View Full Version here: : Best 3 EP's for a 300mm F5 dob
Dobman
04-12-2005, 08:08 PM
:help3: I've had my dob for 6 months and love it. I'm thinking of upgrading my EP's and would like to hear anybody's thoughts on what i should get. I currently have the 2 plossls (9 & 15mm) & the 2" 32MM supplied with the scope (Bintel) My main interset is Deeeep sky- nebs, globs, planetary globs etc and the occasional look at Jupiter & Saturn & I quite like the moon. I find myself using the 32mm 2" a lot and also the 9mm plossl. I got to have a look thru an Andrews 30mm 80' at the last Bridgenorth nite and loved the wide field.:nerd:
The 3 EP's I'm thinking of are: andrews 30mm 2", 9mm & 13mmT6 Nagler and a TV 2.5x Powermate. That would give me mags of 50x, 115x, 167x, 287x & 417x.
If anyone has any advice, I'd love to hear your thoughts.:confuse3:
Striker
04-12-2005, 08:50 PM
Just to make it easy for everyone.
Dobman has a 12" Dob with 1500mm Focal length at F5...the 300mm may throw some people out.
There are plenty here with that dob so they can help you with Eyepieces.
davidpretorius
04-12-2005, 09:07 PM
hi,
the 30mm ultra wide will be the last one i upgrade.
I am like you and thinking around 7mm, 11mm and a 2.5x powermate. I will be going a 60 degree fov i reckon because i should be tracking middle of this week, so a nagler will be a little wasted for me.
That is a good spread of magnifications. If you are going naglers for the wide view for your non tracking dob, then you are pretty right. If not just for wide views then it all gets harder as pentax, uo, meade etc all come into the mix.
Put it this way, i can't see you going wrong with what you have suggested!
Us other lonnie boys will be happy if you go that way!!!!
jackenau
04-12-2005, 09:20 PM
Dobman, I have 12" also, which I also use to go deep, as that is my primary interest at this time.
Have a SV30mm GSO from bintel, which at the time was great for those wide views. IMHO it took longer to cool down to afford good views as opposed to the Naglers and Panoptics I have since purchased.
Would have to recommend the 35mm Panoptic though above this. Crisper images, and a lot lees cool down time (this is a personal thing, not grab and go)
The 35mm Panoptic works a treat. Have not had the opportunity to use a Nagler or similar for comparison, but this is a great ep for locating, before changing down (up, depending on where your coming from).
Love the view also through my 9mm Nagler if viewing conditions are good.
Have also a Nagler 16mm type 2, but not overall impressed with it, however I do use it frequently as opposed to the normal plossls
Ken M
janoskiss
04-12-2005, 11:56 PM
That would leave a BIG gap between the 30mm and the 13mm. Also, the 13mm Nagler and the Powermate will give you plenty of magnification, and the 9mm in the P-mate will be too much for your scope at 99.5+% of the time. So you'd effectively be buying the rather expensive Powermate for use with only one EP. I'd recommend 19mm Panoptic, 13mm Nagler + Powermate. And if/when finances allow, the 24mm Panoptic.
Or, if you don't insist on premium EPs, the Orion Stratus EPs perform exceptionally well at less than half the price of Panoptics. They work very well in my f6 Dob, and are reported to work well in f5 and faster scopes as well. Around $175 each (incl. postage), but you need to order then from the States. Mine got here in 5 days from www.seansastronomyshop.com. Hmmm... best three ..., just get four and forget the barlow: 21,13,8,5mm.
For the widest true FOV I'm thinking of getting a Meade 5000 Plossl 32mm (with 60 deg AFOV) to keep cost somewhat on the sane side. I imagine this would be a better EP than a budget ultra-wide, but having looked through neither, who knows :shrug: That's something I'll have to investigate.
ballaratdragons
05-12-2005, 12:07 AM
I have the 12" GS as well! I have mediocre/good EP's. But may I recommend a 2" Barlow. It will give you twice the variety in your mag range and you can use 2" and 1.25" EP's in it.
Starkler
05-12-2005, 12:11 AM
I wouldnt recommend a 35mm panoptic for an f5 scope. It will give a 7mm exit pupil.
I used to have a 27mm panoptic and thats one of the nicest eyepieces I have ever used.
janoskiss
05-12-2005, 12:13 AM
Ken, I agree. I wish I bought the UO 2" barlow too instead of the Shorty-plus. But if it's a Powermate Dobman's really after, with a 2" you are talking really big bucks. At that point I'd just buy more EPs to fill the gaps instead.
true... a 27mm would be ideal :)
Starkler
05-12-2005, 06:13 PM
If you want to spend money.
27mm panoptic
14mm Pentax XW
7mm Pentax XW
forget the powermate.
Or
27mm panoptic
22mm panoptic
UO 2 inch barlow (the two ep's above should work nicely in the barlow)
7mm Pentax XW for planetary.
Dobman
05-12-2005, 10:31 PM
Thanks everyone for the advice. You're quite right Janoskiss, the 9mm with the 2.5x powermate would be too much. Originally, I was thinking of the 9 & 13 mm T6& the andrews 30mm 2" with a 2x 1 1/4" barlow. That woud give me a spread of 50x, 115x, 167x, 230x, & 334x which I thought was a good spread of powers,The highest power not too extreme for my scope.Then I had to go on the TV website didn't I and convince myself that barlows were no good and I had to have a powermate:P which threw my plans into disarray!!
A few of you have reccommended the Panoptics. They don't give as wide a field of view do they? Are they as sharp or sharper than the naglers? I must admit I'd rather stay as wide as pos. can someone answer me this; If I use say the 9mm with a 2x barlow to look at the moon or Jupiter, will there be any diference in the image size or quality to say, using a 4.5 mm 60 degree EP of similar quality? Or will the image just stay in view longer with less tube moving?
