Tiny Clanger

Some months ago I mentioned to Jasonb that I was writing in a notebook a list of Moore Winter Marathon objects with a note of the page they appeared on in Turn Left at Orion, their Messier number and the Caldwell catalogue number . He said being a computer guy, if he was doing it, and if he had time, he would make a database (or was it spreadsheet ? I still am fuzzy on which is what ... 🙂 ) Then , a week or so ago, while idly researching eye pieces I can't afford , I came across Don Pensack's very useful set of information here https://www.eyepiecesetc.com/INFORMATIONAL_ARTICLES_ABOUT_ASTRONOMY_AND_TELESCOPES_s/1828.htm and , ooh, what's this ?! A beginner's list of 500 DSOs , which Mr Pensack says are ' the 500 best DSOs, as seen in a 4" refractor and 5" Maksutov in modestly dark skies over a couple of years.' https://www.eyepiecesetc.com/500_Best_Deep_Sky_Objects_p/five-hundred-best-dsos.htm I can't resist a free list , and recalling our earlier conversation mentioned the list to Jasonb as a possible base for adding Turn Left At Orion page numbers etc to. He was enthusiastic and had the tech skills and software to set things up, I had some spare time to play at data entry clerk, and we have between us compiled into Don's excellent original 500 some extra information, with added columns for the MWM (Moore Winter Marathon) Caldwell list, Loughton List and page numbers for Turn Left at Orion . There's also a column where we have noted if the object may be too low in the sky for us to see from Ireland/UK An explanation of the original column meanings can be found here : https://www.cloudynights.com/topic/472872-500-best-dso-list/?p=8418052 The file works on whatever (proper) software Jasonb uses, but also on my free 'Open Office' , so everyone should be able to use it. I can't guarantee our input is complete or error free ( I can now add data entry clerk to the giant list of jobs for which I would be severely unsuited ... ) but we thought it might be useful for other folk , so after checking with Don, and getting his OK, here it is : Pensack 500 Version 1.3.ods

As I said, I have the skywatcher barlow , which looks identical to the FLO astro essentials one, a good feature of both is that if you have a DSLR and want to try taking photos through your 'scope, the barlow is threaded to take a t mount adaptor. I can't say you would love the barlow, because I don't but it is a cost effective way of extending your range of focal lengths. If you decide on a 2x barlow and 2 new EPs, try to have EPs which are not twice the focal length , eg your 25mm will become a 12.5mm with the barlow, so best not get a barlow + 12mm ! By the way, I believe FLO will remove the UK VAT when you buy anything from the EU (so my S. Irish friends tell me 🙂 ) , and your local taxes ought to be paid as you import them ...

Yep, you can always spend more , but the improvements per £ are marginal : the ES I'd rather like to replace the 25mm BST i with would be 3x the cost of the BST, but no way would it be 3x better !

I'm by no means an expert on EPs, all I've used is the stock ones, plossls and BSTs , but I just don't much like the 25mm in the dob , the f5 focal ratio shows it's flaws up . It's fine in the mak which is , er, f12 ish , but I actually use a skywatcher 32mm plossl in preference when using the dob. , and it has a very similar field of view. The EP I really loved instantly was my 17mm plossl , turns out that 17mm focal length , giving a 3,4mm exit pupil (with the dob) is , to my eyes, from my back garden, the best. I held off buying the BST 18mm because I so liked the plossl it seemed pointless to replace it, but when one came up for sale second hand at a decent price I went for it , and have found the BST (exit pupil 3,6mm) is even better for me. The 17mm plossl has been shifted over to my ST80 where it does a lovely job too ! I'd think a more forgiving than f5 'scope might not be a problem for the 25mm BST, but I'm not sure where you'd draw the line of acceptability ! Heather

Oh, and by the by, the 25mm BST is, to my eyes, the least good of the set, and the only one I would like to upgrade. So as you were impressed by the improvement over the stock EP of that one, you should be blown away by the others in the range !

