Telescope Reviews: Nikon NAV-10SW vs. Pentax 10 XW

· Get a Cloudy Nights T-Shirt

· Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

You are not logged in. [Login]

Entrance · Main Index · Search · New user · Who's Online
FAQ · Calendar

Equipment Discussions >> Eyepieces

Pages: 1 | 2 | (show all)

chboss
professor emeritus

Reged: 03/24/08

Loc: Tokyo Japan

Nikon NAV-10SW vs. Pentax 10 XW
#5678742 - 02/14/13 03:09 AM

I am wondering how the Nikon NAV-10SW compares with the Pentax 10 XW. I prefer 65-72 FOV eyepieces over larger fields. Any side by side comparisons?
Any other contenders in that range (also weight wise)?

Looking forward to hear your opinions and experiences.

best regards
Chris

Post Extras:

Ava
super member

Reged: 11/30/11

Loc: Sweden

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5678766 - 02/14/13 04:39 AM

The 10mm Tele Vue Delos would be a serious contender. I find mine to be the best wide field eyepiece I have (in close competition with my 13mm Ethos). Reports indicate that performance of the Delos and Pentax XW eyepieces are very similar but some prefer the ergonomics of one over the other. In comparing the Delos to my CZJ 10mm ortho the only easily noticeable difference is that the CZJ has very slightly less scatter. I have no experience with the Nikon NAV-SWs.

Post Extras:

Tamiji Homma
Carpal Tunnel

Reged: 02/24/07

Loc: California, USA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5679169 - 02/14/13 10:56 AM

Hi Chris,

I've done side-by-side comparison of various 10mm eyepieces.

XW 10 v.s. NAV SW 10 is virtually a tie. Both are very good from f/4. As I mentioned before, Nikon NAV SW series has very little rectangular distortion, which results in visible AMD toward edge. Image is clean but size of image gets visibly smaller than on-axis. You can easily tell that double star gets tighter and tighter toward edge.

It puzzles me why Nikon decided to do so when they market NAV SW as astronomical eyepiece. I guess they hope that they could sell NAV SW to spotting scope users. I am not sure they are successful, though

In terms of color rendering, NAV SW has the whitest color when you observe the Moon among wide AFOV eyepieces that I've tried.

Tammy

Post Extras:

PeterWar
super member

Reged: 08/25/11

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Tamiji Homma]
#5679192 - 02/14/13 11:07 AM

Wow Tammy, what an interesting side-by-side comparison! I'm interested to know how well did the Televue 10mm Delos perform against their contenders?

Post Extras:

Nuphy
super member

Reged: 04/23/08

Loc: Newport News, VA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: PeterWar]
#5679254 - 02/14/13 11:33 AM

Tammy, I would be interested to hear how the Tak-10U UW performs in comparison.

Post Extras:

SteveG
Post Laureate

Reged: 09/27/06

Loc: Seattle, WA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Nuphy]
#5679388 - 02/14/13 12:47 PM

Why is the 12.5 in that picture? ;-)

Post Extras:

jrbarnett
Eyepiece Hooligan

Reged: 02/28/06

Loc: Petaluma, CA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5679422 - 02/14/13 01:03 PM

Having now used both head-to-head in 10mm and 7mm, I prefer the Pentax XWs across the board. The NAV-SWs have a cheesy loose screw up eyecup and suffer eyeball glint as bad as any eyepiece I've ever used. They are quality eyepieces other than that, but these are ills the Pentax lacks, and the Pentaxes are easier to get hold of and cheaper to boot.

I like the XWs much better than my Deloses, too.

- Jim

Edited by jrbarnett (02/14/13 01:06 PM)

Post Extras:

Stellarfire
Pooh-Bah

Reged: 07/10/11

Loc: Switzerland

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: jrbarnett]
#5679496 - 02/14/13 01:34 PM

Quote:

The NAV-SWs have a cheesy loose screw up eyecup and suffer eyeball glint as bad as any eyepiece I've ever used.

