Jump to content


Photo

First light with 10" Zambuto mirror

  • Please log in to reply
13 replies to this topic

#1 City Kid

City Kid

    Vanguard

  • *****
  • Posts: 2342
  • Joined: 06 May 2009
  • Loc: Northern Indiana

Posted 30 May 2011 - 11:59 AM

As someone who has given a lot of thought to upgrading the optics in my Orion XT10 I couldn't say yes fast enough when I was given an opportunity by Carl Zambuto to test drive a 10" Zambuto mirror. I've never doubted that a premium mirror would be better than my stock mirror but I've wondered if the improvement would be easily visible in the eyepiece and would it be enough of an improvement to justify to myself spending the money. When it gets down to it I simply don't care if a mirror bench tests better than mine if my eyes can't see the difference when I'm observing.

Last night was actually my second night out with the Zambuto mirror but the first night was spent trying to view Saturn through thin clouds that were more thick than thin. Even so, I saw that night what a big difference there was between the Zambuto mirror and my stock mirror. All I needed was the amount of time it took me to bring Saturn to focus and I could see the difference. The Zambuto mirror snapped to focus in a way that my stock mirror never did. When I got up to 400x and the view was almost as sharp as it's ever been at 240x on a good night I'm sure I had a huge grin on my face.

Last night still wasn't a great night but I could at least see stars so I went out and hunted down a couple bright objects. M13 is an object I've viewed a lot under just these sky conditions so I went to it first. The difference in contrast was easily noticeable. The sky was washed out to the point where I was struggling to see any of the stars in Hercules with my naked eye yet the cluster stood out more against the background than what I'm used to. There was a sharpness and clarity to the view that I normally only get from my refractor.I went to Epsilon Lyrae and at 92x the split was much easier to see than usual at that magnification. When I moved the scope to Alberio one of the things that struck me was how much the view reminded me of my refractor and that's what I've wanted all along.

There was nothing subtle about the difference between my stock mirror and the Zambuto. The difference was quite apparent. Although I was unable to make a direct side by side comparison between the two mirrors my XT10 has been my most used scope since 2002. I am very familiar with it and how everything looks in it. I'm confident that if I did have them side by side it wouldn't take a super experienced observer to see the difference.

Ever since I got my NP101 I've felt that my choices have been the sharpness and contrast of my refractor vs. the bigger, brighter views of my XT10. I wasn't sure how much sharpness and contrast I could expect out of a reflector vs. a refractor. Now I know.

I'm still looking for a good night under a dark sky to see how this mirror performs on faint, extended objects (my primary interest). I hope to have a little more detailed report after a couple of better nights but I've already seen enough to know that, for me, the difference between the Zambuto mirror and my mirror is worth the cost.

If you would like to see for yourself, with your own eyes, go to the 10" Zambuto Mirror Project thread in the Vendor Forum. It's a wonderful opportunity that I urge you to take advantage of if you've ever wondered what a Zambuto mirror is all about.

Another thread of interest is here

#2 GeneT

GeneT

    Ely Kid

  • *****
  • Posts: 12711
  • Joined: 07 Nov 2008
  • Loc: South Texas

Posted 30 May 2011 - 02:47 PM

Zambuto is gaining an outstanding reputation for all his mirror types. I have always felt that paying extra for good optics is money well spent. The problem is that some of the less expensive optics are also excellent. If money is tight, a person could take a two step approach. Buy the less expensive optics, and have them tested. If they are mediocre, then have them refigured, or buy some premium optics.

#3 Relativist

Relativist

    Skylab

  • *****
  • Posts: 4138
  • Joined: 11 Oct 2003
  • Loc: OC, CA, USA

Posted 30 May 2011 - 04:49 PM

Since my primary tested outstanding I will be directly testing this theory. It's one of the main reasons I signed up.

#4 Bill Jensen

Bill Jensen

    Mariner 2

  • *****
  • Posts: 221
  • Joined: 23 Oct 2004
  • Loc: Springfield VA

Posted 30 May 2011 - 04:58 PM

Great report! Let's hope you can get some dark sky observing soon. It will be hard to give it up, won't it?

#5 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1768
  • Joined: 24 Feb 2006

Posted 30 May 2011 - 06:35 PM

There was a sharpness and clarity to the view that I normally only get from my refractor....

Ever since I got my NP101 I've felt that my choices have been the sharpness and contrast of my refractor vs. the bigger, brighter views of my XT10. I wasn't sure how much sharpness and contrast I could expect out of a reflector vs. a refractor. Now I know.


That is exactly the experience I had when I acquired my 8-inch f/6 ZOC dob. It effectively ended my refractor period. Now I have the 10-inch to go with it, and I think about perhaps moving up from my 16-inch Swayze to maybe an 18- or 20-inch Zambuto.

I think you'll find DSOs to be very nice in the mirror as well, although the difference might be more subtle, particularly since you'll be working from memory to make the comparison, and there are so many variables. However this turns out, I bet there's no going back for you at this point!

-geo

#6 Don Allen

Don Allen

    Viking 1

  • -----
  • Posts: 881
  • Joined: 07 Jul 2005
  • Loc: Charleston, SC

Posted 30 May 2011 - 08:39 PM

Was the removal of the existing mirror and replacement with the ZOC mirror an easy change or were there some adjustments to be made?

#7 City Kid

City Kid

    Vanguard

  • *****
  • Posts: 2342
  • Joined: 06 May 2009
  • Loc: Northern Indiana

Posted 30 May 2011 - 09:04 PM

Was the removal of the existing mirror and replacement with the ZOC mirror an easy change or were there some adjustments to be made?

It was an easy change. The Zambuto mirror was slightly smaller in diameter so in order to keep the mirror centered in the cell I took a cardboard box and cut three small spacers and placed them 120ยบ apart in the cell between the edge of the mirror and the cell. Now that I know I'm going to keep the mirror I'm going to find a better solution.

#8 City Kid

City Kid

    Vanguard

  • *****
  • Posts: 2342
  • Joined: 06 May 2009
  • Loc: Northern Indiana

Posted 30 May 2011 - 09:18 PM

[quote name="george golitzin"]I think you'll find DSOs to be very nice in the mirror as well, although the difference might be more subtle, particularly since you'll be working from memory to make the comparison, and there are so many variables.[quote]

Working from memory can certainly present a problem but in this case I think I can reliably judge. There are objects I've returned to numerous times throughout the years with this scope and I'm very familiar with their appearance in my stock mirror. Any major difference is something I will notice even with the other variables.

Which of your Zambuto mirrors do you like best? The 8" or the 10"?

#9 george golitzin

george golitzin

    Surveyor 1

  • *****
  • Posts: 1768
  • Joined: 24 Feb 2006

Posted 30 May 2011 - 10:26 PM

Which of your Zambuto mirrors do you like best? The 8" or the 10"?


That's a toughie. They have different characteristics and are in very different scopes. Of course, I prefer the 10" for DSOs because the aperture difference is significant--globulars are more resolved and galaxies are more interesting. Both do beautifully on planets--again, I like the extra light from the 10-inch--but there's something extra special about the 8-inch. Is it because it's f/6, or because it's in a flocked tube (whereas the 10" is f/5 and in an open truss), or is it somehow just a little bit better, as good as the 10-inch is? I don't know. Stathis Kafalis, a great ATMer, has a link to "Bratislav's Mirror Rating Scale,". On that scale, the 8-inch is surely in the 'You lucky b@$#@rd!' category. Looking through it is like sipping a fine wine. Lunar images, in particular, are just extraordinary, as are open clusters (pinpoints on black velvet) and planets (extraordinary sharpness). Yet most of the time I use the 10-inch, because I like the extra light!

--geo

#10 JayinUT

JayinUT

    I'm not Sleepy

  • *****
  • Posts: 3933
  • Joined: 19 Sep 2008
  • Loc: Utah

Posted 31 May 2011 - 08:07 AM

Phil,

Congrats on first light and I enjoyed your comparison to the refractor. I look forward to hearing about the DSO's. BTW we used some spacers that were similar to the mirror clip as spacers. The actual clips worked, and the mirror was loose but didn't shift. Enjoy your mirror.

#11 City Kid

City Kid

    Vanguard

  • *****
  • Posts: 2342
  • Joined: 06 May 2009
  • Loc: Northern Indiana

Posted 31 May 2011 - 10:09 PM

I enjoyed your comparison to the refractor.


The whole reason I ever started thinking about upgrading my mirror to begin with was because I wanted the razor sharp views I get from my refractor in a larger aperture. I was never sure if that was possible in a reflector. Fortunately for me I was given this no obligation opportunity to find out with my own eyes. I can see now that refractor-like performance is possible in a reflector. Right now the CSC shows all blue tomorrow night at my dark sky site. I'm taking the XT10 and the NP101 to do some side by side comparisons.

#12 UmaDog

UmaDog

    Vanguard

  • *****
  • Posts: 2052
  • Joined: 15 Sep 2010
  • Loc: Basel, Switzerland

Posted 01 June 2011 - 09:13 PM

Interesting! Thanks for the report.

#13 City Kid

City Kid

    Vanguard

  • *****
  • Posts: 2342
  • Joined: 06 May 2009
  • Loc: Northern Indiana

Posted 02 June 2011 - 05:06 PM

Well I finally had a chance to get this mirror out on a good night. I had the best view of M51 I've ever had in my scope at my normal observing site. The spiral structure was clearly visible. I've never been able to clearly see spiral structure in M51 at my yellow zone site and I've spent a lot of time looking. The best I've been able to do is see hints of the arms with my stock mirror. I am positive the reason I saw spiral structure last night was the Zambuto mirror.

I was able to make a side by side comparison with another 10" dob on NGC 6144. It looked brighter and had more of a grainy appearance in the Zambuto mirror as opposed to looking more like a faint blob in the other scope. The other scope's owner was of the same opinion.

I did side by side comparisons with my NP101 as well but that's tough to do with such an aperture difference. When they were operating at the same exit pupil the sky background looked to be about the same in both scopes. The NP101 still seemed sharper but the difference isn't what it used to be with my stock mirror. The atmosphere was very unsteady last night and neither scope was taking magnification very well.

I was also able to log NGC 3912 after three other nights of staring at that part of the sky and coming up empty. I can't say with certainty that the Zambuto mirror is what allowed me to see it but based on everything I saw last night I think it was. I can't wait to use this mirror at the Nebraska Star Party!

#14 uniondrone

uniondrone

    Surveyor 1

  • *****
  • Posts: 1873
  • Joined: 05 Dec 2009
  • Loc: Streetlight Archipelago

Posted 02 June 2011 - 05:34 PM


Thanks for the report! I just installed Z-250-001 in my dob last night and am aiming for first light tonight! :woohoo:






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics