Dave1

That's looking good! Much better. Keep this up and you will have a great telescope.

I have no idea how much it would cost to get it professionally cleaned. Like Jeremy said, if the lenses are pitted no amount of cleaning will help.

Hopefully I wont miss this opposition, I'm looking forward to it. Here's a good page on the A.L.P.O. http://alpo-astronomy.org/jbeish/2020_MARS.htm

@Alan White Hi Alan, yes indeed it is another 0.965" eyepiece. I'm thinking there might be another early morning, so that I can look at Jupiter and Saturn with the CZJ O-10 for first light. David

That is a shame to read you are having these issues. If I were you, I would probably send it back for a full refund. Another option if you are not comfortable sorting the lenses , is to send it to be professionally cleaned. Ask for a quote from the telescope specialist and then ask the previous owner to pay the bill. Or get the previous owner to atleast pay the quoted price up front, and then if there is any difference between quoted and final prices, to settle the final bill. David

Well this is what the postman bought to me this morning. A Carl Zeiss Jena O-10, Orthoscopic 10mm eyepiece. This is actually my first premium 10mm eyepiece ever. Look forward to trying this baby out, David

Hi Mark, Great find and a great introduction to refractors, nice find! David

That's really good feed back @Silent Running. I'm still considering an AZ100. Its good to read how well the Nexus system works. David

@Owmuchonomy yes I have that app on my phone. Very good indeed, I have it set for my UK address, and where I will be moving to in the EU. I still think people should learn to look at the night sky and see what the dimmest magnitude star they can see with the naked eye, its a good measure of transparency. I will quite often use the Ursa Minor for this.

Sounds like a good session. Nice to see somebody else using a long frac. David

Unless you need to sell, to found a new telescope. I'd keep your old one, so that you can compare the visual difference between the two telescopes. Might be worth learning to do star tests, so you can learn to see the 5 Seidel optical aberrations if they are in either telescope. Having two telescope I think is a good aid to learning to star test. David

@ollypenrice My observations are planetary, and stars mainly. When I do critical test it is mainly on Jupiter. I generally very rarely venture out of it. I know Olly that you spend a lot of time on fuzzy targets, galaxies and nebular. Which I really have no experience of. So I can't really comment in that regard. My astro equipment really isn't the best choice for fuzzies. Chris Lord of http://brayebrookobservatory.org/ . Has written some very good articles on seeing, air cell size, with the science to back it up. I have to admit one of my weaknesses is advanced math. Somebody may look at the article, I think good, see it differently, if they understand advance math then they might find fault with the articles. I agree with you on faint targets regarding fuzzy targets in regards to aperture. I would have to guess on faint targets how seeing affects the image at the eyepiece. David

See this thread just proves just how subjective this is. There are plenty of examples here and on Cloudy Nights. Also comments from people historically that belong to Astronomy Clubs, where many telescopes have been compared at the same time at the same target. That will say on a night of poor seeing, that a small telescope put up the better image, with the details on offer more readily seen in the smaller aperture. Some science seems to point to this being because of the smaller amount of atmosphere you are looking through in poor seeing conditions. Basically the air cell size would only support a 4" aperture over a 8" aperture. Since I've started posting here again this year. I have tried to get out under the star once a week. Seeing generally has not been that good, with boiling seen very obviouly in a 3" telescope. The details on offer on the planets not that great. And I've certainly seen far better in a 3". I've done comparisons with my bigger telescope in the past in poor seeing conditions. I certainly don't think it is worth bringing out my 4" in poor seeing, and I have a very fine 4". I see a lot of comments based around the science of resolution, aperture. Not many comment including the science of seeing conditions. David

@Alan White thanks , it's good to be back. I have definitely fallen down the old glass rabbit hole that's for sure. I've already found a 0.965" Tak Ortho MC for sale of the 7mm variety. @F15Rules The Vixen GPDX looks brill and I've heard they are very good. Mind you I'd imagine that a Tak EM2 to be out of this world! David

Hi Dave ( @F15Rules ) Thanks for the lengthy reply! Your Mead 339 set up is very impressive. I doubt you get any problem with dew with a dew shield that size! The rings look very beefy, the rings look like Moonraker build, perfectly matches the mount! I've read the 0.965" Takahashi Ortho are as good as the CZJ Ortho's. Which is good news if its true, as the Taks are usually cheaper from what I've been able to research. The CZJ O-10 is suppose to be a very goot eyepiece. I'm going to be keeping an eye out for any quality 0.965" eyepiece, to see what prices they are. Good quality costs, doesn't matter what size it is. Then make a decision. Funny you mention about your 0.965" eyepiece adapter accepting the Baader 2.25x barlow. I noticed lastnight that my Baader 0.965" eyepiece adapter accepts 1.25" filters, which means it will accept a Baader 2.25x barlow, which I just so happen to have! David

Ah there you go! I remembered the wrong size. Probably a set of 1.25" then! I live and learn.

