If you were me. (1 Viewer)

and you could have just one eyepiece and you liked to look at all sorts of creatures big and small plus do some digiscoping with a Pentax PF 65ED II Angled Spotting Scope what would your choice be? that might unanserable huh. zoom or fixed hows that.

thanks, kirklyn

Hi Kirklyn,

Most folks tend to gravitate towards 30x (±5x) when using a fieldscope visually. It is usually the best compromise of image brightness (~2mm exit pupil) and magnification in most lighting situations for scopes 50mm-88mm in aperture. Zooms are convienent choices but typically restrict you to sodastraw-like FOV and tight eyerelief.

I like the Tele Vue 13mm Nagler Type 6 when used in the Pentax 65ED. Its awesome ultra-wide 84° AFOV is sharp edge to edge with no pin-cushion or field curvature. Eye relief is tight at 12mm though so if you wear glasses then the Pentax 14mm XW or 12mm XF with their 20mm eyerelief are better choices. BTW, the XF's are small and light and were designed specifically for the 65ED scopes.

hope this helps,
Rick

PS. if you want to take pics or digicam, then a long eyerelief widefield eyepiece in the 19mm-22mm focal length range are better choices because you will need bright images to get decent shutter speeds so your pic stay sharp.

I'd get (and I got) a Vixen 8mm - 24mm Lanthanum (see it here: http://www.adorama.com/VXLAZ.html ). This eyepiece has great eye-relief and is very sharp through the zoom range. It is quite a bit better than the standard zoom eyepiece Pentax supplies with the scope kit. If you want to spend more money, the Pentax XW zoom eyepiece is even better, but very expensive.

Ooh, ooh, ooh! (hand raised) I know this one!

Pentax XW14

It'll yield 28x with an apparent FOV of 70 degrees. It has 20mm of eye relief and a great, infinitely adjustable eyecup. It's also waterproof and optically brilliant. Part of the eyecup also screws off leaving 39mm (I believe) male threads to thread on your digiscoping doodads.

BTW, I've tried Naglers on both my PF80 and my brother's PF65 and don't like them nearly as much. They exhibit rectilinear distortion, show much greater color fringing, and have (relatively) poor eye relief. They're not waterproof either, which for a birding scope is fairly important IMO.

Rah, I have the same question as Kirklyn. You mention the pentax xw zoom, I cant find it on the pentax site but I did find an xl zoom. Is this the same one?

Oops, sorry about not responding sooner! I also looked around for the eyepiece I mentioned and cannot find it either. I know they used to make a higher-quality zoom eyepiece, and I am pretty sure it was in their XW line of premium eyepieces. But, I do not know what, if anything, they replaced it with. Their standard zoom eyepiece that comes with the PF-65 models is not as good as the Vixen I mentioned, IMHO.

The newer zoom is part of the XF series of eyepieces and developed to complement the PF65ED series spotters. The fixed 8.5mm and 12mm XF eyepieces are of very high quality with long eyerelief. They are also very small and lightweight when compared to the XW widefields and hit the magnification sweet spots of the PF65ED.

The 6.5mm-19.5mm XF zoom is also a nice eyepiece but does not share the generous eyerelief of the other two XF's. It's mag range is 20x-60x on the PF65ED.

As much as I like the XW series, they are BIG, HEAVY and EXPENSIVE. The 14mm XW is geat if it will be the only eyepiece but you certainly don't want to carry the 10mm XW and/or 7mm XW too. Those eyepieces combined would weigh more than the PF65ED! Besides, the XF's will actually give a slightly wider true field of view than the 10/7mm XWs so those really don't make much pratical sense anyway. Given the 20mm XW suffers from pretty obvious field curvature, only XW focal length that makes sense then is the 14mm.

But if you really desire wide APPARENT field of views, then there are better choices in the Tele Vue Nagler T6 line that don't impose a weight and size penalty. Afterall, if weight size were not a benefit then why get the PF65ED?

cheers,
Rick

Rick makes a good point about size. The XF zoom eyepiece he refers to is the eyepiece that I meant when I said it is not as good as the Vixen. The Vixen is moderate in size too, and actually cheaper than the XF eyepiece - i.e. it is cheaper to buy a PF body and add the Vixen eyepiece than it is to but the packaged deal of the body plus the XF eyepiece.

For a one eyepiece/all around setup there is no question- William Optics Zoom II, it gives 17-52x, bright, long eye relief, large FOV, only weighs 10 ozs. I have had the XF 8.5mm, the XW 14mm, and WO Zoom at the same time and compared all three on my PF 65 EDA II. I have also compared the WO Zoom side by side with another PF 65 ED II with the XF Zoom. WO Zoom is better. No question to me.

