Lyra 152mm f5.9 Achro

[A McEwan]

Hi all.

Somehow I found myself thinking of a "Deep Sky Refractor". I like refractors. I like the fact that they are easier to transport and set up than big Dobs. So my logic was to get a big light-bucket refractor and treat it like a Dob, but in refractor form!

I found out about these relatively new 152mm f5.9 doublet achro's and read up on experiences posted here and elsewhere about them. Then I looked at the various suppliers, and found that the very excellent Glen at Lyra Optics in the UK had one left. Inevitability hit me full in the face and I ordered it.

It arrived today and I spent this evening setting up on my SkyTee 2 for a good old look over it. I'm very impressed!

Good quality pearlescent paintwork, smooth dewshield, smooth 3" (THREE INCHES!!!) focuser, good quality handle on the mounting rings, and a red dot finder included.

Optics look very good - the coatings are very dark purple and the glass disappears under certain viewing angles. Any reflections of lights seen in the glass look very smooth, which I take to mean that the glass has a good smooth finish to it.

The scope is heavy but not unmanageably so. Solid anyway. There's some very small amount of dust, I think on the interior glass surface, but I'll investigate that at the weekend.

In the meantime, some pics of my new Light-Bucketromat!

For reference, the "smaller" scope also on the mount is a 120mm f5 Skywatcher Startravel, which is fairly chunky for it's aperture size in itself!!

Really looking forward to First Light from my Dark Sky Site with this 'scope...

Ant

PS I like refractors!

[John]

It looks a nice scope Ant - congratulations

I've read so much about these over the past couple of years - I'll be very interested to see what you think of it.

[hunterknox]

Nice choice. I'd be interested to know how this does on the sun if you get a chance. I've only heard good things...

[Dude_with_the_tube]

looks quality Ant and congratulations for adding another refractor to your collection

[Moonshane]

Looks lovely but is it really easier to set up and transport than a 6" (ie comparable sized) dob? The views will be ultra nice I think.

[John]

These scopes have caused some heated discussion on the "Cloudynights" forum so it will be nice to have a more balanced viewpoint here

I believe emadmoussa owned one for a while.

[nicoscy]

I had one as well for a few months, solely for DSO and low to mid power views.

The colour issue has been exaggerated quite a bit as people tend to forget that this scope is not:

a) A planetary "killer"

A triplet APO with superb colour correction.

However on DSO it is a beauty to use and if this is a good sample and properly collimated, it will not disappoint. With a Nagler 31mm you have 2.8 degrees TFOV, 29x magnification and 5.2mm exit pupil. It will stun you with the appropriate eyepieces.

I sold mine because the weight was too much given some back problems I have and funnily enough, I replaced it with the ST120mm F5 and I also use the Skytee mount.

[nicoscy]

Hmmm, turned my b with a parenthesis into an emoticon. Must be more careful! Still need 180 posts to edit!!!

[Chris]

Lovely scope Ant, I was looking at these a while ago and from what I read they really punch above there aperture on dso's so I think you're in for a treat :-)

[A McEwan]

Thanks guys!

Shane, to answer your question, it's heavier than a 6" f8 Dob, but shorter. Plus it gives refractor-like views, which a Dob simply can't.

Not that I think a 6" Dob is a poor scope - I don't, but I think in that aperture range I'd rather have a refractor, is all.

I'm looking forward to getting my 23mm Axiom and 17 Nagler T4 into it, Nicosky! And the ES 9mm 100-degree....

Ant

[nightfisher]

Ant, there really is no cure for you, at this rate you will soon have as many fracs as Moonshane   

Thats a nice looking refractor, i had considered one myself a while back, but i know how much a six inch lens weighs, when i had the ST150, VERY front heavy.

I look forward to your views on this and through it

[Moonshane]

Don't get me wrong Ant, it's a beauty and even I have recently learned the benefits of a fraction in your stable :0)

I do still find dobs easier to set up though.

