H V 38 in 15x70

[daveintheshire]

I had the good fortune of finding a copy of the September Sky at Night magazine on the first day of my holiday in west Wales over the last week.  Monday night turned out to be much clearer than expected and despite the lighting on the caravan park I was treated to very good skies.  I got a real kick from setting up the Helios Apollo 15x70 on a mount and working my way through Steve Tonkin's Binocular Tour.

I managed M13, 30 Herculis, the Tau Coronae Borealis group (beautiful with it's triple in the middle), delta Boötis and Harrington 7 (my first sighting and a real delight) with ease.  I had no problem locating H V 38, but I could not even get close to a split.  Two days later I went up into the Elan Valley International Dark Sky Park.  Needless to say, it is very dark!  One of the very best views of the Milky Way I've ever seen, and the skies were so transparent that the fainter constellations became slightly confusing to pick out.  However, despite having looked up the position angle, I still couldn't get anything other than a single point of light.

I know its a challenging one and I hope perseverance and favourable conditions will crack it.  I was wondering has anyone else had any joy splitting H V 38 in a 15x70?

Clear Skies,

Dave.

[mark81]

Hi Dave, nice report there. Interesting to hear about the dark sky park - and it is strange when the constilations seem to get lost amoung the milky way. (I never like to brag, but my semi rural location can be like that on a good night)?

I no longer have my 15x70s and was never really into splitting doubles with them.  I will take a look at it though, maybe with the St80.

[daveintheshire]

Thanks mark81.  I grew up in rural Worcestershire and the skies were pretty good there.  Then I moved to West Bromwich - all bets were off!  The skies where I am now are suburban to semi rural, but nowhere near what I took for granted as a kid.

I'd be very interested in hearing how you get on with H V 38 with the ST80.  I do a lot of travelling (one of the reasons I love binocular observing so much) so I'm thinking of procuring an inexpensive grab-and-go scope.  The Skywatcher ST80 is on the short list, but I have been leaning towards towards the Skywatcher 90mm Mak-Cas for its longer focal length with doubles in mind.

[mark81]

Yeah, st80 not the best scope for doubles - great for low power wide field views - clusters mainly.  The Mak is the way to go. Lots of power in a real compact setup..

[BinocularSky]

Yes, but it was a few years ago. It's a real challenge, mainly because of the magnitude difference. I'll give it another go next time I get a chance and report here.

Also, I concur with what @mark81 wrote about the Mak. I've had an ST80 and, while it's fine for open clusters and stuff, it has too much CA to be particularly useful at high magnification unless you stop it down with the lens cap (has a cap-able central aperture) - and then it's not very bright. I have the 90mm Mak and it's lovely for Moon, bright planets, Sun (with filter!). It's also very easy on eyepiece quality, but my favourite is a 12.5mm Orthoscopic: lovely crisp images. Does need to be properly collimated, of course, and the factory doesn't always do a good job of it.

[BinocularSky]

Update: Had a go last evening at about 22:30 UT - too late; it was already too low and 10th mag stars at that altitude were extincted from my location.

[daveintheshire]

Thank you all for you replies and advice on a grab-and-go scope.

I plumped for the 90mm Mak, and I'm very glad I did.  I currently have it mounted on an old Velbon VE3 tripod with a homebrewed bracket to drop the scope's centre of mass and provide a more convenient point to mount the Rigel Quickfinder.  For a temporary lash-up on a low end tripod its working better than expected.  A 1.5inch galvanised pipe mount atop my Leica Geosystems CTP103 surveyors tripod is not far off complete and should be far more stable.  It arrived in good collimation.  I'm as pleased as can be with this little scope which more-or-less gives me a scope with the portability of a mounted binocular.  I still don't like screwing up my other eye though! ?

H V 38 split easily at 50X, with black sky visible between with ease.  It was still pretty close though - I think my inexperienced eyes would struggle at 15X, but therein lies the challenge.  I just about resolved ("split" would be just slightly too strong a word) the components of Ɛ1 and Ɛ2 Lyrae for the first time last night at 125X

Happy days.

[mark81]

26 minutes ago, daveintheshire said:

Thank you all for you replies and advice on a grab-and-go scope.

I plumped for the 90mm Mak, and I'm very glad I did.  I currently have it mounted on an old Velbon VE3 tripod with a homebrewed bracket to drop the scope's centre of mass and provide a more convenient point to mount the Rigel Quickfinder.  For a temporary lash-up on a low end tripod its working better than expected.  A 1.5inch galvanised pipe mount atop my Leica Geosystems CTP103 surveyors tripod is not far off complete and should be far more stable.  It arrived in good collimation.  I'm as pleased as can be with this little scope which more-or-less gives me a scope with the portability of a mounted binocular.  I still don't like screwing up my other eye though! ?

H V 38 split easily at 50X, with black sky visible between with ease.  It was still pretty close though - I think my inexperienced eyes would struggle at 15X, but therein lies the challenge.  I just about resolved ("split" would be just slightly too strong a word) the components of Ɛ1 and Ɛ2 Lyrae for the first time last night at 125X

Happy days.