That looks like an nice eyepiece, and I have seen other good reviews of it (maybe on this forum). It is about $100 more expensive than the Vixen, however.

The XF line is not the same. They are nice and light, just like their 65mm scopes, but you will be much happier with an XW lens even though they are bigger and more expensive. (Pentax XW and Televue eyepieces are generally given they highest esteem.)
http://www.pentaxsportoptics.com/#section=Astronomy&subSection=Eyepieces&product=XW Eyepieces

You will think you have died and gone to heaven when you see the combination of eye relief, edge-to-edge sharpness, and color fidelity. The 14mm is about perfect for an ideal birding eyepiece for both 65mm and 80mm scopes. I have the XW 8-24mm zoom, 14mm, and 10mm eyepieces, and I hardly ever use the very excellent zoom eyepiece since I got the 14mm.

Similarly, although I used to use a Williams Optics eyepiece for digiscoping, I prefer the 14mm Pentax for digiscoping as well.

Scott

Well Scott I'm glad you chimed in as we're in the same camp here. You must feel strongly about the XWs as you've been a member for over three years and this is your first post!

I think I have an idea of what's going on here. People LOVE zoom lenses. It's the only reasonable explanation. There is not an EP out there that is going to beat an XW14 at that focal length (or near that FL), I'm convinced. The difference is that it's not also an 8mm, 16mm, 24mm, and everything in between.

It's interesting that this affinity for zooms is, by far, a terrestrial observation phenomenon. Among the astro crowd, zooms are rarer than hen's teeth as their shortcomings are well established.

It also explains the wild fluctuation regarding reviews of spotting scopes. These comparos really are tests of the various maker's ZOOM EPs as this is more important to the final results than the scopes themselves and they don't dare test them with fixed FL EPs. Pentax typically doesn't fare too well in these comparos but when people put an XW (for example) on them, all of a sudden they become a world class player.

Though the merits of a wide angle high quality EP has been made in these and other forums many times, along with the logic of a certain range of focal lengths for both spotting and viewing, people largely gravitate to their zooms. I guess zooming is fun!

Well Kevin, that was a breath of fresh air. I'll second all of that and I'm sure KorHaan would too. We both use the 23x eyepiece on our 65mm Diascopes, IMHO the best of the range but Zeiss have stopped production due to lack of demand!

John

John Russell said:

Well Kevin, that was a breath of fresh air. I'll second all of that and I'm sure KorHaan would too. We both use the 23x eyepiece on our 65mm Diascopes, IMHO the best of the range but Zeiss have stopped production due to lack of demand!

John

Click to expand...

Absolutely, John!

I consider myself lucky I got the 23x ep when it was on the brink of extinction. I keep it permanently on my Diascope. It's great!

Ronald

SJ Spangenberg said:

I have the XW 8-24mm zoom

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You'll note in the Pentax Sports Optics link you supplied that this zoom lens is no longer listed. So, apparently I am not mistaken that it did in fact exist at one time, right? Too bad they discontinued it!

Kevin Conville said:

I think I have an idea of what's going on here. People LOVE zoom lenses. It's the only reasonable explanation.
...
It's interesting that this affinity for zooms is, by far, a terrestrial observation phenomenon. Among the astro crowd, zooms are rarer than hen's teeth as their shortcomings are well established.

Click to expand...

I don't think it's all that strange that birders love zoom lenses while astronomy folks hate them. A VERY common use of a spotting scope in birding is to first peruse the scene (e.g. a shoreline) at a low power, just to see what's around (yes, you can do this with binocs, but after doing that, you do it with the scope at somewhat higher power). If you spot something interesting, you zoom in on it.

A zoom is also useful just because spotting scopes do not have finder scopes the way astro scopes do. So you first orient yourself at a low power and then zoom in.

Also, with terrestrial viewing, the shortcomings of a zoom are not nearly so apparent as with astro use.

I have no doubt that fixed eps give a better view, but at least for me the advantages of a zoom outweight the disadvantages.

RAH says-
I don't think it's all that strange that birders love zoom lenses while astronomy folks hate them. A VERY common use of a spotting scope in birding is to first peruse the scene (e.g. a shoreline) at a low power, just to see what's around (yes, you can do this with binocs, but after doing that, you do it with the scope at somewhat higher power). If you spot something interesting, you zoom in on it.

Yes, I've used a spotting scope. What you say above also applies to using an astro scope. First things first, you have to find what you're looking for.

A zoom is also useful just because spotting scopes do not have finder scopes the way astro scopes do. So you first orient yourself at a low power and then zoom in.

Not all scopes use finder scopes. Some use simple pointers that aren't functionally that different from a sighting line on a spotter. The main difference is that with a simple sighting device on an astro scope, one is in the dark. I've seen people with red dot finders on their spotters as well.

