Giles_B

Thanks @Cornelius Varley - that's useful to know, and my apologies for any aspersions about the quality. I guess the question becomes the standard: what does @Jackal1258 want and expect from this scope?

Other than second hand examples on ebay, this is not a brand I've heard of particularly. What are the specs (can you post a link?) My suspicion is that it's an inferior scope, and you'd be better served by a reputed brand such as Skywatcher, Bresser, Celestron etc. etc. These forums will give you plenty of buying advice, but it would be useful to know what you are after and why you think this is a good scope for you. Where are you thinking of buying it from? I'd suggest buying from a proper telescope dealer like First Light Optics, Rother Valley Optics, 365 Astronomy etc. rather than Amazon and suchlike.

As @Philip R says, you will need to turn the other end of the telescope (the OTA - optical tube assembly) upwards to whatever you want to observe. Do you have any eyepieces? It looks like you have only a Barlow Lens in the eyepiece holder (which increases the magnification of an eyepiece) - you won't see anything without eyepieces https://www.firstlightoptics.com/eyepieces-barlows.html Most people start with some Plossls - if the price new is daunting then second hand these will cost around £15-£70 depending on the quality - whichever way you will get what you pay for I'm afraid. I'd recommend UK Astronomy Buy and Sell for second hand equipment if you can't access the classifieds here (you will need to be on SGL for a little while before you can). 2nd hand astronomy stuff from enthusiasts is generally a good buy, but I'd generally be careful about stuff from ebay - the quality can be more variable. Your telescope is a Newtonian - so you will need a collimation cap to line up the two mirrors ("collimate") - they are cheap new - https://www.firstlightoptics.com/other-collimation-tools/astro-essentials-125-collimation-cap.html - there are loads of online guides about collimating, it's pretty easy once you get used to it. I'd recommend the reviews on BBC sky at night website, or member equipment reviews here for buying advice - or you can just post a query to the forums - people on SGL are always ready to recommend great ways to spend your money - but will give good advice in the process! Good luck!

Cripes you were right (no insult taken!) - physical reality is restored, at the cost of some embarrassment to me.... 😳 Shifting the mirror higher did not correct the problem. Once the weather dried out enough to get the scope out in the dark I was able to point the scope at a bright light source. It was much clearer than it had been by daylight that the image was resolving as i racked the focuser out. So it was back focus, and not in-focus that was the problem. Huge apologies for spreading my confusion, and many thanks for prodding me in the right direction!

No, same primary. It doesn't seem to make sense. But if the problem is lack of in focus it indicates logically that I must somehow have set the mirror lower with the new cell. I don't understand how. But I have now raised it, so will check it tomorrow, and see if it resolves the issue.

The old - The old back was 10mm lower. But I wonder if I somehow overcompensated...

Okay - I feel less of a lemon now this has got other people baffled. There is definitely a lack of in-travel for the focuser - I can see the image coming more into focus as the focus tube travels down. Unfortunately there is no way I could mount the cell any lower - and, while it's a good suggestion, I did try to rack the collimation screws back - but thank you @AstroKeith for the idea of a spacer. However... I do wonder , given the opinions here, if the mirror is actually lower than it was rather than higher - I'd assumed I just didn't understand how a Newtonian worked - but as @markse68 says I could have made a mistake here - my conclusion it was higher was based on a bit of dead reckoning - checking the relative position of the mirror in the cells against the position they attached to the scope. If the mirror is lower than it was it would be quite easy to raise it, because there is a second set of attaching holes in the cell - so this is the first thing I'll try tomorrow (unfortunately my astronomy time is out for today)....

When a 9-point OOUK Mirror cell came up on ABS a few days ago I jumped at the chance to replace the sealed 3 point cell on my OOUK VX10 - a 10" f4.8 Newtonian - at a much more modest cost than buying new. I've just spent half the day very carefully drilling the tube to install the new cell (this is the first time I've dismantled the tube), but now I've reassembled it I find I can't reach focus on the usual chimney pots and sundry that I generally test focus on in the day - I don't have enough in-focus at 34mm which is my lowest magnification eyepiece. The position I needed to install the new cell in the tube meant that the mirror is about 10mm higher in the new cell than in the old one. I'd wrongly assumed this might be within a certain tolerance - the way I understood it I might move the focal point slightly, but I would just have to use more back focus, which is not a problem with my focuser. I don't understand why it's in-focus I am lacking. The only ray of hope that I can see is that the view from my garden is quite restricted by trees and buildings - the most distant objects are only a couple of hundred metres away. So my hope is that I might still be able to reach focus on astronomical objects - this is the only reason I haven't reinstalled the old cell straight away - but it might be a while before clear skies will put me out of my misery. Has anyone else ever had this problem, and am I likely to need to go back to the old cell? Could anyone explain to me what I've done to the optical path and what steps I have available to remedy it - the old cell wasn't a big problem, but it did lose collimation regularly, so I'd rather upgrade if at all possible. Photos attached to illustrate what I've done - on the second photo you can see the old set of holes are too low for the new cell, which would only fit into the scope if mounted a little higher.

