Sumerian Canopus 16" review

[Scooot]

I ordered the scope on the 5/9/14 and it arrived on 12/1/15 so about 4 months but I had made it clear I was more interested in receiving a good scope than it being rushed.

I've posted my first pics of the scope in this link. http://stargazerslounge.com/topic/234116-sumerian-16-pics/

Spec.

Sumerian Canopus 16"

Orion Optics 400mm f4.5 1/10 PV Hi-Lux coatings primary mirror.

75mm secondary mirror.

Secondary Dew Heater

Primary Cooling Fans

Encoder Hardware

8x50 right angled finder

€4,566 including €120 shipping

This converted to £3713.40 without a focuser.

Mirrorbox with altitude arms attached 17.35kg

Secondary cage with focuser and finder 3.17kg

Eyepiece height at Zeneth 163cm

Stored height 43.5cm

Packaging.

It arrived in three parcels and everything was very well wrapped. It was done so thoroughly that none were dented or broken I could tell nothing would be damaged before opening them.

The Truss Tubes.

There are 4 pairs made from 18mm aluminium. They feel light but look well made, in fact I wondered whether they were Carbon at first. They were in new condition with no scratches.

The Secondary Cage and Secondary Mirror

This arrived in one piece with the spider and secondary mirror attached. The secondary mirror was wrapped in a small plastic bag. It's collimation screws are adjusted with two good sized wheel knobs, plus one for which you need an Allen key. Presumably because only two need regularly adjusting and my experience so far so that this is true. They are very easy to turn whilst simultaneously looking either through a cheshire or at a laser dot on the primary. The whole mechanism looks substantial and very well made. The secondary also comes with an attached dew heater. The wires for which were neatly taped or strapped to a spider vein leading to a small battery holder which was attached to the secondary by Velcro.

The secondary cage itself is very light. Without a Focuser or finder it weighs only 5lbs. The design had a series of circular holes cut out around the edge. On one of these the wood around the edge looked as if it was frayed a bit and was a bit rough. This is about one of the only things I could find to complain about if I had a mind to. It's very minor and I call it character so it's there to stay. I originally thought these holes were to keep the weight down but this part of the cage is made from very thin wood so I doubt the holes made much difference to the weight. The frame of the cage and its supports are much more substantial and made with care and attention. I had decided to buy my own focuser separately so Sumerian provided a flat base together with the correctly positioned screw holes and screws to attach my focuser. This was fortunate because I needed to attach my feather touch base as well, because it's rotatable and the screws for this were smaller than the holes made by Sumerian. I'd also ordered a right angled finder and the shoe for the bracket had already been attached.

The mirror box and primary mirror

The mirror box and primary mirror is the heaviest component weighing 17.35kg. Despite this, it's not an awkward shape, so I can carry this easily. I wouldn't want to walk to the shops with it, but I can carry it to my observing point without too much trouble. The mirror was wedged in the box with small foam wedges and the clips were protected with cotton wool pads. There was also a wad of cotton wool laying between the mirror and its cover as added protection during transit. The hardboard mirror cover is held in place over the primary with Velcro, and the top of the cover is marked with two black dots to help align it properly when putting it away. The box itself is the work of a good craftsman. Everything is in the right place and fits like a glove. It has a very solid carry handle. The truss holes open and close a small amount to allow the poles to sit correctly on the bottom. Each pair of holes are loosened or tightened with good sized wheel knobs.

The same sized wheel knobs are used for two of the collimation bolts. One collimation knob is adjustable with an Allen key like the secondary. They are all positioned on top so can be easily adjusted from above whilst looking at the laser or switching from looking through a cheshire.

There are also three cooling fans underneath the main mirror. I haven't tested these yet because the lead wasn't included which I've only just noticed. Or I threw it away with the packaging by mistake?

The Altitude Arms

These are very solid with the trademark design holes cut out. They attach to the side of the mirror box with wheel knob bolts that screw into brass threads that were accurately positioned in the mirror box. They are easily removable for transport although I choose to leave them on whilst storing the scope in a shed.