Hey, you callin' me a cat ? I'd be flattered, actually. Back to the topic in hand . Yes, I love my heritage dob , and have BSTs . My dob is the slightly bigger 150mm , which has a focal length of 750mm and a focal ratio of f5 , while the heritage 130 is, I believe focal length 650mm (also therefore f5) So your 130 will get slightly less magnification with a given eyepiece than the 150 does. The greatest magnification BST eyepiece I own is the 8mm, which I would recommend unreservedly, it is great for views of the Moon and planets. The 12mm is just as good. My absolute favourite for faint fuzzy stuff is the 18mm . I have the 15mm, it is fine, but gets less use. I have not bought a 5mm BST, for a number of reasons. I tried the 8mm and 12mm with a 2x barlow when looking at Mars, and found the planet zipped across my field of view so fast that I was constantly nudging the 'scope to keep up with it. So , for me, the 5mm would be a step too far in that 'scope. My (expensive) solution was to buy a 127 mak on and AZ5 alt az mount. This is twice the focal length of the dob, so gets me that big magnification along with slo mo controls to ease keeping the planet in view. In my 150 the 8mm BST gives 93.7x , in your 130 , 81.5x. Both 'scopes being f5, the exit pupil is the same, 1.6mm The 12mm BST gives me 62.5x , you 54.4x , exit pupil 2.4mm The 15mm BST in my 150 50x , in the 130 43.3 exit pupil 3.0 to me the 18mm BST 41.6x , to you 36.1x exit pupil 3.6mm for completeness, the 25mm we both already have is me 30x, you 26x exit pupil 5.0 And a 5mm would give you 130x and an exit pupil of 1mm While the 5mm looks good on paper, I am concerned that you would get less use from it because of the difficulties of keeping the Moon and Planets in view by nudging the dob base. It's not impossible, but it takes a lot of patience and is not ideal. I'd suggest the 8mm as your high power EP. Then where you go for a mid range depends ... if you go on exit pupil, then the 15mm looks like a good mid point, if you look for a mid way magnification maybe the 12mm, but from a light polluted suburban fringe location I've found the 18mm is the ideal exit pupil for me to perceive the faint fuzzies against the night glow infested sky. Here's a random thought : how about an 8mm BST and 2x barlow ? The Barlow would give you the option of using it with the 25mm to give you 12.5mm , and the 8mm to give a (probably seldom used) 4mm . Some Barlows allow you to unscrew the lens part and use just that minus the tube to get 1.5x mag over that of the eyepiece alone, so the 25mm becomes a 16mm , the 8mm becomes effectively 5.3mm. I believe there is a BST barlow available on FLO , for a bit less than the price of a BST eyepiece, although I've not looked recently. The good thing about Barlows is that they instantly double (or triple if you can unscrew the lens) the number of focal lengths available to you. The bad thing is that they are a faff , and cheap ones can be poor. I bought a skywatcher one ( I believe it is their 'super' model ) and I just don't like using it . But, it is an option, and could show you what focal lengths you are likely to find useful. Heather

From what I've seen, sometimes wildly optimistic asking prices do get accepted , it just depends on someone thinking they are happy to pay that price and have the cash burning a hole in their pocket at that moment ... you only need one such person to see the ad. ! On the other hand, you sometimes see stuff which the seller feels is more valuable than any potential buyers do, so unless the price is reduced, it languishes unsold. Things that are small and relatively robust (therefore easily posted), desirable (known good brands) easily assessed from photos for condition, and under about £100 get snapped up as long as the price is right : put a BST starguider EP ( FLO price £47) up for £40 plus P&P, watch it languish, but for £35 including P&P it will be gone in an instant. 2/3 of new price seems a good starting point. On the other other hand, a huge dob for several hundred pounds, seller wants collection only from some deeply rural location far from major centres of population ? That's not going to appeal to lots of people : a long , expensive, time consuming drive, possibly to find the 'scope is not something you want ? Really specialist, niche stuff by its very nature has a limited audience too, it might get a good price but that could take a while. Location is another factor : the way import regulations are at the moment, buying or selling internationally can be a factor, and there's also the seller's reputation . I've bought a refractor , a diagonal, some filters and several eyepieces from various folk on here. To start with, when I was new to SGL, I checked out the seller's previous message history to be confident my money was going to a genuine honest person. Now I'm familiar enough with the flow of conversations to recognise quite a few names, and can often make an instant decision. But if I saw an unfamiliar name, I'd still hesitate and check them out. What have they posted before ? Do they contribute , or just seem to sell ? Do they say whereabouts they live ? Do they give an impression of being a careful person or do they seem a bit slapdash ? When it comes down to it, a thing is only 'worth' what someone is willing to pay for it. If the seller thinks it's worth more to them , that's their belief, and they can keep the item, or leave the advert up in the hope that someone feels the price is reasonable, or reduce the price to turn the item into less cash than they anticipated .

Yep, that missing bit of info about the OP's location changes things greatly (as I suspected it might, which was why I asked !) Having bought one a few months ago, I'd suggest a decent alternative for wide field, low power sky sweeping might be a short tube 80mm 'scope , with a 32mm EP in it's 400mm focal length, mine might as well be half a pair of 12x80 binos . OP would do well to search out Ed Ting's you tube review for the ST80 .

Do not confuse 'high power' with 'good', that's a fiction perpetrated by the sellers of cheap 'scopes to exaggerate claims in adverts. Big binoculars, just like big 'scopes need big. steady, heavy mounts. Read some of the pages in the link I gave you, all the information is there.

