Mark at Beaufort

1 hour ago, Ricochet said:

Did you buy the standard one or the solar version? Is there any reason to buy both? 

No I just bought the standard hood which I found okay for both solar and night time use.

I always use a hood when solar observing. As @mikeDnightstated above it's a great accessory for viewing faint DSOs. I bought mine from R-Sky a company in Russia. Many members on SGL did the same.

Very nice Francis you are really becoming a visual observer first a 16" Dob and now a 4" ED Frac - it must be the dark skies in the Golden Valley.. Hope you will be able to bring it along later in the month. 

16 minutes ago, John said:

What fitting is the centre threaded hole in the base of the AZ75 Stu ?

(apologies if you have already mentioned this)

Yes that is the info I require. I have the AZ5 metal tripod which is 3/8th thread same as a standard photo tripod. If it fits I fancy this new mount but don't want to purchase another tripod.

Alan this is really good news and I pleased that you and @Stu are doing the review. You partly answered a concern that I had about the Rowan mounts. I have a Skywatcher AZ5 mount and I use the metal tripod with a 3/8th thread. I was wondering whether I could use this 3/8th tripod with the Rowan mount so I think your comment suggest that I can.

Alan look forward to your review in due course.

Thanks Stephan a very enjoyable read. Certainly I always look for the propeller when using my 12 inch Dob. I like your suggestion it resembles the Mercedes badge.

Charl very nice image. I am clouded out at the moment but going away for a few days so won't be able to take the scopes. It means I will rely on images from SGL - so Charl keep them coming.

8 hours ago, Luke said:

That's a result with the scope, Mark! It looks nice in the piccies online. Looks like it has a dual-speed focuser? Is it a good focuser? It sounds nice and compact for travel at F5.5.

Luke I am very pleased with the scope and yes the focuser is dual speed - very smooth. I may purchase a Herschel Wedge in the future but I am happy with the Astrozap filter at the moment. Certainly the Baader Continuum filter has improved contrast.

That is interesting Andrew. I assume that my inexpensive 90mm f5.5 Achro will not benefit buying a prism diagonal. Whereas a quality scope like a Tak might???

1 hour ago, Astrobits said:

In microscopy the higher magnifications produced by shorter focal length objectives ( steeper cones of light ) require an adjustment to correct for the thickness of the cover slips.  A cover slip, which is a plane sheet of glass, introduces spherical aberration in the converging/diverging optical path. A correction for this aberration is achieved with an adjustable ring on the higher power objectives which alters the spacing of the objective's elements. Applying this to telescopes, a prism is effectively a plane sheet of glass ( albeit folded ) in the converging beam from the objective. It must, therefore, introduce some spherical aberration to the image. This aberration will be worse with smaller F/ ratios ( steeper cone of light ) and will always show up more at higher powers. Hence the comments in the posts above.

I very much doubt that any telescope manufacturer will design their objectives to correct for the use of a prism diagonal as when used without a prism there would then be spherical aberration of opposite sign present in the image.

A further consideration is that a prism diagonal has three surfaces with which the light interacts giving three opportunities to add their own errors to the wavefront while a reflecting mirror only has one. The reflective surfaces of both the mirror and diagonal will add double their surface errors. The plane surfaces of the prism are transmitting the light and their individual errors affect the light much less than a reflective surface, but there are two of them.

 

Nigel

Nigel what a fantastic reply and really explains the situation. This confirms my intention to get a dielectric diagonal.

There have been some excellent replies. This is not my main scope and I think I will go with dielectic diagonal. 

I will undertake a review in due course. 

I recently purchases a SvBony f5.5 Achro refractor and I have been very pleased with the results. I have not seen the requirement to purchase any of the Baader correction filters.

When I first obtained the scope I bought a StellaMira erecting prism -https://www.firstlightoptics.com/diagonals/stellamira-125-90-erecting-prism-diagonal.html because I was going on holiday and wanted to undertake some terrestrial viewing. The quality that I obtain was very good including many delights of Sagittarius.

Although the StellaMira diagonal is very good and I have viewed many DSOs recently (some with a TeleVue Nebustar filter) M11, M16, M17,M20, M21, M13, M92, M2, M15, Helix Nebula etc to give you an idea. I am wondering whether I could improve things a bit more by obtaining a normal star diagonal.

I have looked at this Tak prism - https://www.firstlightoptics.com/diagonals/takahashi-125-diagonal.html or a quality dielectric diagonal - https://www.firstlightoptics.com/diagonals/stellamira-1-25-90-di-electric-diagonal.html

I have never used a star diagonal prism and I am wondering which might be best - hence the question.

Enjoyable report John. It's good to hunt down M33 and to try and view NGC 604. I find there is a triangle of stars with the bottom two pointing straight to the object. Viewed it last night using the 6" Newt.

Nice one Francis. The big test will be seeing the Horse Head using a Hb filter - should be doable from your location. I tried this morning at 4am - no luck.

36 minutes ago, Dave scutt said:

Don't know why I always add multiple photos he only got the one phone. 

Help mark at Beaufort.

There you are Dave. 

4 hours ago, Rainmaker said:

Skylight AR101.15 looking up at the Light in the Sky

Matt that looks absolutely lovely. I also like the Herschel Wedge and the Televue 26mm Nagler 😀

Lovely refractors. I often looked At Richard Day's lovely instruments. The Moonraker scopes by Mark are such beautiful instruments. I remember Astrognome brought his to a SGL star party.

Thanks Alexander your work is much appreciated.

I have just been observing in both Ha and WL - some brilliant views

In Ha with PST + DS some plage around AR2880 and AR2877 but the Proms nearby 2877 is impressive. On the other side Proms close to AR2880 but there is also a filaprom. A few other Proms around the disc.

I recently bought a SvBony 90mm F5.5 Achro, mainly for travel but also WL. I have an Astrozap filter but also purchased a Baader Continuum filter which they state improved Achro fracs. How, right they are!!. Both sunspots are very sharp and the view is an improvement over the non filter - glad I purchased this from FLO.

Worth a look if you can.

Wonderful find Nigella. I also collected these cards and they still in the album. We organised an Apollo 11 50th anniversary and the album was on display. I was fortunate to meet Thomas Paine (Head of NASA) in February 1970 at the Royal Society and he spoke about the Grand Tour which is contained in the album.

The Proms are still impressive and there appears to be more activity taking place on the edge between the Proms. I have high cloud at the moment so hoping for a better view later.

Paul I am so glad you looked at GONG and then rushed home. I certainly would not have known about this without your thread 'heads up'. I had to take my granddaughter for a dance lesson otherwise I would have looked a bit earlier - still impressive all the same.

20 minutes ago, paulastro said:

I'm glad you're having some good views Mark.  I could see the three filaments ok in better moments, they must be nailed on with the double stack 🙂.

Yes really pleased I got the double stack. Obtained it via the SGL classifieds. It does make the view darker but I always use a black hood.

10.35 viewing with PST only - impressive. Thanks again Paul.

Now added the double stack and the 3 filaments nearby are very clear.

Thanks Paul for the heads up I will get the PST out.