The Turntable.

This arrived in one piece but comes apart to enable the tension to be adjusted if it's either too loose or stiff in operation. As before it's very well made but also very light. The turntable also has a transport tensioner to secure the mirror box when required. I had specified encoder hardware and this was supplied with the appropriate encoder arms and encoder shaft already in place.

Putting it together.

I suppose my other minor gripe is that the instructions aren't very good. They amount to photos together with annotations which basically say things like: "3. Place the altitude bearings and stabiliser".

Most of putting it together is common sense, but for someone like me that hadn't used or assembled a truss Dob before not everything was immediately obvious. It took me a little while to work out where the side stabilisers attach although they can only go one way but if the instructions were clearer it would have saved some time. Also the instructions refer to "traveling locking bolts" which I spent too long looking for. I subsequently discovered they're not on the current model but were on an older model. The instructions for the Sumerian Alkaid had also been included which mentioned this but I didn't read these because I had the Sumerian Canopus. I only mention these failings for the sake of completeness because overall there was not really very much to complain about.

Once the mirror box is complete with altitude arms, it fits snugly into place on the turntable. The truss tubes sit in their shoes nicely and the secondary cage, which still only weighs 7lbs with focuser and Finder attached was easy to hold one handed whilst positioning and tightening the little wheel knobs that hold it it place. The second time I put it together took me 5 minutes which included the time to carry the bits from the shed. I'm very pleased with this, because one of my concerns about buying such a large aperture scope was setting up time putting me off. Or just as importantly putting away again when I'm tired. So no such worries with this.

Pre use tests.

Collimation

Not surprisingly the collimation was a long way off at first so I started with the Cheshire. Both the secondary and primary were easy to adjust with the two wheel knobs for each. I finished with the laser although as I was doing this in daylight, and I've yet to buy a shroud, it wasn't as easy to see the laser dot. The second day I set up I checked with the laser. The secondary was out a touch, or it wasn't in the focuser exactly the same. The primary had moved a lot but it only took a minute or two to realign.

Truss rigidity

I was a bit concerned about this before I'd received the dob as I'd read how important the strength of the scope is. The tubes seemed rigid enough to me, I would certainly have to use a lot of effort to bend them, but I wanted to test how well they hold collimation whilst moving the scope. I decided to do this by watching how the laser dot moves. I'd recently read an article on David Lukehurst's website about this which basically says it's nearly impossible to eliminate all movement. So I wasn't expecting it to be perfect. I'd collimated the scope with it at roughly 45°. As I lowered it, the dot moved a fraction downwards and settled just inside the bottom of the central marker ring on the mirror. As I raised it from the 45° it moved upwards by about the same amount. So it was moving about 2mm either way. Whist rotating the scope it didn't move. I'm not sure how good or bad this is deemed to be but I thought it was quite good.

Balance.

I can't fault this it's perfect. Either with my heaviest eyepiece combination (26mm Nagler and Paracorr), or without an eyepiece at all I can move the scope to any position and it stays there. It also moves very smoothly with very little effort. Rotating the scope is also smooth but requires a little more effort.

Equatorial Platform

I haven't tried it yet but it seems to fit on my Watchhouse UK Equatorial Platform which is an added bonus. Might need a small step when using it like this.

Using the Scope.

As mentioned it takes about 5 minutes to move it into position and attach the secondary cage. Collimating the scope is a breeze, and it has only required some minor tweaks so far. I do think a laser makes this so much easier to do in the dark. I can stand next to the scope, reach across to the secondary collimation knobs and watch from the side as the laser dot moves onto the centre. Similarly, crouching at the bottom to turn the primary knobs whilst looking up is just as easy.

I'm also very pleased with the supplied right angled finder. I think it's better than my current one and I find it a lot easier to use than my straight through finder, I wish I'd bought one earlier.

As mentioned I've yet to use the primary mirror fans.

I have used the secondary heater and it didn't dew up. On the second night the dew point was within 1 or 2 degrees of the temperature so I may well have had a dew problem without it. However I don't like the fact you can't tell if it's working, there's no light to indicate the batteries are ok, so as far as I can see, the only way you can tell if the batteries are flat is if the mirror dews up. Having said that I wouldn't want a little light right near the Focuser so maybe that's why rechargeable batteries are supplied. Charge them every time and you know they're ok?

Moving the scope around is smooth, I tend to hold the mirror cage with my left hand. It requires a little more effort in azimuth than altitude. Nudging whilst at the eyepiece is much the same as my 10". Sometimes at higher powers, when fine sensitive movements are required, it might take a bit of fiddling to centre it but it's very much as I'd expect.

On the two occasions I've used it I thought the optics were superb. I actually think this mirror is a little better than my 10".

The lightweight feathertouch focuser that I bought separately is superb. As smooth as I could want. It's handy that it rotates to move the knobs into the preferred position.

My two first light reports in these links tell the story of my views to date.

http://stargazerslounge.com/topic/234269-first-light-terrible-conditions-sumerian-canopus-16/

http://stargazerslounge.com/topic/234403-excellent-2nd-light-sumerian-canopus-16/

The 3 cooling fans below the feet.

It fits on the platform

Me posing at my normal observing spot in the back garden.

I was hoping for a high quality, manageable Dobsonian with a large aperture without the need of a ladder, and that's what I think I now have!

I hope this is balanced and helpful.

[mister_wavey]

Great writeup. Thanks for taking the time to do such a good job.

[Dannae]

Hi Richard,

Lovely write up and the scope looks great - I like the subtle counterweights. Are the poles shrink wrapped, painted or anodised - they look good

Is the mirror supported by fixed points or a sling?

Best wishes for you and the new scope.

Regards

Dannae

[bingevader]

Yep, good detailed job.

[mapstar]

A lovely write up Richard with plenty of detail thankyou. Nicely finished by the sounds of it and works well

Cheers

Damian

[Scooot]

Lovely write up and the scope looks great - I like the subtle counterweights. Are the poles shrink wrapped, painted or anodised - they look good

Is the mirror supported by fixed points or a sling?

Best wishes for you and the new scope.

Regards

Dannae

Thanks Dannae, I don't know about the poles I'm afraid, is there an easy way to tell? I'm pretty sure they're not painted, when I look into the tube it looks as if there is some sort of coating so I'd guess they're shrink wrapped but I've got to get n touch with Michael so I'll ask him.

Same with the mirror, I'm not sure but I think it's slung because I can see wire around the edge if this is a clue. It's visible in one of the pics.

[faulksy]

lovely report richard, its like a marriage made in heaven. glad your happy, i would be to. thanks for posting and sharing your happiness

[niallk]

Great write up + pics!! I think it is a class looking scope, and sounds like mechanically it is working sweetly. With premium optics and convenient setup/teardown/portability - sounds like a great investment. "Well wear" as they say in these here parts in Cork!

[clarkpm4242]

Hi

Nice write up.  Hope it continues to perform as good as it looks!!

The primary has a wire sling for low altitude support and 6 'floating' support points.  These are on each end of the 3 metal pivot bars below the mirror (they aren't counterweights).

Cheers

Paul

[Scooot]

Hi

Nice write up.  Hope it continues to perform as good as it looks!!

The primary has a wire sling for low altitude support and 6 'floating' support points.  These are on each end of the 3 metal pivot bars below the mirror (they aren't counterweights).

Cheers

Paul

Thanks paul, good to know, my brother was asking about the mirror support points.

[alan potts]

Richard,

I very well writen and nicely balanced report, you can almost see the look of relief on your face after the 4 months wait. I hope to have mine very soon.

Alan

[swamp thing]

Nice review mate.

Make sure you don't step in that pond in the dark  

[Scooot]

Thanks Dannae, I don't know about the poles I'm afraid, is there an easy way to tell? I'm pretty sure they're not painted, when I look into the tube it looks as if there is some sort of coating so I'd guess they're shrink wrapped but I've got to get n touch with Michael so I'll ask him.

Same with the mirror, I'm not sure but I think it's slung because I can see wire around the edge if this is a clue. It's visible in one of the pics.

Just heard back, the truss poles are shrink wrapped.

[Dannae]

Hope you are having fun with the new scope I have specified a red lightweight feathertouch for my new scope so perhaps we can start a trend!

Regards

Dannae

[mapstar]

Hope you are having fun with the new scope I have specified a red lightweight feathertouch for my new scope so perhaps we can start a trend!

Regards

Dannae

Having the same for mine, shame they don't do them in televue green though? I may ask?

Damian

[Scooot]

Having the same for mine, shame they don't do them in televue green though? I may ask?

Damian

Hi Damien, off topic but I've noticed you have a 13mm ethos and 17.3mm delos. Do you use the latter much? I wondered because the FOV is about the same.

[mapstar]

Hi Damien, off topic but I've noticed you have a 13mm ethos and 17.3mm delos. Do you use the latter much? I wondered because the FOV is about the same.

Hello Richard

Yes I have, I bought the delos first although I'm planning to change all my eye pieces to ethos so it will be leaving me in the not too distant future.

There is a slight difference although It's that long since I've used either I can't remember but the ethos provides slightly better contrast.

[niallk]

Hi Scooot, quick noddy question about the focusser if you don't mind - how does it rotate? Do you set the angle when mounting onto base plate, or is it adjustable 'in use'? Thanks, Niall (I'm looking at a FT for new scope)

[Scooot]

Hi Niallk, it's a good question, you can't tell from the pics of them. The Focuser itself just sits in the baseplate as opposed to screwing in on a thread. In the side of the base plate opposite each other are two tiny grub screws that tighten to hold the focuser on the plate. To rotate it you just loosen these and turn it.. You leave the base plate attached to the OTA whilst doing this. You need to use the supplied Allen key, so i don't think its intended to be done in the field on a regular basis , so to speak. It's best to set it to the desired position before hand. One thing I have noticed using it, because it's got such a low profile, the knobs are very near the bottom and you need to rotate it to a position that ensures ones fingers don't get squeezed between the knobs and the base screws . It's a minor inconvenience that would be fixed if the shaft holding the knobs was longer. I've set mine so the side with the 10:1 reduction on it is completely clear but a big handed person might not like using the other side on mine. A couple of risers would solve it though.

[niallk]

Thanks for that Scooot! Despite several searches I couldn't find a description for the Newt focussers - no obvious 'lock ring' in pics. Even the Starlight website seemed vague on this - though I may have missed it. Hope the skies your way are letting you get out to explore! Thanks again for the detailed reply - Niall

[swamp thing]

Niall

If you go with the SIPS system it lifts the focuser up and away from the base plate. So you get superb coma correction plus finger space

You can also then turn the focuser without using tools into any position that's comfortable for you. Win, win, win. The only loss.........the contents of your wallet

[niallk]

Hi Swamp Thing - thanks for the suggestion! Yes I have been googling to check retro fitting the SIPS system at some point in the distant future - seems possible... Over budget already so its not something I'll be considering (or a paracorr2) anytime soon! I'm looking at f/4.5 so I plan to see how it goes. I guess these don't come up often 2nd hand?! Thanks Niall

[Scooot]

Niall,

I've just been looking at my focuser again and the knobs an bolt problem aren't the focusers fault but my scopes. The bolts that come with the focuser and base plate are countersunk so if I'd been able to use those there'd be plenty of room for large fingers.

Mine came with pre made holes which use slightly larger bolts on which I attach the base plate, don't know if I can change these easily.

[cotterless45]

Just noticed this,

http://www.astrobuysell.com/uk/propview.php?view=92593

[mapstar]

Hi Richard

I'm sure you'll be able to replace the screws for counter sunk ones. They're probably imperial like most of the American stuff.

Nick that's a decent price wonder why he's selling it? Looks a good buy