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erick
02-08-2007, 02:19 PM
It was time to upgrade the low magnification end of my eyepiece range. I have the standard 26mm and 40mm Bintel Kellners. I've been having fun with them, but now the low performance characteristics have been pointed out to me, I figured let's take the next step. Time to go for some "width" in my viewing. But the piggy bank is decidedly in drought, so I'm in the budget section of the shop.

So here I am looking at these 30mm 2" ultrawides (spec'd at 80 deg AFOV) that seem to have come on the market over the last year or so. Several people on this forum and elsewhere reckon they are pretty good value (as low as $99 retail in Australia) - some seem to love it! I must report, however, that some reckon they are rubbish, but they seemed to be using them in scopes faster than f6. I'll be using them in my f6 8" dob.

My research suggested all these 30mm Ultrawides are coming out of the same Chinese factory - they sure look the same and have the same specs.

So, it's off yesterday to the friendly guys at Bintel, Melbourne, to have a look at their version - referred to on their site as the "Bintel SG Wide Angle 30mm (2")". After Roger quizzing me about my focal ratio, and expressing relief at the "f6", I walked out with one - parting with only $109. Not too chunky or heavy - but there is a huge expanse of glass in it. Glad I have an observing chair with wheels - I think I'll need it to get my eye around every corner of the view! :lol: Now it does look cheap from outside, but seems to have everything needed. Holding it up to the light, there is distinct orange/yellow colour around the very edge of the view. It's threaded for filters etc. I've already unscrewed my GSO barlow lens and checked that will screw in place, given a recommendation on this forum that doing this transforms it to a 20mm pretty sharp to the edge of field. The rubber cup also unscrews to reveal a thread which, apparently, takes standard T-mount stuff to connect a camera for eyepiece projection (if I've got that right). Also came in a nice enough bolt case. One silly thing - came with two identical caps - one fits neatly on the field end, the other doesn't fit on the eye end, just drops onto the lens :rolleyes:. Roger found a binocular cap that fitted well over the rubber cup - thanks Roger. OK, it's out of the bolt case now and has found a home in my eyepiece case, ready for first light. (and I'm overdue for a report on what I think of my new second-hand 6mm and 10mm Vixen LVs :doh: )

Of course, I look out the window and it's wall-to-wall cloud! Sometime next week? Perhaps not until my next Snake Valley visit. :sadeyes:

Eric :)

casstony
02-08-2007, 03:03 PM
I'm curious to see what you think of your new purchase Eric - boat anchor or challenger for the Naglers?

I haven't had enough experience with mine to decide where it sits yet. It's definitely a great finder eyepiece. At f/5 the outer field is horrific. It's somewhat improved in a paracorr but I need another chance to check this out to quantify the improvement.

erick
02-08-2007, 03:15 PM
Tony, we'll see. Of course, if I had the readies for a 2" 31mm Type 5 TV Nagler, I wouldn't be fiddling around with $100 eyepieces. Of course, I also wouldn't be using an 8" budget scope ;) . My hope is that I don't groan when I look through it the first time. Anything better than that will be a bonus! :)

janoskiss
02-08-2007, 06:08 PM
From memory, without a barlow at f/6 you can expect to see a warp drive through wormhole kind of effect. The inner <~60 degrees are usable. In a 2x barlow it does quite well even at f/5.

erick
02-08-2007, 07:16 PM
Thanks Steve, I'll remember to hang onto my observing chair when I first look! It actually looked promising as I left work - lots of blue sky. By the time I got home, I was in a downpour! :sadeyes:

astropolak
05-08-2007, 05:16 PM
Erick
One of the IIS members is selling a KK widescan III 30mm, I think those will be far superior than its Chinese clones... I got the 20mm - not bad and in good condition too....

RGDS

erick
05-08-2007, 06:39 PM
Thanks astropolak, but I cannot spot the post selling this eyepiece -can you direct me further, please. Eric

ausastronomer
05-08-2007, 07:34 PM
Joe,

Those KK Widescans and their Chinese clones are pretty poor performers at anything faster than about F8 IMO. In a slow scope (F10 or slower), it is worth paying the extra money for the genuine Japanese made Widescan. In a fast scope it isn't worth the extra money of the Japanese made product. High quality Japanese made seagulls look identical to low quality Chinese made seagulls. If that is the eyepiece Eric can afford then that is fine, as Steve points out it will give good views over about 60% of the FOV, which is all you can expect for $100 in an F6 scope. The $300+ genuine Japanese made Widescan III will really not do much better at F6. In fact the University Optics 30mm MK80 is a better eyepiece than the 30mm Widescan, for a little less money. Similarly however, it isn't much good at anything faster than F7 or F8. In a slow scope it is an outstanding eyepiece.

The next mid priced upgrade for an F6 scope would be a 30mm Orion Stratus or the new 30mm Paragon, when it arrives. Unfortunately they both cost a lot more than $100.

Clear Skies
John B

astropolak
06-08-2007, 08:35 AM
John and Eric
John once more you are spot on, the eyepiece suffers from astigmatism in the outer 20%. I bought it as calibration eyepiece and then found how good it is - if you forget about the seagulls it has very nice construction, very good coatings and no light scatter - I find all KK made eyepieces very nice indeed.
Eric if you just want to spend $100-150 it will be a better solution. Those eyepieces were $300-400 new...

Joe

erick
06-08-2007, 12:44 PM
Thanks John and Joe. There is one thing to be sure of in this hobby - there is always an upgrade path in front of you, always!! :D

I haven't had a chance to look through the eyepiece yet - 1) have been away a few days, and 2) need I say it - clouds/rain/sleet/snow etc!

erick
07-08-2007, 01:56 PM
Well, it wasn't raining last night - finally. There were even some breaks in the clouds (!!) so I set up. Got a few breaks in clouds in the mid evening but not really enough for some calm observing and comparing. Clear sky at 5am this morning - so I could finally have a look at M42 with and without the borrowed DGM Optics NPB filter. (plenty moonlight in the sky, but the view with the filter convinced me that I won't be sorry for ordering one.)

Back to the 30mm Ultrawide. I tried it in a bit of a rush. I'm comparing to the GSO 26mm and 40mm Kellners. I also tried the trick of screwing in the GSO 2" barlow lens.

I guess I have to say of first impressions - no "Groan", but "Hmmmm....." I'll get back to you after I get a more relaxed early evening's viewing in good conditions - hopefully this coming weekend.