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New Celestron Ultima DX 10X50 impression

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#1 RussL


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Posted 23 March 2008 - 01:12 AM

First light this past Thursday night. This is not a very technical report on them as I do not have any truly accurate tools to measure with other than a metric ruler, but I have studied the concepts of what specifications mean as applied to binoculars extensively. I'm no professor, but no dummy.

First of all, the construction feels sturdy enough. I believe they would hold up in the field. Friction is nice and stiff for iinterpupillary adjustment (the way I like it, at least). They seem to hold their position well. Also, diopter adjustment is stiff, almost too stiff for me, especially for use with the thin, almost sharp (due to the stiffness) tabs that protrude from the adjuster. Focusing is smooth with a proper resistance, but herein lies my first fault with these binoculars, namely an undue amount of play in the mechanism. This is most annoying to me, making it difficult to reach optimmum focus when changing directions. I have overcome this by usually trying to reach optimum from one direction only. But this should not be necessary, of course.

Image quality is stunning to me as compared to what I have been using. I cannot compare these to higher quality binoculars since I do not have experience enough. But to those who are looking to upgrade from cheap optics and coatings I would recommend these, based solely on image quality. And the price is moderate. (I found these for one-third the list price).

Exit pupil appears to be 5mm, and aperature 50mm. I cannot speak for effective aperature or magnification.

Eye relief is too much. This is my single-most gripe with these binoculars. I wear eyeglasses, moderately thick ones, so the listed 19mm seemed to fit. I further thought that the listed specs may not live up to this (as in not accounting for the distance from the edge af the eyecup to the lens itself). I may have gotten the full 19mm from the eyecup to my eye, it seems. Whatever the number, the kidney bean/blackout effect is present. I must hold my eyes in a restricted area to reduce this effect with the eyecups fully down. Better viewing is found with the eyecups twisted up two to three mm inorder to still see the full field of view (or 90%). The effect is less distracting the further the eyecups are twisted out. Of course the field of view becomes less.

Apparent field of view should theoretically be about 65 degrees, and this appears to be the case when roughly viewing Orion's belt. I know this is not accurate, but it "feels" right.

The twist-up eyecups work well, although they are not click-stop (except at fully closed and fully open). That's ok. Theystay where I put them, but I must think about how far each one is in order for them to be equal. That's ok,too, since they are infinitel adjustable between stops.

So, overall, actually a very nice pair. They are a little bulky, not bad. For me it's the blackout that bothers me most.

I'm sure someone else could do a better job of reporting than I, but I just wanted to give my two-cents.

#2 ronharper



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Posted 24 March 2008 - 12:56 AM

Thanks for your review. Questions about the new DX series come up here from time to time, and until now, nobody had a clue. There have been the usual rumors that because the previous model was made in Japan and the DX is made in China, it must of course be a disaster that will probably fall apart in your hands the first time you use it!

I have and old-style 10x50 Ultima, and the eye relief is a bit excessive on it, too. But it's field of view is only 50 degrees, and there is no problem with blackout. 50 degrees can feel quite spacious if the sharp "sweet spot" is large. Mine is very sharp and contrasty in the center, but the edge corrections are not so good, and the feeling is claustrophobic. I bet the blackout effect in yours goes away if you use it at night to look at the stars, that's usually the way it goes as it depends on the eye pupil's opening. It sounds like raising the eye cups is a workable solution. The focus on mine has no play, but won't stay put with any pressure on the eye sockets. Your observation that the optics are obviously better than a cheapie is very good news. I wonder if the backlashy focuser is just a bad unit and might warrant replacement?

#3 RussL


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Posted 27 March 2008 - 03:02 PM

Hi, Ron,

I had almost quit looking at this post, thinking no one would reply. Just saw yours today.

No, the blackout is still noticeable out in the dark, too. But I don't have a very dark sky. Twisting the cups out does help, but then I,m missing part of the field of view. Funny, I have a pair of $30 Tasco 7x35s that have the most comfortable view of anything I've ever seen. No blackout whatsoever. They're even more comfortable than some $1000 binocs I looked through recently. They have a theoretical 56-degree afov and probably about what seems to be 5mm of eye relief. I'm probably seeing only 40 degrees with my glasses on, but I use them alot because they're so comfortable.

I forgot to mention that the Ultimas, like the ones you mentioned, are not tack-sharp to the edge. And I think that resolution could be better as well as collimation. It may just be that these are not perfectly collimated.

I could send them back, I guess...maybe. I only paid $81 for them, brand new (not from Celestron--list is $247, and I've seen them elsewhere for $159 usually). I think they were from the gray market. Although that's perfectly legal, I'll just bet it will be a real pain to return them and get them back, or get a refund. Besides, even if I try to, my wife will roll and roll her eyes at me. Why do they do that when you're analyzing something, saying, "You're never satisfied with anything"? Ever hear that?

Anyway, I'll just keep them and try to learn some more before I buy another pair. Thanks so much for replying to this post.

Russell :bow:

#4 brt209


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Posted 08 May 2008 - 01:48 PM

Hi there,I posted a quick review nearly 2 years ago on this forum to warn peope that these binoculars were optically a piece of garbage (despite being very well built)...out of collimation,flaring,poor sharpness etc...
The title of the thread was "Celestron Ultima DX 10x50 big disappointment".


#5 cota_scope


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Posted 08 May 2008 - 05:17 PM

big disappointment is right, had a pair not good at all unless i got a reject. john

#6 ronharper



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Posted 09 May 2008 - 12:15 AM

Thought you'd died for sure. Or gone blind at least.

#7 Geo557



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Posted 09 May 2008 - 11:46 PM

Nice to see you back John!

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