First Light - 35mm Panoptic

[Stu]

Well it's been a long time comming but the first look through an eyepiece has finally and absolutely blown my mind!

It's happened once before but it was a telescope that did it (5" Fluorite Tak).

It all started this morning when I got a phone call from a well known Panoptic advocate on the mornington peninsla (Ha! You know who you are...), congratulating me on my 35mm Panoptic purchase. He told that it was the best wide field EP in the world, better than a XXXXX and a XXXXX. And added that I should never sell it. I thought, umm... I had actually better look through this eyepiece because now I feel like I am missing out on something.

Well, it's still not dark yet, but the moon is up, the sky is a deep blue and the are plenty of green trees all around in the distance. So I set up my LXD75 mount and put the ZS80 in it's pride of place on top. I first focused on the moon in the 22mm Panoptic; nice but the sky was still a bit bright for it. I targeted my favorite tree in the distance. I am still amazed by this setup for daytime viewing, the ZS80 has no CA at this magification and the scope and EP combination are as sharp as I've seen in daylight.

I was a bit worried about how the 35mm Panoptic would go during the day. In my scope the exit pupil would be 5.8mm, which is great at night but during the day my pupil size is a lot smaller than that.

Anyway, in true Aussie spirit "She'll be right mate" I chucked (read: placed gently) the 35mm it in the 2" diagonal...

FAR OUT!!!!!! The 5 degree field of view was stunning. So bright and sharp! The real suprise was I had great difficulty finding the field stop without shifting my head around quite large distances. I'm sure it was partly due to my small pupil size but suprising none the less. The leaves of trees stayed perfectly in shape as they disappeared behind the field stop. Now that I think about it, I couldn't see any field curvature, but I didn't look for it either. Man it was good. Way good.

I don't own any other big name wide field eyepieces to compare it to, so I don't really know if it is THE best. But I honestly couldn't give a ..... I am sooo glad I decided to buy it now.

[davidpretorius]

keep us updated tonight mate, i would love to know your thoughts and feelings!

[h0ughy (David)]

the little white truck with the padded walls will be over pick up a dribbling wreck of a man in the morning after he has has an all nighter looking at the sky with that eyepiece. Whilest not green with envy, I do appreciate a nice 2" eyepiece!

[davidpretorius]

Originally Posted by h0ughy

I do appreciate a nice 2" eyepiece!

a wee understatement!

[Robby]

Mate, that's bigger (& probably heavier) than your OTA

[h0ughy (David)]

I thought it was a converted OTA Robby, but mighty nice, with that little dielectric thingamagig and that plastic tasco replica scope! nice optical train - woooo hoot, eye meladdy she'e a wee eyepiece alrighty, eh davo buddy boy!!!


so what is the eye relief?

[Stu]

WOW! This puter screen is so bright! Where's my sunnies, oh yeh I don't have any I live in Melbourne...

Righty-o, I've had my first hour with my new 35mm toy in dark (dark blue) moon lit skies. The eyerelief is stated as 24mm, I think it's more like 20mm but it's still a bit too long for me, I like to mash my face against the eyecup to keep my head steady. Having said that, the 35mm seems to be a bit more forgiving of my head placement than the 22mm. But because I can rest my head on the 22mm panoptic's eyecup my head doesn't drift around much anyway, so it's all swings and roundabouts (horses for courses).

The star image looks exactly the same right up against the field stop as it does in the center of the FOV. I spent a while comparing the 22mm and 35mm to see if there was any difference in sharpness, but couldn't detect any. Each time a I thought one was sharper I switched over and the other one was just as sharp. The 35mm seems a lot brighter though.

There was a big difference when looking at the Pleiades. In the 22mm pano I could fit about 2 Pleiades widths across the FOV (about 3 degrees). They were framed quite nicely. In the 35mm I could fit about 4 Pleiades widths (5 degrees) and they looked spectacular! There is not much else around them but that extra space made them look so much more important. I could clearly see that they were a real star cluster, not just a bunch of stars scattered around the FOV. They really did look different. Much more enjoyable to look at.

The good news is I no longer have to worry about what widefield EP I should buy next. I'm quite happy as I think I have two good ones, that like short F ratio scopes. Now all I have to stress about is the 15 to 6mm range.

[Dave47tuc (David)]

Good stuff Stu

The winter milky Way will be a fine sight indeed with the 35 and 80mm

[davidpretorius]

thanks for sharing your thoughts stu, i will go the 27mm panoptic and we can share!

yup, starting in the south and then winding you way past lagoon and his freinds will be a real treat in winter.

[iceman (Mike)]

I was thinking of what widefield eyepiece I might get one day, and the 35mm Pan was an option, but I remember Geoff saying that it'd be no good at f/5 due to the exit pupil being too large?

Has anyone used one in a 10" dob?

The 27mm Pan might be the next best option if the 35mm is no good.

[davidpretorius]

in another thread from John B:

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
gee you know your eyepieces. thanks!!!

Would you recommend the same for a f5 10" dob?
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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.

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
Would you suggest a 35mm panoptic over a 27mm panoptic?
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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.

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
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.
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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.

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
I do like your thoughts on a dedicated planetary ep instead of a powermate.
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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.

