Denkmeier II Bino OCS

[FlashDrive]

I already have this Denkmeier OCS ....came with my Denk Bino Set.

These are screwed ' IN TO ' not ' ON TO ' a TeleVue or Astro Physic 2'' Diagonal there by ' shorting ' the focal path when using the Denk Bino II in Refractors ..... completely eliminates any ' vignetting ' ( on certain f/l eyepieces ) with the Denk II Bino's....

Here is a ' clip ' from Russ Lederman showing the OCS in question.

http://www.youtube.com/watch?v=EvXlrrba8gA&feature=youtu.be

This ' screw in ' OCS does away with the standard ' screw on ' OCS generally supplied with the Denk II Bino's.

Some how I have ended up with 2 of these ' newer ' OCS .... 1 is used on my NA140 . . . the other is in a box housed in its aluminum holder.

BTW the new OCS is called ' SR ' . . . or Part No SR

Flash . . .. .

[PlanetMan]

Hi Flash

The screw 'in' OCS isn't a standard OCS for the Denk II Binos but something Denk designed subsequently as an additionally accessory - it essentially replicates the OCS system they originally had in the Denk 1s. The vignetting is dependent on the F ratio of your particular telescope relative to the eyepieces used. It is only an issue when using low power eps above roughly 22mm. As all of this was a bit confusing and frustrating for some when they experienced vignetting with the standard OCS systems from the Denk ---II s they redesigned their Binos slighly with a greater/wider degree of light path travel and 27mm prisms which solves the problem completely irrespective of whatever Denk OCS you might use. The catch of course being that the new Denk Binos are roughly $1500 but will provide a slightly brighter image for that price.

Take home message to all of this is that none of this is really a concern unless you are trying to use EPS above 22MM and then only in certain telescopes:thumbsup:

[PlanetMan]

BTW - I am not sure they still make the SR part with Binotron being their flagship bino.

The other point I forgot to mention is that this SR part was only really needed for folks using one piece diagonals such as everbites etc where the nose can't simply be unscrewed - otherwise the idea was to unscrew the nosepiece of the diagonal and attach the OCS in its place

[FlashDrive]

Quite correct on both accounts ..... not necessary with the new Binotron . . . and the SR was especially designed for the TV & AP 2'' Diagonals.( as indicated in the video clip ) . . . these work very well indeed...... they are not cheap either $275.00US + Postage from Russ.

Col . . . .