The planets ,all but Uranus, Neptune (and, if you insist, Pluto) can be seen with no optical apparatus but your eyes ... mind you, you have to be up around 3am for Jupiter & Saturn at the mo ! Head here https://binocularsky.com/ download (or sign up for) the monthly newsletter , read up a bit on recommended binos and supports, find out what is possible for under £100 . That's less than the cost of a mid range telescope eyepiece.

I agree completely with this : I've been (repeatedly) unable to perceive faint fuzzies even when I know I have been looking directly in the right place with my 150mm dob , (cough, Leo Trio, only ever managed one and a suspicion, never all 3) it can take persistence, averted vision , and swapping between eyepieces to eventually see what is in an area. You don't mention your location , if you are by , around or near street lights, what you can have pop out obviously against a truly dark sky will be far less . For random scanning, or even for learning your way around the sky, binoculars would be a good purchase. There's a whole section on here devoted to binocular astronomy, it is not a poor relation , but an alternative approach.

Here's a few EPs from the same brand who offer lines with different apparent FOV : https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-62-series-ler-eyepieces.html 62 degree apparent FOV, 20mm £85 https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-68-degree-series-eyepieces.html 68 degree apparent FOV , 20mm , £135 https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-100-degree-series-2-inch-eyepieces.html 100 degree apparent FOV, 20mm / 2" barrel .... wait for it ...... £479 Those big windows don't come cheap !

The simplest explanation of apparent vs actual field of view I came across (and I was bemused enough by the subject to need very simple ) was to imagine you are looking through a small window at the view outside , then imagine not moving , but putting a bigger window in the small one's place. That is a wider apparent field of view. However, the apparent FOV of an eyepiece is not the end of the story : different focal length eyepieces (e.g. the 10mm or 40mm of yours) in combination with the rest of the telescope optics, magnify by different amounts. So actual field of view is a function of the magnification the eyepiece / telescope combination , the more magnification, the less sky you will see in one view. As has been said, wide FOV eyepieces need big glass (and maybe 2" diameter barrels too ..) and therefore cost far more than narrower ones. Heather

Patience is essential ! 🙂 I've had plenty of frustrating viewing sessions, and early on got in the habit of finishing such a session with an easy win to make up for the (many) annoying failures: it used to be the Pleiades back in the winter, and maybe the Orion Nebula, now it is Albireo and the Ring Nebula , Saturn and Jupiter were an unanticipated but very welcome extra . With a bit of luck, I might get to see the planets in my mak at a rather higher magnification this week , the highest the ST80 could manage with my 6mm eyepiece is about the same as the 25mm BST shows in the mak ! Probably with both planets still very low in the sky conditions will not be ideal for huge magnification, but you never know ...

Sounding dangerously Yoda like, I'd say 'Raise the dob., lower the observer, one or the other, or both, whatever works . I have a heritage 150 dob, which has a low tabletop base , so have built a rough little sturdy stand to raise it off the (usually wet) grass, and an adjustable height observing chair ,you can see both here What do you hope to observe with your 'scope ? That would be an important factor to me in a decision between dob and mak . Heather

There's an entire sub category here to read : https://stargazerslounge.com/forum/18-diy-astronomer/

Exciting isn't it ? 🙂 Saturn was the first thing I saw through my heritage dob, on the day I bought it, and even through a window , with the stock eyepieces , dob balanced precariously on it's own cardboard box , it was a memorable sight ! Last night I was out with my heritage dob around 1am, but while the seeing was steady, the poor clarity and light pollution frustrated my DSO hunting 😞 but as I packed up at 3am I saw Jupiter and Saturn were just climbing over the houses , too low for my dob (the fence was in the way ) so nipped in to grab my ST80 on its nice tall tripod, and see how it coped : surprisingly well ! I've seen both planets in my dob and mak last year, this was my first look with the tiny frac, I didn't expect much but it was actually a quite nice view , cranking up the ST80 with a 6mm ortho to a not-at -all massive 66X mag. , some colour banding , sharp tiny rings, all 4 Galilean Moons ... That right hand 5th moon you and I saw was a star which just happened to be in line with the moons (HP 109720) , having counted 5 points of light myself, I checked with stellarium when I came indoors, the line E to W went Io, Jupiter, Europa, Ganymede, Callisto, star . Heather

I drilled holes in my heritage dob (a process I admit that I found nerve wracking 😉 ) , but only after testing if the spot I thought best would work by attaching the shoe with a little patch of several 'no more nails permanent fixing pads' ... they actually did the job for a few weeks, I only removed them and drilled the holes when the pads started to let the finder wobble. Heather By the way, that wonky thing in the centre of the dob base ? It's a magnet salvaged from an old speaker. I used it as a counterbalance when I had a mixture of very light & slightly heavier EPs , when not in use it stuck on the central nut.

