Eye Relief Advice? (1 Viewer)

[rtclemen]

Hi, all. I went shopping for scopes the other day, and I was surprised. Everything I looked at seemed to have short eye relief -- much shorter than I can handle with my eyeglasses.

First, I'm surprised by this -- I had no problem finding binos with good eye relief. What's up?

Second, I'm asking for advice from other eyeglass wearers. I'm looking for a compact, 60mm scope, mid-range price ($400-$700). The Nikon Fieldscope III is the right package, but with eye relief of about 13mm, it barely worked for me at 20x. Beyond that I couldn't even come close to seeing the whole field of view. (Tried both the 20-45 and 20-60 eyepieces.)

Any other suggestions for scope-and-eyepiece package that might work for an eyeglass wearer? Thanks

 

[iporali]

Any other suggestions for scope-and-eyepiece package that might work for an eyeglass wearer? Thanks

Could you consider fixed eyepieces? Kowa has some compact, lightweight scopes and very good eyepieces with excellent eye-relief (20-32mm). I would warmly recommend their ED scopes (TS600 or TSN660), but you probably won't get them for $700 (non-EDs are $350-450). OTOH Nikon's fixed 24/30x WA has a fairly good ER (18 mm IIRC).
HTH

Ilkka

 

[RAH]

The new Pentax PF-65ED scope fits your price range. From my readings on this forum, it seems that you should buy the body and add the Vixen 8-24 zoom eyepiece (which has an eye relief of 20 throughout the zoom range), instead of the bundled Pentax eyepiece. I'm planning on getting this combo myself pretty soon.

 

[rtclemen]

Thanks!

Thanks! The Pentax-Vixen combo does make good sense. And good prices on the Pentax PF-65EDA currently. Lowest I found was $435 for the body.

Astronomers have poo-poo'ed the zoom lenses for ages, and as an amateur astronomer I've always stayed away from them. But this sounds like a great opportunity to get a zoom that would work well with my telescope.

 

[henry link]

I would try the Vixen zoom with your eyeglasses before you commit to this combination. I doubt that the 20mm eye relief spec will hold up over the entire range, although it could still be long enough even at its lowest point. I've seen actual measured curves for the eye relief of the Zeiss, Swarosvki and Leica zooms and have measured the Nikon 20-60x, Zeiss and Swarovski myself. All show pronounced drops in eye relief in the middle of the zoom range. I would be surprised if the Vixen doesn't do the same thing.

I would also consider the possibility that such a large heavy eyepiece stuck on the back of a small light telescope might create balance problems and perhaps be prone to loosening and falling off in the field since it is not secured by a bayonet mount.

 

[Humboldt Jim]

Hi, all. I went shopping for scopes the other day, and I was surprised. Everything I looked at seemed to have short eye relief -- much shorter than I can handle with my eyeglasses.

First, I'm surprised by this -- I had no problem finding binos with good eye relief. What's up?

Second, I'm asking for advice from other eyeglass wearers. I'm looking for a compact, 60mm scope, mid-range price ($400-$700). The Nikon Fieldscope III is the right package, but with eye relief of about 13mm, it barely worked for me at 20x. Beyond that I couldn't even come close to seeing the whole field of view. (Tried both the 20-45 and 20-60 eyepieces.)

Any other suggestions for scope-and-eyepiece package that might work for an eyeglass wearer? Thanks

By coincidence I just picke up the Orion branded Vixen Zoom and tried it out this noon viewing Humboldt Bay through my PF-65ED

The most spectacular viewing was at the lowest power (16.5) It is like looking through a perfect window to the extend that I forgot I was not looking through a telescope. As I zoomed up to the maximum of about 48.25x, however, I got some CA. Viewing a large sign across a 200 yd. channel I got some yellowish fringing at the edges of black letters on a white background. The day was briliant and the sun was at my back.

According to the mm scale on the eyepiece, quality started to decline at about the 10 mm focal length. I am going to compare this with a 10 mm Vixen Lanthanum fixed eyepiece later.

Overall, I find 16.5x to about 40x acceptable, particularly with the good eye relief.

Something that most birders don't consider is the use of a polarizing filter on a spotting scope. On brilliant sunny days on the water, this can dramatically improve the apparent image and reduce eye fatigue. I will be testing this with my new zoom eyepiece to see if it affects the CA at high powers.

I wish Pentax had gone to a bit more effort to make a better, compact zoom for the PF-65ED with more ER.


also, the cover zips over the Vixen eyepiece.

