Posts Made By: Ron Bee

Hello there Todd,

Depending on the focal length of your scope, the difference
in magnification attained by 4.8mm and 4mm eyepieces could
be large! So perhaps, a better comparison might be 4.8mm
vs 5mm ;-).

I've found that the Radians have sufficient FOV to be
satisfactory without tracking on my Dob. And with my
8" Discovery PDHQ f/6 Dob, the 6mm and 5mm Radians are
my most often used eyepiece at my location (and at times the 4mm Radian). Its clarify and brightness are close to my superb 3-element TMB SuperMonocentric eyepieces.

Ron B[ee]

It's one of the prime benefit of owning a Tele Vue product ;-). His son David seems to have similar patience and enthusiasm as well.

Ron B[ee]

As far as I know, sadly the site under the telescope section has not changed since I looked at it in Jan/Feb of ***2003***. Equally sad is the company's business models which appears to be putting updates, specification/product changes in the Yahoo eGroup instead of doing business like any other internet-aware astro-companies :-(. It is my fondest wish that the corporation will improve/change its business practice with more update-to-date advertising/information down the optical road.

Ron B[ee]

Hello there Paul,

If I maybe so bold then to suggest an 85mm TV-85, so light, so well built, so portable! And if you're already thinking of an EQ mount, why not also consider the RA axis drive which I've found will keep the Sun in the FOV for quite a very long time (this is how I use my TV-102 with the Baader solar filter on driven my SP mount). A small EQ mount will hold the TV-85 very well. And as your ambition has already suggested ;-), the Coronado filter may come in handy for this later on (I certainly drooled everytime I look through one ;-).

Ron B[ee]

Thanks Michael. I just tried my 2X Ultima barlow but the combo would not come to focus :-(.

Ron B[ee]

"Proper collimation is very important and all tools need to agree. You mentioned that in was not all dark in your auto but the Cheshire need to be tweaked."

Thanks Michael for your additional thoughts. It would have been great to have a bad mirror to look at ;-).

I did a poor job of reporting. When I mentioned that the autocollimator wasn't all dark, it was because I played with the collimation nut (as I wanted to see how the collimator works). However, when I got it collimated, the collimator did go dark. What surprised me was there was some "degree of play". That is, the Cheshire showed it's still slightly off and after I adjusted so slight and centered the Cheshire and put back the autocollimator, it still showed dark. Could this be because my mirror is f/6?

Thanks,
Ron B[ee]

Given the 3 choices Joe, I'd indubitably go with the TV-76. Being an APO, it will give you the most optimized focus light for a 3-incher and maximum flexibility for a very wide view to high power. I thought I saw one on Astromart in the $9xx range! But the largest small ;-) you might want to consider is the still highly portable TV-85 and not far behind in performance compared to a 4-incher.

Best wishes on your quest.

Ron B[ee]
PS - I've found refractor ideally suited for my hectic, impromptu observing lifestyle.

That was a great first light report, Vincent! May I ask if your Denke comes with the Power Switch X? I wonder how well does it works (as well as a zoom eyepiece?)

I look forward to more of your observation with your 4-incher ;-).

Ron B[ee]

Really superbly neat photographic-like sketch, Carlos! I've been dying to observe Uranus but no dice as mornings have already been cloudy :-(. I look forward to see more.

Ron B[ee]

Hello there Vincent,

Well, the Radian is surely heavi-er but the NT6 ain't no light weight either ;-).

I've been doing patty-cake comparison between my 5mm Radian and 5mm NT6 using my 4-inch TV-102 APO and my 8-inch Discovery PDHQ Dob (with very nice mirror) for a few months now since RTMC. Test subjects have been mainly Jupiter and the Moon. Magnification was 176x with my TV-102 and 250x with my Dob. BTW, when the seeing steadied or on good nights, the view of Jupiter was simply jaw dropping at 250x!

At first glance, the two eyepiece gave the same view (except for the difference in the FOV of course). I tried very hard to find ultra-low contrast features on Jupiter as well as on the Moon. Several time, I thought I found some really tough features that was just barely made out with the Radian and I was sure the NT6 would not show it (sort of like stacking the card comparo I would admit ;-). But the NT6 showed it too! And vice versa. Same color cast with both eyepieces: ie slightly warm compared to my TMB SuperMono. I tried to find contrast and brightness difference and failed miserably so far (whereas there were noticably difference in this area compared to my TMB SuperMono). Both are sharp to the edge of the FOV though both exhibited lateral colors near the edge of FOV as well.

The bottom line in my opinion: you can't go wrong with either. It's remarkable when I think about it - how "equal" the view looked between the Radian with 60d AFOV compared to whopping 82d AFOV! The choice then come down to simply: which do you prefer? Eyerelief vs AFOV? BTW, you can still use glasses with the NT6 but you won't be able to see the entire FOV without folding down the cup (and if you do you'll have to deal with stray light).

Lastly, there's one thing I've found superior: the Instadjust works much better for me than the simply rubber eye cup of the NT6 ;-). One caution: I found it difficult to take the *entire* view in when used on the Moon with the NT6 whereas with Jupiter it was a non-issue.

Best wishes on your quest,
Ron B[ee]