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Posts posted by E621Keith
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Very nice set up Olly.
Do you know what is missing from that X'mas tree - decoration. It needs some cables and colour filters hanging off it and may be a statue of Sir Patrick Moore to go on the top.
Awesome-looking set-up. Why not put four Taks on there for R, G, B H-alpha, or O-III, S-II, H-alpha and whatever else you feel like
Why not go all the way and build a WASP with eight FSQ.
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Curious how much these will retail for and in the 100 - 150mm F3-F5 range which scope would be king ?
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The only other scope in this segment is the Tak FSQ106 which retails at £5k. I reckon this Vixen will be in the same region.
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... At F3 it would surely be the fastest production apochromat in history, no? ...
Borg made a 125mm F2.8(native) a few years ago, so this is not the fastest 'apo' astrograph in history, but it is probably the fastest in production.
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Keith, could this be against 'budget' Petzvals like this?
Good point. May be they compared the VSD with their DED-108SS rather than Pentax's 100SDUF
SA,CA, pinched optics. The DED-108ss had it all.
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I just noticed in the Vixen announcement, it claimed the Strehl intensity of the VSD is 10% better than a 4 element Petzval. If I remembered correctly, Pentax Petzvals had Strehl ratio of 0.96 or better, so what could this 10% mean? Obviously it's impossible to have a Strehl ratio of 1.06
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Any news on the price yet?
The price tag of Pentax scopes used to made Tak's looked cheap, but this is a Vixen so it will probably be more affordable.
I don't think it will cost a lot more than a FSQ106, but I also doubt it will be much cheaper. I guess £5k for the OTA and around £1.5k for the reducer.
Do you have to use a specific spacing to get a flat frame, and if so, is it more than the 55mm that some manufacturers hamper their scopes with?
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A flat field scope like the SDUF and FSQ have flat focal planes. These scope have no field curvature when they are in focus, so there is no need to worry about spacers.
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A group photo of my zoom eyepieces before they go their separate way
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Just added the Pentax XF 12mm and changed the foam the medium density, i think that's about it as far as EP buying goes.....
Just 2 more to go and you will have the whole set of XW.
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It's not a bad idea to have parfocal eyepieces in the same case. My cases used to be quite chaotic as well, because different eyepieces was added at different time.
Eventually I bought some foam from fleabay and reorganised them into two sets once I was happy with my collection.
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Alan, That's a lovely collection of eyepieces. Can't wait to see your collection when you start binoviewing
Just out of interest, is there any particular reason why 21 and 10 Ethos is kept in one case while the 8,13 and 17 is kept in another?
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Reverse polarity damage is quite common for Vixen mount. Vixen motors uses Japanese centre negative connector, so plugging a western centre positive cable will fry the mount.
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Anyone know what foam to use for an eyepiece case. Heard some can damage the optics?
You should always use eyepiece caps. Caps prevent things from touching the glass in your eyepiece.
Otherwise, every type of foam will damage your optics, because foam is really good at trapping dust, grit and sand.
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Apologies for the late reply. I’ve had a busy week.
I’ve been looking into scopes and the good advice given (thankyou) and I think I have warmed to the idea of the Heritage Dobsonian Flextube linked earlier http://www.firstligh...p-flextube.html
In all honesty, excusing my ignorance or maybe snobbery, I looked at the Dobsonian type and with perhaps less engineered construction, and to the laymen a rudimentary mount and materials i.e "flextube" it made me dubious of it.
I’ve seen some recommendation and for my budget that Dobsonian type is indeed probably is going to give the best image. I understand the Dobbins have less cost in the mount and this more money into the optics.
I do however wonder if having to manually track and item will drive me mad, that I can’t answer. I presume anything I have in the viewfinder will move out of it in about a minute’s time, and I am guessing that without a finder scope you really are point and find. Finding, and refining sounds tedious.
Please correct me if I am wrong, I don’t have any first hand experience. This kind of make me feel if you lose track of something (say after reviewing a planisphere for a minute or two, you may have to drop down magnifications in order to find the object again, to then increase the magnification once found; sounds tedious).
That may or may be not be a real concern; I’m just using my imagination here. So if anyone can give a flavour of first experiences with Dobsonians would be good?
