PF 65 ED eyepieces? (1 Viewer)

[Sancho]

Hi,
I'm half-thinking of pulling the trigger on one of these, as I need a smaller, lighter, mid-size scope. I am a bit challenged technically and am confused about stuff like focal lengths etc. Can anyone tell me what mag the XW14 ep gives on the PF 65? I'd be happy with a fixed 27 or 30x, I don't expect a zoom ep to perform miracles on a 65mm scope. (I think the Pentax zoom eps go up to 60x, which is asking too much). Any advice appreciated.

Edit: I've just read with thanks Jmepler's advice on a Pentax thread, saying divide the focal length of the scope (390mm) by the focal length of the ep. I don't even know what focal length means, but the ep I'm looking at is called XW14, so maybe the focal length is....14? That would give a mag of just over 27x. Am I even half right?

 

[jring]

Hi,

yes, the focal length of the XW14 is 14mm... scope bodies and eyepieces both have a focal length - you get the magnification by dividing the one of the body by the one of the EP.

The focal length is the distance behind some optical instrument where parallel beams (like sunlight - but be very careful not to burn anything) converge into one single point.

Joachim

 

[Sancho]

Sincerest thanks, Joachim. That means the Baader zoom should give about 16-48x. Interesting. Up to 35x might occasionally be useful. Although I do realise that the Baader would require some adaptation.
In a thread from last January, giosblue shows how to get infinity focus on the PF65, with the Baader, with some clever usage of one adapter ring and some duct-tape.

Edit:
I also saw a Baader 13mm. I thought, using the 390÷13 formula, this would give 30x. But the seller's description of the 13mm ep saud its focal length was 5mm. Now I really am confused!

 

[jring]

Hi,

well, a 13mm EP should not have a focal length of 5mm...

Here's a link to the whole Baader Hyperion line - including the 13mm and the 5mm versions.

https://www.baader-planetarium.com/en/accessories/optical-accessories/eyepieces/hyperion.html

That being said, I would not recommend the Hyperion fixed magnification EPs for very fast scopes like spotters - they tend to work best at focal ratios of around f8 or slower and your Pentax is quite a bit faster at f6...

Joachim

 

[Sancho]

Hi,

well, a 13mm EP should not have a focal length of 5mm...

Here's a link to the whole Baader Hyperion line - including the 13mm and the 5mm versions.

https://www.baader-planetarium.com/en/accessories/optical-accessories/eyepieces/hyperion.html

That being said, I would not recommend the Hyperion fixed magnification EPs for very fast scopes like spotters - they tend to work best at focal ratios of around f8 or slower and your Pentax is quite a bit faster at f6...

Joachim

Thank you Joachim. I am very grateful for your advice!

 

[gcole]

Hi,
I'm half-thinking of pulling the trigger on one of these, as I need a smaller, lighter, mid-size scope. I am a bit challenged technically and am confused about stuff like focal lengths etc. Can anyone tell me what mag the XW14 ep gives on the PF 65? I'd be happy with a fixed 27 or 30x, I don't expect a zoom ep to perform miracles on a 65mm scope. (I think the Pentax zoom eps go up to 60x, which is asking too much). Any advice appreciated.

Edit: I've just read with thanks Jmepler's advice on a Pentax thread, saying divide the focal length of the scope (390mm) by the focal length of the ep. I don't even know what focal length means, but the ep I'm looking at is called XW14, so maybe the focal length is....14? That would give a mag of just over 27x. Am I even half right?

Not too long ago this little spotter was the top dog in our discussions here because of it’s moderately low price, it had Ed glass with the option to use other brand eyepieces other than Pentax. How quickly we forget, but the Little Pentax is still here still being sold worldwide. For the cost, especially when these can regularly be found deeply discounted here in the states the Little Pentax in my opinion is one of the best value if not the best performing small spotting scope in its price range. Of all the small scopes I have handled or owned I always end up going back to the Pentax EDAII. When you consider its outstanding optical qualities, in combination to being I think one of the most versatile higher end small quality(Japan Sourced) spotting scope you can buy today .. what’s not to like. Over the years I have handled many small aperture spotting scopes, not one has ever been as versatile with giving the user the option of using so many different 1.25” eyepieces both in focal length and brands. If one has the imagination, with some basic skills the ocular port can be adapted to work with eyepieces thought never possible as can be seen with this example of a Nikon EDG FEP25 eyepiece I permanently attached to this Pentax 65 EDAII. Unless someone can point to another, this Pentax with the Nikon FEP eyepiece is the only one proven to exist :eek!: and can only be seen here :t: I say go for it Sancho, let your imagination go wild 3