[A McEwan]

Not at all, Shane. I'm not anti any design of scope. They all have their benefits. And Dobs do great for low cost large aperture light buckets, but I think in the smaller sizes this suits me better.

Mind you, it was about 3x the price of a 6" Dob!

I hope I get to look through it over the weekend, and not just AT it!

Ant

[vlebo]

Hi Ant

Is the scope you purchased from Lyra optics the same as the one Teleskop Service have for sale ?  http://www.teleskop-express.de/shop/product_info.php/language/en/info/p2229_Individual-152-900mm-Gro-feldrefraktor---3--Crayford-Auszug.htm  

Also how does the Sky tee 2 cope with it with a decent eyepiece fitted ? 

Look forward to a first light report.

Good luck

[Marki]

Looking forward to reading your report!

[A McEwan]

Vlebo, that's exactly the same scope.

The SkyTee 2 takes it well. I've only had it set up indoors, but it moves around fine and doesn't wobble or shake, and vibration damping time is very short. Mind you, that's on a Berlebach wooden tripod. I'll be interested to see if it needs a counterweight on other side or a second scope perhaps.

Also we should bear in mind that it's really not going to be used at high power, so minor wobble/focus wobble shouldn't be a problem.

The other mount I'll have it on is my HEQ-5 and although I haven't tried it yet, I have absolutely no doubt that it will be a dream on that mount!

Ant

[nightfisher]

Ant it will be rock steady on the HEQ5, these mounts handle heavy scopes well and this frac is short, like you say more for lower power work, you will be unlikely to go much above x80 on this set up

[Dave Lloyd]

That`s a nice scope, refractors look so right (excuse my bias)

[Joseki]

Very nice, I hope to own one in the future.  Reading reviews which focused on it's performance on planets is a bit missing the point, so I'm keen to hear how you find it on the DSOs.

[A McEwan]

First Light!

Not much of a First Light - I only got about 30 minutes but the sky was good and clear. I set up in my usual dark sky site, on my SkyTee 2 with a small counterweight to balance the scope.

I lined up the red dot finder with the scope pointing at Polaris. Using a 32mm Plossl I found the view to be quite astigmatic, but I think that's me - the exit pupil would have been 5.4mm and I find anything over 5mm shows up my eye's astigmatism. Upping the power to a 18mm Orthoscopic improved it, but showed coma at the edges. Again I wasn't too disheartened at this. It's a fast scope and Ortho's aren't optimised for performance at f5.9

But we know what is, don't we... Naglers! So in went the 17mm T4 and WOW - perfect flat field with pinpoint stars across it! I panned around for a bit. Brighter stars did show a blue/violet fringe but not anything to worry about, and easily overlooked.

Next target was the Double Cluster. With the 17T4 still in, the field was filled with stars, and the two dense "clumps" were superbly defined. I removed the 17T4 and popped in my Celestron Axiom LX 23mm. Just as good a view, but slightly wider. Stars at the edge were still nice and pinpoint, until the very very edge of field where they fell off a small amount. Perfectly acceptable! The slightly wider field framed the group more nicely.

Swung back to find M81 and M82 and they were very easy to see! The definition of the galaxies against the background sky was great, but after a while I was tempted to screw in my Astronomik UHC filter. Sadly it pulled too much light out of the view and did nothing to improve it. I don't use this filter much. Switching the N17T4 back in the detail level increased and it was "probably" the finest view of these galaxies that I've had through a refractor of any type or aperture.

Next target was M51, but just as I got it in the field of view - bang, the clouds swallowed it up, along with the rest of the sky. Shame as I really wanted to get to the globular clusters and more galaxies!

I found that the focuser needed most of its travel to get the eyepieces I used to focus. It was not near the end of its travel; maybe about 75% out, so there was room for adjustment. The focuser was quite nice, though something kept squeaking. The fine-focus had no issues at all and was very useful. I did not need to tighten the tension knob, despite using two quite heavy eyepieces.