Any opinions on the TV 2x 1 1/4" barlow?:confuse3:
Starkler
05-12-2005, 10:59 PM
There are very few eyepieces sharper than the panoptics, that includes naglers.
68 degrees is wide enough for many , and the panoptics are considerably cheaper than similar focal length naglers.
I wouldnt worry too much about super high magnifications as seeing conditions rarely support powers over 250x, and 90% of my planetary viewing is done at about 200x.
davidpretorius
05-12-2005, 11:01 PM
well i have just came in from viewing / imaging mars. i had my 6.5mm series 500 and a 2.4x barlow ie less than 3mm and i was able to see detail.
a very good seeing night out there at the moment!!!
i can see 6 stars in the trapezium!
given seeing conditions here in tassie, i would be tempted to have a 9 and 2.5x barlow or powermate. I have used my 6.5mm and 12.5mm in combo with my 2.4x and have been very happy on at least 6 occassions in two months.
Dobman, I wouldn't worry about the field of view in a big panoptic. The bigger they are the harder it is to find the field stop. Tonight through my 22mm panoptic I found it quite difficult to see the field stop when looking in the center of the eyepiece. I have to move my head to look around to the edges and at that point it is uncomfortable anyway.
Panoptics are generally slightly sharper than naglers but is all a bit of swings and round abouts. There's not much in it. Naglers are wider, slightly warmer, but have slightly less field curviture (but it's only really noticable during the day if you ask me, or, if you look though the eyepiece at a magazine which is a stupid idea anyway).
You will also get less kidney beaning in large panoptics. I find it hard to use the 31 nagler, but people that wear glasses love them. I think the advange of naglers becomes more apparent when you get into lower focal lengths because the eyerelief is better.
But as Geoff said, the pentax might be a good option at lower focal lengths. I have not compared them, but I have heard the the penax eyepieces have a more natural color tone than naglers and radians.
But having said that I'm about to get a 4mm radian and 35mm panoptic. I would try them first if possible because you might like something better. I think panoptics are the best (at the moment).
Dobman
06-12-2005, 01:20 AM
:tasdevil: The Panoptics sound good. A query on FOV. I'm talking about the actual FOV you see when looking thru the EP. You get wider FOV with longer F.L EP's amd narrower FOV with shorter FL EP's. Am I right? If so, (remembering I like Wide Fov's) if I,m getting 2 good EP's & I'm tossing up between Naglers & /or a Panoptic, should I get say, a 15mm Panoptic & a 9mm Nagler? My reasoning behind this is this; the 15mm Panoptic has a narrower FOV but because of its longer FL this wont be as noticeable and the 9mm nagler has a wider FOV but the shorter FL will counteract this. Does any of this make sense? I'm also thinking of a TV 2x barlow & a 30mm 2" Andrews EP. This combo would give me 50x, 100x, 167x, 200x & 333x. Any thoughts out there?
I have been thinking about this since I posted my last post (above) last night. I can't explain why this is so... But I definitely notice a difference when I look through EP's with different focal lengths and the same AFOV.
Why? Why!
I thought that it might have something to do with the EP relief. Maybe when I look though some naglers I have a tendancy to view from too close to the lens. This make makes it easier to see the field stop. Could this be it? :confuse2:
My experience at star camps looking through lots of different naglers is that sometimes it is impossible to see the field stop and other times it's way too easy. That's one of the reasons why I'm happy with the 22mm pan, because the field is way bid enough, getting the extra bit from the nagler would be a waste. But with another focal length comparison the nagler would kick it's buttt. I can't remember whether it was longer or shorter FL that made the difference now...:mad2: :mad2:
I would be intrested to hear if anyone else has had the same experience. Is it an eye relief issue?
Starkler
06-12-2005, 10:51 AM
Dobman, I suggest you do a lot of research before laying out the kind of funds we are talking about here. All the premium eyepieces types are not equal and have varying characteristics, even within the same line. eg there are different series of naglers, all different.
I advise you to do some comparisons in the field and see what characteristics are important to you, especially:
FOV
eye relief
sharpness across field
2inch or 1.25
contrast (mainly for planetary)
Starkler
06-12-2005, 10:56 AM
The definition of eye relief is the farthest distance from the eyepiece that the full field stop becomes visible. Correct eye placement should be at around this distance. As you get closer it becomes harder to hold the image.
Stu , yes it sounds like you are used to short ER eyepieces and are getting too close.
ausastronomer
07-12-2005, 11:26 AM
Stu/Dobman,
You need to understand the difference between Apparent Field of View (AFOV) and True or Actual Field of View (TFOV).
The AFOV is that specified by the eyepiece manufacturer and is determined by the eyepiece design and its field stop diameter. This does not change regardless of which telescope you use the eyepiece in. Hold the eyepiece in front of a light source and look at the size of the light circle through the eyepiece. This basically represents the angle that the light source enters the field lens of the eyepiece. This is around 45° for an orthoscopic, 50° to 55° for a plossl design, 60° for a TV Radian, 65° degrees for the Vixen LVW, 68° for the TV Panoptics, 70° for the Pentax XW series and 82° for the TV Naglers and Meade UWA.
The TFOV is the actual angular size of the targets' field that you see through the telescope. It is calculated by dividing the magnification that the eypiece gives in a particular telescope by the AFOV. Consequently as the focal length of the eyepiece increases the magnification drops and the TFOV is increased. eg a 30mm 50° Plossl gives a larger TFOV than a 20mm 50° Plossl, when used in the same telescope, because it gives lower magnification in that telescope.
Example:
Assume a 200mm (8")/F5 newtonian. The aperture is 200mm the focal length (FL) is 1000mm.
(Eyepiece magnification is calculated by dividing FL of scope/FL of eyepiece)
lets go back to the 20mm and 30mm 50° plossls.