 

[Sancho]

Thank you Gwen! Duct-tape is definitely the optics-loonies' friend.
I hope you and yours are well!

 

[Boogieshrew]

Hi Sancho,
The Pentax is a nice little scope. I remember it fondly. I used the xw14 which is 28x if I remember rightly.
I tried various Astro ones too but the XW was my favourite. I wish I had bought the xw20 (19.5x) but I went down the scope rabbit hole and sold the Pentax and am now several models further down the hole.
All the best, Martin

Ps. It’s very compact so great for travel.

 

[gcole]

Thank you Gwen! Duct-tape is definitely the optics-loonies' friend.
I hope you and yours are well!

Yes, Duct Tape is the universal tape used throughout the known universe . When those space ships finally appear in the sky above all our government capital building’s all our government leaders will just have to wave their rolls of duct tape high over their heads. Once those invaders from outer space realize we have advanced Repair Duct Tape Technology, they would not dare to attack such a advanced species they call “ Pink Skinned Humans ”. :-O :-O :-O. .. Yes, I am well as with everyone I love. Thanks for asking .....Gwen

 

[eitanaltman]

I used the PF65 for years and my favorite ep was the XW14. The 28x view with the extreme wide field provided by the XW14 on this little scope is virtually identical to the view through alphas at 30x. If that's enough mag for you, there's really not much need to carry anything bigger, heavier, or pricier.

Unfortunately I never found a zoom that made me happy with it and the image seems to degrade considerably once you get to 35-40x. A good sample of this scope would shine with a 15-45x wide FOV zoom but for the years I had it the Baader was never a proper fit.

I'm not particularly interested in doing any modifications or making my own adapters, and I love wide field zooms, which means the little Pentax isn't a great fit for me anymore. But it's really an all-time "bang for the buck" gem and for someone who likes a fix wide field view the PF65 + XW14 combo is virtually unbeatable for the price and compact package size.

 

[jring]

Hi,

yes, the Pentax XW series is highly prized in the astro scene for nice moderate wide angle views with good eye relief in a small package (sorry, no, 68 degree afov does not qualify as extreme wide angle - that would be 82 degree and beyond). But they are also quite expensive... and the xw14 is considered the weakest of the series due to some field curvature...
Which otoh might work to counteract the field curvature of the short focal length spotting scope body - was the image with the PF65 and XW 14 sharp to the edge?

Joachim

 

[Alexis Powell]

I love the idea of the astro eyepiece versatility of the Pentax scopes, so tried several Pentax PF65 and at least a couple PF80 but never found one up to the resolving ability of any of the several Nikon 60ED, 78ED, and 82ED scopes that I've used. With premium eyepieces, the views were nice but in direct comparison didn't match the level of finest detail. It left me with the impression that assembly standards are on the low side for the PF series and that, if planning a purchase, it might be even worthwhile than usual to screen a number of samples to find a cherry.

--AP

 

[eitanaltman]

But they are also quite expensive... and the xw14 is considered the weakest of the series due to some field curvature...
Which otoh might work to counteract the field curvature of the short focal length spotting scope body - was the image with the PF65 and XW 14 sharp to the edge?

It's been many years since I had this combo but from memory it was basically a pristine image edge to edge, perfectly clear and crisp with almost no color fringing. But, again, it was many years ago and I may not have been as aware of things like field curvature or edge sharpness.

I love the idea of the astro eyepiece versatility of the Pentax scopes, so tried several Pentax PF65 and at least a couple PF80 but never found one up to the resolving ability of any of the several Nikon 60ED, 78ED, and 82ED scopes that I've used. With premium eyepieces, the views were nice but in direct comparison didn't match the level of finest detail. It left me with the impression that assembly standards are on the low side for the PF series and that, if planning a purchase, it might be even worthwhile than usual to screen a number of samples to find a cherry.