Glad to hear you went for the Mak 90.  It is a scope that I am considering as I could mount it on my az3 with no problems.  

Keep the reports coming on how it performs with splitting... ?

[BinocularSky]

I had it at the weekend in 16x70s (monopod & trigger-grip), but it was darned difficult, partly because it was quite low by the time I got around to it, but also because it is darned difficult! I didn't have 15x with me, but I'm pretty sure it would have been possible. I think I might avoid this one in future and might go back to my initial criteria, which I've let slip in the search for new objects: all 15x70 objects must be visible, in a decent semi-rural sky, in 10x50, and all 10x50 objects must be visible in 8x42.

[BinocularSky]

On 30/09/2018 at 09:58, daveintheshire said:

 I still don't like screwing up my other eye though! ?

Eye patch.

[daveintheshire]

On 30/09/2018 at 10:26, mark81 said:

Glad to hear you went for the Mak 90.  It is a scope that I am considering as I could mount it on my az3 with no problems.  

Keep the reports coming on how it performs with splitting... ?

Right then.  We've had some cloud recently and I'm silly busy with work at this time of year so capitalising on the clear spells has been difficult.  However, I have managed to get my little mak to somewhere near where I want it (I'll be sewing up a dew shield after this post).

I have got it mounted on a homebrewed pipe mount on top of a Leica Geosystems surveying tripod.  This set up is more stable than I could ever have hoped.  It still (for me) classes as grab and go.  The pipe while solid as a rock is lighter than it looks.  For maximum "grab-and-go factor" the scope lives inside the house while the tripod and mount lives in the shed - to look at it no self-respecting thief would be interested, and even if they did pinch it I could just build another one for cheap.  Stiction is less with oil than with grease and I suspect something that is specifically good at low temperature would be even better than the rather thick bicycle chain lube my eyes fell on first in the shed ?  anyway, I digress...

I've been really enjoying my doubles with this little scope.  I've made a little adapter so I can fit my Rigel Quickfinder to the finder dovetail, which all works well.  I have added the EPs from my TAL-1 to the supplied EPs.  The TAL 25mm Plossl is a lovely thing and while the stock 25mm is not at all bad given it's price-point, the TAL does seem to show off colours better.  The TAL 15mm Kelner is also good for a nice "showcase" split on brighter pairs, but you start to loose the advantage around Mag 10.  The stock 10mm EP is not really much use except for lunar stuff, but given its price-point and the scope's aperture  it's hardly surprising.

From my notes:

09/10/2018:  Seeing: V.good. Transparency: 6 ( https://www.astroleague.org/content/seeing-and-transparency-guide )

ɩ Cassiopeiae A/C: 4.6/8.7: 7.4" Easy split, colour difference (orange/blue) noticeable but not as pronounced as most web sources claim. C faint, but clear with direct vision in 25mm. Unable to detect B even at higher powers.

η Cassiopeiae A/B: 3.4/7.5: 13", Much easier split than iota. Not dissimilar to splitting Polaris (which I "warm up" on most nights).

Double cluster occupies the FoV @ 25mm nicely and looked stunning.  Chains observed in a lovely view of NGC475.  Ring nebula showed some "hollow looking" structure with indirect vision. Dumbbell nebula a big, bright smudge.

18/10/2018: Seeing: V.good. Transparency: 6

γ Delphini: 1/2: 5.1/4.3: 9" Forget iota cas. For me this is "the other Albireo" - an absolute gem.  Very easy split and brightness allowed for use of 15mm to good effect.  Picked up Σ2725 in the same FoV. Mags 7.5 and 8.2, 6" separation.  A lovely little pair that held up well at 15mm, but still a good clean split at 25mm. Just an elongated smudge at 10mm, no matter how much twiddling I did.

β Lyrae.  Being a variable with a bunch of companions I haven't put the effort in for the numbers!  Suffice to say an easy and very attractive split with the two 10th mag companions sitting on the borderline of direct/indirect vision, with indirect making them easy in the 25mm TAL EP.

ζ Lyrae: 1/2: 4.4/6: 44" Standing-on-you-head easy split, but bright and lovely to behold.

η Lyrae:  Hmmmm.  I have a poor sketch of what I saw but I'm losing conviction on this one!

Σ2474 ( 6.78, 7.88, 15.9")and Σ2470  (7.03, 8.44, 13.8") (Lyr):  "The Other Double Double in Lyra").  Very pleased to have seen these.  A clear and not too difficult split, but then I realised I was quite dewed up by this point.  The fainter one in 2474 needed indirect vision to split, but the numbers show that this was due to the dew and not really representative of anything meaningful.

So there we go - I hope that's of some use and not too dull!  I really love this little scope for doubles.  Most of the ones above are easy splits and this reflects my level of experience, I'll post some more when I get a few closer pairs under my belt.  I think a finder scope in addition to the Quickfinder would be nice, but then we might be getting into the realm of the tail wagging the dog!

 

 

[mark81]

@daveintheshire Glad your enjoying that mak.  I've been thinking of getting a 90 as it will sit nicely on my az3.  Keep the reports coming.....? great stuff