I have a copy of a short and simple book with a guide to locating the constellations, and a section with the classical constellation myths retold briefly in a way suitable for telling to children : A Walk through the Heavens By M D Heifitz and Wil Tirion Last time I mentioned it to someone, I looked on Amazon and found plenty of second hand copies for sale . Heather

That's beautifully simple, but there's a lot of contact with the ground , which on my bumpy garden grass would be a problem , also it would wick up damp. So a good solution for some dry, level surfaces, but not mine ! 🙂 Heather

Funny isn't it, of the 3 EPs you mention (SW bundled 25mm, 32mm plossl, 25mm BST) I can see there is an improvement in quality at each step up in price , but am not happy with the edge image in the BST, therefore find the plossl preferable (but only in my f5 dob) and for me the plossl is very esy to use. But you prefer the bundled SW to the plossl ! It shows that while statistics will tell you a certain amount, these things are very subjective I've never actually seen anyone discuss or review the ES 52 degree EPs mentioned by Alan, which is slightly strange, but I guess as they are in the same approximate price range as the BSTs but a bit more expensive they may be seen as less of a bargain. There certainly is a tendency towards quality EPs being wider, which means they are necessarily bigger, heavier and inevitably more expensive. The one thing you can guarantee about suggestions on what eyepieces you should buy, is that many suggestions will blithely stretch or totally ignore any budget you mention ! I think this is an interesting thread, I've not looked up the focal ratio of your 'scope, which is an important factor , but this deals with a query related to a fast (low number) ratio device : Heather

Ah, shame about the KYRRE being too small for the 150 base. Mind you, if it is a flatpack item, it could be a source of 3 legs to bolt on to a larger top ... with the original stool seat fixed below as a shelf to brace the legs and store eyepieces, as on an astro tripod ... Do show your dad the link to Jerry Oliton's chair diagrams too, see if he will make you one of those as well ! The variable height is brilliant, and seated observing is much more comfortable. Heather

Check the BST 25mm page on FLO https://www.firstlightoptics.com/bst-starguider-eyepieces/bst-starguider-60-25mm-ed-eyepiece.html if you scroll down it, you will see an image which shows you the field of view of an eyepiece, you can change the telescope, and delete / add any eyepiece views as you wish. Try using it to compare the view of a 25mm BST to that of a 32mm plossl , they are very similar ! I have both, and in my f5 dob, I actually prefer the view in my 32mm plossl, and use it rather than the 25mm BST . The BST shows some aberration around the edge of the view. The BST 25mm is fine in my less picky f11 .mak though. From what I can see (and I've looked around a fair bit !) to get an eyepiece significantly better than the (under £50) BST, I'd need to spend at least 3x that, and the gains would be marginal. Explore scientific get recommended a lot , https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-68-degree-series-eyepieces.html or folk mention liking the Baader Mortpheus for about £180 https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-68-degree-series-eyepieces.html I'd suggest you buy a BST 25mm, and see how you get on with it : buying online means you can return an item as unsuitable , FLO or Alan at Sky's the Limit https://skys-the-limit-108154.square.site/shop/1-25-bst-starguider-ed/8 are sellers I'd trust to do the right thing. Heather

I'm not sure if the 150 dob base is the same diameter as the 130 dob base, but if it is, I've read of many folk using the 130 heritage on an Ikea KYRRE Stool, they only cost £10. I made my heritage a 3 legged triangular table out of scrap wood and some metal legs which cost me around £12 on Amazon (for a set of 4 ! ) You can see it in photos here : I'm not sure if the 150 dob base is the same diameter as the 130 dob base, but if it is, I've read of many folk using the 130 heritage on an Ikea KYRRE Stool, they only cost £10. I made my heritage a 3 legged triangular table out of scrap wood and some metal legs which cost me around £12 on Amazon (for a set of 4 ! ) You can see it in photos here : I'm not sure if the 150 dob base is the same diameter as the 130 dob base, but if it is, I've read of many folk using the 130 heritage on an Ikea KYRRE Stool, they only cost £10. I don't think adjustable height legs are needed if you just use 3, as with a tripod, 3 points of contact with the ground makes a nice stable arrangement . I made my heritage a 3 legged triangular table out of scrap wood and some metal legs which cost me around £12 on Amazon (for a set of 4 ! ) You can see it in a couple of my photos here : https://stargazerslounge.com/topic/376543-£355-scope-chair/ Heather

No gnus is good gnus