The 30mm Plossl gives a magnification of 33.3X (1000/30)
The 20mm Plossl gives a magnification of 50X (1000/50)
Hence the 30mm Plossl gives a TFOV of 1.5° (50/33.3)
and the 20mm Plossl gives a TFOV of 1° (50/50)
I hope this helps, if its not clear let me know.
CS-John B
ausastronomer
07-12-2005, 01:50 PM
Dobman,
I will make a couple of very important assumptions in recommending the following eyepieces:
1. You do not need glasses on at the eyepiece to observe ?
2. Your normal observing conditions are under dark skies (ie Mag 6 or better)
3. You are under 50 years of age. (Pupil dilation reduces as you age)
If the above 3 assumptions are not correct then my recommendations would be a lot different and for very important reasons.
I would forget about the Andrews 30mm 80° eyepiece. It's not at its best in a scope as fast as F5 and is not nearly in keeping with the quality and EOF performance of the other eyepieces you are considering. A bit like buying a new Jag and then putting a $30 CD player in it.
For low power widefield viewing I would recommend the 35mm TV Panoptic, which will work very well as a finder eyepiece and also for low power views of extended objects. This gives 43X with a TFOV of 1.6° and a 7mm exit pupil, so you will need dark skies.
For medium power the 13mm Nagler T6 gives 115X with a TFOV of .7° (42') and a 2.6mm exit pupil.
For medium/medium high power the 9mm Nagler T6 gives 167X with a TFOV of .5° (30') and a 1.8mm exit pupil.
Basically I think you were pretty much on the money excepting the 30mm 80° Andrews Eyepiece which is not near the standard of a TV Nagler or Panoptic, mind you its not near them in price either. If you wanted a cheaper option the 30mm GSO Superview (also available from Andrews) performs a lot better in an F5 scope than the 80° Andrews eyepiece, but it only has an AFOV of 65° thus giving you a magnification of 50x with a TFOV of 1.3° and a 6mm exit pupil.
The barlow. With the eyepieces chosen I think you are wasting your money on the 2.5X TV powermate, which is an exceptional barlow BTW, as the powers with the 2 Naglers will be too high IMO on most occasions. The 13mm T6/2.5 PM combo gives 290X and the 9mm T6/2.5PM combo gives 417X. I doubt that the seeing would allow you to use these powers very often. I would forget about the barlow and put the money into 2 or 3 specialist planetary eyepieces like the 5mm, 6mm and 7mm UO HD orthoscopics at about $120 each, consequently 2 of them will cost less than the barlow. They will give the following mags 7mm=214x, 6mm=250X, 5mm = 300x. If I was to only buy 2 orthos in your case it would be the 6mm and the 7mm. Another option may be the 7.5mm and 5mm Takahashi LE's again an outstanding planetary/high power eyepiece.
CS-John B
PS: I personally prefer the 10mm Pentax XW over the 9mm and 11mm Nagler T6's, by a small margin but they are both exceptionally good. If you are heartset on a couple of Naglers they are an outstanding eyepiece so go for 'em.
davidpretorius
07-12-2005, 02:43 PM
gee you know your eyepieces. thanks!!!
would you recommend the same for a f5 10" dob?
i will have tracking hopefully this week
over the last 2 months i have used the series 500: 6.5mm with a 2.4x barlow and 12.5mm with a 2.4x barlow and see detail on mars on say 4 times, ie every two weeks on average.
i have been thinking a 7mm radian or pentax, and a 11mm radian or pentax, based upon the number of times i have successfully used my combinations of the series 500 6.5mm and 12.5mm and the barlow.
i do have dark skies, ie both clouds and milky way easily viewable from my driveway.
i feel a move to a 9mm a step in the wrong direction for me.
however i do like your thoughts on a dedicated planetary ep instead of a powermate..
Would you suggest a 35mm panoptic over a 27mm panoptic?
I am thinking:
UO orthos: 4mm & 5mm
Series 500: 6.5mm
Radian / Pentax: 7mm
Radian: 11mm
Series 500: 12.5mm
Series 500: 25mm
Panoptic 27mm
Andrews ultra wide 30mm
Panoptic 35mm
and a 2.4x barlow
janoskiss
07-12-2005, 03:16 PM
Word of warning on the HD orthos. I find the 7mm usable, but the eye relief is getting pretty short. If it was any shorter I would not be happy, and probably would not use the EP very much if at all. When you're talking of getting 6,5, and especially 4mm HD orthos, be sure to understand that you are effectively buying a contact lens stuck to the end of a 1.25" barrel.
ausastronomer
07-12-2005, 03:56 PM
Steve,
Your right, the eye relief is short and it gets shorter the shorter the focal length of the eyepiece. However you may find that as you become more experienced the short eye-relief is not such an issue, in some cases you learn to cope with it, some people never learn to cope with it. They don't make a 4mm HD ortho, they used to make a 4mm in the old volcano top style but chopped it due to its short eye-relief and subsequent user feedback. The eye-relief in an orthoscopic eyepiece is also fractionally better than an equivalent focal length plossl. ie The 5mm UO HD ortho has 4mm of eye-relief, a 5mm Plossl like the Celestron Ultima has about 3.7mm of eye-relief and the 5.5mm Meade Series 5000 Plossl also has about 4mm of eye-relief. Personally I have no problems using the 5mm UO HD orthoscopic but I was also raised on short eye-relief eyepieces.
CS-John B
janoskiss
07-12-2005, 04:11 PM
The 5.5mm is a special one in the Series 5000 Plossl line, with 6 elements for longer eye relief, 9mm I think. I tried one at Snake Valley, and found it very comfy.
Edit: Make that 7mm of ER: http://www.bintel.com.au/Meade5000PL.html
ausastronomer
07-12-2005, 04:35 PM
Thanks Steve,
I haven't used it and didn't realise it was a different design to the others and different to the Series 4000 short focal length plossls.
