UO 32mm MK-80 in slow scope

[astropolak (Joe)]

Hi Everyone
Did any of you try this 82deg 2" eyepiece in slow scope (LX-90 8").
I would like to get quality low magnification eyepiece and the Mk-80 does seem to fit the bill, but I will only buy it if I get quality views right to the edge (well 80% of it anyway). Not willing to spend ~$1k on the more obvious choice here.
As an example of bad choice I can give you Meade QX 20mm - it is ****** awful in my scope.

I respect the opinion of the members of this forum, please let me know what you think, perhaps I should be looking at different brand or model?

RGDS Joe

[chunkylad (David)]

Hi Joe

There is a revue of the UO MK80 here:http://www.cloudynights.com/documents/konig.pdf

Cheers

[astropolak (Joe)]

Hmmmm
I have seen reviews of the Meade QX 20mmm as being good to very good in SCT's - this is not true. My eyepiece case is getting rather full of substandard eyepieces...., this has to change for the better.
Any of my standard Plossls will outperform the cheap "wide angle" eyepieces. I feel like I am just wasting my hard earned money.

Just in case one thinks there is something wrong with my eyes or the scope - my Pentax 10mm or Meade series 5000 14mm perform very well indeed.

RGDS Joe

[ausastronomer (John Bambury)]

Hi Joe,

As you have discovered with the Meade QX there are any number of inaccurate reviews out there. Anyone is free to post their opinion or a review on the internet, the difficult part is sorting out the wheat from the chaff. This is the reason "Cloudy Nights broke up their equipment reviews into 2 sections, "Cloudy Nights Reports" and "User Reviews". The user reviews can be submitted by anyone and in a lot of cases are inaccurate, I take zero notice of them in most cases. The Cloudy Nights Reports are different, they are submitted by a small group of very experienced observers who have conducted a large number of equipment reviews previously for astronomy magazines, books or equipment websites. The link to the review on the UO 32mm MK-80 that Dave gave you is a Cloudy Nights Report, conducted by Tom Trussock, I know Tom and respect his judgement. I have read that review and pretty much agree with it.

Whilst I haven't used the UO 32mm MK-80, I have used the 25mm and 40mm MK-70's which are very similar. They are made in Japan and the machining, fit, finish and mechanical quality is 1st rate as you would expect with a Japanese made product. Optically they do a very good job in a slow scope like your F10 SCT. The slower the scope the better they work.

Many people will tell you that in a slow F10 scope they will perform just as well as a Nagler, Panoptic or Pentax XW, this is simply not true. They are not quite as good regardless of the scopes F-Ratio. The performance difference in a slow scope is minimal, in faster scopes the performance differential is major. In your F10 SCT I am sure that you would be happy with performance of the UO 32mm MK-80.

Another good option to consider at the mid price level is the the 2" 30mm Kokasai Kohki Widescan III, which costs $399.

http://www.sirius-optics.com.au/widescan.htm

Like the UO MK80 this eyepiece will be pretty useless if you subsequently buy another telescope with a fast F-Ratio, but it will work very well in your F10 SCT, again the slower the scope the better they work. This eyepiece may be a better choice than the UO MK-80. Here is a link to a "Cloudy Nights Report" again by Tom Trussock. I know Tom well and can email him and ask "which he liked the best between the Widescan III and MK-80" if you like ?

http://www.cloudynights.com/documents/widescans.pdf

CS-John B

[astropolak (Joe)]

John
Thank you very much for your message. Could you please email Tom and ask him for his opinion.
One thing, do you ever see any reviewer marking an eyepiece as bad?
I think they all are too polite and do not want to offend anyone with their reviews.

On another note - is it possible to make a fully corrected 80+ deg eyepiece with 5 elements only (the KK eyepiece has 5), the UO MK-80 has 6 elements, the UO MK-70 has 7 and the Naglers have 8 or more...?

RGDS Joe

[ausastronomer (John Bambury)]

Originally Posted by astropolak

John
Thank you very much for your message. Could you please email Tom and ask him for his opinion.

*********************************** *********************
Hi John,

I'd recommend the UWAN 28mm at $400 - it's on sale right now, and at f5
and up, it performs as good as my naglers (haven't checked it faster
yet). If that's too much cash, I liked the 32mm MK80 better than any of
the other ones you've listed.

Fact of the matter is, tho, at f10, they should all perform pretty well.

Tom T.