- Jim

I tried Nikon NAV 14mm SW and NAV 17.5mm SW pairs in the Baader Mark V binoviewer. I found that the very bulky eyecup design of the NAV-SW's causes annoying nose clearance problems to me, no matter how low or high I adjust the cups. Regarding nose-related eyecup comfort problems, the 14mm was worse, the 17.5mm is barely acceptable. Of course, the eyecup may me completely unscrewed if desired. But for binoviewing, I prefer eyepieces with eyecups (in particular soft rubber eyecups), which are helpful to hold the eyes well positioned and centered.

Speaking of widefield eyepieces, I feel very comfortable and happy with the bino-friendly TV Delos models, and also the terrific Docter UWA 12.5, as discussed elsewhere on this CN forum, is da bomb in the binoviewer.

Stephan

Edited by Stellarfire (02/15/13 05:50 AM)

Post Extras:

coutleef
Post Laureate

Reged: 02/21/08

Loc: Saint-Donat, Québec, Canada

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: jrbarnett]
#5679529 - 02/14/13 01:46 PM

Quote:

I like the XWs much better than my Deloses, too.

- Jim

why do you prefer the pentax over yhe delos??

Post Extras:

Tamiji Homma
Carpal Tunnel

Reged: 02/24/07

Loc: California, USA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: SteveG]
#5679649 - 02/14/13 02:41 PM

Quote:

Why is the 12.5 in that picture? ;-)

Hi Steve,

If you look at 1.25" nosepiece of NAV HW 12.5 carefully, you find Nikon EiC-10 Barlow lens attached.
It is designed for HW 12.5 to make NAV HW 10mm

You can look at the full resolution photo.
http://www.pbase.com/tammyhomma/image/143754314/original.jpg

Tammy

Post Extras:

Tamiji Homma
Carpal Tunnel

Reged: 02/24/07

Loc: California, USA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Nuphy]
#5679683 - 02/14/13 02:54 PM

Quote:

Wow Tammy, what an interesting side-by-side comparison! I'm interested to know how well did the Televue 10mm Delos perform against their contenders?

Quote:

Tammy, I would be interested to hear how the Tak-10U UW performs in comparison.

Hi Peter/Stephan,

I've posted short impression here before:
Takahashi UW Eyepieces

Tammy

Post Extras:

chboss
professor emeritus

Reged: 03/24/08

Loc: Tokyo Japan

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Tamiji Homma]
#5680169 - 02/14/13 08:30 PM

Hello all thank you for your feedback!

Tammy your picture is great for comparing the size and visual appearance of all contenders. That strange winged eyecup on the Nikon did not work for me on other eyepieces in the past and the optical issue you mention is a show stopper.

My understanding is that this Nikon eyepiece came from the spotting scope side and was modified for astronomical use, that might explain your findings.

Jim thank you for your impressions, eyeball glint is an issue that I'd rather stay away from. So the Nikon is definitely a no go.

Looks like the Pentax 10 XW will be the next addition to my lineup.
The Delos does not please my eye and living in Japan the Pentax is cheaper to buy than the TeleVue.

best regards
Chris

Post Extras:

ausastronomer
Carpal Tunnel

Reged: 06/30/03

Loc: Kiama NSW (Australia)

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5680198 - 02/14/13 08:53 PM

Quote:

Looks like the Pentax 10 XW will be the next addition to my lineup.

best regards
Chris

Hi Chris,

The 10mm Pentax XW is one of the very best eyepieces money can buy, at any price. I am sure you will be very happy with it. Any differences with other premium eyepieces at this level are subtle at best and in many cases just personal preference, or brand loyalty. I haven't used any eyepiece in recent years; and I have used a lot, that would in any way make me inclined to sell my 5mm, 7mm and 10mm Pentax XW's, which I have owned for 10 years now.

Cheers,

Post Extras:

george golitzin
Pooh-Bah

Reged: 02/24/06

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: ausastronomer]
#5680658 - 02/15/13 03:54 AM

Quote:

Quote:

Looks like the Pentax 10 XW will be the next addition to my lineup.

best regards
Chris

Hi Chris,

The 10mm Pentax XW is one of the very best eyepieces money can buy, at any price. I am sure you will be very happy with it. Any differences with other premium eyepieces at this level are subtle at best and in many cases just personal preference, or brand loyalty. I haven't used any eyepiece in recent years; and I have used a lot, that would in any way make me inclined to sell my 5mm, 7mm and 10mm Pentax XW's, which I have owned for 10 years now.

Cheers,

I've had some differences with John over the years, but not on this issue--I'm in complete agreement. And you can add the 3.5mm XW to his list.

-Geo.

Post Extras:

Scott99
Carpal Tunnel

Reged: 05/10/07

Loc: New England

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: jrbarnett]
#5681245 - 02/15/13 11:42 AM

Quote:

Having now used both head-to-head in 10mm and 7mm, I prefer the Pentax XWs across the board. The NAV-SWs have a cheesy loose screw up eyecup and suffer eyeball glint as bad as any eyepiece I've ever used. They are quality eyepieces other than that, but these are ills the Pentax lacks, and the Pentaxes are easier to get hold of and cheaper to boot.

I like the XWs much better than my Deloses, too.

- Jim

oooh, I was going to keep quiet about it to not diss the Nikons, but I was thinking the same thing - forget the optical differences, I like the XW body much better than the Nikons. Nikon seems to have bungled the ergonomics part, the eyepieces have a bulky ring that bounces around loose.

The XW's are big & heavy, but they really hit a home run with the overall use-ability of it. (Except for the safety groove of course). You can precisely dial in the eyeguard position, which combines with a rubber outside for protection and grip-ability. For years Tele Vue and others just sort of "mailed it in" in terms of the eyeguard, they were never the correct height. Pentax realized how important the eyeguard & eye position are with long focal length ep's.

With the XW's Pentax brought the rugged "sport optics" mentality to astronomy, and combined it with coatings and glass on par with Zeiss.

Post Extras:

SteveG
Post Laureate

Reged: 09/27/06

Loc: Seattle, WA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Tamiji Homma]
#5681371 - 02/15/13 12:39 PM

Quote:

Quote:

Why is the 12.5 in that picture? ;-)

Hi Steve,

If you look at 1.25" nosepiece of NAV HW 12.5 carefully, you find Nikon EiC-10 Barlow lens attached.
It is designed for HW 12.5 to make NAV HW 10mm

You can look at the full resolution photo.
http://www.pbase.com/tammyhomma/image/143754314/original.jpg

Tammy

Ah - you got me on that one Tammy! BTW, I really enjoy your posts and great equipment pictures.

Post Extras:

Stellarfire
Pooh-Bah

Reged: 07/10/11

Loc: Switzerland

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Scott99]
#5681450 - 02/15/13 01:08 PM

The optical qualitiy of the Pentax XW line is undisputed. But it would be great if Pentax would consider bringing a modified XW version with slightly reduced shroud diameter, which would greatly enhance the binoviewer-friendliness.

TeleVue did the same with the Ethos 13mm: Narrowing the barrel diameter from 63.5mm (Version I) to 62mm (Version II) made it more binoviewer-friendly to users with ~62mm IPD.

Stephan

Post Extras:

Stellarfire
Pooh-Bah

Reged: 07/10/11

Loc: Switzerland

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Scott99]
#5681469 - 02/15/13 01:16 PM

Quote:

Nikon seems to have bungled the ergonomics part, the eyepieces have a bulky ring that bounces around loose.

Yes, the bulky and rattling eyecup of the Nikon NAV SW's is a bad joke.

Stephan

Post Extras:

csrlice12
Post Laureate

Reged: 05/22/12

Loc: Denver, CO

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Stellarfire]
#5681487 - 02/15/13 01:23 PM

Quote:

The optical qualitiy of the Pentax XW line is undisputed. But it would be great if Pentax would consider bringing a modified XW version with slightly reduced shroud diameter, which would greatly enhance the binoviewer-friendliness.

TeleVue did the same with the Ethos 13mm: Narrowing the barrel diameter from 63.5mm (Version I) to 62mm (Version II) made it more binoviewer-friendly to users with ~62mm IPD.

Stephan

If they do that, MrNutty (John), is gonna, well, to be truthful, he'll probably buy the whole set.....and may have to start wearing two eyepatches.....

I actually know people who DO bino with these.

Post Extras:

csrlice12
Post Laureate

Reged: 05/22/12

Loc: Denver, CO

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: csrlice12]
#5681935 - 02/15/13 04:46 PM

Just got the call, my Pentax 10XW is in!!

Post Extras:

gb_astro
sage

Reged: 01/01/08

Loc: Sydney, Australia

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: csrlice12]
#5682101 - 02/15/13 06:15 PM

On the 10SW I found the winged eyecup one of the best things about it.
Faces differ and for me this design almost completely blocks external light.

gb.

Post Extras:

MRNUTTY
Carpal Tunnel

Reged: 11/22/11

Loc: Mendon, MA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: csrlice12]
#5682251 - 02/15/13 07:55 PM

I may have to invest in a smaller bulls eye on my back! :-)

Post Extras:

ebone
journeyman

Reged: 03/09/08

Loc: Brazil

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: gb_astro]
#5683788 - 02/16/13 04:02 PM

Quote:

On the 10SW I found the winged eyecup one of the best things about it.
Faces differ and for me this design almost completely blocks external light.

gb.

+1 on NAV-SW design.
I consider the Nikon's winged eyecups first class.
Very effective and confortable. If you want it's super eazy to take off and put back.

Post Extras:

Tamiji Homma
Carpal Tunnel

Reged: 02/24/07

Loc: California, USA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5685054 - 02/17/13 11:56 AM

Quote:

Tammy your picture is great for comparing the size and visual appearance of all contenders. That strange winged eyecup on the Nikon did not work for me on other eyepieces in the past and the optical issue you mention is a show stopper. My understanding is that this Nikon eyepiece came from the spotting scope side and was modified for astronomical use, that might explain your findings.

Hi Chris,

I did another side-by-side comparison (Nikon NAV SW 10, Pentax XW 10, and Televue Delos 10) with faster scope (f/4). It showed something I couldn't see before with slower non-flat field f/5.5, f/7, f/8 scope.

Overall, astronomical use, I think Delos 10 is the best among three. NAV SW 10 is best among three in lateral color toward edge. XW 10 shows visible weakness beyond last 10% of field at f/4, image is visibly softened comparing to the others.

By the way, SW may have heritage of spotting scope eyepiece but HW is very different from SW.

Tammy

Post Extras:

ausastronomer
Carpal Tunnel

Reged: 06/30/03

Loc: Kiama NSW (Australia)

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Tamiji Homma]
#5685941 - 02/17/13 08:53 PM

Hi Tammy,

Just curious what scope you used to conduct the testing at F4. I am thinking that the softening you saw in the 10mm Pentax XW in the outer 10% of the FOV could have something to do with the scope / eyepiece interaction.

I have used the 10mm Pentax at F4.2 in an 18" Obsession Ultracompact for the last 6 or 7 years, and do not see what you saw. However, I do use a paracorr type 1 in this scope which eliminates coma and effectively makes the scope an F4.8 scope, so that could explain the difference in what we are seeing also. In all my other scopes which are all F4.5 and longer newtonians, it gives my a perfectly sharp field right to the fieldstop.

Cheers

Post Extras:

chboss
professor emeritus

Reged: 03/24/08

Loc: Tokyo Japan

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: ausastronomer]
#5686020 - 02/17/13 09:37 PM

Hi Tammy

Thank you for this report.
Did you use your Pentax f4 (Modified Petzval) refractor for the comparison?

Most of my visual instruments are f8 and longer, so the performance at fast focal ratios is not a big problem for me.
Which one do you consider the best performer in terms of on axis sharpness and contrast?

The HW from Nikon seems to be a new and design, but the price and the large FOV are not my cup of tea.

best regards
Chris

Post Extras:

ausastronomer
Carpal Tunnel

Reged: 06/30/03

Loc: Kiama NSW (Australia)

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5686041 - 02/17/13 09:49 PM

Hi Chris,

Sometimes theres a lot more involved here than just the F-ratio, which really only affects the steepness of the light cone entering the eyepiece. In a lot of eyepiece/scope combinations it's the interaction between things like the curvature of the focal plane of the eyepiece and the telescope, in addition to the focal length of the telescope.

For example a 20"/F4 newtonian will exhibit the same amount of field curvature as a 10"/F8 newtonian, because they both have the same focal length. The 20"/F4 will have a lot more coma than the 10"/F8.

People often make poor eyepiece choices concerning their F10 Schmidt Cassegrains, which usually have an F2 spherical primary. An F10 SCT will have about the same amount of field curvature as a 10"/F5 newtonian and more coma.

It really depends what aberration Tammy is seeing to cause the field to soften in the outer 10% of the 10mm Pentax XW. ie. Is it field curvature, is it off axis astigmatism, or is it coma from the scope, or the eyepiece?

Cheers

Post Extras:

chboss
professor emeritus

Reged: 03/24/08

Loc: Tokyo Japan

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: ausastronomer]
#5686050 - 02/17/13 09:52 PM

Hi John

You have a valid point, this is why I asked about the scope he used for the comparison.

regards
Chris

Post Extras:

Stellarfire
Pooh-Bah

Reged: 07/10/11

Loc: Switzerland

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: chboss]
#5686456 - 02/18/13 05:38 AM

I think Tammy is referring to his new Pentax 100 SDUF II f/4, as presented by him in the Refractor Forum on 11/12/12 (OP #5566331).

Stephan

Post Extras:

chboss
professor emeritus

Reged: 03/24/08

Loc: Tokyo Japan

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Stellarfire]
#5686550 - 02/18/13 08:11 AM

Hi Stephan

That was my guess...

regards
Chris

Post Extras:

Tamiji Homma
Carpal Tunnel

Reged: 02/24/07

Loc: California, USA

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: ausastronomer]
#5687305 - 02/18/13 04:54 PM

Quote:

Just curious what scope you used to conduct the testing at F4. I am thinking that the softening you saw in the 10mm Pentax XW in the outer 10% of the FOV could have something to do with the scope / eyepiece interaction.

Hi John,

The test was done with Pentax 100 SDUF II f/4, flat field imaging scope.

I could be witnessing DM curve of XW 10 shown below but since we don't have similar design parameter published by manufacturers to compare, it is just my wild guess

http://pentaxplus.jp/archives/tech/xo-xw/64.html

I do see better edge image quality in Delos 10 than XW 10 with the scope. I don't (can't) see the difference with TMB 92SS f/5.5, or slower. From f/7.5 on, XW 10 and Delos 10 look almost identical to me under night sky.

Tammy

Post Extras:

ausastronomer
Carpal Tunnel

Reged: 06/30/03

Loc: Kiama NSW (Australia)

Re: Nikon NAV-10SW vs. Pentax 10 XW new

[Re: Tamiji Homma]
#5687686 - 02/18/13 08:07 PM

Hi Tammy,

I think your assumption is correct. The 10mm Pentax XW does have a touch of inherent -ve field curvature. This doesn't manifest in newtonians which have inherent mild +ve field curvature, but it could manifest when used in a flat field 4" F4 imaging scope, which only has a focal length of 16". I don't think this is likely to be a concern for the greater majority of visual observers, who wouldn't be using such a scope for visual work. It's a bit like saying the brakes on my new Ferrari work really well when I drive it on the bitumen, but they don't work very well when I drive it on the grass. How many people buy a Ferrari and drive it on the grass?

What do you think is causing the softening in the outer 10% of the 10mm Pentax XW, Field Curvature, Astigmatism or eyepiece Coma? My guess as I indicated above, is that it is slight -ve field curvature.

Cheers,

Post Extras:

Pages: 1 | 2 | (show all)

Extra information

15 registered and 22 anonymous users are browsing this forum.

Moderator: ausastronomer, Scott in NC, iceblaze

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Thread views: 1673

Jump to

CN Forums

Home

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics