Posts Made By: Peter Bilotta

I know there is probably a very simple answer for this. Many long eye relief eyepieces like the Vixen and Orion Lanthanums drop from a standard 50 degree FOV to 45 degrees once your get into the sub-7mm range. Why is this?

Yes, I know it is all determined by the physical field stop between the upper and lower elements, but why is this narrower field necessary? What happens to the usable field if the stop is removed?

Just curious.

Sorry for the cheap Wizard of Oz parody, but the Wizards of Eyepieces seem to be churning out a large number of affordable long eye relief eyepieces lately. Our selections include Celestron X-Cels, Orion Epics & Expanses, Antares' new W70s and the venerable Vixen Lanthanums. There has been a lot of discussion of all these on this forum lately.

I've never quite understood the need for a long eye relief eyepiece above 15mm, but obviously those of us who wear glasses like them in the 5mm to 12mm range for higher power lunar and planetary observing. Given the options we now have available, is there any consensus on which ones are the best in sharpness and contrast for planetary use?

I'd appreciate some feedback on the Vixen/Televue/Meade LV Zoom stacks up against the fixed focal length LV's at higher powers (I've heard reports both ways). Thanks for your opinions.

I picked up one of the cheapo Scopetronix/GTO/Apogee 7.4-21mm zoom eyepieces (all look like the same manufacturer) just to play with it. Its performance has been nothing less than astounding for the $40 used price. Great coatings, nice eye relief, contrasty and sharper & brighter than my Vixen LVs on Jupiter and Saturn.

Does anyone know who makes these little gems or what they actually are? The almost seem like a spotting scope zoom eyepieces with a 1.25" barrel screwed on. And, why are they so inexpensive yet good? Just curious.

On a 4.5-6 inch Newtonian . . . is a 2 inch off-axis solar filter of adequate aperature to provide a decent image? This is the hole that many tube caps provide, but it seems small to me.

OR . . . in a scope this size, is it better to use a full aperature filter?

For my 6 inch f/5 I need higher power, high contrast options with longer eye relief, primarily for planetary and brighter deep sky. I'd appreciate some opinions on the virtues of going with fixed focal length Vixen LV's vs. the Vixen/Televue/Meade 8-24mm LV zoom to cut down on the number of eyepieces I own. Are either better in terms of sharpness, brightness and contrast?

Someone mentioned to me that there are old and new models of the Meade ETX-125 scopes. Does anyone know the differences between the two, particularly any external features that would allow one to easily identify one from the other? Thanks for any help you can provide.

This past week, I enjoyed another flawless transaction with an great Astromarter who sold me a Celestron MZ 8-24mm Zoom eyepiece. I had never seen one of these before, but discovered, after a little research, that it is actually the zoom eyepiece from the Celestron Ultima 80ED spotting scope.

The eyepiece appears identical in construction, mechanics and optics to a Vixen 8-24mm LV Zoom with a barrel that is 1/8 inch longer. Last night I compared it side-by-side with the Vixen and found views of both deep sky and Saturn to be virtually identical, with the exception of the Celestron zoom having a noticably wider field of view and slightly higher magnification in the 8-15mm range lengths (perhaps caused by the slightly longer barrel). All in all, extremely good.

Does anyone know if this Celestron spotting scope zoom eyepiece is indeed the same as the Vixen/TeleVue/Meade 8-24 zooms, or is it different in some way - eg: glass, coatings, # of elements, etc.

I'd like to know what I've got here. Thanks for any insight you can provide.

- Peter

The forum from earlier this week lauds the 2.5x Powermate (as does everyone who ever talks about it). For a less expensive option, how does the older Televue 2.5x barlow compare? Is its performance similar to that of the new 2x and 3x Televue barlows? I'd appreciate feedback from anyone who has used it.

A question for those optical and vision experts out there . . .

I am an experienced observer and generally used Ultima eyepieces and an Ultima barlow for my planetary observing in my 6" f/5 Newt and 8" SCT. Thanks to another great Astromarter, I acquired a Televue 2.5x barlow several weeks ago for a head-to-head comparison test. Over the past two weeks, I have done side-by-side comparisons between the Ultima & Televue barlows at identical magnifications.

As has been noted many times on this forum and in reviews, both barlows performed well with excellent contrast. The Ultima is a little dimmer and imparts a slight tan tint, and the Televue brighter and truer in color - maybe even sharper.

Here's the pickle . . . brighter, truer and sharper means better, right? That's why Televue barlows are so highly lauded. So how come I feel that I can see "more" using the Ultima? It seems that with the slightly darker and tanner tint of the Ultima, I can actually see finer planetary detail, particularly in Jupiter's cloud bands, the GSR and Saturn's subtle banding.

Frankly, I've noticed the same thing when I have used orthos - they are sharper, truer in color and brighter, but I can see more detail in the slightly dimmer and tinted Ultimas and Lanthanums.

So, I'm confused. How can dimmer and tinted beat out truer, brighter and better contrast? Is this an optical illusion, a comfort factor or something that is perhaps unique to my eye's color receptors? I'd be curious as to others' experiences and insight.