AP - totally agree, which is what I was getting at with my comment about the 65 being problematic at higher magnifications. The truth is it's a lot easier for a decent 65mm ED scope to look great at ~30x than at 40x or 50x magnification (or more).

So if you are happy with a fixed, wide field eyepiece at 30x or less and you want an inexpensive, compact package, the Pentax is great. Although I wouldn't argue with you for a minute if you preferred to find a used Nikon Fieldscope 60ED and a fixed wide eyepiece.

But if you want higher power and/or a wide field zoom, the Pentax isn't a good choice IMO. I would seek out a used Swaro ATM/ATS 65 with the 20-50x wide angle, or if the budget is skimpy you can get a Vortex Razor HD 65mm body much cheaper and use the Swaro zoom with it.

 

[mayoayo]

I bought at least three of the original PF65ED,more than 15 years ago (maybe 18?)when it was first released.The star test was horrible on all and the variations on aberrations were amazing.. All kind of colors and shapes.!.. But the image was good... If you stayed low power. At the max magnification of the zoom range, non of the scopes had enough resolution to be usable..soft images and a lot of CA for an ED scope, but it was my first decent scope( I kept one for years, coupled with the Swarovski astronomy zoom!!!!) and up to 30x performed great..It was also compact, had great coatings /contrast, a nice case and I didn't know better, so I loved it.. But I don't think is a great scope for someone that has used the best and expect some performance.. I had a 65 regal that was WAY better, but I don't know if they have any unit to unit consistency either..

 

[Singlereed]

Hi there, I enquired a couple of weeks ago about availability of that Pentax scope and eyepieces in Europe. Apparently, they can get the scope and a couple of the fixed eyepieces (XW7 & 20) but most of the rest of the range is not in stock with the distributors; delivery was unclear but probably 4-6 weeks. You could get the scope (Bristol Cameras have good prices) and then try and find your chosen eyepiece somewhere in stock elsewhere in the EU. I decided not to bother in the end as I reckoned it could be a bot tricky to assemble what I wanted, let alone see it and try it so I went for an Opticron MM4 ED 60 and the latest SDL v3 eyepiece - its a bit more expensive but I was able to try it all and it's quite easy to find the other eyepieces and accessories in stock in the UK.

 

[eitanaltman]

The Opticron 60 ED is a great little scope (as is the 50!) and it's what I have now (SDL v2). I prefer zooms in general, although I do wish it had a wider FOV.

The Pentax ED is superb as a VALUE, not in the absolute sense. I certainly wouldn't bend over backwards and deal with importing and waiting several weeks for that scope. The value proposition evaporates when it becomes a hassle.

 

[Sancho]

Thanks to all. I abandoned the idea, and pulled the trigger on a Zeiss Victory Diascope 65mm with the 15-45ep. It's described as new, boxed etc. How it survived seven years unsold is anyone's guess but we'll see how it fares when it arrives!

 

[gcole]

Thanks to all. I abandoned the idea, and pulled the trigger on a Zeiss Victory Diascope 65mm with the 15-45ep. It's described as new, boxed etc. How it survived seven years unsold is anyone's guess but we'll see how it fares when it arrives!

Sancho. ... I am sorry you have given up on the Little Pentax. Even with its limitations, given a chance with the right fixed eyepieces .... say in the 16 power to 20x I believe it would hold its own if not beat any 65mm spotting scope you can buy today. One does not have to go to the extreme with the example I made with permanently attaching a Nikon FEP 25W eyepiece to the Little Pentax as can be seen here .... using the Pentax’s XW14 or XW20 eyepieces with this scope will prove this. If you were not so far away, if you were here in the states I would send this to you so you could compare the view to the Zeiss in the 20x power.