With 6 elements, a 60° AFOV and 7mm of eye-relief it's a long way from a true plossl. Most likely an 11mm 4 element plossl with a built in barlow, or something very similar, hence the preserved eye-relief, but then it's not a plossl is it :) Nothing new here from Big Blue.
CS-John B
bytor666
07-12-2005, 08:12 PM
John, I have tried both the 30mm 1rpd , (which is basically the same as the Andrews 30mm EP), and the 30mm GSO Superview.
The 30mm 1rpd outperformed the 30mm GSO Superview in a very big way in my 12" F/5 Gso reflector!!!!...the edge of my 30mm 1rpd wasn't bad at all as compared to the 30mm GSO Superview which was bad edge wise and did not appear to even have a field stop.
I hope I am correct in saying that the 30mm 1rpd is the same EP basically as the 30mm Andrews EP.
________________________________
Mark
12" F/5 reflector
2" Extension tube
30mm 1 rpd
21mm Vintage TeleVue plossl
14mm Meade series 4000 UWA
10mm Pentax XW
2" GSO Barlow
Sony Dig 4.1 Mp Cam
janoskiss
07-12-2005, 08:21 PM
That's what I've read (on these forums) about the cheapo ultra-wide too, Mark. I was actually thinking of getting one to replace my GSO 30mm SV, till I read John's post today. I think it was Mike who wrote that the edge of field was as bad (apparent degree-for-degree) in the ultra-wide as in the SV, but given the wider field of the ultra-wide, this amounts to a lot more usable field than the SV has. :shrug:
Gosh, I wish I looked through Davo's 1rpd at star camp... :(
ausastronomer
07-12-2005, 11:21 PM
Mark.
I have also tried the 30mm 1rpd in a 12"/f5 GSO dob.
I also own a 30mm GSO Superview and a 27mm TV Panoptic in addition to having used most things in this focal length vicinity, including all the 2" Panoptics and Naglers and most of the non 2" versions for that matter. If the 30mm 1rpd belonged to me and not someone else I would have thrown it in the bushes. It took me about 20 seconds to give it back to the bloke that owned it and stick my 27mm Panoptic in his scope in its place. The 30mm GSO Superview isn't as good as the Panoptic but its about 80% as good and about 800 times better than the 1 sample of the 1rpd that I have used. Maybe there is some variable quality with these eyepieces. I have used several different examples of the 30mm GSO Superview and I rate it fair, all have been consistent and it represents good value for money. However, a 27mm Panoptic its not, you just dont buy a $500 eyepiece for <$100. Its worth noting that the 1.25" versions of the GSO superviews are considerably inferior in quality to the 2" versions.
FWIW the 30mm GSO Superview doesn't have an internal field stop. But what does that affect? I look at targets within the field, not at the field stop !! That's only aesthetics.
CS-John B
janoskiss
07-12-2005, 11:39 PM
Thanks John! You've probably just saved me about $70-100 (No you can't have a cut! :P ). I'll go to Bintel and try out one of the 32mm Meade S.5000 Plossl.
Dobman
08-12-2005, 12:00 AM
John, thanks for the reply on Afov & Tfov, I think I've got the gist of it.
You were correct in your assumptions although i do a fair bit of observing from lite polluted Launceston but do get out to dark skies as often as possible.
Any thoughts on the meade UW's, specifically the 8.8. Im also reconsidering the 2.5 TV powermate and maybe going for a 2x barlow( shorty or TV) as this would give me a more usable spread of mags. I dont look at the planets much, thats why i was considering the barlow option so i keep the ER of the longer FL EP's(and the wider AFOV) and can double up for the occasional planetary peep. I,m also a bit concerned about what all this may cost, hence the andrews 30mm and the meade option
Going to melbourne on the weekend so I must decide b4 I get to the Bintel shop!
Oh the pressure!!:confuse2:
janoskiss
08-12-2005, 12:20 AM
Dobman, Just have a look at the Bintel website for the range of EPs they have; which is essentially cheapies, + the current Meade and Televue range. Try before you buy!
From the Bintel selection I'd personally go with 32mm Meade 5000 Plossl, 24, 19, 15mm Panoptic and I'd look elsewhere for shorter focal length EPs (or get a Powermate). But I have very limited experience and my Stratus EPs will do me nicely.
bytor666
08-12-2005, 07:32 AM
John, I also used to own a 27mm Panoptic which I have now sold for the 30mm 1rpd and a 21mm TV Vintage plossl. I have also tested several naglers and pans and I will say that the naglers are nice eyepieces and the pans as well.
You wanted to throw that 30mm 1rpd in the bushes?...well, that's EXACTLY what I wanted to do with the 30m GSO Superview the night that I tested it and compared it to the 30mm 1rpd. I know it is a personal thing when it comes to eyepieces, and when I get one with a blurry fieldstop,(the 30mm GSO Superview), I want to get rid of it right away , which is just what I did with the 30mm GSO the very next day after testing it.
My particular 30mm 1rpd has EXCELLENT on axis sharpness and the images are very pleasing 90% of the way out, maybe you had a lemon or something as these eyepieces are real "sleepers". I mainly use it for star-hopping to get to my destination and finding star asterisms is very easy having 1.6 degrees of sky in the 30mm 1rpd compared to only getting 1.2 degrees of sky with the 27mm Pan.
The edges are NOT that bad as it just shows a slight amount of COMA and not ASTIGMATISM. I can also use a 2" barlow on it to get 106x/43' field without any vignetting .
The 27mm Pan I had didn't barlow good at all, (it vignetted), because I didn't have a panoptic barlow interface , and I wasn't about to go out and buy one either.
I could also use an extension tube in the barlow and insert the 30mm 1rpd for a mag of 133x/36' field.
I guess it just boils down to asthetics when viewing thru an eyepiece, but I prefer to have one with a nice sharp fieldstop instead of a blurry one, and I will put up with the 10% of abberations and have that 1.6 degree field and a 5.8mm exit pupil.
