medinabrit
Well-known member
I Dont dont know about the zeiss zoom compared to the pentax zoom ,But you will find it hard to find better EP,s than the pentax xw series.
Brian.
Brian.
lachlustre said:well, actually, first: thanks to you all for all the advice in this forum. For someone like me who's just thinking about getting their first spotting scope, its been pretty educational!
I have a few questions about all the different eyepieces available for Pentax scopes:
1) A variety of astronomical eyepieces have been recommended. I'm guessing that all of these are not waterproofed in any way. How big a disadvantage is this (yes I'm stuck in a fairly wet climate, but then so are a lot of you using these eyepieces)? When you buy the scope body, having it waterproofed is a major selling point (one of the main reasons why the astronomical scopes are not always recommended for birding, right?). Why does this not apply to the eyepieces? (Sorry if this is stupid, I really am new to this!).
2) I'm considering getting a package including the 65mm scope + the Pentax zoom lens, because I found a good offer, and I don't need glasses at all, yet, wrt eye relief. Therefore, I'd also like to invest in one fixed eyepiece for digiscoping, and out of curiosity from the positive reviews they've received here (so far, I've only used zoom eyepieces). As an all-round eyepiece (price range up to $200) , what would you recommend? I'm intrigued by the Vixen Laudanum Wide range, but I haven't seen much discussion of them here.
3) If I don't get the Pentax scope, I will probably get the Zeiss Diascope 65mm (and make a bigger hole in my bank account...). Therefore, another combination that sprung to mind was the following: Pentax 65mm body + Zeiss zoom eyepiece + Zeiss eyepiece converter to 1.25". Without excessive bargain-hunting, I reckon that this will still only cost 60-70% of a brand-new Zeiss. Given some of the comments I have read about eyepieces being the critical factor in the end, and the positive reviews of the Pentax body, I am wondering whether this would basically result in me getting a scope as good as a Zeiss for substantially cheaper. I've also read that I might have some problems with focusing: would I be able to overcome them?
Well, this is only my second posting on this web-site. Forgive me if my questions are not very clear!
Rob
mmdnje said:I have a pentax XW20mm, Orion stratus 13mm and DCL-28(24mm). For general birding I prefer the XW20. For handheld digiscoping I'm using the orion 13mm with a fuji S5100 (no vignetting at wide angle). The DCL-28 is great for digiscoping with my CP4500 although sometimes the magnification is not enough.
If I had to choose one to keep, I'll keep the XW20 to wich I can also attach the CP4500 with a step-up ring as it has a 43mm thread. Jose Navarrete
henry link said:I think you will find that the best zooms have light transmission and center sharpness as good or better than complex wide field eyepieces like the Pentax XW or TV Naglers, Radians and Panoptics. Most of them, zoom or wide field, have 8 or 10 glass to air surfaces and usually have transmission percentages from the upper 80's to the lower 90's. The highest transmission eyepieces are the simple ones like Plossls and Orthoscopics. The best of those can have peak transmission between 98 and 99%. The trade off at short focal lengths is short eye relief and narrow fields. Even the highest transmission eyepieces can't brighten the image but so much at high magnification. Changing from an 90% eyepiece to a 95% eyepiece has about the same effect on brightness as changing the scope aperture from 80mm to 82mm.
I've tried nearly every eyepiece out there that looked promising. I've found that almost all premium quality eyepieces, simple or complex, have about the same center sharpness. At high magnification the scope objective is the limiting factor for resolution, not the eyepiece. That's true even if the scope objective is essentially perfect. In spotting scopes the situation is worse. Except for the rare cherry specimen, the build up of wave front error has already compromised the image before the light ever reaches the eyepiece. The eyepiece just magnifies the aberrations that are present at the focal plane of the objective. The noticeable differences in eyepieces are in edge performance, brightness and contrast. The brightness and contrast of the Pentax XW's stands up well among the complex eyepieces, better than the TeleVues. The TV Naglers and Panoptics are quite sharp at the edge, but have huge amounts of pincushion distortion which the Pentax XW's don't have. The very highest transmission complex eyepieces I've seen are the Swarovski and Nikon spotting scope eyepieces. I would estimate their transmission is perhaps 94 to 97%. Curiously, the Swarovski and Nikon zooms are the very brightest. The Nikon zoom is a real stand out, with brightness and contrast nearly as high as a Zeiss Abbe Orthoscopic.
henry link said:Sout Fork,
I doubt that you will be dissappointed in how your Pentax compares to a Nagler Type 6. I think the Pentax is superior in almost every way.
Regards,
Henry