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Posts Made By: Russell Lederman

September 14, 2002 06:17 PM Forum: Equipment Talk

February 18, 2003 08:14 AM Forum: Binoviewers

Siebert review of Deepsky Binoviewer (Standard)

Posted By Russell Lederman

Here is a review of our Standard Deepsky Binoviewer that Harry Siebert (as himself) posted on Excelsis a few weeks ago. The "revenge" thing: I have no clue about what it is even supposed to mean. We believe in the Golden Rule: Live and Let Live. What you would resort to doing to a competitor is obvious to anyone not in a coma.

I received one of the early models of the Denkmeier Bino's and I was quite impressed. They were not complete at that time and needed a little refinement, but that came later. I also helped them to develop an optical corrector that is now called the OCS. This was a great addition to this setup although it was not perfect, it was later improved. (2' OCS) The OCS is a little long but other then that gives good performance. The early models were a little heavy but I hear they have been lightened up a little. The light thoughput was great as you might expect from a unit that has 26mm's of aperture throughout. A slight different color was noticed from side to side but it was not objectionable and in fact this seems to be the case in most Bino's The collimation was dead on. The image quality was excellent as well. In most respects I would say it was as good as the Televue binos I have tried. Although the Televues don't seem to have the slight color difference from side to side. (Not a major issue) For the asking price they are a bargain. The OCS does raise the price some but considering the value for the price, if you have the money I would even recommend them over my 1.25 units and that's saying something (see my new review on Todd Gross's website) So for me to say this, these have to be good.

I am not motivated by a quest for revenge, so even though I have receive some bad hits on my Binos I would never resort to doing this to a competitor. I hope this honest unbiased review will set a good standard for reviews.

Harry Siebert
Overall Rating: 9
Performance:9 Value:10
Weight: 10 (Trustworthy Vote)
Date: 01/30/2003 07:24:09 AM PST
By: Siebert

July 23, 2004 08:12 PM Forum: Binoviewers

Forum: Could be better

Posted By Russell Lederman

>P.S. already know how I feel about vendors on the forums. I've never hesitated to contact you directly for info and the chance for >a more personal Howdy-do.

Sure. In some instances, I absolutely agree that Vendor presence can be a negative force. Still, vendors are people and people are diverse. I'm all for whatever one group or another decides as the rules for the particular forum. You will not have an argument from me.

I glanced at this forum less than one week ago. I recieve 30 posts per page with my browser. On the first page, over 30% of those posts were from a "vendor". That's just plain wrong. Now, my two posts are way enough for a day or two or more as far as I am concerned!

Discretion ,taste and restraint (many of us may tend to self-promote in one way or another if we eradicate our social filters) should be the order of the day for _any_ participant, and one hundred fold for a "professional".

OK, no lobby here. I'll check in when I have a chance and hopefully may add something here and there. It would be nice to see the negative association attached to binoviewers and the folks that use them eliminated.

Whether you all agree or not, I feel that this is an opportunity to turn this forum into a useful and pleasant discussion venue featuring all products rather than a vehicle for the resolution of one person's personal problems and associated anger.


August 31, 2004 10:06 AM Forum: Star Parties

Denkmeier at Black Forest

Posted By Russell Lederman

Hi all. Denkmeier Optical will be attending Black Forest in Cherry Springs SP. We will be there from Monday through Sunday. Please look for our banner. We will have quite a few demo Binoviewer Systems and we intend to lend them out to folks for use on various telescope designs. Email me or see us there for signing out a loaner.

We will also be donating a Standard Power switch binoviewer system as a door prize. Good luck!

We will be introducing our new 2" SCT Power Switch Star Diagonal as well. See our new ad under "Telescopes:Catadioptrics" in the classified section. We will have three prototypes. An SCT user can change from F/6.6 to normal to 2X instantly with a single eyepiece in this diagonal. No more screwing with the visual back of your SCT!

OK. We hope folks take advantage of using these things firsthand at Black Forest Star Party. It's a beautiful place and I can't wait to get there!

Russ Lederman/Denkmeier Optical

May 16, 2002 07:06 PM Forum: Equipment Talk

Deepsky Binoviewer

Posted By Russell Lederman

An impartial review of our product should appear soon on the Cloudy Nights web site. We welcome such an assessment and hope it turns out well.

Russell Lederman / Denkmeier optical Company

August 24, 2002 11:40 AM Forum: Equipment Talk

Canon IS binoculars 15x50 vs. 18x50

Posted By Russell Lederman

Hi Greg. I am not sure why the 18s are more money. It seems analogous to the 16X vs the 10X Fujinon situation. Maybe it is a bit more costly to retain eye relief with higher power oculars because I do not believe the Objectives would be made to any higher standard to accomodate more power.