~Clear skies to you John~
----------------------------
Mark
12" F/5 reflector
2" Extension tube
30mm 1 rpd
21mm Vintage TeleVue plossl
14mm Meade series 4000 UWA
10mm Pentax XW
2" GSO Barlow
Sony Dig 4.1 Mp Cam
ausastronomer
08-12-2005, 03:21 PM
Steve,
I haven't used the 2" 32mm Meade Plossl but just checked the specs on it. It has only 6.8mm of eye-relief and you may find this tight based on what you said regarding the HD orthos. I suggest you try it before you drop your coin.
CS-John B
janoskiss
08-12-2005, 03:43 PM
John, the specs I was reading specify over 19mm eye relief. :shrug:
Striker
08-12-2005, 03:54 PM
hahah
I read it has a 10.4mm Eye relief.
http://www.telescopetown.com/products/Meade_Super_Plossl_32mm_Eyepiece_-_2_Inch_31920.html
Must be adjustable eye relief....lol
janoskiss
08-12-2005, 04:13 PM
Gosh, they are all over the place! Why is it that Meade does not publish the full specs on their website? Their "specs" page consists of FL, AFOV and RRP, and that's it.
22mm is what I just read on a similar site, Tony, alongside the list of features with the ER=10.4mm you have linked. I think 22mm sounds about right, with the FL=26mm having ER=19mm, and FL=40mm having ER=30mm. (these numbers are from Bintel's page: http://www.bintel.com.au/Meade5000PL.html)
ausastronomer
08-12-2005, 04:52 PM
Dobman,
Your last post gave me a bit more to work with in terms of what may be important to you. I have changed the order of your comments around a little to break it into sections and to indicate what's important and whats not so important.
Well, buying from Bintel in Melbourne on the weekend is ultimately going to save you about $15 in postage. :o Rushing in and buying eyepieces that may or may not be right for you could cost you $1,500, false economy IMO. My advice is think long and hard about this, take your time, do all the research, then hopefully buy the right eyepieces 1st off and live happily for a long time after. ;)
If you have to think how much its all going to cost, you can't afford to think about Naglers and Pentax XW's, because if you get 1 you will then want a boxfull of them and that will ultimately cost you a lot more than you can afford to spend. Personally I don't like the idea of having a couple of premium eyepieces intermingled with cheap ones, because you end up not using the cheap ones despite the fact they are a different focal length. You find yourself trying to "avoid" them. I own a 30mm GSO Superview for the sole reason that its "a party eyepiece" that I use for school and public viewings and I don't cringe when it gets encapsulated in "chocolate coated fingers". I own the 27mm Panoptic which I use myself.
If some of your observing is from dark skies and some is from light polluted or less than pristine skies, I think you need to limit yourself to an eyepiece with a maximum exit pupil of between 6mm and 6.5mm, this rules out any eyepiece with a focal length longer than about 32mm in combination with your F5 scope. (Exit pupil = Eyepiece Focal length/Scope F-Ratio)
Given what I have said above things have changed considerably. Forget the 35mm Panoptic on the grounds of cost and exit pupil size. Also forget about the Naglers. The only Series 5000 Meade UWA that I have used is the 14mm, which Mike and I tested in comparison with the 13mm Nagler T6 and the 14mm Pentax XW and the S4000 Meade 14mm UWA. In short, it didn't compare and I thought it was pretty average by comparison, certainly better than the cheap chinese widefields but not a competitor to the big boys. However, I have since been informed that the S5000 14mm UWA is by far the worst of the entire series and the other focal lengths perform a lot better than the 14mm. I haven't used any of the others to comment here, but that having been said they are about $100 cheaper than a TV Radian and about $180 cheaper than a Nagler T6 or Pentax XW, so may be worth considering. There is some feedback on Cloudy Nights that maybe you should try and read, however be aware that with any of these forums like Cloudy Nights you need to sort "the wheat from the chaff". There will always be opinions expressed that you need to put less emphasis on than others.
Whilst I haven't used the Orion "Stratus" line of eyepieces I can tell you the following about them.
Orion USA previously had an eyepiece line called "Orion Lanthanum Wide" made by Vixen Optical in Japan. These eyepieces were almost identical to the "Vixen Lanthanum Wides" which are an outstanding eyepiece in almost every respect. They offer 20mm of eye-relief in all focal lengths and a 65° AFOV. They offer 95% of the performance of Naglers, Panoptics and Pentax XW's, they also sold for nearly $400 in Australia. Recently (in the last 6 months) Orion USA dropped the Orion Lanthanum Wides and replaced them with the Orion Stratus eyepieces which are basically a Chinese made clone of the Japanese made Vixen product they previously sold. I have corresponded with a couple of colleagues in the USA (whose opinion I respect) and the feedback I got was that these eyepieces perform at about 90% of the level of the Vixen made product at about 50% of the price and also that they do well in scopes as fast as F5.
Maybe you should consider shipping the Orion Stratus eyepieces in directly from the USA as they may fit your needs and budget nicely. Steve (janoskiss) just bought 4 which cost him about $700 including shipping.
http://www.telescope.com/jump.jsp?itemID=73598&itemType=PRODUCT&path=1%2C2%2C6%2C36&KickerID=686&KICKER
Orion USA won't ship to Australia but if you are interested in these, I can give you a couple of reputable USA or Canadian dealers that I trust.
Maybe a possible option would be either the 28mm or 34mm 2" Meade S5000 UWA from Bintel (which 1 would depend on how often you view from light polluted skies) complimented with the 21mm, 13mm and 8mm Orion Stratus eyepieces and the 2X Orion Shorty Plus Barlow. You could juggle things around a little with the 3 Orion Stratus eyepieces, you may even decide on 4 of these or 2.
