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Andy_E

ES 68 24mm first light

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Managed about three hours out with the ES 68 last night with the intention of giving it a thorough run through next to the 19mm panoptic. I think I should state that I feel this is both fair and ruthlessly unfair in equal measures; I don’t have access to a 24mm pan'(optic) (hence the ES) and to my eyes, 20mm seems to be a cut of point in my telescope where coma goes from manageable to annoyingly distracting. Pitting a 24 against a 19mm EP is also a bit mean in terms of edge performance. However, I can't help but get the feeling that ES is INTENTIONALLY putting itself in the TV firing line with it's eps... taking on the Ethos, Nagler and Panoptic range respectively. This is of course open to interpretation, and one must take very realistically the price differences between the lines (the ES cost £94 delivered and the 19mm pan' a shade over £200). For these reasons I chose to asses the ES on its own merits, but drawing on comparisons to the TV when it seemed applicable.



Just a couple of things before I start. The purpose of this ep in my collection is as a dedicated wide field for observing large(ish) open clusters ... not 'finder' ep. I have always found these objects quite demanding on eps as the 'ideal' view is a flat, contrasty FOV with pin-point stars from edge to edge. My observations were soley through a 10”/f4.7 with no coma corrector (hence my 'ideal' view has never been achieved :) ).



Ok, enough about all that, lets talk glass and stars! All comments refer to the ES unless stated.



Initial impressions


At 333g (by may scales) this ep is something of a mid-weight, and certainly doesn't cause any balance issues in a dob. Build quality is pretty good (as with most eps in this price range) and certainly feels on par with the pan' on this issue. I must say, I am a big fan of the tapered barrel design in the ES line which makes changing ep a far smoother affair than the notched designs of most other eps (I find these tend to 'jam' a little on occasion). Oh yeah, and the new ES boxes are cool!


A quick look through the ep reveals a comfortable eye relief of around the stated 18mm. However, the recessed eye lens does give the impression of this being slightly tighter, but still very comfortable with the rubber eye guard rolled up or down. Whilst aligning the finder scope, it also became apparent that there is an ever so slightly warm colour cast, recalling that of the TV radian. I have never found this to be a problem.


Lets get this thing pointed at some open clusters then...



eyes to the skies – optical performance


Telescope pointed at NGC752 and ready to go. On axis stars really are quite impressive, being wonderfully sharp little point of light. A quick change to the pan' reveals a very similar performance between the two eps in this respect (honestly too hard to call a winner). Returning to the ES, contrast really is very good, and seems to cut through the suburban sky-glow to reveal a dark sky littered with diamonds. I was quite surprised to note similar performance in both eps considering the larger exit pupil of the 24mm... thumbs up ES!


So on axis performance is looking pretty good, and in my opinion genuinely rivalling the pan' giving a real sense of depth to the cluster. Off-axis, the ES is a little behind the pan'. It's hard to be precise (going by instinct alone), but things start to get a little mushy around 10-15% away from the edge, with the outer 5% being pretty poor. In comparison, the pan' only shows degradation around (roughly) 5% from the edge. As stated above, differing focal lengths may be playing a part here, but these are simply my observations. It is worth noting that the field stop is nice and sharp in the ES.


Not suprisingly, coma becomes quite an issue on off-axis stars, seeming not as well controlled as with the pan' (though it is certainly still detectable). Again, to what extent the differing focal lengths are playing a part here I cannot say. The good news is that careful inspection reveals little if any field curvature, and no astigmatism masquerading as coma (I found the latter quite evident in the Baader Hyperion).


Switching over to M37 and it becomes a slightly different story. Framed entirely within the 'sweet spot' of the ep, the view really is rather impressive revealing hundreds of twinkling points of light. The rendering of the dark sky against this cluster really is a joy to observe through the ES. The same story goes for M36 & 37, and with the added context of more sky in the FOV, I genuinely preferred viewing these through the ES to the pan'!



A number of clusters later, I decided to point the scope at something all together more fuzzy. To my surprise, a very faint impression of dust lanes was visible in M31 even from my suburban sky, and had to check a number of times to ensure I wasn’t engaging an over active imagination. I have no doubt this is down to the way the sky is rendered through this ep, along with the pleasingly contrasty views.



One thing that does let it down is the noticeable amount of flare on very bright objects. A quick look to Jupiter reveals an orange halo not visible in the pan'. However, this was only visible on Jupiter, and became a non issue when viewing Sirius and Capella. How relevant this is to a wide field ep is down to interpretation. On a quick final note on optical performance, I did try the ES with 2x barlow (not that you would want to barlow a 24mm ep, but hey, these things are there for trying). Not surprisingly, this made viewing rather uncomfortable and the eye relief was altered to the extent that the field stop was not visible. I should state that I'm not in the barlow fan club, and only ever usually use it on the 6mm radian when seeing is exceptional, ergo this is for me a non issue and only done out of interest.



And finally...


Overall impressions so far are quite impressive... there are a lot of good things about this ep. On axis stars are sharp, and the dark rendering of the sky with good contrast is superb (an area in which I felt it easily matched, if not slightly outperformed the pan'). The pan' still remains king in terms of edge-to-edge performance here, but I can't help but feel that with the inclusion of a decent coma corrector, the ES 68 could give it a serious run for it's money. So is it a poor man's panoptic? This is a hard question to answer, as both eps excelled in slightly different areas, but for what it's worth I certainly don’t regret the purchase of this ep, and see it as somehow complementing the pan' in my ep collection as opposed to fighting against it. It's hard to make long lasting impressions over the span of just one observing session, but I optimistically look forward to putting it through it's paces over the coming months!



Oh yes, it's high time I invested in a coma corrector anyway :)



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I have the 24mm maxvision from ES and it is an excellent eyepiece.

I know what you mean about the flare from the brighter stars, and a sky full of diamonds.

The eyepiece really makes them sparkle.

I am looking to get the 11mm 82 degree - probably from the US.

Which supplier did you use?

Agena has been recomended on here before.

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Very nice report Andy. The one thing I would love to know is are these the same as the older Meade 5000 SWA. I would really like to do a side by side test myself. This is something that could be done at SGL 9.

Alan

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Cheers guys. I can't find any full reports for these in the UK so thought it only fair to (try!) and do it some justice.

Reeny, I too used Agena astro... excellent service. Only took 4 days to arrive and dodged the charges :grin:. I got mine from their ebay shop as they had none in stock for their online store and still received good service.

Alan, I'd love to find out how similar they are to the Meade 5000s too. Of course they'll be heavily based on them, but I've seen reports on cloudy nights that the 82 series has a slightly different optical design to the Meade UWAs... so who knows.

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I have one also, and find it to be equal to the Pan24 optically.  The ES has much more eye relief and I can use it with eyeglasses.

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I have one also, and find it to be equal to the Pan24 optically.  The ES has much more eye relief and I can use it with eyeglasses.

That's very interesting. Like I said I've had no experience with the pan24 so I've been left guessing a little!

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Andy,

The 82's or the UWA as they got called by Meade do have two very obvious differences, ExSC offerings has an 11mm in the range and the 18mm is a 2 inch eyepiece where as the Meade was the smaller type of 1.25 inch.

However the SWA range as I am sure you have seen are punch for punch the same focal lengths, now Meade hit the market with these before I believe ExSc even existed as a Company. You could of course say that after the launch ExSc had a chance to improve on the design or have better coatings added but the Meades remained more costly even after the ExSc launch ot the 68's range. I would love to know if they are same, better or worse.

As for the 24mm Pan I too had one and my Panoptic was better in all 4 of my scopes at the time, though not by a country mile.

Alan.

Edited by alan potts
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