about these "Myriad's" before. I'll consider them if the seller will not accept my offer for the ES. Thanks for all your opinions!

You will also find them branded William Optics, Telescope Services (TS) and a few others - the design is popular !

[alan potts]

Hi,

At F4.5 coma will be a problem though not so much as my Dob which is a little bigger and a bit faster at F4.3. I use 82 degree eyepieces on it in the shape of the 31mm Nagler which is excellent with the paracorr taking care of the coma.

The trouble as I see it is that your scope is fast enough to find out lesser eyepieces and I would say go for the ExSc at the minimum and if possible a Paracorr as well, believe me the wide field of 100 degree really serves up the coma and cheaper eyepieces could well show other abberations as well. I use TeleVue eyepiece which sadly are very expensive, however I take the approach that why pay for top quality if the eyepiece is let down by scope generated coma. The view with your scope and a Paracorr with a 21mm Ethos or 20mm ExSc would be superb and would not be a bad move, unfortunately this move is not cheap but it is for the life of your interest.

Good Luck !

Alan

[michael.h.f.wilkinson]

I have looked through the Ethos 13mm and Nagler 12mm Type 4 using Olly's 20" F/4.1 Dobson. The seeing wasn't good enough to see any difference in image quality, but the Nagler 12T4 won in terms of eye relief. If I squeezed my glasses against rubber eye cup of the Ethos, I could see the field stop, but the Nagler was more comfortable for me. If the Ethos had just a mm or so more eye relief, I might well have gone for them. The Nikon NAV HW apparently has that mm extra. I might have a look at them. For me, the 82 deg FOV is already highly immersive.

[Sporadic Dobstronomer]

On 21/02/2016 at 12:30, Rig3l said:

...Explore Scientific Maxvision 24mm 82° (very cheap! but it should be the same as meade 5000, right?)

For a 100°, I could pick one in the "second hand"market, because of the price. For example:

Explore scientific 20mm 100°

 

I know about coma problem, but is it so evident? Could I manage coma in the future with a coma corrector?

 

I have a 16" f/4.5 so I had a similar decision.  My choice was between the 26mm Nagler type 5 and the 21mm Ethos.    These two have nearly the same true field of view and are not very different from the ones you are interested in.

The advantage of the 82° 26mm is that the lower magnification gives a bigger true field that you can take in without having to move your eye around.  Having said that, I also have a 100° eyepiece (not the 21mm) and I do experience that the bigger apparent field does make you feel nearer to what you are looking at.

So the answer is: it is a matter of personal taste!

 

Regarding coma, I find that coma is clearly visible but it is a personal thing if it offends you or not.  I do have a coma corrector and it does work very well although I don't use it much.  For me, whether it is worth the effort of using it depends on what I am looking at.  If the item of interest does not fill much of the field of view then I don't bother with the coma corrector.

(By the way, being able to see coma can be helpful when you are collimating your telescope)

In short, the answer to this question is simple: try it, see if coma offends you or not, and then buy a coma corrector if you need one.

[jetstream]

One of the things I love about Televue is Naglers concept of "Majesty Factor", I find the presentation that the Ethos and other 100 deg eyepieces provide is excellent- and hard to describe to people who havn't used them.

http://televue.com/engine/TV3b_page.asp?return=Advice&id=114

[alan potts]

21 minutes ago, jetstream said:

One of the things I love about Televue is Naglers concept of "Majesty Factor", I find the presentation that the Ethos and other 100 deg eyepieces provide is excellent- and hard to describe to people who havn't used them.

http://televue.com/engine/TV3b_page.asp?return=Advice&id=114

Can I try.  On my scope, and I know this is not cheap, the stunning quality of the FOV when the 21mm is used with a Mk2 PC for me simply takes astronomy, like Spinal Tap's amplifers , to eleven. It is just that one louder.

[John]

I feel that it's important to mention that, IMHO, 100 degree eyepieces such as the Ethos have more to them than just the larger AFoV. The overall quality of the image they present in terms of light scatter, light throughput, neutral tone etc, etc seems that little bit better than their 82 degree counterparts.

Thats the point I was making when I posted about the quality of 100 degree eyepieces.

 

[niallk]

Dammit guys - you're at it again being TV's best salesmen I'm reading this thread with interest as I wrestle with the decision to buy a 9T6 Nagler and be done for a while; rather than biting the bullet, following my heart and going for an 8mm Ethos for my 15".

I had just convinced myself that the Nagler was surely the far more sensible option (cost, ergonomics - no faffing around: no balance issues, all my eps would sit at the same Paracorr2 setting, good all round performer). My fear is that I'd like the Ethos sooo much that I'd feel a burning need to add the 13E and eventually the 21E, and end up selling my present collection and doing unspeakable things to fund my addiction...

[Paul73]

nThere will be some coma in 100° eyepieces. But, it is at the edges so not too intrusive as you can't take in the whole 100° without moving your eye. That said, it is nice to get to a good 72° with virtually zero coma. I have a Paracorr but rarely use it.

The ES 100° is in the same ball park as the TV offering in terms of performance for a lot less money. That said I do have the Ethos 21mm rather than the ES equivalent.

Paul

[Moonshane]

I was always impressed more with contrast and transmission of the Ethos I had (a 13mm) than the field. In the end I wanted to raise money for something else and sold it. I have never really missed it as I seem to have an issue with newer wider field tvs on the moon and wanted my eyepieces to be good on everything.  I have now settled on Panoptics and Delites as these have the qualities I want. That said, even though my 26mm Nagler is terrible on the moon,  it's such a wonderful eyepiece I keep it even though I have a 24mm Panoptic as the latter is so good in my refractors.

 

 

 

[Mrbloke]

If your deal does not go through and you are willing to wait, 'display item' eyepieces are often added to this site.  The ES 100° 20mm is *sometimes* for sale on this site for 275 Euros (+10 Euro delivery).  I purchased one from here and am very happy with it - I haven't used my 24mm 82° Maxvision since.  I have seen it on offer at least 3 times in the last 8 months.  The ES 100° 20mm is my favourite eyepiece in my collection and great for DSOs. 

http://www.bresser.de/en/Sale/Display-Items/