I hope I have steered you in the right direction, if you have any further questions let us know :)
CS-John B
ausastronomer
08-12-2005, 05:06 PM
Steve,
6.8mm of eye-relief didnt sound right to me but here's where I got it from
https://www.bintelshop.com.au/Product.aspx?ID=6979
You would expect a 32mm plossl to preserve about 70% to 75% of its Focal Length as Eye-relief ie. about 20mm to 22mm. However these are far from a standard plossl, with a 60 deg AFOV. Some eyepiece designs, notably modified Konigs and Erfles (and a few others), have short eye-relief combined with a medium wide field, so I wasn't sure.
CS-John B
janoskiss
08-12-2005, 05:24 PM
One thing to add re the Stratus EPs. You will really need a 2" Barlow with them (or you could forget the Barlow and get the 5mm instead). They are very heavy and the 2" barrel right above the 1.25" makes it very awkward to tighten the screw on a 1.25" Barlow. It's doable but far from ideal, and my R&P focuser + 1.25" adapter would be really straining under all that weight and torque.
janoskiss
08-12-2005, 05:29 PM
Silly Bintel sods! That's the description and specs for the 9mm eyepiece. A 2" 32mm EP weighing 69 grams? :P
ausastronomer
08-12-2005, 05:40 PM
David,
Before I answer you more fully can you tell me what the 2.4X barlow you have is ?
The only "good" quality 2.4X barlow that I am aware of is the 1.25" 2.4X Dakin barlow made by Vernonscope in the USA. Vernonscope are also the manufacturers of the Brandon eyepieces which are supplied standard with the "famed" Questar telescopes.
Any Optical "System" is only as good as its weakest link. If the barlow is poor the whole system will be poor
$5 telescope + $5 eyepiece + $5 barlow = $5 optical system
$5,000 telescope + $500 eyepiece + $300 barlow = as good as it gets $5,800 system
$5,000 telescope + $500 eyepiece +$5 barlow = $5 optical system
Hence you would be wasting your time using premium eyepieces with a 2nd rate barlow. If your barlow is a Dakin it will be fine, if its not there may be some issues using it with high quality eyepieces.
CS-John B
ausastronomer
08-12-2005, 05:46 PM
Steve,
Good call, I didnt even look at the weight of the thing :nerd:
CS-John B
davidpretorius
08-12-2005, 06:17 PM
I am thinking:
UO orthos: 4mm & 5mm
Series 500: 6.5mm
Radian / Pentax: 7mm
Radian: 11mm
Series 500: 12.5mm
Series 500: 25mm
Panoptic 27mm
Andrews ultra wide 30mm
Panoptic 35mm
and a 2.4x barlow
the bolded ones are the ones i am thinking of purchasing. The non bolded ones are what i have already. I would not be using them with this barlow. It is a cheap one.
I was going to go 2.5x powermate with the 7 and 11, but have ditched that and thinking 4 and 5 planetary eps. either uo's or vixens etc.
ie please disregard 2.4x barlow in calculations. It is iceman's old one! It is nice with the series 500, but i do not intend it to be giving me the range.
thanks john for your help
Starkler
08-12-2005, 06:33 PM
Dave how often do you reckon you could get to use a 4mm ?
I would go a 5 and a 6 (we have the same scopes), with the 6 getting 80% of the use on planets.
davidpretorius
08-12-2005, 06:50 PM
geoff,
weather ie clouds aside, i believe i am blessed with better than average seeing conditions here in tasmania. 6 stars in the trap over the last two month is the norm. (ie more than 50%)
i have been using the 12.5mm and 2.4x barlow (=5mm) alot on mars and saturn with pleasing results.
i have a 5mm lv to try of asimovs.
plus i am reluctant to discard the 6.5mm series 500 immediately. it is still an ok eyepiece.
yes eventually, a 4,5,6 in good planetary eps, 7, 11 (or 9,12) in a radian or pentax and then a great low power is my thinking.
on about 25% of the occassions, i have used the 6.5mm and the 2.4 barlow (less than 3mm) with satisfactory results.
This is my thinking and testing the 5mm vixen will soon help my final decision.
seeing is king, so if i am lucky with it here, i would like to make the most of it
Sorry to back track a bit but I haven't learnt how to use the "subscribe to thread" thing yet so I miss some replies...
John, I am very aware of the difference between AFOV and TFOV (which I just call FOV) and spend much of the night during the calculations in my head...
But what I was trying to say is that if I get (for example) a Nagler and a Panoptic with the same FL side by side (in my scope...one after the other), if I can see the field stop in the Nagler it gets me a bit :mad2: :mad2: :mad2: because I feel ripped off.
If I struggle to see the field stop in a panoptic and can see it in a Nagler then I don't know how the Nagler could ever win my heart :( because the panoptic has other very slight benifits. Also I have found that some Naglers I can see the field stop and others I can't.
I think that Geoff solved the problem. Some of the longer focal length Naglers I am getting to close to (the lens). The field stop becomes much easier to see at that point and the image is not as good. I have to learn to step back a bit and then I might appreciate the disappearing field stop...
janoskiss
08-12-2005, 11:36 PM
Stu, I think you have kind of answered your own question. When you cannot see the field stop in an eyepiece, it does not have enough eye relief.
You should be able to see the field stop in a good eyepiece, unless it is approaching close to 180 degree apparent field of view (not likely to happen within our lifetime). If you cannot see the field stop, i.e., the full field, you are missing out on some of the view, which defeats the purpose of having an eyepiece capable of presenting the full field. Am I making any sense? :confuse3:
davidpretorius
08-12-2005, 11:51 PM
ok, just been comparing asi's vixen lv 5mm and it has a lovely field stop. I now know what one looks like. The 6.5mm series 500 is very unclear in its field stop.
great eye relief. colour abberations were similiar on mars as the series 500 around the edges. little fireflies occassionally ie reflections were a little distracting.
nice eyepiece. is it worth the $250, not sure????
by the way, mirror cooled to ambient, seeing at around 7/10. 6 stars in the trap. average detail on mars
janoskiss
09-12-2005, 12:00 AM
Does not sound like it, esp. if it's a narrow AFOV EP.
ausastronomer
09-12-2005, 12:29 AM
David,
IMO No its not. (Sorry john) These eyepieces are clearly inferior to their big brothers the Vixen LVW. They are a very good eyepiece, don't get me wrong here, but I think their are clearly better eyepieces available for less money.