My fears about the heavy dinner-plate metal lens-cap were confirmed. It is difficult to re-fit after observing, in the dark with cold fingers, and it took a few tries. At least I did it with the dew-shield extended so there was less risk of clanging the objective!

Only a few objects seen, but it's very obvious that this scope will excel as a DSO tool. The combination of mount and scope was very good but I need a slightly shorter pier extension for this scope. The eyepiece height was always just a little too high for seated viewing and just a little too low for standing!

Looking forward to Second Light now, hopefully it will last a little bit longer!

Ant

[RT65CB-SWL]

Hi Ant, that is a nice refractor!

[vlebo]

I think this is a clone of yours as well Ant. https://www.altairastro.com/product.php?productid=16699&cat=270&page=1

I quite fancy one of these on one of Altair Astro's Sabre Mounts for some quick grab and going. Tring Astronomy are suppliers of Altair gear so if and when they have one on display I must take a look.

[A McEwan]

Yes, that's the same model. It was Ade Ashford's review (linked to in that product page) that finally tipped me over the edge...

Ant

[damnut]

Hi Ant,

Great frac, I have the Meade 152mm petzval and it is a great DSO hunter, feed it with axiom 23mm , 13mm nagler an 100deg 9mm... Very little ca. I too have it on skytee ii balanced with dual mount 120mm and a 150mm mak on an ae pillar. You will be very pleased with it.

Congrats.

[A McEwan]

I finally had a second light!

Tonight in fact. I took the scope on the SkyTee II to my dark sky site and set up before the Moon rose.

In that brief half hour or so before the waning Moon washed out the sky, I was able to observe some of the objects I'd missed on the first session.

M13, the Great Hercules Cluster was ....rather great! I used my 9mm 100-degree eyepiece for 100x and a field of one degree - a nice combination for many DSO's - and found that what I had expected was indeed the case: that it was very resolved and a very handsome view!

With the same eyepiece I slewed over to the Double Double in Lyra. This is a beautiful par of fairly tight double stars that I try to test new scopes on as soon as I can, and in the Lyra 152 the two pairs were split cleanly at 100x with the tiniest sliver of black space between them. It was tight but clean. Later on, when I revisited the pairs with the Moon higher in the sky, the split was not so obvious, and slightly higher power was required to see the split with the same clarity.

The Pleiades were remarkable using the 23mm Celestron Axiom. Although the Moon was rising nearby, and all hint of nebulosity was washed out, the stars themselves were bright tight little diamonds across the field of view. Lovely view, and I only wish the Moon had been absent so that I could have explored the nebulous patches in the cluster.

I very briefly visited M81 and M82 again, but the sky was by this point so washed out that there was little to see.

Facing defeat, I finally swung the scope over to the Moon, about 20 degrees above the horizon: low, bright and big. A pretty tough target for a big f5.9 achromat huh?

Well the image snapped instantly into view in my 25mm Plossl and was clean and sharp all the way! Only a merest hint of CA at the very edge of the limb, and craters, mountains and rilles were easily seen, and clearly, across the whole sunlit portion of the disc. Increasing the magnification to 100x and 128x showed images that were sharp, crisp and stable. Focusing was easy, and the amount of CA visible at these higher powers was not distracting. At the limb there was a noticeable halo of blue, but looking away from that, towards the details within the disc itself, this was very easily overlooked. What did spring out was the amount of detail that 6" of unobstructed aperture (and good well-made aperture at that!) can show!

I had thought that this would be an "occasional lunar look scope", but given the view I just had, I'm not so sure. It would have been good to compare it with my ED100 and see the difference in resolved detail, but I hadn't thought to take the ED100 with me. At this stage, albeit perhaps still suffering symptoms of honeymoon optimism, the scope actually fells like a good "all-rounder", not just the dedicated DSO scope that I had originally purchased it as.

Next steps are to flock the dew-shield and OTA front, and do some minor adjustments to the focuser. It's a little rough and squeaky in coarse focus mode.

Am I pleased with this scope? Oh YES! I'll try and pop some pics of it up soon too...

Ant