Additionally, how do people use such dobsonians out and about? Do you have to buy a tripod to attach it to or use some other means to raise it from the floor and give a sturdy platform? I would want to take it up my local hill away from light pollution.
It is I admittedly difficult for me to quantify the picture difference I would get between http://www.firstligh...p-flextube.html and say http://www.firstligh...hawk-1145p.html
Like you said, most of the dob's cost is spent on the optics and less on the mount. However dob mount is very simple and generally more sturdy than cheap equatorial mount such as the one on the Skyhawk. EQ1 and EQ2 mounts are really poor quality, unstable and not very durable. EQ1 and EQ2 doesn't give you tracking either, unless you spend more on the motors, but it will be a waste of money anyway.
Nudging the dob every half a minutes is't too bad. You will get used to it quite quickly.
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If you can stretch to £140, then the Skywatcher Heritage 130p dobsonian mentioned by Knobby is highly recommended
http://www.firstlightoptics.com/dobsonians/skywatcher-heritage-130p-flextube.html
A dobsonian mount is very cheap to make, so most of that £140 goes into the telescope optics. As a results the scope will show you dimmer objects than others in the same price range.
If you buy the Seben, you will either be extremely disappointed with the view and give up astronomy, or having to spend another £140 to get a real telescope which adds up to a total of just under £200.
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I think you need to get your eyes checked Keith if you think they are a matching pair!
they are in the dark
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Very nice Keith, I didn't think the Nikons were available in England. Do you know how they compair with Televues?
Alan.
They weren't, I bought 12.5HW and 10SW in Japan while I was there for the Venus Transit. I wanted to see what they are like because the are far less common than TV or Pentax. It turned out I liked them a lot, so I bought the other three when I was in Japan for conference a few months later.
I have yet to look through an equivalent TV so I don't know how they compare.
Hopefully someone will let me have a look through their Ethos and Delos at SGL8.
I bought the Nikon MC on fleabay and one on ABS, sometimes they come up at a bargain price. The biggest problem with the MC is 1.25"-MC adapter is very hard to find.
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Reading through 25 pages of this thread, genuinely excited by other astronomer's eye piece cases has absolutely confirmed that I am an utter geek.
Just 25 more to go. You will get there.
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For some reason I cannot paste my case pic.
_______________________________________
Shaun
Scope:Celestron Nextar 6se with Goto mount
Eye pieces :Celestron X-cel LX 18,12 & 2 x Barlow. Celestron 8-24 Zoom. PLOSSl 32
Sun Filter, Moon Filter, Celestron dew sheild
Huge Power supply that lasts for weeks:-)
so you get a sun filter with yours aswell then, what was the total price and where did u buy it from?
Since this is a eyepiece discussion thread, I just want to make it clear, solar filter must be front mounted ahead of the telescope.
Eyepiece mounted solar filter can crack easily from the sun's heat and is extremely dangerous and should be disposed of immediately.
While Pig's signature isn't clear, I suspect his solar filter is front mounted.
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That's a great idea. Is this for flat plate adapter only or do you do round adapter for different threads as well?
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RIP Sir Patrick Moore. It's a great lost to the world of amateur astronomy.
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The reason I don't think SCT focus range is related to its focal length is because large dobsonians have similar focal lengths to SCTs. However large dobs use the same focuser as smaller newtonians so they must have the same focus travel range as their smaller cousins.
It's my theory anyway.
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I just assumed the SCT's go so far over focus due to their large f/l. My 8SE has a f/l of 3032mm.
I thought an SCT's focus range is related to the their moving primary focusing mechanism. The secondary mirror magnifies the primary mirror by 5x, and I assumed it also magnifies the focuser (primary mirror) movement by 5x.
Show me your eyepiece/accessories case, please.
in DIY Astronomer
Posted
Like others said, lens pen has a soft brush and a microfibre pad for cleaning optics. While it's a nice gadget, I would not recommend it because it's a dry contact cleaning method.
If you need to clean your eyepiece, first try a air blower. If you can't dislodge it, then you should consider wet clean method such as Baader fluid + thick lens tissue. Dry contact cleaning methods, such as dry microfibre cloth and lens pen, are mostly likely to scratch your optics.