John

Actually it's still looking pretty good here as well - my earlier post might have been too pessimistic

Not a good forecast down here but you never know !

Thanks for the heads up anyway

On 07/08/2019 at 05:09, Stu said:

..I assume you've seen it in the 12"?

Yes indeed I have but the presentation of the stars is preferrable to me with refractors when observing doubles. You know more distinctly when you have a split and when you don't with the refractor image IMHO. They have that "text book" quality to them.

I've done Zeta Herc a couple of times with the Tak FC-100DL over the past couple of weeks as well. Remarkably similar image to that of the ED120 given the aperture difference but I've noticed that the Tak does rather well for it's aperture on most targets !

Some small fragments of the Allende Meteorite which fell in Mexico in February 1969. It's one of the best studied meteorites in history, perhaps at least in part because it fell just a few months before the Apollo 11 mission lifted off, interest in space exploration was high and many instututions in the USA were geared up to study the rock samples from the Moon. The Allende Meteorite fall gave them some early extra-terrestrial rock to examine !

Allende is classified as a carbonaceous chondrite meteorite and contains calcium-aluminium-rich inclusions or CAIs (the irregular white shapes) which are thought to be some of the structures that formed in the earliest stages of the solar system. They have been dated at 4.568 billion years old.

An interesting little addition to my meteorite collection

One area that the TV plossls are simply superb at is light transmission. I've seen independant measurements that put them higher even than orthos on that.

17 minutes ago, cloudsweeper said:

@John - would you say the Vixen NPL is significantly better than the others I mentioned?

 

I've compared it with the Baader 32mm plossl here:

I've not compared those with a Meade or Celestron Omni 32mm plossl although I have owned and used both at some time over the years and found them OK but nothing special.

The Vixen NPL 30 is not as good as the TV 32mm or Ultima / Ultrascopic 30mm either in build terms or optically but I felt that it was pretty decent for a 45 quid (new) eyepiece.

If you are looking for TV plossl quality then I can't think of anything other than the TV 32mm or the Ultima / Ultrascopic that really ticks that box though.

I think Dave has set out what my thoughts on this would be as well

If you go for a TV 32mm plossl it is worth budgetting for one of the eye guard extenders to go with it. They make using the eyepiece much more comfortable in terms of eye positioning.

A low cost alternative to the above would be a Vixen NPL 30mm which I liked a lot when I had one.

2 minutes ago, russ said:

Just bought an Astrotech AT66ED for a small and light travel scope that will sit on my Manfrotto geared head. I'm hoping its so small and inconspicuous that my wife won't notice it packed for our camping trips. Also hoping it will make a good scope paired up with the Fujifilm X-A10 for a little imaging too. First light sunday if the forecast holds.

I used to have a WO 66SD on a mini Giro some 10 years ago now and loved that. So hoping the AT 66 will be a direct replacement.   

I wondered who went for that one

4 minutes ago, A McEwan said:

John, this is what I decided to go for. I've ordered a SW 6x30 RACI and a Tak bracket for it to go in. I notice your bracket is black - is this because it is the DL model's version?

Mine was the last of the 1st run of DL's available in the UK. They had a black focuser so I went for the ADM Tak quick release bracket which I thought suited the scope better and it was half the price of the Tak quick release finder bracket:

https://www.firstlightoptics.com/finders/adm-takahashi-quick-release-finder-bracket.html

The 2nd run of DL's used the new Tak duck egg blue colour for the focuser.

I didn't get on with the Tak 6x30 finder that came with my FC-100DL package. It was straight through and the cross hairs were indistinct. It was very nicely made and sold quickly so no harm done !.

I now use a Skywatcher 6x30 RACI in the Tak finder bracket and attached to the scope via an ADM quick release mount. I'm very happy with this arrangement and it does everything that I want it to do

Jupiter well past it's best here tonight so I've moved over to Saturn and the views of that are pretty good

I can see that my fun is not going to last though - more and more patches of cloud are scudding across the sky.

If I get another 30 minutes observing I'll be doing well. It's been a nice session though so thanks for the "heads up" David

Seeing is fair to middling here. Good enough to see GRS plus main belts clearly with some structure, other belts less clearly. Jupiter currently behind a tree though so an enforced break in planetary viewing to take in some Summer binaries. More planetary soon I hope

Nice views here currently

Interesting to compare the apparent diameters of Ganymede and Europa while they are relatively close to each other in the sky. Ganymede has a noticably larger disk through the eyepiece at around 130x. It's apparent diameter is 1.5 arc seconds compared with Europa's .90 arc secs according to Cartes du Ciel.

