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Evostar 6" F8 Refractor first light


F15Rules

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It's actually really a quick compilation of two sessions, last Saturday night and tonight..last week was better as there was no Moon, but the urban light pollution that plagues the Midlands never goes away.. although I live in a semi rural area, we are surrounded within 10-15miles by Leicester, Derby, Coventry, Birmingham, Nuneaton and Hinckley..and for some reason, a small nearby town, Coalville, has some of the worst lighting for industrial parks that I've ever seen..so the sky always has a noticeable orange glow a fair way up.

Firstly, I'm chuffed to bits with the Evo scope. The objective is a corker, and although an achromat at F8 will inevitably have some CA, it truly is very well controlled on this sample, and not at all invasive. I've also noticed that certain eyepieces seem to almost negate or certainly reduce it to a point where you don't even notice it.

Targets in the two sessions were:

M13, M92 (both globulars in Hercules), Mizar, Vega, Saturn, the Double Cluster in Perseus, the Double Double in Lyra, M57 (Ring Nebula in Lyra) and Delta Cygni.

The globulars were very pleasing indeed. I'd really recommend M92, it is quite bright but smaller and tighter than M13, but both show peripheral stars at high magnification (over x100 to x200). The higher mags also darken the sky background, making more stars "pop out".

Mizar is always an old favourite and I never tire of looking at this multiple system. In a new (to me) Konig MK 70 2" 40mm 70 degree wide field eyepiece this system was stunning, framed against a lot of fainter stars. Vega too, was lovely, with a little violet due to the CA and brightness, but so sharp and again against a pleasing background of fainter stars.

Saturn was only a quick look last weekend as it is all but gone now. The Cassini Division was clearly seen, and one major belt, but not much else...oh, and two of the moons.

The Ring was easy to find in Lyra using the big Konig as a wide view finder, but it also is easy to find using the Tal 50mm finder as well, by lining up the two brighter stars either side of it and the ring is roughly in the middle of them. Again this took higher magnification well, and the slightly elliptical shape was well seen at x120.

Next up was Delta Cygni..this star has always been so difficult for me to say I have definitely, without doubt, split it, but now I can say just that!:)..at x160 with a Celestron Ultima 7.5mm there was the companion, just about sitting on the first diffraction ring, but when I barlowed this ep to x320 there was clear dark sky evident between the two components. I think this was the most pleasing observation as it showed that the objective is truly well figured and collimated, and also the image was so steady due to good seeing (for once).

I split Delta both last Saturday and again tonight, no doubt about it.

I also had a lovely clean split view of Epsilon Lyrae, the double double with black sky between both pairs at x120. I love the way each pair is a right angles to the other in orientation, and each component so evenly matched with its twin.

Lastly, I had a look at the double cluster, which is still very low down even at 2am in the morning! I had a lovely view in the Konig, with both clusters in the middle of the view, with lots of sky around them - this is a view I just couldnt get in my Lomo Mak, as the FL of F14 just gives too narrow a view. Great to see it starting to rise in the east again.

All in all I'm a happy bunny tonight, though cold now and tired..the big Evo is performing as I had hoped, and my love affair with refractors is as strong as ever:p..

Am off to bed now, hope some of you have managed to get out tonight wherever you are... been a nice calm night out.

Dave

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Hey, what a great first (and second) light report. You certainly made the most of the short nights. When you have a good session it really does put a smile on your face.

It is good to hear how other people get on with the Evostar 150, I bought one in February and have been very pleased with it.

I would concur with your experience with double stars, this 'scope does exceptionally well and can take high magnification (seeing permitting). I got a 6mm University optics ortho eyepiece at SGL6 and find that a very nice combination for planetary work.

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Great report Dave :icon_eek:

I managed Delta Cygni myself last night with my 6" mak-newtonian and, a bit to my surprise, my C5. It's a really nice challenge for 5"-6" aperture scopes.

M92 is a much overlooked globular I agree - I guess it's "in the shade" of M13 :)

I'm glad the big Evostar is delivering the goods :rolleyes:

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Hi Bucklamp,

I'm glad you enjoyed my report:)..did you buy the newest Evostar or is yours, like mine, one of the older ones (mine's about 6 years old)?

I did notice that the sky background, even at the zenith, was never that dark, and that's due to the short nights, rather than the light pollution, and I know that objects like the double cluster will look much better in the autumn:p.

John, that's interesting to hear you split Delta with your C5..that's clearly a good scope you have there;)..I reckon my Lomo would split it under calm skies like last night, and I'll be making that a target for the Lomo next time conditions are ideal for high power.

I've decided to avoid getting both Evo and Lomo scopes out together too much...it just means I spend too much time fiddling between the two, and not enough with quality observing time..although it is fun to do a head to head sometimes, isn't it?:)

TBH it was just nice to be able to get some startime in, it's been a bit of a wait since last Saturday!

cheers

Dave

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Hi F15Rules,

My Evostar is in the newer black and white livery. I have it mounted on a standard EQ5 which I find ok for visual and webcam work, though we always aspire to have better.

