Best 3 EP's for a 300mm F5 dob

[davidpretorius]

Originally Posted by ausastronomer

35mm TV Panoptic
13mm Nagler T6
9mm Nagler T6 / 10mm Pentax XW
5mm, 6mm and 7mm UO HD orthoscopics

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 (Steve H)]

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 (John Bambury)]

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 (Steve H)]

Originally Posted by ausastronomer

the 5.5mm Meade Series 5000 Plossl also has about 4mm of eye-relief

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 (John Bambury)]

Originally Posted by janoskiss

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

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]

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 (Steve H)]

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.

Gosh, I wish I looked through Davo's 1rpd at star camp...

[ausastronomer (John Bambury)]

Originally Posted by bytor666

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

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 (Steve H)]

Thanks John! You've probably just saved me about $70-100 (No you can't have a cut! ). I'll go to Bintel and try out one of the 32mm Meade S.5000 Plossl.

[Dobman (Simon)]

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!!

[janoskiss (Steve H)]

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]

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 (John Bambury)]

Originally Posted by janoskiss

Thanks John! You've probably just saved me about $70-100 (No you can't have a cut! ). I'll go to Bintel and try out one of the 32mm Meade S.5000 Plossl.

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 (Steve H)]

John, the specs I was reading specify over 19mm eye relief.

[Striker (Tony)]

hahah

I read it has a 10.4mm Eye relief.

http://www.telescopetown.com/product...nch_31920.html

Must be adjustable eye relief....lol

[janoskiss (Steve H)]

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 (John Bambury)]

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.

Originally Posted by Dobman

Going to melbourne on the weekend so I must decide b4 I get to the Bintel shop

Well, buying from Bintel in Melbourne on the weekend is ultimately going to save you about $15 in postage. 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.

Originally Posted by Dobman

I'm also a bit concerned about what all this may cost, hence the andrews 30mm and the meade option.

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.

Originally Posted by Dobman

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.

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)

Originally Posted by Dobman

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.

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?it...rID=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 (John Bambury)]

Originally Posted by janoskiss

John, the specs I was reading specify over 19mm eye relief.

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 (Steve H)]

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 (Steve H)]

Originally Posted by ausastronomer

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

Silly Bintel sods! That's the description and specs for the 9mm eyepiece. A 2" 32mm EP weighing 69 grams?