Pentax 10mm XW (Second light)

[F15Rules]

18 hours ago, 25585 said:

How is the zoom performance optically for 10 to 20mm focal lengths compared to the XW 14 & 20? Is eye relief less?

Hi,

I believe the optical quality is very close to that of the fixed length Pentax's. 

I'd sum up the pros and cons of the zoom as follows;

Zoom Pros.         

- Versatile, just dial in any magnification from 8mm to 24mm to suit the prevailing conditions

- save time having to swap out various fixed length eyepieces

- optically very good. In particular does not suffer from FC as do the 14m and 20mm XWs. Contrast is very very close to the XWs IMO, maybe 96-97%..

- eye relief is a minimum of 18mm and a maximum of 22mm (source: Ricoh website specifications). Very comfortable at all settings.

- Superb, exemplary build quality- maybe even a notch above the XWs..

Zoom Cons

- Big and heavy compared to fixed length units (zoom is 550g Vs 405g for the 7mm XW...shorter FL XWs are heavier than the 7mm but here the 7mm is the nearest magnification match to the 8mm-24mm zoom)..see photos below, for scale, of left to right the Zoom, 7mm XL, 10.5mm XL, and Vixen LVW 22mm..Note:. My XLs shown in the photos are slightly different dimensions to the later XWs, but very similar for the purpose of this comparison☺.

- Narrower field of view versus XW and XLs. This is the single biggest negative against the zoom. In fact I honestly believe that if the FOV range was more like 50-65 degrees these zooms would have sold in much higher numbers. The XWs are slightly wider field (70 degree) than the older XLs (65deg). I personally find the difference very slight.

- not so much a Con, as a note of interest. The zoom, being JIS4 water resistant, has an internal O ring seal which can make the zoom rotation seem a little stiff. The solution is to mount the zoom in your diagonal or focuser using a Baader clicklock 2" to 1.25" reducer. This grips the zoom very tightly and really makes zooming in and out very easy.

Note on Prices

 - although not cheap to buy new (£329 currently), that one zoom eyepiece covers 4 individual XW focal lengths (7, 10, 14, 20mm), each of which new (assuming all are still available) would cost £249 each, or £996 for the set! As used buys, you should get a zoom for c £250, whereas used XWs average around £170 each, or £680 for the 4..

Hope that helps?.

Dave

 

 

 

Edited December 22, 2017 by F15Rules
Corrections and Photos added

[25585]

Many thanks! Seems better than the Baader or Vixen/Tele Vue 8-24 zooms. 

Lots of points worth considering. 

[Highburymark]

Interesting comparison from Dave. The other thing worth mentioning is that I remember the Pentax zoom being considerably more expensive than it is right now. If you don't mind the weight and fov, it's clearly a nifty option.

[F15Rules]

On 22/12/2017 at 18:21, Highburymark said:

Interesting comparison from Dave. The other thing worth mentioning is that I remember the Pentax zoom being considerably more expensive than it is right now. If you don't mind the weight and fov, it's clearly a nifty option.

I had an hour outside last night in sub zero bright moonlight.

I was checking out the Plato area on Luna and also M42.

The seeing wasn't much good, neither was transparency, but I just wanted to get outside for a bit. Specifically, I wanted to compare the Pentax SMC zoom with my 7mm and 10.5mm XLs. 

The conditions were tough on all the eyepieces..I am only the most casual of Lunar observers, and I tend to usually just have a 5 minute scan around and then move on to something I'm more interested in.

Last night, I didn't have much choice, given how bright the moon was, as so many favourite objects were pretty washed out. Anyway, I had a good look at the Plato area and I thought all 3 eyepieces did well, but the 7mm just made the shimmering of the atmosphere all the more apparent. The 10.5mm was better, but the zoom really was the best choice last night, having the flexibility to dial in different mags without swapping eyepieces about.

I saw some nice detail in general, but no sign of any craterlets, the conditions and brightness of the 3/4 full moon being just too much, washing out the contrast almost completely.

M42 was a similar story, but again the zoom at between the 24mm setting down to the 12mm setting was best on the night. Actually, the view at 24mm was lovely, the one I enjoyed most. It looked almost like a photograph, with the nebula framed beautifully against a surprisingly dark sky and the Trap fully resolved into 4 sharp individual points, with the bat wings clearly evident despite the moons' proximity. And this was a FOV of only 40 degrees, yet it never felt tunnel like.

Each time I use the Pentax zoom I like it more and more. Yes, it's a big eyepiece, but with it securely held in the Baader clicklock the zoom action is very smooth, and the build quality is the best of any eyepiece I have owned IMHO.

I see that FLO have a brand new SMC zoom on their sale at £296 at the moment..considering a single XW new is £249, to me that price makes this zoom wonderful value. Add a decent SWA Pan 24mm, LVW 22mm (my choice), or ES24mm and you could have some great observing sessions with just two eyepieces?.

Dave

[Highburymark]

On 29/12/2017 at 16:41, F15Rules said:

I had an hour outside last night in sub zero bright moonlight.

I was checking out the Plato area on Luna and also M42.

The seeing wasn't much good, neither was transparency, but I just wanted to get outside for a bit. Specifically, I wanted to compare the Pentax SMC zoom with my 7mm and 10.5mm XLs. 

The conditions were tough on all the eyepieces..I am only the most casual of Lunar observers, and I tend to usually just have a 5 minute scan around and then move on to something I'm more interested in.

Last night, I didn't have much choice, given how bright the moon was, as so many favourite objects were pretty washed out. Anyway, I had a good look at the Plato area and I thought all 3 eyepieces did well, but the 7mm just made the shimmering of the atmosphere all the more apparent. The 10.5mm was better, but the zoom really was the best choice last night, having the flexibility to dial in different mags without swapping eyepieces about.

I saw some nice detail in general, but no sign of any craterlets, the conditions and brightness of the 3/4 full moon being just too much, washing out the contrast almost completely.

M42 was a similar story, but again the zoom at between the 24mm setting down to the 12mm setting was best on the night. Actually, the view at 24mm was lovely, the one I enjoyed most. It looked almost like a photograph, with the nebula framed beautifully against a surprisingly dark sky and the Trap fully resolved into 4 sharp individual points, with the bat wings clearly evident despite the moons' proximity. And this was a FOV of only 40 degrees, yet it never felt tunnel like.

Each time I use the Pentax zoom I like it more and more. Yes, it's a big eyepiece, but with it securely held in the Baader clicklock the zoom action is very smooth, and the build quality is the best of any eyepiece I have owned IMHO.

I see that FLO have a brand new SMC zoom on their sale at £296 at the moment..considering a single XW new is £249, to me that price makes this zoom wonderful value. Add a decent SWA Pan 24mm, LVW 22mm (my choice), or ES24mm and you could have some great observing sessions with just two eyepieces?.

Dave

Agree that's a bargain Dave

[25585]

On 29 December 2017 at 16:41, F15Rules said:

I had an hour outside last night in sub zero bright moonlight.

I was checking out the Plato area on Luna and also M42.

The seeing wasn't much good, neither was transparency, but I just wanted to get outside for a bit. Specifically, I wanted to compare the Pentax SMC zoom with my 7mm and 10.5mm XLs. 

The conditions were tough on all the eyepieces..I am only the most casual of Lunar observers, and I tend to usually just have a 5 minute scan around and then move on to something I'm more interested in.

Last night, I didn't have much choice, given how bright the moon was, as so many favourite objects were pretty washed out. Anyway, I had a good look at the Plato area and I thought all 3 eyepieces did well, but the 7mm just made the shimmering of the atmosphere all the more apparent. The 10.5mm was better, but the zoom really was the best choice last night, having the flexibility to dial in different mags without swapping eyepieces about.

I saw some nice detail in general, but no sign of any craterlets, the conditions and brightness of the 3/4 full moon being just too much, washing out the contrast almost completely.

M42 was a similar story, but again the zoom at between the 24mm setting down to the 12mm setting was best on the night. Actually, the view at 24mm was lovely, the one I enjoyed most. It looked almost like a photograph, with the nebula framed beautifully against a surprisingly dark sky and the Trap fully resolved into 4 sharp individual points, with the bat wings clearly evident despite the moons' proximity. And this was a FOV of only 40 degrees, yet it never felt tunnel like.

Each time I use the Pentax zoom I like it more and more. Yes, it's a big eyepiece, but with it securely held in the Baader clicklock the zoom action is very smooth, and the build quality is the best of any eyepiece I have owned IMHO.

I see that FLO have a brand new SMC zoom on their sale at £296 at the moment..considering a single XW new is £249, to me that price makes this zoom wonderful value. Add a decent SWA Pan 24mm, LVW 22mm (my choice), or ES24mm and you could have some great observing sessions with just two eyepieces?.

Dave

Got one in the sale! 

[Alan White]

As this older post was just liked after some years, I thought an update was due.
The 10XW noted in this post was sold in a reshuffle and regretted after, but it sits with a fellow SGLer.
I bought another this year and it impresses again, but so does the Morpheus 12.5 and my other EP.
 

I now wear glasses to observe, so the longer Eye-relief is key as well as fine optics.
All those in my present Signature meet that double requirement.
In all honesty, the Morpheus is the XW's equal.

 

[HollyHound]

10 hours ago, Alan White said:

As this older post was just liked after some years, I thought an update was due.
The 10XW noted in this post was sold in a reshuffle and regretted after, but it sits with a fellow SGLer.
I bought another this year and it impresses again, but so does the Morpheus 12.5 and my other EP.
 

I now wear glasses to observe, so the longer Eye-relief is key as well as fine optics.
All those in my present Signature meet that double requirement.
In all honesty, the Morpheus is the XW's equal.

 

That like was from me...

been reading through reviews of the XW range and the particularly the 10mm and 7mm... which I have ordered this weekend 😃

I had noted you sold the XW10 and then reacquired again, so that in itself speaks volumes about its quality and place in your collection 👍

I did a similar thing, bought and sold an XW40, a few months back, due to not getting on with it (weight and balance only!) in my StellaMira. Now that I have a 10” dob, I had to have one back... although this time, I’ve chosen the XW30, as I feel the exit pupil of 6mm vs 8mm and slightly increased magnification, should offset the slightly reduced FoV (which is massive enough anyway) vs the XW40.