[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