 

[CMB]

A lot of folks comment on the Pentax XW eyepieces being very good when paired with the Pentax scopes. But if you read some more recent reviews of astro eyepieces the Televue DeLite equals it, and in some situations has improved resolution. While the Televue DeLos has been rated by a number of reviewers as having better optics across the board than the XWs. Both Televues have easier eye placement and are more comfortable to use. (and yes, I have compared the 14mm XW and the Televues listed myself, and I also found the Televues to have easier eye placement and to be more comfortable).

This is one of several reasons we went with the Telvue DeLite and DeLos eyepieces in our Pentax scopes.

The Pentax XW series provides some drizzle, fog, splash protection that the Televues lack, but there is no reason you can't have both eyepiece lines in your kit for different conditions.

What I do find interesting is the current need to have a zoom eyepiece on all scopes. Viewers will accept a substandard zoom eyepiece over a high quality fixed eyepiece. Sure costly zooms have greatly improved, but they also may sacrifice other traits one might need (eye relief), or like (a large sweet spot).

The spotting scope industry has reached a point where there are very few brands that offer fixed eyepieces, and those that do offer a very limited variety. Most setups have zoom eyepieces. If that one zoom eyepiece that Brand A sells doesn't work for you for some reason, then Brand A is out of the running as a scope option. Or if Brand B's zoom does work for you, but is 4x what you can afford, then what other options are out there?

I am also surprised at the number of people who buy a scope that takes astronomy eyepieces, then spend as little on an eyepice as possible and comment that it's a bad scope. The eyepiece is a very critical component on a scope and should not be cheaped out on.

This is why I like the Pentax PF line, and the approach of the Celestron Regal M2 line. The buyer can find an eyepiece that meets their need without being locked into one option.

 

[eitanaltman]

A lot of folks comment on the Pentax XW eyepieces being very good when paired with the Pentax scopes. But if you read some more recent reviews of astro eyepieces the Televue DeLite equals it, and in some situations has improved resolution. While the Televue DeLos has been rated by a number of reviewers as having better optics across the board than the XWs. Both Televues have easier eye placement and are more comfortable to use. (and yes, I have compared the 14mm XW and the Televues listed myself, and I also found the Televues to have easier eye placement and to be more comfortable).

In my case, I haven't owned the Pentax scope in close to a decade, so those eyepieces didn't exist

I'm just commenting that the XW views were brilliant back in the day when I had it.... not at all in doubt that even better options exist now.

What I do find interesting is the current need to have a zoom eyepiece on all scopes. Viewers will accept a substandard zoom eyepiece over a high quality fixed eyepiece. Sure costly zooms have greatly improved, but they also may sacrifice other traits one might need (eye relief), or like (a large sweet spot).

While I do agree it would be nice to have more options, the fact of the matter is that the modern crop of zoom eyepieces are no longer "substandard" or much of a "sacrifice" vs fixed eyepieces for field use. And even if there is arguably still a small optical sacrifice at a given magnification, the versatility and convenience FAR outweighs it for a field user (birder, hunter, etc).

I'm pretty confident nobody who uses the Kowa 25-60x WA zoom feels like there's any sacrifice in clarity, FOV, or sweet spot size. Sure maybe there's some extra barrel distortion on the low end or maybe a dip in eye relief in the middle of the range, but the convenience more than makes up for it as a field instrument.

Carrying multiple eyepieces and changing them in the field is a huge pain. Every time I've tried it I hated it, and I would never want to do it when I'm out in the field birding. Extra stuff to carry, potential for getting dust in the optics, etc.

For many types of birding the versatility of switching magnifications *without* having to change the eyepiece is of enormous benefit. You can spend 95% of the time with a very convenient, wide angle 25-30x view and then wait, what's that shorebird over there? and boom, you're at 50-60x and can make the ID. No muss no fuss.

Of course not everyone uses their scope in the same way, and if you're mostly doing stationary viewing from your deck or using the scope for astronomy, then having multiple fixed eyepieces and changing them is no big deal. But *in the field* it is a really big deal, so it shouldn't be any surprise that a MASSIVE increase in convenience and versatility is preferred by most end users to a slight increase in optical quality. That was true 10-20 years ago when zooms were clearly inferior, and the fact that modern wide angle zooms have come so far in quality is why the zoom has basically killed the fixed EP in contemporary birding scopes.