I have been following your thread about fitting the crayford focusser, very interesting. This is something that I may well consider in the future.

I think that I missed a good observing night last night. Clear but bright at 10pm and still clear here at 4am (don't ask :)) Rain from about 6am - still going.

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...John, that's interesting to hear you split Delta with your C5..that's clearly a good scope you have there;)..I reckon my Lomo would split it under calm skies like last night, and I'll be making that a target for the Lomo next time conditions are ideal for high power.....

Dave,

I'm sure the Lomo will deliver an excellent view of Delta Cygni and split it under decent seeing conditions.

TBH I'm a bit surprised at the performance of my C5 and slightly perplexed by it (in a good way of course). I guess it's an example with good optics and I must have the collimation spot on. The views of Saturn last night with it were superb and only slightly inferior to the views through my Intes 6" mak-newt but I would have expected there to be more of a performance gap :)

Anyway, enough of my scopes - this thread is about your wonderful new big beast of a refractor and it's a lovely and desirable scope IMHO :)

Thanks for the observing report - I look forward to reading more ;)

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Great report Dave glad your coming back to big refractors:)

Have you tried Porrima in it yet, its opening up now and is well worth a look when next you look at saturn being only a nats whisker from it. My 5" splits it with a bit of mag 150-200x it'd be interesting to hear how the extra inch of resolution helps.

These scopes are super performers the ones Ive looked through have all been corkers and as you say are well corrected for CA. The F8 gives it the nuscle for planetary but still keeps DSOs nicely. I must admit I have been tempted over the years to get one.

They are pretty good on planetary imaging as well the 6" brings in loads of light so you can barlow to good effect.

Philj

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Hi guys, thanks and it's great to know there are so many big achromat fans out there:icon_salut:.

I'll continue to do bits as and when funds allow...I managed to find a nice Televue Everbrite 2" diagonal which, when compared to my Revelation Dielectric definitely shows a larger FOV with the same Eyepieces (daytime testing only so far).

I have a local mast about 200m away which I use for daytime testing and I estimate that I see about 10-15% more FOV with the Everbrite than with the Revelation...any ideas why that would be? Also, the focus point is a few mm back from the Revelation..

Phil, I'll certainly give Porrima a try if I can get out early enough (I lose Saturn behind a neighbouring house after about 10.45-11pm:eek:

I also want to try some doubles with the lens stopped down to 4.5" which gives F10 on the EVO...really getting into my long focus frac territory - and the CA reduces even more.

I must say that the CA on this scope is absolutely not a major problem. If anyone is thinking of a big F8 and is put off by CA, then don't be...you can always get a Fringe Killer or other filter, but honestly I don't feel the need to on anything I've looked at so far.

Can't wait to get the darker skies of autumn to see what the scope can really do...but don't tell my other half I'm wishing for summer to be over, or I'm toast!:).

Greetings also to Southern Man down under..enjoying your winter dark skies, I hope;)..c

cheers

Dave

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....I managed to find a nice Televue Everbrite 2" diagonal which, when compared to my Revelation Dielectric definitely shows a larger FOV with the same Eyepieces (daytime testing only so far).

I have a local mast about 200m away which I use for daytime testing and I estimate that I see about 10-15% more FOV with the Everbrite than with the Revelation...any ideas why that would be? Also, the focus point is a few mm back from the Revelation...

I have 2" Everbright and WO diagonals and the light path through the WO is a few mm longer than the Everbright. This really mattered when I was using the Chromacor as the eyepiece focal plane > Chromacor distance has to be pretty precise for best performance. I think it's to do with the fitting of the mirror which is recessed in the Everbright. I'm assuming that the Revelation will be similar to the WO in design.

WO diagonals also use quite a thick collar to attach the eyepiece tube to the diagonal body. This definately causes vignetting in eyepieces with large diameter field stops in the 1.25" version of the diagonal. Maybe the Revelation uses a similarly thick collar ?.

A really good test double for a 6" is Iota Leonis I found - everything needs to come right to make a clean split. Pity Leo is setting rather early now but I'm sure there are others coming into view. You can try for Sirius B later in the winter :)

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Interesting stuff John:)..can't wait to try out the Everbrite at night with the Konig MK-70..

Have you ever seen Sirius' pup? I've always thought it would be to dim in the glare of the primary, but maybe it'll be worth a try in the Winter..anyone else seen it, if so what with?:)

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Interesting stuff John:)..can't wait to try out the Everbrite at night with the Konig MK-70..

Have you ever seen Sirius' pup? I've always thought it would be to dim in the glare of the primary, but maybe it'll be worth a try in the Winter..anyone else seen it, if so what with?:)

The short answer is "no" Dave, for me at least. You may find this thread of interest on that topic:

http://stargazerslounge.com/observing-imaging-double-variable-stars/125968-sirius-b.html

I believe SGL member Lunator (Ian) did manage to see it at the SGL6 star party with his OO 10" mak :)

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