mikeDnight

That's a really nice report on your observing session Mark, and quite a selection of deep sky targets you managed to bag with your 90mm. I don't know how others feel, but I find reports like your's really encouraging for those with relatively small aperture scopes, proving such instruments are serious kit and not just meant for a quick glance at the Moon or Saturn's rings etc. And also proof that we don't have to live in Hawaii to see deep sky with a nice little refractor. Brilliant! 🏆

It may or may not be of interest, but the pseudo Masuyama's such as the Ultima's, are taken from the Zeiss Astroplanar. It has been suggested on CN that Takahashi somehow influenced the Japanese manufacturers of the pseudo Masuyama's, after the death of Mr Masuyama, to stem the flow to Celestron, Orion, and Park's. How true that is I really couldn't say, but it's interesting that Takahashi's LE series appears to be based on the same design, though I personally feel the Ultima's, Ultrascopic's and Park's Gold etc have the edge over the Tak's by a considerable margin, particularly in the longer focal lengths. I'd truly love to get my hands on an authentic Zeiss Astroplanar.

Unfortunately I only have a pair of 25mm Parks Gold, so nothing you'd be interested in Steve. In fact come to think of it, I have a box full of those exquisite pseudo Masuyama's, (mostly in pairs).

Best to keep your eye on that 32mm Erfle Peter. You know how untrustworthy these binoviewer users can be!

Is there a vintage jewel in your collection that stands out as something special? With so many modern eyepiece designs available to us today, it can sometimes be that older vintage eyepiece's get overlooked as if they'd outlived their usefulness. In this case, let's define Vintage to mean any eyepiece that is nolonger in production. So what is your secret treasure, especially those that stand out from the crowd. Although I have a number of real eyepiece gem's, I'll start us off with just one. This is one that was very kindly donated to me by paulastro. It's an old volcano top Erfle, and boy is this little eyepiece good. It's the sort of eyepiece that causes gasp's of awe and wonder when seasoned observers take their first look in the dark, without actually knowing what it is they are looking through.

It started me off too around the same time (1980). At the time I had just bought a 60mm Prinz Astral. It broke my heart when I read I needed a 3" to do any serious observing. I lusted after Patrick's 5" refractor as shown in the book. I never wanted anything other than a refractor and it's largely down to Patrick's little blue book. It took me 27 years before I actually got my hands on his 5" refractor, by which time it was looking a little sorry for itself which was sad but by that time Patrick was not in the best of health and couldn't maintain it.

Yes, many times. There are many man made objects that are orbiting the earth which at times may cross the line of site of a earth based observer. Nice images by the way!

Hi Justin, Yes, I couldn't be happier with the Takahashi Prism. I'm pretty sure you'll find it works fine on your Tal too. 🙂

An interesting comparison! We're both scopes working at the same magnification? I know the SW ED's are not totally CA free, but may be the CA visible in the ED was due to atmospheric haze? When I bought a SW Equinox ED80 many years ago, it soon became my most used scope, and the one I'd go for when I wanted a quick few minutes observing before bed. The trouble was I'd often find myself sat on a frozen garden bench an hour later, still completely engrossed in the view of the Moon. Jupiter was very nice too with the red spot and jet black shadow transits laser etched. My 120ED would often remain on the side lines due to the ease of using the little ED. I did use a cheap binoviewer though, which makes a massive difference to the viewing experience.

Thanks for this Nick. I've screen grabbed it for reference and for a clear night.

That sounds fantastic! It might be an idea to let your neighbours know about your hobby then you dont get arrested. May be invite them round on a mild spring evening for a coffee and a look at the Moon through your telescope.

I think the LE's had some issues that may have made them unpopular with some. I've owned quite a number over the years, including the Hi LE's. Some had annoying ghosting that was so bad that the Moon could be seen as a ghost even though it was out of the field. Then there was Tak's puzzling decision to set the eye lens on the 30mm deep inside the barrel, reducing the physical eye relief close to zero. By comparison, Celestron's old Ultima series, 5 element pseudo Masuyama, was way more comfortable, and much better corrected towards the edge.

I think they should resurrect the Tolles eyepiece. Minimal glass with near zero eye relief and a teeny weeny field of view. I'd buy em!

I somehow came into posession of a Nirvana eyepiece quite a few years ago now. I can't remember if it was a 4mm or 7mm, but what I do remember is that it was terrific. I've owned nearly every Nagler over the years, and found some to be great while others just didn't do it for me. I'd be very happy with the Nirvana alternative without feeling I'm missing out on much at all.

That certainly looks like a very nice site to observe from. Hopefully your neighbours won't have insecurity lights. A nice pier at the top of that garden path would be my first project.

Have you ground any telescope mirrors before? If you're going to make two 4" for a binocular scope they will need to be of equal focal length. It is very easy to get it wrong when making identical optics. Once I'd achieved the right initial curve I would use the same tool for both, swapping mirrors regularly as i went along, so at least I'd keep identical curves during fine grinding. The 6" scope would be less challenging as you'll have less to worry about.