Happy scoping

Jim :cat:

 

[Humboldt Jim]

I would try the Vixen zoom with your eyeglasses before you commit to this combination. I doubt that the 20mm eye relief spec will hold up over the entire range, although it could still be long enough even at its lowest point. I've seen actual measured curves for the eye relief of the Zeiss, Swarosvki and Leica zooms and have measured the Nikon 20-60x, Zeiss and Swarovski myself. All show pronounced drops in eye relief in the middle of the zoom range. I would be surprised if the Vixen doesn't do the same thing.

I would also consider the possibility that such a large heavy eyepiece stuck on the back of a small light telescope might create balance problems and perhaps be prone to loosening and falling off in the field since it is not secured by a bayonet mount.

FYI, the Vixen zoom is not that heavy and is as secure in the colett as any other 1.25 eyepiece. I moved the balance plate a scosh forward on my 701 head and achieved near neutral balance.

I did not notice a significant change in ER. but then I only need 17 mm with my glasses on.

That my objective, er, occular opinion

Jim

 

[mrpjdavis]

I've got exactly the same problem with my spectacles. I am long sighted (+4.5 dioptres) and use varifocal lenses. When I tried a Nikon (80ED?) and a wide angle (40x, I think) I could not see more than a quarter of the field of view. A Swarovski was better, but not much. I eventually settled on a Zeiss 85. With that, I could see the whole field of view at 20x, using the 20-60 zoom. The Zeiss has the widest fov (Although a little soft at the edges, this is not a problem). Out of curiosity, I tried some of my old pairs of glasses-I keep them as emergency spares. One pair was even worse. Today, I made an appointment with my optician to see if she can make me a pair of glasses which will help. The problem seems to stem from the size of the distance between the eyeball and the front of the spectacle lenses. I'll let you know how I get on. In any event do try as many scopes and eyepieces as you can - and keep notes, so you really pin down the best one for you. In all probability, it will be the only scope you buy, so it's worth getting it right. (The quality remains, long after the cost is forgotten)

 

[iporali]

When I tried a Nikon (80ED?) and a wide angle (40x, I think) I could not see more than a quarter of the field of view. A Swarovski was better, but not much. I eventually settled on a Zeiss 85. With that, I could see the whole field of view at 20x, using the 20-60 zoom.

The Zeiss zoom has the widest fov but its eye-relief is actually a couple of millimeters less than that of the Swaro zoom. http://www.tvwg.nl/testrapporten/telescoop/zeisstelescopen65tflen85tfl.htm

Ilkka

 

[mrpjdavis]

Ilka
Thank you for that link - it's very interesting and I'll take a copy of it when I see my optician. It certainly explains why I had such problems with my Kowa! This met an untimely end when I fell down a cliff path. Happily, it was covered by insurance - hence the upgrade. Other problems with the Swaro were:- price (another £200), the zoom seemed very stiff and I did not like the focussing.

 

[sandokan]

For the same reason I have bough on Ebay 2 Vixen Lanthanum eyepieces, 9mm and 20mm (the last one for digiscoping). I paid 68GBP for both + shipping.
I will combine this with my Pentax 65 body, which will be bought soon (I hope...) and will give 43x (9) and about 20x (20) magnifications.

 

[rtclemen]

Field report on Pentax-Vixen combo

I purchased this combination and tried it out this past weekend. Tried it under many different lighting conditions. Here's what I found:

At 25mm, the eye relief is indeed about 20mm, and very comfortable. Beautiful image when paired with the Pentax PF-65 ED. The eye relief is NOT 20mm over the whole range (and to be honest, I didn't expect it to be). At 8 mm it's about 15 mm, which works OK with my spectacles. I have to push in a bit to see the whole field of view. The good news is that the rubber eyecup did not smudge my glasses.

By the way, the eyepiece is not parfocal with itself. That is, you zoom, and you have to refocus slightly. I guess that's not unusual.

With the scope more-or-less level, the balance is fine with the eyepiece. But it is a little back-heavy if you tilt up to look high in the sky. The retaining ring that holds in the eyepiece is very secure, though, so I wouldn't worry about the eyepiece falling out as someone suggested.

Yes, the scope's case fits over the Vixen zoom eyepiece. But the case is nothing to write home about. Compared to others it's a little cheesy, doesn't zip over the tripod mounting plate.

I compared the Vixen zoom with a relatively inexpensive set of fixed Plossl eyepieces from Orion (their "Sirius" line). The Vixen compared really well. At 25 mm, the image was at least as good. At higher magnification, it still was good (if you are really picky, you might have found the fixed eyepieces slightly better), and the eye relief was a whole lot better than those short-focal-length fixed lenses. Based on that alone I decided that the Vixen eyepiece was a keeper.

Finally, I also compared the Pentax-Vixen with my old Celestron Wildlife Viewer. No contest. That Celestron is now for sale ;-)

Thanks for the suggestion. This worked out really well for me.