This is very sad. I'm very new to astronomy so I don't think my time on SGL coincided with John's, but I feel I know him a little, and have learnt a great deal, from reading so many of his prolific posts on this site. In that sense his wisdom is very much living on on SGL.

I've now been regularly observing the sun in both Ha and white light for about six months, and I've noticed an odd feature of Ha viewing - the view gets gradually more detailed and as I spend time observing. I fear I'm not describing it very well, so I'll try describing it a different way. When I observe in white light I can immediately see all of the features of the sunspots and any granulation. There is no real change to the view, and certainly if the seeing is good enough for lots of detail it doesn't fade in or out - the seeing stays very constant to outward perception. However, when I then use my Ha scope in the same session, the view often begins with a low level of detail - that is, the detail is quite unfocused and not always obvious, but as I maintain my visual attention on a particular feature, further detail seems to emerge, as if, without touching the focuser, I were bringing a rather soft focus into sharper relief. Has anyone else notice this? What is causing this effect? Is it because the solar surface is changing as I look at it (in which case why does the detail always grow but never begin to fade)? Is it all in my head? Or is it some known artefact of using a Hydrogen Alpha filter (or indeed the type of filter I am using - a Daystar Quark)?

Nice scope - 130mm will get you great views of the moon and planets, and open star clusters. For the planets you will have to wait until late summer before you will get good views of Saturn and Jupiter as they are currently getting very low in the sky - and then only very late at night / early in the morning. Mars is still well positioned but probably is less of an exciting sight for young eyes - and it will be very bright without a filter. It will be worth getting a decent book on some of the features of the moon - I'd recommend John reed's '50 things to see on the Moon' - review here: https://astronomytechnologytoday.com/2019/03/26/50-things-to-see-on-the-moon/ - it's aimed at young people (probably a bit older than 7) but I find it a great guide for myself too. It's in English and I'm afraid I don't have a recommendation for a book in Portuguese. Solar observation is also a great suggestion. I would wait and see before getting any more eyepieces - you can always get more, bigger and better, but the ones you have should be adequate to get you started.

Thanks for the recommendation - I have the Lunt wedge now, although I haven't seen the sun yet to try it out. Do you have the Hercules paired with a Scopetech refractor? Certainly the design looks quite similar to the Lunt.

Thanks, that's very enlightening - and an insight into the perils of eBay. I'm assuming the lens in a Nagler is unlikely to come loose, so presumably the eyepiece being taken apart is in itself a bit of a red flag inasmuch as it's been done either to treat fungus, or remove abnormal deposits of dirt or moisture from inside etc. etc.

I don't often buy used astro gear from eBay - its often not been cared for well - but this doesn't stop me browsing incessantly, and this nagler caught my eye. More specifically, the wear by the objective intrigued me - it looks like the blacking has started to peel off. The full ad is here; https://www.ebay.co.uk/itm/284964073292?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=49OMbyrJSom&sssrc=2047675&ssuid=PC3vhF5hRE2&widget_ver=artemis&media=COPY What causes this? Manhandling? Or does this just happen after a few years of normal use? If so, is it avoidable?

Final update on the original Herschel Wedge question as it may be of interest to someone with a similar question in future. I've now taken delivery of the scope (thanks @bomberbaz) and finally had some sunshine - but I cannot bring the Lacerta Herschel wedge to focus with any eyepiece in my collection, not even the simplest Baader Plossl or Circle T orthoscopic - there is just not enough in-focus. This is despite doing what I can to shorten the focal train I e. Removing the spacer between the eyepiece holder and the ND4, using only the UV/IR cut in addition to the ND4 and using a vixen to T2 adaptor to directly connect the wedge to the focuser. I will have a play over the next few sesions to see if there is any way focus can be achieved - some posts on cloudy nights about gaining more in-focus on the Baader Herschel wedge suggest that adding a Barlow after -or before- the wedge may help, although I'm cautious about placing one before the wedge for a sustained period. Ultimately my suspicion is that the Lacerta wedge is just not going to be a long term good choice in this setup. Having been advised by FLO that the Lunt Herschel Wedge will come to focus with simple eyepieces with this scope, I'm now looking out for a Lunt (wanted ad posted!). It's a shame because I really like the adaptability of the T2 connectors on the Lacerta. But my experience of astronomy so far us that the lure of one thing inevitably seems to lead to the necessity of buying another thing to get the first thing working / better!

I'd second the use of a variable polarizing filter - I've found it much more satisfactory than a Neutral density filter in cutting down brightness (an ND 0.9 makes things too dark for my eyes) I've found a combination of variable polarizing filter plus neodymium filter brings out a lot of detail on Mars. Also consider using an IR/UV cut filter, which sometimes helps when the seeing is poor (which is the case on most warmer nights).

For the record, the results of testing are: 130mm straight through with no wedge vs 43mm with the Herschel wedge - so an 87mm real world light path - quite in excess of the T2-T2 light path quoted on Teleskop Express. The eyepiece was with a 30mm Baader Plossl plus three stacked filters (to simulate the continuum, UV/IR cut and the polarising filter). The wedge had the ND3 removed (necessitating holding the eyepiece on with tape as the ND3 had a male thread both sides), but the filter stack was a little thicker than usual (for transparency I used coloured filters and a skyglow), so it would be a fair approximation. Edit - I had this reply from Lacerta: "the backfocus needs of our Herschel wedges: 1.25" Version: 61mm from T2 to T2 ("S"-Version ca. 89mm) 2" Version: 81mm from M48 to M54 ("S"-Version with Rotationadapter ca. 106mm)" "S" Version - I guess the version with a nosepiece and eyepiece holder - is pretty near to my measured light path. In fact (lightbulb moment) the 2mm shortening could be due to removing the ND3.0

Yes I did worry that might happen Steve

No worries, this has been a lot of hekp. For me the uv\ir cut is better safe than sorry - the forums have a lot of conflicting opinions although I can see the logic that a narrow band filter should do the job, i know there is a lot I don't know - so I'll stick with the uv\ir cut. On the other hand i've never tried observing without the polarising filter, so i might try without - although I don't see anything in the continuum that would reduce the intensity of the light - but like I say, there's a lot I don't know...

Polarising filter, UV/IR cut and a Contiuum. Actually it's the altair contrast booster version, not the Baader continuum, so a bit thinner, but all 3 are still a good few mm all told. The Lacerta also has the ND3.0 built in. I've just now found on Teleskop-Express for the bare T2 version of the 1.25" Lacerta wedge - "Light path from T2 to T2 is 61 mm" - so a bit less than the Tak diagonal. Still I'll test tomorrow to be sure.

Thanks @Stu I knew I had read about having to shorten the OTA on a Japanese refractor, but couldn't remember where! The inward focus might just do it - Steve thought the light path might be reduced by about 20mm on the 1.25".... still it does sound like it will be touch and go, and as @Carbon Brush says, there will be not one but three filters in the light path if I'm using a continuum filter (and I'm a real convert to that piece of kit) - so some definitive measuring of the light path is in order - I'll report back after some testing tomorrow.

I hope so - it's a lovely scope. I'm going to try to work out the light path tomorrow by focusing with and without the Wedge on the Meade (if I can find something bright enough to see, even without the ND3.0)

@wookie1965 Okay - it looks like you have the Lunt Herschel Wedge - mine is the Lacerta Herschel Wedge, which has a "Brewster angled" eyepiece holder (which Lacerta claim helps polarisation). So I surmise the long light path is probably not down to the Brewster angle.

@wookie1965 is that the Lacerta wedge? The 110mm is quoted for the 2" version - I googled in haste. Not sure if the Brewster angle on its own would necessitate a longer light path. Anyway, the 1.25" should be less. I rarely get good enough seeing to get to a 4mm eyepiece - my garden faces west, so the sun gets fairly high, and the seeing us usually poor, before I can start observing.

I do have the 1.25" wedge - so this is better news - 110mm is a lot of focus.