Also, with terrestrial viewing, the shortcomings of a zoom are not nearly so apparent as with astro use.

I don't know about that. Narrow FOV and short eye relief are issues with both camps, as is the "aesthetic" quality of the view.


I have no doubt that fixed eps give a better view, but at least for me the advantages of a zoom outweight the disadvantages.

Now we're at the heart of the issue. I would just argue that most of the "advantages" are just perceived advantages and, in use, most disappear.

I think one of the foremost reasons zooms are far more popular with terrestrial viewers is that they are often afield on foot and want to keep their kit concise, yet not wanting to give up all those focal lengths. The night sky observer has the luxury of being stationary, usually with a box of EPs close at hand.

Let's review:
I'm sure you're aware of the following as many are but here's some fun facts...

Kowa's 20-60 zoom yields 97' @ 20x, while their 30xw yields 126' on the 60 and 66
Swaro's zoom (20x) on their 80 gives 108', their 30xw 126'
Pentax' XF zoom on their 65 provides 117' at 20x, when the XW14 gives 132' @28x.

All while providing better eye relief

So, which EPs are easier to spot with?
These fixed wide EPs also converge where the most useful magnification is and where still friendly exit pupil lives.
Regarding the very high end of mag with a zoom, at times I'll concede it can be useful though often, unless conditions are exceptional, it is mostly "empty" magnification.. not yielding greater resolution.

Most makers have similar specs as cited above.

So I guess you are saying that the wider view of the fixed EPs overcomes the problem of their higher magnification for initial scanning of an area (e.g. a 30x fixed shows you more area than a 20x zoom). Well, I guess that would answer that objection.

I bird with a person whose scope has a fixed EP. And I have admired the view, but it seems that at least once or twice in any birding excursion he'd be wishing he could either pull back or zoom in some. For example, an owl in a tree that is actually too close for a comfortable view with the scope (no fun looking at its left nostril!), or as you say, not enough mag for a bird far away (I agree that some mag at the top of a zoom is meaningless).

Having said all this, however, I had thought about trying a fixed EP that gives about 30x (my Pentax 65 has a focal length of 390). Can you recommend any that cost less than $250, have a 70 degree angle and an eye-relief of at least 16? I might spring for one. I see Vixen makes some that meet that criteria, but there are so many brands and varieties that it is hard to figure.

Also, I do NOT want to modify my scope in any way (apparently the Williams zoom requires this, although I am not sure about their fixed EPs).

I've been following this thread with considerable interest. The zoom vs fixed debate is an old one. I've always used small astronomical refractors for birding and have used many eyepieces over the years. Right now I have a collection of seven zoom eyepieces and a drawer full of fixed magnification EPs, including the Pentax 14mm XW recommended above, The Zeiss 23/30x Diascope EP and various TeleVue Nagler and Panoptics.

Twenty years ago there were no good zoom eyepieces and all the arguments against them made perfect sense. That changed for me around 1990 with the introduction of the first Swarovski zoom, which is still an excellent EP. Now there are at least several zooms that are so good that I can't see much point in giving up the advantage of quick changes in magnification for the hassle of carrying 2 or 3 eyepieces and fumbling around to change them in the field. I seldom use my scopes below 40x except for quick scanning and find high magnification useful much of the time. If magnification above 40x is "empty" most of the time that's a bad sign for that particular scope's optics.

I think low opinions of zooms must come from experience with bad ones. I haven't tried any of the really inexpensive ones, but I have tested both of the Pentax zooms. They were the worst performers I've seen. IMO, the XF is a poor eyepiece with so much lateral color quite close to the center at high magnification that a truly sharp image is impossible. The XW I tested was not much better. I wouldn't recommend either of them. Given the excellent quality of other Pentax eyepieces it's hard to understand how they went so wrong with these zooms.

I use Baader, Zeiss and Swarovski zooms most of the time. Those have reasonably long eye relief throughout their ranges and are fully comparable to high quality wide field fixed eyepieces at high magnifications where their apparent fields are around 70-72 degrees (Baader and Zeiss) and 66 degrees (Swarovski).

BTW, my favorite of all fixed magnification wide field eyepieces (including Televue and Pentax XW) is the Swarovski 30x (15.4mm). It's an eyepiece that manages to do everything well. It has very high light transmission and contrast and a nearly flat field with almost no rectilinear distortion, astigmatism or field curvature.

Very interesting. What is your current "small astronomical refractor" preferred for birdwatching? It is an alternative I have been thinking about.

Dave this should answer your question about what astro scopes Henry uses.

http://www.birdforum.net/showthread.php?t=125302

Regards,Steve