12.5mm Docter Eyepiece

[LewisM]

No doubt about it Col, you are a junkie. Is there an eyepiece obsession help clinic?

Very gaudy box for a German product - usually so restrained and "old school", but boy is that leather case typically German (I had similar with my WW2 German optics items). Quality all round.

Now you need a big Tak to put it in. I hear Matt is wanting to sell his TOA for a fictional 140mm fluorite doublet...

[Kunama]

It sure ain't a lightweight !!!
Looking forward to your review.
No the TOA is not for sale !!!

[FlashDrive (Poppy)]

Originally Posted by Kunama

It sure ain't a lightweight !!!

Just over 1/2 kilo.....

Col....

[FlashDrive (Poppy)]

So far I have looked at Jupiter and Moon and I have to say, this is the most ' sharpest ' - ' contrasty ' - ' comfortable ' Planet viewing eyepiece I have EVER used .....

The Moon is breathtakingly sharp to the edge....right across the fov.
Craters reveal such ' sharp ' edges and shadows flow into the terminator with distinct clarity.

I was looking at Jupiter even before the Sun set to the west ... again, very sharp , the Bands stood out as clear and distinct as ever and the view was pleasantly bright.

Focusing is very ' spot on ' ....move it a little each way and you have ' missed ' it.

From what little use I have had with it so far ~ about 1 hour .. Saturn is going to be a real treat to see....without a doubt.

I have to get up early .... so jewel box / Omega and Eta will have to wait till tomorrow night ... barring bad weather..... be interesting to see how it performs on DSO etc.

Am I happy .....answer...... is the Pope a Catholic ...!!

Col......

[Kunama]

Sounds very promising Col. I'll bring my gear up there sometime over winter for a comparison.

(You will also have a delivery of 2 parcels tomorrow, keep on tracking' )

[rrussell1962]

Col, just look at what your new eyepiece has done to the weather! Seriously though if you want to do a review in different 'scopes we can drag out the Obsession, the 8se and the TSA120 one evening when the weather clears up. No - not just an excuse for me to get my eye on the end of it!

[N1 (Mirko)]

Flash, how are you liking the Docter? Have you had a chance to do some more observing?

[FlashDrive (Poppy)]

Originally Posted by N1

Flash, how are you liking the Docter? Have you had a chance to do some more observing?

See here....

http://www.iceinspace.com.au/forum/s...d.php?t=134724

Flash....

[ab1963 (Andrew)]

Hi
I have recently purchased the docter eyepiece and don't claim to be a expert in the hobby but last night I had my first opportunity to use it extensively and all I can really say is that its the most fantastic experience in this hobby I have had so far,it is so immersive ,sharp and contrasty and gives you a feeling of being out there litarally,dark background with very natural colouring with a depth of field I have not seen in anything else I have ever viewed through,i feel like I got my moneys worth last night and the price tag is small potatoes for the experience you get,blows my mind thinking what the view would be like through a set of binoviewers

[Don Pensack]

I did a comparison of the Doctor 12.5mm and the TeleVue Nagler Type 6 13mm last night.
A few remarks:
--the Docter is more difficult to use and hold the eye exactly enough in position to avoid blackouts and still see the field of view.
--the Docter is possessed of an unusual amount of angular magnification distortion, such that a globular cluster moving toward the edge as the scope drifted actually compressed in the radial direction and distorted noticeably.
--it could not be used as a 2" eyepiece in the Paracorr because it required more out-movement than the tunable top allowed. It could only be used as a 1.25" eyepiece. That's not unusual--the 6mm and 8mm Ethos are the same way.
--the Docter was not any brighter in terms of the field, or faintest stars seen, than the T6.

Overall, it was not sharper than the Nagler; nor did it produce a brighter image; and it was more noticeably distorted at the edge for astronomical use.

I note, however, that the things I found less favorable for astronomical use might make the daytime use better. If residual AMD is visible, then RD is reduced, and that would make daytime images better. Likewise, any illumination difference between it and the 13 T6 would be unimportant in daytime use.

For this observer, though, many years of 13mm T6 usage came flooding back to me, as that eyepiece is one of the 5 sharpest I have ever owned out of 315 personal eyepieces owned. Had I not replaced it with a 13mm Ethos (I'm one of those for whom the wider undistorted field is a plus), I could have happily lived with the 13mm T6 for the rest of my life.

[N1 (Mirko)]

Thanks Don for this write-up. Keeping my 13T6.

[FlashDrive (Poppy)]

Don.....You should have gone to ' Spec Savers '

I love my Docter...

Flash

[ariefm71 (Arief)]

I'm keeping my 13T6

[ausastronomer (John Bambury)]

Hang on I just get a shovel outta my shed. I would bet London to a 2 bob knob of goat shyyt that a couple of you that have expressed an opinion here, have never seen a 12.5mm Docter, let alone used one.

Cheers
John B

[ausastronomer (John Bambury)]

Arief, Mirko,

Have either of you ever actually used a 12.5mm Docter in a decent telescope?

Cheers
John B

[Allan]

Originally Posted by Don Pensack

I did a comparison of the Doctor 12.5mm and the TeleVue Nagler Type 6 13mm last night.
A few remarks:
--the Docter is more difficult to use and hold the eye exactly enough in position to avoid blackouts and still see the field of view.
--the Docter is possessed of an unusual amount of angular magnification distortion, such that a globular cluster moving toward the edge as the scope drifted actually compressed in the radial direction and distorted noticeably.
--it could not be used as a 2" eyepiece in the Paracorr because it required more out-movement than the tunable top allowed. It could only be used as a 1.25" eyepiece. That's not unusual--the 6mm and 8mm Ethos are the same way.
--the Docter was not any brighter in terms of the field, or faintest stars seen, than the T6.

Overall, it was not sharper than the Nagler; nor did it produce a brighter image; and it was more noticeably distorted at the edge for astronomical use.

I note, however, that the things I found less favorable for astronomical use might make the daytime use better. If residual AMD is visible, then RD is reduced, and that would make daytime images better. Likewise, any illumination difference between it and the 13 T6 would be unimportant in daytime use.

For this observer, though, many years of 13mm T6 usage came flooding back to me, as that eyepiece is one of the 5 sharpest I have ever owned out of 315 personal eyepieces owned. Had I not replaced it with a 13mm Ethos (I'm one of those for whom the wider undistorted field is a plus), I could have happily lived with the 13mm T6 for the rest of my life.

G'day Don. I don't see this mentioned anywhere, wondering whether you have. But, I see strong rectilinear distortion in my Ethos when I use them in my NP101is. I just put it down to a combination of the ultra wide eyepieces struggling in the wide FOV of the refractor. The Ethos in a typical dob FOV I find essentially perfect. Delos in the NP101is are absolutely perfect.

[N1 (Mirko)]

Originally Posted by ausastronomer

Arief, Mirko,

Have either of you ever actually used a 12.5mm Docter in a decent telescope?

Cheers
John B

I was genuinely interested in doing so, but after reading this from a seasoned eyepiece expert:

Originally Posted by Don Pensack

--the Docter is more difficult to use and hold the eye exactly enough in position to avoid blackouts and still see the field of view.
--the Docter is possessed of an unusual amount of angular magnification distortion, such that a globular cluster moving toward the edge as the scope drifted actually compressed in the radial direction and distorted noticeably.
[...]
--the Docter was not any brighter in terms of the field, or faintest stars seen, than the T6.

Overall, it was not sharper than the Nagler; nor did it produce a brighter image; and it was more noticeably distorted at the edge for astronomical use.

I will most certainly NOT go out of my way for it now. Unless of course, advice from even a "seasoned eyepiece expert" should be taken with a grain (or a mountain) of salt. Probably not a bad idea:

Originally Posted by ausastronomer

...a couple of you that have expressed an opinion here, have never seen a 12.5mm Docter, let alone used one.

Yeah the mods have been slack, haven't they? Allowing lowly Docter non-users to have an opinion AND post it in this thread.

Finally, if you think I shouldn't keep my 13T6, feel free to make me an offer.

[ausastronomer (John Bambury)]

Hi Mirko,

Sometimes we need to see the forest through the trees.

Originally Posted by N1

I was genuinely interested in doing so, but after reading this from a seasoned eyepiece expert, I will most certainly NOT go out of my way for it now. Unless of course, advice from even a "seasoned eyepiece expert" should be taken with a grain (or a mountain) of salt. Probably not a bad idea:

Well of course Don is an eyepiece vendor and Televue Dealer who sells Televue Eyepieces. Don doesn't sell Docter eyepieces. Even prior to starting his own business with eyepiecesetc.com ; Don was an employee of Scope City who also sold Televue eyepieces.

Finally, if you think I shouldn't keep my 13T6, feel free to make me an offer.

The 13mm Nagler T6 is an excellent eyepiece and anyone who owns one and likes it has no reason to replace it with anything else. If it was the the only eyepiece available at this focal length would I be happy? Very happy, I would have one. Do I think it is the equal of the 12.5mm Docter? Not even. It's also inferior IMO to the 14mm Pentax XW and the 13mm ETHOS (both of which I own) in many respects and I rate both of those behind the Docter.

While I don't own a 13mm Nagler T6 it's an eyepiece I have spend a lot of time with over a lot of years. We have 4 of them in our 3RF eyepiece kits. 2 that go with 2 different 18" Obsession telescopes and a pair of them for the 12" binocular telescope. I also helped Mike Salway do the testing of the 13mm Nagler T6 and all the other eyepices in this review 10 years ago.

http://www.iceinspace.com.au/42-245-0-0-1-0.html

I already own a number of eyepieces at this focal length including a 12mm Nagler T4, a 12.5mm UO HD Orthoscopic, a 13mm ETHOS and a 14mm Pentax XW. I have never wanted to replace any of those with the 13mm Nagler T6. In fact when combined with a paracorr the 14mm Pentax XW gives it a horrible hiding. The Pentax clearly goes deeper with better light transmission and contrast on threshold targets for any given telescope aperture. For instance on 47 Tucanae using a 10" telescope the 14mm Pentax XW shows a lot more stars in the core than the 13mm Nagler T6. On HN40 which is the multiple star at the centre of M20, the 14mm Pentax XW easily shows the "d" star with direct vision in my 14" SDM whereas the 13mm Nagler T6 struggles to show it with averted vision. The 13mm Nagler T6 does have a larger AFOV and is a lot smaller and lighter. The 14mm Pentax XW has much better eye relief and is a lot more comfortable to use IMO. Size, weight and AFOV aren't so important for me. I will add a comment here. The 14mm Pentax XW does exhibit field curvature in many telescopes, including all my Newtonians. However, when combined with a Paracorr the 14mm Pentax XW offers a very sharp flat field view right across the entire FOV and I prefer it to the 13mm ETHOS and the 13mm Nagler T6. Without a Paracorr I would take the 13mm ETHOS every time.

I have also used the 12.5mm Doctor on a couple of occasions. At no time have I ever had any issues with comfort, ergonomics or eye placement with it, nor have I ever read anything to that effect from anyone who has used it, other than Don. In fact I find it be one of the most comfortable easy to use eyepieces I have ever used. In fact, the overall viewing experience with it in terms of comfort, ease of use and optical performance, is about the best I have ever had from any eyepiece I've ever used, and I 've used a lot of them, over a lot of years. I am aware of about a dozen online reviews of this eyepiece and most express a similar opinion to mine. Don is the first person who has not been totally impressed with it and the first person who would not put it clearly ahead of the 13mm Nagler T6 in a direct comparison.

Yeah the mods have been slack, haven't they?

Well they have because on a properly moderated and controlled forum like Cloudy Nights, Don would not have even been allowed to make that post as he is classified as a vendor and precluded from commenting on products that he sells, unless asked a direct question about his products; and he is not allowed to comment on products sold by other vendors. Slight conflict of interest there don't ya think? And I know that because I have been a moderator on the eyepieces forum on Cloudy Nights for over 5 years

Cheers,
John B

[simmo]

Why are eyepieces so controversial? Take a chill pill and just enjoy what you got.

[Moontanner (Ross)]

Originally Posted by simmo

Why are eyepieces so controversial? Take a chill pill and just enjoy what you got.

No need for chill pills. It's great to see some varied opinions from people with different types of experience in the matter.

It's only controversial because there is the potential for people to spend
substantial amounts of money on these things in worthwhile volumes. That makes it a hotly contested area for businesses, and one which will always attract plenty of attention. (15 odd years of selling non astronomy services to the upper end market is my experience).

Anyway, thanks to all for the reviews so far. I don't have any experience with this particular eyepiece and that's why I'm here.
Keep the comments coming.