John and Sue Bambury wrote:

> Hi Tom,
>
> I have a colleague who owns a Meade 8"/F10 LX90. He is looking for
> a 30mm 2" eyepiece at the mid price level. We have both read your CN
> reviews on both eyepieces. I have used the 30mm Widescan III and the
> 25mm and 40mm UO MK-70's but not the 32mm MK80. Just wanted your
> opinion on which you think would be the better choice between the 2
> for his F10 SCT. The cost differential between the 2 is not an
> issue. I am thinking possibly the Widescan but wanted your thoughts
>
> CS-John Bambury
*********************************** *********************

The 28mm UWAN is the new Williams Optics wideangle eyepieve but my guess is that it will be well over $AUS 600. I am checking on a price with Daniel from Frontier Optics for you.

On the basis that the 28mm UWAN is likely to be to expensive the UO 32mm MK80 is probably the way to go.

Originally Posted by astropolak

One thing, do you ever see any reviewer marking an eyepiece as bad? I think they all are too polite and do not want to offend anyone with their reviews.

I probably agree with this to a certain degree.

Most reviewers don't slam the product outright, but they still get the message across in a subtle way. However, you need to be able to extract the message the reviewer is trying to get across. If you read Tom's reviews on the Widescan III's, he doesn't come out and say "they are no good in a fast scope and don't buy them", but he may as well have. He says they work very well in slow scopes and are highly recommended, they are recommended with reservations in scopes from F6 to F10, and you should try before you buy in scopes faster than F6. Does he really need to spell it out ?

In a lot of cases the favourable reviews about poor eyepieces you read on the internet are written by beginners and people that have never actually used a "good" eyepiece. Consequently they have no clue that the eyepiece they are using (reviewing) is in fact no good. As I said before, you need to sort the wheat from the chaff and there is an enormous amount of chaff available on the internet.

Originally Posted by astropolak

On another note - is it possible to make a fully corrected 80+ deg eyepiece with 5 elements only (the KK eyepiece has 5), the UO MK-80 has 6 elements, the UO MK-70 has 7 and the Naglers have 8 or more...?

Yes but there will always be compromises. In the case of the Widescan III it is its inability to eliminate off axis astigmatism and field curvature in fast F-Ratio scopes. The cheaper the eyepiece the more compromises it will have. Naglers and Panoptics have compromises as well, but the compromises are "left in" to allow other more important issues to be corrected and increase the viewing pleasure for astronomical viewing. These compromises are minor issues that have minimal effect on astronomical observations. eg Panoptics suffer minor pincushion distortion, which is a lot more detectable in the daytime on land based targets than it is in the night when observing astronomical targets. Also be aware that the levels of these compromises in premium eyepieces like Naglers, Panoptics and Pentax XW's are significantly less than you get in cheaper widefield eyepieces and are almost undetectable at night.

CS-John B

[ausastronomer (John Bambury)]

Joe,

Here is a follow up email exchange I had with Tom Trussock:-

*********************************** ****************************

John,

EXTREMELY close performance to the naglers. If you'd choose a
nagler over a panoptic, I'd get a UWAN. Otherwise get the Pano.

I spent the better part of an hour comparing the 16 uwan to the 16t5,
last night at f7, and performance was so close that I forgot which
eyepiece I had in. I thought I had the nagler and went to grab the uwan
only to find that I already had the uwan in there.

Performance is extremely good down to f5 on them as well. Haven't done
the f4.5 thing yet.

If money is a bigger factor then: I liked the 32mm MK-80 better than the
Widescan III, and both should perform well at f10 (in all honesty,
performance was similar and I wondered how close the optical design was
- however, I liked the ergonomics of the MK-80 better - it just seemed
to dissapear). If he never sees himself using the eyepiece on a fast
scope then save the dough and go for one of the cheaper eyepieces
otherwise I'd go for the UWAN or Pano.

T

John and Sue Bambury wrote:

>Thanks for that Tom,
>
>I hadn't thought of those as they are new. I have a friend who is the WO
>distributor in OZ, I will check the price with him but I am thinking it
>will be well at least $AUS 650 at which price he can buy a 35mm panoptic. Is
>it as good as the 27mm/35mm Pan's ?
>
>The UO 32mm MK-80 and the Widescan III are both in the $AUS 300 to $400 bracket.
>
>CS-John B

[MarkN]

astropolak

When I spoke to Daniel re the 32 MK80 vs the 60 deg. version he commented that there would be vignetting in the LX90. There is some seagulling in my 60 deg. AFOV version in outside the 10%.

That said I regard it as a good EP for the outlay ($200 or so delivered) and will be getting a UO planetary EP in the near future. Unless there's a fire sale of Naglers or Panoptics somewhere I won't be adding anymore to my EP collection. Marvellous oculars, just not worth the cash for me.

Mark.