I'm using the Tak FC-100DL this evening.

I use a Tele Vue Ranger 70mm on a photo tripod with a Dwarfstar alt-azimuth mount. The whole lot weighs about 3kg. I have a 3 piece travel eyepiece set which gives me from a 3 degree low power view to 150x. The performance of this little scope has often surprised me

Clear here too, currently

Probably best if you keep them all for now, try them and over time decide which do the best job in your eyes.

Of the ones you list, the BST Starguiders and the Skywatcher UWA 58's are the ones that are best corrected for a fast scope such as your F/4.7 250PX.

Thats a fair point - the used market usually has a number of item X for sale, when you are not looking for one, but when you are looking, nothing to be seen for ages ........

12 minutes ago, parallaxerr said:

Well blow me. A significant Skywatcher price hike just landed and they're even more expensive now, £537 for an ST150 at FLO. Too rich for me 😥

It's much better to buy these and the F/8 achromats on the used market. They depreciate a lot from the new price.

My point is that from my back garden a 21mm eyepiece (or thereabouts) is generally better for observing fainter objects than a 32mm.

You may well find an 18mm or 25mm eyepiece (or something around those focal lengths) more effective than a 32mm or similar.

With galaxies, the old joke is that the best accessory to spend money on is some fuel for your car to get you and your scope under darker skies. Dark skies make all the difference to the amount of detail you can see when observing galaxies. 

Rob has given some good tips above and they are really all about darkness for you and your scope.

My garden has some LP issues but I've found workarounds which include having scopes which I can move about to find the darker corners, waiting until all around me have gone to bed and switched off their lights (including my own family !), waiting for my targets to rise high enough in the sky to be less affected by the horizon skyglow and also from the effects of atmospheric extinction (dimming) and getting my eye truly dark adapted and keeping it that way by avoiding any light, even red ones. Filters work well on many nebulae but not on galaxies. I find a 21mm eyepiece is more effective for galaxies from my garden than a 32mm with my F/5.3 dobsonian because the exit pupil is more efficient and the higher magnification darkens the background sky a little.

Observing galaxies from sites that have some LP is quite challenging but success can be had if you work at it and employ some smart tactics. I've had sessions where I've racked up dozens of new-to-me galaxies from my back garden when things come together but also many where even the "easy" galaxies are far from their best so its been obvious that the best decision to move to a different target type.

I see quite a few reports from folks that are happy with an ED120 on an AZ-4 mount. Personally I didn't find it a satisfactory pairing but I guess different people have a different take on what is OK for them.

I feel that a Skytee II is right at it's limit with a 6 inch F/8 refractor on board (it's a much more robust mount than an AZ-4) but some people have used much larger and heavier scopes than that on one. Look at these pics from an Astronomy Now review of a 200mm F/5.9 refractor for example:

Heaviest and longest scope that I've tried on my AZ-4 was an Intes MN61 mak-newtonian. That is a 152mm F/6 scope which weighed around 10kg. The AZ-4 did a pretty good job on that but, oddly, it does not seem to cope with my ED120 F/7.5 refractor well other than for low to medium power viewing.

If the 200mm newt was an Orion Optics one then the AZ-4 would do better - OOUK scopes are lighter and a touch slimmer than the chinese equivalents.

I think that is an issue with the cement holding the lens elements together as Alan / Alien 13 says.

I've seen fungus on a lens and it looks different. More like this:

8 minutes ago, Highburymark said:

That’s awful John! It’s a dream of mine to see clear Southern Hemisphere skies. Always presume clouds are a largely northern hemisphere problem, but obviously not.

We had very good weather during the day - it was just the nights that seemed cloudy !.

Hopefully Arizona will do better in a few weeks time.

Congratulations on the forthcoming Vixen 102F Rob !

My Vixen is not a fluorite but an ED doublet from around 2000 / 2001. The Vixen you have ordered is the 1st generation Vixen 102mm fluorite (the 2nd gen were F/9) and could well be from as far back as the 1980's. I used to really lust for one of those but they were way out of my price range back then 

The performance of the Vixen 102 flourites is, I understand, very, very, very close to that of the more recent Takahashi FC-100's which Stu and I and a few others are lucky enough to own.

Top of the performance tree as far as 4 inch refractors go I think