I tested a pair of 15X Cannons. They were excellent. Under 5th magnitude skies, NGC 204 and M1 could easily be seen while hand holding this unit. However, it is a heavy binocular and after a minute or so, I needed to lay on my back. Still, it was very rewarding using these. The optics were simply outstanding to the edge of the field. Saturn at Zenith could be easily elongated and I nearly thought many times i could resolve the ring system but it was a "suspected" observation. Would the 18X unit have done the trick? 3X more...maybe but so what? This is a casual use instrument and can be gotten for ~$825 or so.BTW, the Lunar views were really good. It is strange hand hoding a binocular and seeing the Moon floating quietly with no shakes. My feeling is that the 18X is better used in daytime but there may times wjen you think that 3X more would net a feature or object that the 15 can't.

Russ / Denkmeier Optical

September 1, 2002 09:45 AM Forum: Equipment Talk

Binoviewer edge performance?

Posted By Russell Lederman

Hi Dave. The 2.5X Powermate and a 13mm or 9mm eyepiece may be creating mega amplification (4X plus). The Binoviewer should not contribute to any downfall in edge performance. I tested our Deepsky Binoviewer in a 20 inch F5 with the 1.2X OCS and found that the performance of 24mm plossls were improved on the edge over a single non-bino view with said eyepieces. I used 19mm panoptics to test for edge performance with this same setup. I let Epsilon Lyra drift from center to edge and then out of the field. The components remained beautifully divided throughout with no aberrations created.

I would recommend that until you recieve the OCS, you try a standard barlow if you have one and see if matters improve. It would be interesting if you could estimate the true amplification factor that the powermate is creating with these combinations. I have a suspicion that the 9mm may be acting like a 2mm and the 13mm like a 3mm. Do you see this field edge deterioration in other longer FL eyepieces? I have heard from someone using a 16mm Nagler type 5 plus the 1.2X OCS and the performance is said to be wonderful. Again, the 19mm panoptic field edge is close to immaculate. Seems like the extraordinary high power is the wildcard here.
Russ/ Denkmeier Optical

September 10, 2002 07:03 PM Forum: Equipment Talk


Posted By Russell Lederman

Ours and most other non-mirror type binoviewers transmit the focal plane created by an objective and other components of an optical train in the same orientation that is seen in a single eyepiece.

If you see an upside down (inverted) image in a single eyepiece view, it will be the same in the binoviewer eyepieces. For daytime viewing through telscopes that produce an inverted image, an erecting prism diagonal must be employed. This will allow you to view birds, trees etc. in their proper orintation through a single eyepiece and through most Binoviewers.
Russ/Denkmeier Optical

September 14, 2002 06:30 PM Forum: Equipment Talk

Posted By Russell Lederman

Hi all. We are trying to compile some data which will allow us to address the in-travel problem for refractors when using 2" star diagonals and a binoviewer. We want to make our OCS for low power binoviewing in refractors with 2" diagonals as efficient as possible. To do this, we would hope that those who use various brands of refractors with assorted 2" diagonals could provide us with information regarding in-travel remaining after a single eyepiece in 2" diagonal is focused at infinity. You may email us at Anyone providing information will be given a discount if they ever decide to purchase our products. Information should include:
2" Diagonal brand
eyepiece(s) used (FL and brand!)
Refractor brand used (include model)
in-focus remaining after focusing on a star or solar system object.

The data we are concerned with must come from views made with single eyepieces in a 2" diagonal in commercial refractor of any brand.

Russ/Denkmeier Optical

February 16, 2003 02:20 PM Forum: Binoviewers

Denkmaier via BW Binoviewer

Posted By Russell Lederman

Hi Markes. I had asked Mike Harvey if you climbed his ladder and also saw the “G” star in the Trapezium through the Denkmeier Standard Deepsky Binoviewer and the 2” OCS. He and several others did and also observed tack sharp images of Jupiter and Saturn. Transmission of Deepsky was deemed incredible too. Please indicate the dealers that did not like our unit as I am interested in contacting them.

You raise a few issues that I would like to address. But before I do, I would like to say that I consider you to be a reliable judge of quality. However, I do not think that you or anyone else would actually see dimmer views through the Denkmeier Standard Deepsky Binoviewer when compared to a BW Optik unit _in a telescope_. I have closely compared the two. I found the images to be brighter in the Standards that I compared to the BW Optik. But, then I am the president of the corporation. That’s why I refrain from mentioning other’s products except in rare instances like now.

(Continued next post)