The 0.965" Pentax SMX Ortho's are on my "watch" list. They are suppose to be as good as ZAO-I. You know going back 3-4 years ago, there was a fairly complete set of Clave Plossls on eBay. At the time, I thought "they're expensive for what they are". If I new then what I know now! In hindsight they were not that badly priced at all! Even had the wood presentation box. A 0.965" Clave Plossl with 48 degrees is more than my 1.25" Brandon, Edmund RKE, and Ortho's. The Clave having 48 degrees, sounds good to me. David

So lastnight I gave my CZJ H-25 and H-16 its first light. I used my Towa 339 80mm F15 to conduct the test. What can I say, other than they gave very sharp views. So sharp I was taken by surprise. I looked at Jupiter, Saturn, Arcturus, Castor, Beehive Cluster, Iota Cancri. I think I also looked at 17 Comae Berenices, but I need to check that. At times when looking at Jupiter I could see 4 belts. North and South equatorial belts, and north and south temperate belts. I could see structure in the north equatorial belt particularly, a dark concentration. Why I say these CZJ Huygens surprised me, is because for the first time in a long time, I got lost in the moment. I got that good warm fuzzy feeling inside when something is just "right". I stuck the CZJ H-25 in and just browsed cruised the night sky, sitting at zenith for awhile, happy just to aim indiscriminately, with out a care at what I was looking. If I found something interesting. Then I would swap out the H-25 for the H-16. Then back to the H-25 and I would just pan here or there. Its been a very very long time since I did this, was just content. I did compare the H-16 to my nearest eyepiece at the beginning of the evening. Which was a Edmund Optics 15mm RKE. I thought the H-16 was just a tad sharper and rendered high contrast details better. Subconsciously the H-16 stayed in my diagonal! That is just it and the real indication for me. That the CZJ Huygens eyepieces stay in the focuser subconsciously. I am an observer that is always swapping eyepieces to see which one is best. Well not tonight! And that says a lot in itself! I am now in a position of, do I keep an eye out for WW2 era Zeiss Huygens, so I can get shorter focal lengths, the brass body Zeiss Huygens are suppose to be even better optically. Or even get CZJ Ortho's or Pentax SMC Ortho in 0.965". Lastnight was a real eye opener just to what a very good 0.965" eyepiece can do. Believe it or not I was going to try and go down the one eyepiece line root, thought it would be Brandon's ! Not so sure now! Still buying different eyepieces trying to decided which eyepiece line to choose 🤣

Very good Mike, always admire your skill as a sketcher. Do you use filters when you sketch? David

So I was looking at the galleries of the ALPO. I was looking in the Jupiter section of the galleries. I looked at the 2020 opposition gallery and the Jupiter 1966 gallery. What was interesting is comparing the instruments used today, some of them being 355mm SCT's and some instruments going upto focal lengths of F30. The instruments used back in 1966 were of course a lot more modest. In the 1966 gallery a lot of the images are sketches. Quite interesting to see what the standard of sketches were, what instrument they were completed with, from 6" refractors through to 24 " reflectors. One striking difference between the 2020 opposition and 1966. Reflectors or SCT's are to goto choice it would seem nowadays, with very few refractor images shown. Where as in 1966 there were far more refractors used, the biggest refractor I have seen is 12 ". I bet in 66 is wasn't an ED or triplet. In 66 you see some examples of very early astrophotography. I am surprised what some people saw with a 6" reflector in 66. Worth a browse if you are interested in the Planets! http://www.alpo-astronomy.org/gallery3/index.php/Jupiter-Images-and-Observations/1966-Apparition

The postman today, primarily bought my "light" filters for my small refractors 100mm and below. The filters are Wratten #56,#21#23A,#8,#82A. I got these as an upgrade to replace my Tal filter set. As the Tal filter set, doesn't have any Wratten numbers on the filters or even general nomenclature like "light red". I suspect the Tal filter are normal filters not "light" filters like I need. I like these new filters as they have the Wratten number on them. Plus they come with pretty good cases, which I didn't know at the time of ordering! David

Yep I saw them too. About twenty or so. Quite bright. Surprised me. There was the odd satalite out of line, and not all evenly spaced.

Well here they are. My first ever Carl Zeiss Jena Eyepieces 😁 They are Huygens in 25 and 16 mm focal lengths. Like new and unused! I figured if I wanted to try the best Huygens there is, it would have to be CZJ! Very happy. David

Congratulation on the new telescope, I'm sure you will enjoy.

Very nice 6" F12 John. Istar still make the normal achromat 6" lenses in F12 and F15. Not in the R35 or R50 Anastigmatic lenses though. David