I will send you a detailed reply to your earlier posts tomorrow. I will send it from work if I get a chance. My apologies as I did say I would do it today, but I was flat tack at work all day and its now quite late and I have to work early in the AM.
CS-John B
davidpretorius
09-12-2005, 12:35 AM
there is no need for you to apologise.
I am having fun learning. I was able to hold the vixen up to my eye and swirl it around like a wine buff noting the colour of the wine.
had no idea what i was doing, but i sure looked like i did.
I like the series 500, but it is nice to start comparing field stop etc, contrast
asimov
09-12-2005, 12:50 PM
Where did you pull that price from Dave?? An LV 5mm is down to $170-$180 I thought..
No need to apologise to me either John-B :) ....I just happen to be one of many around the world that own one of the LV line. At the time that I bought that EP I was truly uninformed & I was willing to buy anything rather than continue to use .965" EPs for visual use :lol: If I wasn't on a continuous budget I would have ended up with the most expensive EP rather than an vixen LV ;)
Dave, try that EP on the trap & saturn etc before coming to a conclusion. I think that EP was the only one I have that could split antares. To solve the internal reflections on mars I used a contrast booster with it....But then I was getting some reflections from the filter itself! (Can't win!!) :nerd:
davidpretorius
09-12-2005, 02:32 PM
Asi, Latest AOS ad in the AS&T. it says from $250 and the LW's fro $385 i think.
No conclusions yet, just passing thoughts as i go along.
It is the best eyepice i have looked thru for any length of time. There was a few at star camp, but not a solid hour of observing like last night.
As i was explaining to my brother, it may well be a case of "Gee this grange hermitage tastes not better than cask wine!"
I have to ask myself with such little experience, do i really know what i am looking for in trying to compare ep's
This vixen was lovely with the field stop, very distinct at the edge and so the planet had a better contrast because of the fixed area of viewing. There was no fading off to the edge that the 6.5mm series 500 suffers from.
On axis and off axis, i have trouble comparing sharpness or contrast between the two. The trap looked better with this one.
I have a lot more experimenting to do. And i tell you what, i didn't touch the toucam at all last night, i was having far too much fun observing!!!
No one should get me wrong about the LV, am i having fun using, you bet, would i buy one, not sure yet!
ausastronomer
09-12-2005, 03:46 PM
Hi David,
Finally !!!!!!!!! I got some time to answer this :)
I own the same scope as you and have used lots of different eyepieces in it so I can at least give you my thoughts on it. If I had to rate any one eyepiece as truly outstanding in my scope and my absolute favourite it would be the 10mm Pentax XW. If I was only ever allowed to use 1 eyepiece I could live happily with the 10mm Pentax. Remember however, that eyepieces are a very subjective thing and what suits one persons' observing style and preferences may not suit everyone. For instance I am not overly impressed by the enormous FOV phobia, that rows a lot of peoples' boats. I would prefer to accept a smaller FOV and have a smaller exit pupil which gives better contrast with my ageing eyes. There are only a few selected objects that you need a large FOV to observe, maybe 5 in the entire sky, over 1.5 degrees that aren't better suited in Binoculars. I prefer to have improved contrast on the 000's of other targets, than be able to fit those extra 5 targets in.
No I wouldn't quite recommend the same thing for the 10"/F5 scope as I did for the 12"/F5, due to its slightly shorter focal length but certainly pretty close and those options would work fine if you chose them.
In my case definately not !!!! My maximum pupil dilation is about 6.0mm under dark skies consequently the 7mm exit pupil of the 35mm Pan causes a slightly washed out background and a loss of contrast. In the 10"/F5 scope the 27mm Panoptic gives 46X, a TFOV of 1.5° with a 5.4mm exit pupil which suits me perfectly, it provides excellent contrast and is very sharp to the EOF. I actually think the 27mm Panoptic is a fraction sharper than the 35mm Panoptic but they are both excellent. I recommended the 35mm Pan for the 12" scope due to its longer focal length. In the 12" scope the 27mm Panoptic gives 56X and a TFOV of 1.2°, consequently if the skies are dark I think the 35mm Panoptic is a better choice in that scope. If the skies are light polluted at all I would also recommend the 27mm Panoptic in the 12" scope as well.
If you have really dark skies (> Mag 6) have a pupil dilation over 7mm or very close to it and appreciate the larger FOV the 35mm Panoptic may be a better choice for you, but otherwise I would run with the 27mm Panoptic.
Of all my eyepieces the 3 that get used the most (and by a good margin) are the 27mm TV Panoptic and the 10mm and 7mm Pentax XW's. My 10mm Pentax XW is easily my most used eyepiece as it creates the desired 2mm exit pupil which is ideal for most DSO observation. The 7mm Pentax XW also does exceptionally well for higher power viewing of DSO's and for medium power viewing of moon/planets and double stars. The 10mm gives 125X and the 7mm gives 180X.
Other options would be to go with 2 of 3 from say the 12mm, 10mm and 8mm TV Radians, or 2 of 4 from the 13mm,11mm,9mm and 7mm T6 Naglers. Having used them all, I rate the 10mm and 7mm Pentax XW's as marginally superior to the TV offerings as they are sharper on axis and have higher light transmission, I also find them the most comfortable to use with their 20mm of eye-relief and screw up/down eyecup. However, they are all outstanding eyepieces and you wouldn't go wrong with any of them. The Vixen LVW's are another excellent premium eyepiece option.
You need to think about what focal lengths may suit you the best and buy the eyepiece type that come in the right focal lengths to suit your needs, they are all very good but be aware of the eye-relief issues.
Some people would think there is too large a gap from the 27mm Panoptic to the 10mm Pentax XW. I also own the 20mm and 14mm Pentax XW's and rarely use them, invariably I go straight from the 27mm Panoptic to the 10mm Pentax XW. I think you need more eyepieces at the high power end than you do at the low/medium power end, others may not agree.
If you went with the eyepieces I have suggested thus far:
27mm TV Panoptic
10mm Pentax XW
7mm Pentax XW
I would add the 5mm and 6mm UO HD orthos as specialist planetary eyepieces and I think you would then have most options covered.
I agree with Geoff's comments concerning the 4mm volcano top ortho. I just don't think you would get to use it often enough and eye-relief is very tight, a lot tighter than the 5mm UO HD ortho in relative terms.
When you look through a Pentax XW or a UO HD ortho you will "see the light". About 20% more in fact than your seeing through that series 500 plossl ;)
The Vixen LV are a very good eyepiece and images are sharp. However I find the images a little dimmer and light transmission to be inferior to a high grade orthoscopic or plossl
CS-John B
asimov
09-12-2005, 03:55 PM
G'day John. http://myastroshop.com.au/ They did have the LV 5mm on site but it seems to have been taken off just recently.
After knowing what I know now, I'd have to say the pentax XW gets my vote (theres too many good reviews on it to ignore) although I've never used one! (hope to one day)
asimov
09-12-2005, 03:59 PM
BTW I paid $300 for that LV 5mm 2.5 years ago....:sad: but that's the way the cookie crumbles! :) Not sure why but mars brings out the worst in that particular eyepiece. :confuse3:
davidpretorius
09-12-2005, 04:09 PM
Mike, i have just voted for the first time on a thread. Can i also vote on the contributor???
John, i can't thank you enough for your efforts. This is an excellent summary on eyepieces that i have simply copied onto my computer to work through next to Bird's notes on processing! I wil have to digest it and go and do more research and of course trials, but I fell very confident that i am on the right track!
I will shut up now before i make an idiot out of myself!
thanks again!
ausastronomer
09-12-2005, 04:51 PM
David,
I just followed the link that John posted to Steve Massey's website. The 6mm is $165 !!! Where did you get $250 from ?
At $165-00 you gotta think long and hard about them !!! They are marginally inferior in terms of light transmission to a high grade orthoscopic or plossl but the upside is the extra eye-relief and that is very important to some people. They have 20mm of eye-relief in each focal length and are very comfortable to use.
$165-00 is a good price and if you like them go for them. At $250-00 each they weren't such a good buy ;)
CS-John B
davidpretorius
09-12-2005, 04:59 PM
this months as&t ad for AOS i think.
it says "from $250" for lv and "from $385" for lw
i will check again.
when i was comparing last night, i had $100 to $200 in my mind from a quality point of view. I have looked (drooled) over the different suppliers of ep's in AS&T and the vixen have caught my eye every time along with TV's etc.
When I saw "from $250" i fell over and thought, "no way, not that good"
I will check DEC AS&T again tonight.
It is very pleasing to look through. Beautifully made and the view is nice. Mars still had chromatic abberations on the edges as it trundled across the fov. I really want to try the UO HD against this vixen. Saturn and jupiter need to be looked at as well!
asimov
09-12-2005, 05:06 PM
TV plossl is a good option as well. Chromatic abberations!? Don't remember seeing that in that EP.
janoskiss
09-12-2005, 06:11 PM
It's there though. Try looking at the Moon with one of them. It has a yellow outline in my 15mm TV plossl (both in the Dob and the ED80). No false colour in the centre of the FOV. The closest to CA-free EPs I tried are the HD orthos.
Dobman
29-12-2005, 11:30 AM
After much hair pulling & head scratching:confuse2: I finally took the plunge & bought my first decent Ep. Thanks to everyone for your advice, but as lots of you have said ,nothing beats trying out an EP b4 you buy. A friend of mine in Melbourne has a meade s5000 8.8 UW & i got to have a look thru it recently & was very impressed with it. So much so , I bought one!:)
Only used it a couple of times so far but very happy with it. Most of the reviews I've read, put it 3rd behind the nagler & pentax's but a whole lot cheaper.
My 1st impressions are
1. build quality is very good. This EP really looks like a premium EP!
2. I love the twist up eyeguard. I dont wear specs, so I just twist the guard up and basically snuggle my eye right into the guard ( a bit like using an eye bath!). The grease on the barrell isnt a problem once you know its there-just remember to twist it down b4 you remove it from the focuser
3. Absolutely love the wide field. I can place an object right on the edge & let it drift into and out of view. To my untrained eye ,I cant really detect much difference in sharpness across the field.At this stage i cant see myself ever going for any narrower FOV eps. Why would you?. havent noticed any kidney bean effect yet.
Must go, If i have any more thoughts I'll post them
davidpretorius
29-12-2005, 02:45 PM
well done simon, bring it along sunday and we can compare with the 5mm vixen
33South
29-12-2005, 10:01 PM
You wont regret it, I bought one earlier on in the year and its my favourite:love: (http://misc.php?do=getsmilies&wysiwyg=1&forumid=20#) by a long way.
With the LX90 the Moon and Orion Nebula stopped me in my tracks, it was like Id never seen them before.
I use it more than all the others put together. But then it did cost twice as much.
Im hoping :prey:someone at Lostock will let me have look-see thru the equivalent Nagler to see if its worth the extra money - I doubt it.
But I have been wrong before.....
ausastronomer
30-12-2005, 11:02 AM
Well !!!! If you ask me really really nicely :lol: I will let you look through my 10mm Pentax XW which is better than the equivalent Nagler, IMO ;)
CS-John B
33South
30-12-2005, 12:15 PM
:prey: < me asking nicely
Thanks, would be greatly appreciated
Chris.
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