Franklin

What a fabulous post from Qualia on Planetary Nebula.

I never cease to be surprised and amazed when searching through the archives of this site.

What an absolutely outstanding resource SGL is and its members, past and present are. 👍

50x per inch of aperture gives and exit pupil of 0.5mm, anything smaller than this and eye defects such as floaters become a major problem. I've found that backing off from the higher magnifications allows me to see more detail, all be it on a smaller scale. It also helps train the eye to see finer detail. Ultimately it all depends on the sky conditions. I'm lucky to be able to use 40x per inch under my bortle 6 skies and only then when the seeing allows.

I've opted for the minimalist approach.

In his excellent book "Guide to the Moon" Sir Patrick Moore wrote in the mid-1970's that he fully expected a manned return to the Moon by the 1990's and possibly even a full scale lunar base!

Traditional Achromatic refractors suffer from chromatic aberation, where the different frequencies of light are focused at slightly different points. Making the focal length of the lens longer helps to reduce this aberation. Before the invention of the Crown and Flint doublet lens, which also reduces this CA, they made what were called Ariel telescopes which had focal lengths of 50+ft. The objective was positioned on a tall mast and the eyepiece was held at the end of a taught piece of rope! So glad they developed the modern lens designs.

27 minutes ago, Stu said:

Hope it’s not like the Wild West until things settle down!

I thought Devon was lovely the last time I visited.🙂

1 minute ago, johninderby said:

Ah The Dark Side of The Moon 😁

Best album ever made!

Do they still call them albums?

4 minutes ago, johninderby said:

NASA will launch the first test flight of the Artemis  moon capsule early next year.

Hopefully they will put Messrs, Branson, Bezos and Musk onboard and drop them off on the dark side of the Moon!😃

I don't think there is any reason for people to go to Mars. The robotic instruments they send seem to be doing a fabulous job and without the risks to human life or the extra expense.

Same goes for the lunar landings back in the late sixties. I think back then it was just a race to prove who was the most powerful nation. A bit silly really because again, robotic landers are more than capable of doing good science up there.

Looking at the present climate with private companies getting involved with "Space Tourism", if some one is willing to pay to go to the Moon or Mars, then someone else will be only to happy to arrange it for them. Crazy, if they ever do go back to the Moon or even Mars they would probably just build a McDonalds up there! 😃

8" Dob and a Skymax127 👍, any of the above eyepieces will be great and you've already got a long focal length 2". Happy stargazing! 🙂

22 hours ago, Andrew_B said:

With the 2.25x Barlow you get a very flexible setup covering 3.6-10.7mm and 8-24mm and I've liked using mine and felt it was good value for money.

Second that. Add a 2" low power widefield and you may not need to ever buy another eyepiece. Well, not until you catch the astro-kit bug! It's highly infectious! 🙂

Can't go wrong with the BST's for a first upgrade. The BCO's are fantastic but are traditional style and have a smaller field of view. Great for higher power planetary viewing but maybe not for searching around finding stuff. Baader zoom and barlow combo is my most used astro kit, don't leave home without it.

Just been re-reading all of this thread Alan and your mammoth efforts to re-build/re-create your LX70 mount. I think it is amazing what you have done and the whole documentation with all the pictures you have posted will be a welcome resource for others wanting to re-vamp their EQ5 style mounts in the future. Should be a sticky. 👍

Meade LXD75 N6 @ $160 is a good deal and the LX70 as well. See this thread https://stargazerslounge.com/topic/378907-a-restoration/?do=findComment&comment=4102525

Your finder is the wrong way round. 

Wasn't me.

Set up out the front and do another one of your excellent Astro La Vista YouTube videos. Make the subject "light pollution and how it affects peoples view of the universe". You never know, if they see it, they may be shamed into pulling the switch!

I have recently been reading Harold Suitors excellent book on Star testing Astronomical Telescopes and have been testing my scopes. Fortunately for me, all is well and my scopes are, I believe, performing to the best of their optical ability.

One thing that has been drawn to my attention from doing all of this, is the placement of the diagonal in the drawtube before observing.

When checking the collimation of a refractor, we are told to use the short cheshire straight through, Japanese style and there is good reason for this. When checking the tilt of an objective using the cheshire reflections technique the light enters the cheshire window, is turned through 90degrees, sent down the tube and reflected back off the rear of the lens elements and is then viewed through the cheshire peephole. Any slight tilt is revealed by the reflections not being concentric. This test is extremely sensitive! If you perform this test with a diagonal in place you are effectively making a double pass through the diagonal which will increase the senstivity of the test exponentially. In this case the light enters the cheshire window, turns 90 degrees, passes through the prism or off the surface of the mirror and is turned another 90 degrees, down the tube, reflected back off the lens elements and then through the diagonal a second time to be viewed through the cheshire peephole.

I can only think that a lot of perfectly good diagonals have been condemned as "out of collimation" because of this. Thinking of this I tested my diagonals with the laser and they are both spot on. I set up the cheshire test with the diagonal in the image train but did not tighten up the visual back. When viewing the reflections through the peephole whilst wiggling the diagonal around I could plainly see the effects of mis-collimation and managed to hold the diagonal in the correct place and tighten up the clamp whilst sighting the concentric reflections through the cheshire.

So from now on, when setting up for an observing session I will not be just sticking in the diagonal, but aligning it correctly so my scopes can perform to the best of their ability. Not having a rotatable focuser and using a GEM can put the eyepiece at some hard to view positions. The number of times I have loosened and turned the diagonal to get a better viewing position unaware that I am putting my scope out of alignment everytime. I will be loosening the tube rings only in the future.

I am surprised that I have not heard of this before for visual and I am sure that the imagers wouldn't dream of rotating their camera assemblies without checking if everything was still square on in the image plane afterwards.

Has anyone else noticed this? Do others fret over their diagonal placement? Or am I just fussy? Maybe I am fussy, but it only takes a minute to pop the cheshire in the diagonal whilst fixing it in the focuser. From now on doing this is definately going to be part of my observing routine.🙂

You love it! Finding stuff in the night sky the traditional way with a manual mount and a star atlas is half the fun! I've never owned a goto and never done any imaging but after 30+ years of stargazing I know the sky like the back of my hand. My other half has taken an interest and she has an app on her phone which she points at the sky and it shows her what's up at the time. She's telling me what I can see tonight! It also works whilst sat in the living room pointing the damn thing at the ceiling, which she prefers because it is too cold outside at night 😀. I said that was ok, because you can see the universe on your phone dear, no need for both of us to get cold. 😀

4" ED scopes are great. Big enough to see plenty and small enough to get out and use at a moments notice. Don't think you can beat the Starwave 102ED for it's price point really. I have the f/11 version and it's a big improvement on the achromatics I've had in the past. 👍

There will be noticable CA on bright objects, particulerly at higher powers. Large, fast refractors excel at low power, wide field observing. I had a 150mm f/8 achro and the views of starfields were amazing but with higher powers on lunar/planetary stuff the minus violet filter had to come out. I've now got an ED102 and the difference is chalk n cheese. When the seeing allows, I can get upto 200x and the detail is still clear and sharp.

The one in the picture needs a bigger mount.

On 13/10/2021 at 22:44, callisto said:

Here's my little 80M on vixen GP mount 😊      (excuse the mess behind 😳)

Think I'll change the D/Tail bar to black 🤔

Just noticed I never put the ext bar & weight on 🤣

 

Hi Callisto, nice setup. I've been thinking of getting the SXG tripod like yours for my GP2, but mine's the older 60mm base version. I see you have the 60mm to 45mm conversion adaptor on your tripod, how do you find it? Does it still offer a solid and rigid enough fixing?

1 hour ago, jock1958 said:

There is a way you can directly connect the WO BV to the 1.25 Baader prism diagonal but not sure how to do it?

Adaptor made in Russia, available on Ebay. You would also need a T2 locking ring.

T2 female to M26x0.75 male thread adapter for binoviewer

That's a good mirror, nice find. 

If you're going down the newt route John I can always find a home for the DL? 😀

Set of 32mm, 15mm, 11mm, 8mm Televue Plossls @ £40 each on ABS. Bargain!