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Just a few Pentax XW questions

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#26 John Huntley

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Posted 28 July 2021 - 12:16 PM

One element is a group when we consider the air gap. grin.gif

Is Ricoh era air as good as the original Pentax era air ? grin.gif 


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#27 j.gardavsky

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Posted 28 July 2021 - 12:21 PM

One element is a group when we consider the air gap. grin.gif

You can alternatively count on the Pentax Marketing drawings the air gaps,

when the reading glasses can't count the groups,

like  1   1   1   1   1 ...

 

Best,

JG


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#28 Greg77

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Posted 28 July 2021 - 12:41 PM

...I have compared old and new 2" XW versions with my scope. No diference..but...I have only my old Meade series 5000 127/f7.5 ED as a reference. ;)
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#29 areyoukiddingme

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Posted 28 July 2021 - 01:16 PM

I have compared the old Pentax green-box 5mm with the new Richo silver-box 5mm, and they were identical as far as I could see.

 

The only questions for me are whether there are any changes with the 30 and 40, and it's sounding like probably not.

 

And both were equally stinky :-)


Edited by areyoukiddingme, 28 July 2021 - 01:17 PM.

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#30 25585

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Posted 28 July 2021 - 01:59 PM

I just really don’t see any substantive difference between the new and the old XW’s.   IMO worrying about this is pointless.  

 

But here on CN we sometimes like to over analyze. Based upon my experience with both Pentax and Ricoh XW’s - including the 40mm XW for both, I see no reason to worry about whether or not they made small changes. 

 

The most substantive difference between them is that the Ricoh XW’s have a much weaker rubber smell than the Pentax XW’s.  lol.gif

The smell goes. 

 

I had a 5 XW green box, sold it, tried a 5 XW silver box, returned it. Both had great optics but both also had eye placement issues (as did the 7mm). But there was no difference optically apart from box colour.  

 

If the Ricoh guy said there is no difference between Rs & pre-Rs, he would know surely?


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#31 25585

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Posted 28 July 2021 - 02:09 PM

Ricoh's top, from Astroshop.eu bottom.

Attached Thumbnails

  • XW-Series_Eyepieces.jpg
  • Pentax-SMC-XW-3-5mm-1-25-eyepiece (1).jpg

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#32 j.gardavsky

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Posted 28 July 2021 - 02:24 PM

Ricoh's top, from Astroshop.eu bottom.

The Pentax SMC XW on this page are the old ones, before R.

 

The XW 30 (no R) I have, shows with the laser beam tracing exactly the same, as in the drawing.

No difference. As the front meniscus can be unscrewed, the laser ray tracing is easy. And it is no problem, when I start it from the eye lens inside.

 

It will take me two or three weeks to get the new Pentax SMC XW R 40mm in my hands to test it.

 

However it will be likely a piece via Ricoh Imaging U.K., and not via Ricoh Imaging Phillipines,

where Ricoh is suspected to mount the eyepiece lenses during the breaks between making the digital cameras. Sorry.

 

Best,

JG


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#33 j.gardavsky

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Posted 29 July 2021 - 03:20 AM

By definition, if Pentax says "7 elements in 6 groups", only one pair can be cemented.

By definition,

if Tele Vue Marketing is listing no lenses and no groups in

Ethos, Delos, DeLite,

https://www.televue....page.asp?id=214

are these eyepieces, according to the marketing, just a not cemented air gap?

 

Thank you for the chuckle,

JG

 

PS: My Delos has some lenses inside, regardless of what the marketing is writing


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#34 25585

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Posted 29 July 2021 - 05:17 AM

The Pentax SMC XW on this page are the old ones, before R.

 

The XW 30 (no R) I have, shows with the laser beam tracing exactly the same, as in the drawing.

No difference. As the front meniscus can be unscrewed, the laser ray tracing is easy. And it is no problem, when I start it from the eye lens inside.

 

It will take me two or three weeks to get the new Pentax SMC XW R 40mm in my hands to test it.

 

However it will be likely a piece via Ricoh Imaging U.K., and not via Ricoh Imaging Phillipines,

where Ricoh is suspected to mount the eyepiece lenses during the breaks between making the digital cameras. Sorry.

 

Best,

JG

I am sure you will like your new XW 40, regardless of new or old waytogo.gif


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#35 j.gardavsky

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Posted 29 July 2021 - 06:57 AM

I am sure you will like your new XW 40, regardless of new or old waytogo.gif

Sure,

if I will keep it, it will find a memorable place next to the Rodenstock.

 

Thank you,

JG


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#36 zakry3323

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Posted 29 July 2021 - 08:34 AM

I had no idea that Pentax XW's could be so contentious. I would say shame on Pentax/Ricoh for bringing the 30/40 XW's back with a new designation, but not being crystal clear about them. But then again, here we are a while after the re-introduction still talking about them.

In any case, it looks like their correction, quality, eye-relief, weight, and ability to accept my dioptrx makes them worth a try for me.

So...if anyone wants to buy a 31mm aspheric just let me know :)

#37 25585

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Posted 29 July 2021 - 11:57 AM

Sure,

if I will keep it, it will find a memorable place next to the Rodenstock.

 

Thank you,

JG

That's where mine is, next to the Rodenstock. Space left for a Leitz next to my XW 30.  


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#38 j.gardavsky

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Posted 29 July 2021 - 12:44 PM

That's where mine is, next to the Rodenstock. Space left for a Leitz next to my XW 30.  

I have the "collectible" Wild Heerbrugg Big Monster to part with.

Should you like to have it, then we can make a good deal.

 

Best,

JG


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#39 25585

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Posted 29 July 2021 - 01:58 PM

I have the "collectible" Wild Heerbrugg Big Monster to part with.

Should you like to have it, then we can make a good deal.

 

Best,

JG

PM sent :)


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