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
Plus i am reluctant to discard the 6.5mm series 500 immediately. it is still an ok eyepiece.
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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

<TABLE style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset" cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2>Quote: Originally Posted by davidpretorius
This is my thinking and testing the 5mm vixen will soon help my final decision.
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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
<!-- / message --><!-- sig -->__________________
Heavily modified 10"/f5 dob with AN DSC's.
A box full of eyepieces from UO orthos to Pentax XW's.
Oh !!! and for those that think I am against Televue ???
a 27mm Panoptic and a 2.5X Powermate
a 2X Orion Shorty Plus and a 2" 1.6X Antares APO barlow.
Astronomiks UHC, OIII and a heap of other less useful filters
8 x 40 and 16x60 Pentax PCF WP binoculars.

[iceman (Mike)]

Thanks DP

[ving (David)]

you really get a sense of scale seeing that EP in that scope. what i wouldnt give to have a gander.

[Starkler (Geoff)]

Originally Posted by iceman

I was thinking of what widefield eyepiece I might get one day, and the 35mm Pan was an option, but I remember Geoff saying that it'd be no good at f/5 due to the exit pupil being too large?

Has anyone used one in a 10" dob?

The 27mm Pan might be the next best option if the 35mm is no good.

Mike the 27 panoptic is a winner in a 10" f5 dob. I used to own one until I got the 31nag and 24 pan to replace it. I miss the 27 !

The exit pupil on the 35mm will be 7mm, which will result in a milky white sky background in anything than very dark skies. The 5.4mm exit pupil gives a darker sky background which is a lot more pleasant.

[ving (David)]

geoff, with a exit pupil of 7 would the central obstruction come into play (if even if viewed during the day)?

[ausastronomer (John Bambury)]

Originally Posted by ving

geoff, with a exit pupil of 7 would the central obstruction come into play (if even if viewed during the day)?

Hi David,

That depends on several things.

In the daytime the answer would be "yes" in most cases because the observer has a dilated pupil significantly smaller than the 7mm exit pupil. In the evening in most cases the answer would be "no" because the observers pupil will dilate to a much larger size due to the low light levels. However, if you observed an extremely bright target like the full moon you would invariably see the secondary holder because your dilated pupil would shrink due to the exceptionally bright target. That shouldn't be such an issue as most people wouldn't use this scope/eyepiece combination to observe the full moon.

For viewing of dim targets you woudn't see the secondary holder but if your pupil dillation is not close to 7mm and the skies dark, the background sky when looking through the eyepiece takes on a somewhat "milky" appearance and images appear washed out and the selected targets, particularly extended diffuse targets like galaxies and nebula, lack contrast. FWIW this doesnt worry some people and they prefer to use such a combination to gain the additional TFOV. However its not something I like at all and prefer a smaller TFOV with better contrast and an ink black background sky.

CS-John B

[ving (David)]

thanks john, it much as i figured. I have noticed the said effect on the moon before with my 30mm GSO SV and my digicam. I am guessing that the size of the chip is much smaller than the exit pupil of the EP

[Dave47tuc (David)]

Originally Posted by iceman

I was thinking of what widefield eyepiece I might get one day, and the 35mm Pan was an option, but I remember Geoff saying that it'd be no good at f/5 due to the exit pupil being too large?

Has anyone used one in a 10" dob?

The 27mm Pan might be the next best option if the 35mm is no good.

My thoughts are a 35 mm Pano would be ok in a 10"Dob. If you change scopes in the future say to a SCT or Refractor then the 35 is perfect.
John has explained it well above.

But a 27mm Pano or 26 Nagler would be slightly better in the Dob.

Any high end Ep's is good. We seem to juggle high end Ep's a lot !

To me it's a matter of personal choice and finances. A second hand 27 Pano is much better on the sky rocket.

[ausastronomer (John Bambury)]

Mike,

Its not that the 35mm Pan doesn't work in the dob, it does and lots of people use exactly that combination. Being an old fart with small pupil dilation I prefer the 27mm Pan because of its better contrast, that doesn't mean its the best choice for everyone. For your younger eyes the 35mm Pan may be perfect. You need to consider your sky conditions that you will usually use the eyepiece under. In addition, Dave correctly points out, if you were to subsequently buy a slower scope the 35mm Pan would be a better choice in that slower scope.

I own a 27mm Pan and Gary Kopff owns a 35mm Pan. I plan to do a fair bit of observing over the Xmas/New Year break at Kulnurra so I will drag Gary K along to one or more of those and you can compare them both in your scope. Failing Gary coming along I will ask him to loan me the 35mm Pan so you can do a direct comparison. The next option is to wait till the Lostok Star Party at the end of Jan and you can compare them both then. Money unlimited my 1st choice is the 26mm Nagler T5, I actually prefer it over all the other options as the low power eyepiece of choice in an F5 scope, but she's a lot of hoot.

CS-John B

[astroboy]

Hi

Thought i wold chime in with my 2C worth.
I use both the 27 and 35 pans both great EPs the bigest drawback with the wieght you have to re balance a dob a 27 is about the same as 16mm Nagler and 12mm Nagler.
Mind you I somtime use the 35 on the NGT18 ( F4.5 ) to get as wide a field as possible and not worry about the light loss . The fornax cluster looks great with 10 or 12 galaxies in the one field.
Use the 35 a lot more on the 12" SCT nice combo and no worries about balance. and if you have a 20mm Nagler you can use them both as exercise weights , you should see my biceps.