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Binoviewers and Correctors

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Posted 17 May 2003 - 12:18 AM

Binoviewers and low power optical correctors offered by Siebert Optical and Denkmiere Optical

These two Optical companies have raised the level of Binoviewer innovations. Over three years ago, Siebert Optical had pioneered the low powered optical corrector that today is known as the OCA, it can be used with all binoviewers. It was 1.7x back then, and now they offer 1.25” and 2” optical correctors in powers of, 1.3x, 1.8x and a 1.5x or optional 1.3x that comes with the most innovative binoviewer to date, the 2” binoviewer. Their 1.3x and 1.8x optical corrector, have been optimized to be used with all binoviewers. Denkmiere Optical has their low power corrector that came out one year ago and is called the OCS. It to is made in a 1.25” and 2” format, and works at 1.2x, and is optimized to work with their binoviewer.
Denkmiere has also done a little pioneering themselves with the making of an innovative f/5 focal reduce to be used with its binoviewer for use in SCT’s. Not long after Denkmiere Optical came out with their focal reducer, Siebert Optical came out with their version of an f/5 focal reducer that works with all binoviewers in SCT scopes.
Within the last two months or so, both optical companies have put together package deals. Siebert Optical came out with an offering of their Black Night binoviewer and 1.8x optical corrector and wide field eyepieces for under $600.00. To see their other package offerings go their website. Not long after Siebert Optical started the offerings of their packaged deals, Denkmiere came out with a kit offering of their own, and you can also go to their website to see their kit offerings. The fit and finish of both binoviewers are of the highest quality.
Where all other company's have not done anything to update their units, I feel that the Binoviewing world is going to start seeing a lot from the likes of Tele Vew and others, because of these two company’s.

Here is a short observing report I have done with each binoviewer in the last two day’s.

I will start with the multi-coated Black Night from Siebert Optical.

When I opened the case that the unit came in, the first thing I noticed was the work that went into the eyepiece holders. These eyepiece holders are self-centering, and the eyepieces are held in place by a compression ring. To lock down the eyepieces all I had to do was twist the upper part of the eyepiece holders (super smooth) and that was all that was needed. As I worked the unit checking the inner ocular distance out, I could not get over how smooth the unit worked, no roughness or stiffness at all, just nice and smooth.
The only other thing left to do was to take the unit outside and give it a good test on planetary and deep sky objects, with and without its 1.8x optical corrector.

Planetary and Lunar observing 05/13/03

I used my 7” f/10 Intes Mak and my 6” f/8 APO for the testing of this binoviewer, do to the fact that I can really push the power with these two scopes, on planetary objects. Jupiter was the target, so I placed a pair of 12.5mm Ultima’s into the bino, and placed the setup into my 7” Mak and checked for out of field reflection by letting Jupiter drift into view, and no reflections were seen. Next I quickly swung the scope over to the moon and let it drift into view, and still no reflection was seen.
I observed the moon at powers as high as 350x in the 7” f/10 Mak, and the view was nice and sharp, with lots of contrast. The low power views would give that 3D affect, while the high power views would give a gain in low-level contrast views over a single eyepiece set up. When using the 1.8x optical corrector, the image seemed brighter, which I would not think possible with the extra glass elements.
On Jupiter I used the 1.8x corrector with the bino and a pair of 12.5mm Zeiss orthos with my 6” APO. The first thing I noticed was how the image snapped into focus with ease. I put in a pair of 6.7mm Meade UWA eyepieces to up the power over 300x. There was a wealth of small-scale detail within the belts and zones (lighter bands are called zones, and the darker bands are called belts), particularly at the boundaries. There was, wavelike features of all sizes and colors, with ovals being seen as well. One of the best views I have had of Jupiter when using a binoviewer.

I did not do any deep sky observing with my 12” f/10 LX200, as the Moon was 94% illuminated, so a good test of deep sky objects will come at a later date.

A short observing report using the Denkmiere Deep Sky binoviewer

The Deep Sky binoviewer also came in its own case, and was order by my son in-law with the 2” OCS. This binoviewer also comes with very well made self-centering eyepiece holders. As I worked the unit checking the inner ocular distances, I liked the smoothness and noticed no stiffness at all.

Planetary and Lunar observing 05/13/03

The first thing I did was to check for out of field reflection. I used my 7” f/10 Mak, and put a pair of 12.5mm Ultima’s into the binoviewer. I used Jupiter and let it drift into the field of view, of which I did not notice any reflections in the Denkmiere. I than swung the scope on the Moon and let it drift into view, and again no reflection was noticed.
I observed the Moon with powers as high as 350x with the 7” Mak, and the views were nice and sharp, with lots of contrast. The low power views did give that 3D look, while the high power views gave the same gain in low-level contrast as the Siebert Black Night binoviewer did. No advantage was seen in one binoviewer over the other on the Moon.
When viewing Jupiter using the 6” APO, and using the 2” OCS. I had noticed that the only way to give a good comparison was to set-up my son in-laws 6” APO also. My scope had the Black Night in it and my son in-laws scope had the Denkmiere. Both binoviewers showed the same amount of low-level detail. The only difference was that the Black Night and the 1.8x OCA seemed to come to focus easier than the Denkmiere and the 2” 1.2x OCS. The only thing I did notice when using the 2” OCS, is that when Jupiter was in the field of view, there was minor ghosting. Being that there was no out of field reflection, my first thought was that it might be the Ultima 12.5mm eyepieces. So I used a pair of Olympus eyepieces, and then a pair of Zeiss, but the in field ghosting was still there. Without the 2” OCS, and the binoviewer used in the 7” Mak, no in field ghosting was seen. Until I can find out what is going on with the 2” OCS, I have to give this one to the 1.8x OCA.

I like these two binoviewers very much, as one has no great advantage over the other. Both are very well made, and fully illuminate a 30mm eyepiece.


7" f/10 Mak / 6" APO
10LX200 GPS / 12"LX200 GPS

Black Night / Denkmeire
Siebert 2" / BW Optik
Zeiss / Siebert 1.25"

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