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Midnight Messiers with a 120 Year Old Clarkson 3" f15.


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I hadn't expected to be out observing on Friday night as the forecast here was for cloud until well into the wee small hours. As I was about to lock up around midnight however I noticed it clearing, almost like a lid being lifted and the sky looked superb, very steady seeing, dark and transparent.   Earlier in the day I'd been clearing space for my new Dob to live and as I was moving things around realised it had been a while since I'd taken out my lovely old brass Claskson 3" f15.  This sudden clear sky inspired me to give in to the urge and I mounted the Clarkson up on the Report 312 & AZGTi used unpowered as a manual setup, taking care to find the balance point exactly as this scope is long! 

Decided to go after some of the Messier objects remembering that he made many of his discoveries (I believe) with a 3.5 inch so I should get some fairly authentic as-he-saw-them views.

I used a 32mm Plossl for widedfield (well, 1.39 degree anyway) and finding (c. 37x), an 18mm Baader Classic Ortho for a closer look (67x) and occasional higher power views with a 10mm Baader Classic Ortho (120x) through a Tak Prism. 

Started with M3 which was high in the SE and got a great view - no stars resolved but a bright mist with a hint of granularity. 

In finding M3 I'd looked at Cor Caroli to get oriented (M3 lying just over half way along the line from Cor Caroli to Arcturus) and the view in this scope and the 18mm BCO was beautiful, an uneven white pair burning steadily in the rock-steady seeing. 

M13 was super and definitely sparkly with AV.  Nicely framed between its 2 sentinel stars. 

M92 surprisingly bright ball with a tight core. 

M57 next and found the Ring Nebula with ease tonight, transparency was excellent at this point.  Racked up the magnification to 120x and could just about discern the inner ring. 

M29 - Hunted a while for this and found it smaller than I remember - like a tiny Pleiades. Not the best view in this 'scope. 

M39 - Beautiful, bright open cluster trailing Deneb, like a half-Beehive. 

Tried for some galaxies and certainly picked up M81 & M82,  couldn't do better than a "maybe" on M65/6 so had a look at Algieba instead.  Splitting well with the 10mm BCO, a pair of golden headlights. 

Same story as in Leo with Virgo, I'd tried earlier in the session but seen nothing but after 1 am (!) some local car park lights go out and I thought I'd have another crack at the Markarians chain area.   A "maybe" on something where M84 & M86 ought to be and a similar trace around where M87 should hang out. 

Decided to stick what had been working and go back to M13 and watch it drift across the field a few times, loving slewing this 120 year old scope around the sky and getting some really satisfying views.  On very bright stars at high mag there is some optical error that I can't quite work out, diffraction patterns skewed to one side. But at lower mags faint to medium brightness stars appear like little balls on a black background and the colour rendered by uncoated optics is really beautiful and natural. 

Lyra had risen quite high by now and I thought there was a shot at M27 just coming up over the roofline. Dropping down from Lyra to hunt for it I was surprised to pick up M56, a globular but quite diffuse, more of a misty patch. I swept away and back a couple of times to confirm but yes it was positively there.   

On South and was thrilled to pick up M27 - couldn't really tease out much in the way of form, more of a grey misty patch but its an object I often forget to look for so was pleased to get the authentic Messier-like view of this one and chalk up another object viewed in the "gentleman's telescope". 

Rounded off on Alberio and, like the view of Cor Caroli earlier, breathtaking Sapphire & Gold in the steady seeing, framed in the pea-shooter field stop of the f15 Clarkson. 

I had stayed out way longer than intended and had I not had a longish drive the next day (Kingston Uni open day with son no 2!) could happily have stayed out all night, although I'd have needed to nip in for my big coat as there was frost and numb fingers by this stage.   

Have left the Clarkson set up ready to go, it looks fantastic and an easy carry out to the garden for future "quick" sessions like this one. 

 

 

327FAC4E-497E-43C6-B0EC-21341963E088.jpeg

Edited by SuburbanMak
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Excellent report. I'm messing about with a slow 80mm just now and you've suggested some good targets.

M94 in Canes Venatici should be a suitable target galaxy. I can see it in 10x50 binos in Bortle 6.

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15 minutes ago, Pixies said:

Excellent report. I'm messing about with a slow 80mm just now and you've suggested some good targets.

M94 in Canes Venatici should be a suitable target galaxy. I can see it in 10x50 binos in Bortle 6.

Thank you and a good shout onM94, that’s one of those I swept up in my first flush of Messier hunting early last year and haven’t looked at since - I’ll definitely give it a go both with the Clarkson and the new Dob. 

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That's an excellent report, and your 120 year old refractor has probably seen more action with you as its current custodian than throughout its previous life. Brilliant!

It might be worth having it collimated as it's star images should be exquisite, then it will give superb views of the planet's too. 

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Thanks @mikeDnight - it’s a splendid thing and I’d certainly consider having it “tuned” - the lens cell is not obviously collimatable however so not quite sure how I’d go about this. If any knows of someone who does this I’d love to investigate. 

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37 minutes ago, SuburbanMak said:

Thanks @mikeDnight - it’s a splendid thing and I’d certainly consider having it “tuned” - the lens cell is not obviously collimatable however so not quite sure how I’d go about this. If any knows of someone who does this I’d love to investigate. 

Often these refractors rely on a the lens cell fitting flush to a squarely cut tube, so it could be that the cell is out of flush with the tube, or possibly that the objective has slipped slightly to one side after a knock during its long life. Another possibility may be that the focuser is slightly askew. Whatever it is, its almost certainly a small thing and certainly rectifiable. Es Reid may be willing to take a look at it if he has time.

Some old lenses were held in position by a brass split ring that acted like a spring clip and could easily be knocked out of alignment. 

Edited by mikeDnight
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Posted (edited)
21 hours ago, Paz said:

Great report! Are you able to use a diagonal with that or do you have to use it straight-through?

Thanks @Paz
After tinkering around a bit I found that if I remove the long focus extension tube, what’s left is precisely 1.25” in diameter, so I can use my Tak prism and there’s enough in-focus to get things sharp with just a couple of mm to spare. 


I use Baader Classic Orthos and simple 32mm & 40mm Plossls so as not to overtax this push-fit arrangement and all is nice and snug. 

I have a box of RAS fit eyepieces, which are interesting to try but mostly poor views, with the notable exception of a Charles Frank “wide” which I believe is a 40mm which is fantastically sharp but has eye-relief measured in miles. 

 

Edited by SuburbanMak
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