I think the gap between Premium and mass produced anything, be it refractors, reflectors or eyepieces, has closed dramatically over the last 20years. A mass produced Dob with a top quality eyepiece will likely deliver better views than a premium Dob of the same aperture, that's using a mediocre eyepiece. The eyepiece after all is half the telescope. And there are many premium quality eyepieces to choose from, not just Televue.

Swift are really Takahashi, so I'd suggest you treat your beautiful Swift to a Takahashi 1.25" prism diagonal. These are superb quality and allow for exquisite images with no light scatter.

That looks merely like a scratch on the rear surface of the mirror which will not affect performance in any way. Have you checked the collimation is ok? If the mirrors are out of alignment it may give you an impression of hideous coma.

Mine has a floating wooden floor made from 3/4" ply screwed to 6" joist's. There's no underfloor insulation but the floor is covered with black interlocking rubber exercise matting, which is acts as a protective insulating layer. The floor has a 1cm gap around the pier, but the rubber matting butts upto the pier closing the gap. There is no vibration from the floor transferred to the pier. After 11 years of use I couldn't be happier!

I'd like to simply say that if you did decide on an FC100DC or DF, you really won't need an extender'Q. At it's native f ratio of F7.4 the DC/DF will deliver as much power as you'll ever need on a good night without running out of steam. Honestly, the FC's are cruising at 300X to 400X on double stars, while offering a beautiful bright wide field of 3.25° with a 35mm Panoptic. The Q will give you F11.8, but they are fiddly to connect and disconnect due to their fine threads. (Tak love their fine threads and extension tubes!) I was unaware of any meaningful field curvature at F7.4. I'm not saying it wasn't there, just that I didn't notice it, so the Q for me was an expensive misadventure. If you like to use longer focal length eyepieces for high powers I'd suggest using a barlow or powermate. Alternatively a barlowed binoviewer would up the amplification significantly to produce comfortable high powers. Good quality plossl's, orthoscopic's or Tak Le's are good choices.

I have two sketch books on the go at any one time. The first is a field sketch book, which contains scribblings and corrections drawn at the eyepiece. I'd imagine there are very few observers who sketch a beautiful observation at the eyepiece. In a rough sketch book you can relax a bit as it doesn't matter if you make errors in placement of detail. You can add side notes and use a grid to aid with placement. I use a numerical method of noting planetary or lunar albedo, with 10 being jet black and Z rather than 0 to represent brilliant areas, as 0 could be misconstrued to be a crater. You'll soon find a method that suits you as there are no hard and fast rules. As for star placements, its rare you'll ever get things perfectly placed. What I tend to do is to add a side note to a finished drawing saying Stars are only approximately placed. Once you have a completed eyepiece sketch, you can then draw a cleaned up version in another observing sketch book. I use a rough sketch book for the telescope and one with a higher quality paper for completed drawings. I keep notes to a minimum as the drawing tells most of the story, though I will write about points of interest. Below are a few examples of various targets with different amounts of notation. Ring Nebula Lunar sketch. Venus Mars.

Neil is absolutely right in what he says. I suppose its down to what you expect of a telescope. During the last Mars apparition I used three different scopes, a 10" F6 Dob, a 8" F6 Newtonian, and a 4" apo. There was no question that the larger apertures revealed more, but they didn't show an image as well defined. The 10" Dob was just awkward to use, which made observing less pleasurable. The 8" Newtonian and the 4" apo were mounted on my Vixen GP which made observing more comfortable. Below is a comparison between the 8" F6 and the 4" F8. Below, Mars as observed with an 8" F6 Newtonian and a 4" F8 apo 27/9/2020 How much detail do you want to see on Jupiter? Below is a sketch made on a night of exceptional seeing when Jupiter was riding high. The 10", 8", and 4". Despite the superiority of the 10" over the 8" and the 8" over the 4", the 4" gave the most pleasing views. And although much brighter in the first two, the laser etched detail in the 4" gave up little to the larger scopes.

I'm sure you're right Neil. No need to run; we're all grown-up's! 🤬

I get around the short focal length eyepiece dilemma by using long focal length eyepieces in a cheap binoviewer. With a 2X short barlow attached to the nose of the binoviewer the amplification increases to approx 4X, so a pair of 18mm eyepieces in my F8 refractor gives ~X178 which is perfect for Jupiter or the Moon. And because you use both eyes, the views are so sharp and detailed you'll see fine detail much more easily. Also, you don't need expensive eyepieces, as good plossl's or Orthoscopic's will perform as well if not better than the finest eyepiece in mono mode. The short focal length eyepieces below cost approximately £1000, where as the binoviewer, plossl's and 2X barlow combined cost approx £250. I use the binoviewer for 99% of my lunar and planetary observing, and 99% of the time the binoviewer image out strips everything else by a large margin.