M68 ClickLock® Mirror Diagonal

This diagonal is supplied with a 2 inch Click Lock on the eyepiece-side and a M68 male thread on the telescope-side. If you also want to use an m68 thread on the eyepiece-side, then you need the M68 female adapter with the part no. #2458234. We recommend the adjustable pin type face wrench ø 2mm part no. #2450062 for installation of this adapter.

You can equip the standard 2" Clicklock star diagonal with a M68-thread using Baader M55/M68 (Zeiss) Adapter for 2" CL-Stardiagonal # 2956110 (https://www.baader-planetarium.com/en/baader-m55m68-(zeiss)-adapter-for-2%22-cl-stardiagonal.html), but then you still have a 2"-star diagonal basically. The M68-star-diagonal hasn't got this simple option for reconfiguration to 2"-SC-thread. But you can use - Baader M68 Conversion Ring # 2458195 to change the male M68-thread of the star diagonal to a female thread (https://www.baader-planetarium.com/en/baader-m68-conversion-ring.html) - M68 to 2" UNFi Conversion Ring # 2458232 to change the female M68 to female SC-thread (https://www.baader-planetarium.com/en/m68-to-2%22-unfi-conversion-ring.html) - Baader 2" NexStar locking ring. # 2458270 as a counter nut to set the orientation of the star diagonal at the telescope (otherwise it would stop wherever the thread ends). https://www.baader-planetarium.com/en/baader-2%22-nexstar-locking-ring..html Of, course, this isn't a cheap solution as one more adapter is required, but I'd recommend the NexStar Locking ring whenever you want to screw a star diagonal onto a Schmidt-Cassegrain.

This will not work. You need the ClickLock 2" 2956100 and unscrew the 2" barrel on the back. There is a 2" inner thread that can be connected with the telescopes 2" thread. And there in between you can mount the Locking Ring, the part 2458270, so that you can arrest the mirror in any direction you want

We received this question (with more content and images) via email and published the question & answer including images on our blog: https://www.baader-planetarium.com/en/blog/optical-tube-lengths-of-2-clicklock-and-bbhs-mirror-diagonals/

If you want to observe the sun in H-Alpha, we recommend the standard dielectrical Clicklock mirror (# 2956100) in combination with a suitable filter combination, because the dielectrical filter reflects less radiation below 380nm and above 740nm. This way, the mirror can reduce the strain on the following filters at least a little bit.Please do also use an energy rejection filter in front of the telescope to reduce the strain on the filters as much as possible. We highly advise against visual calcium observations of the sun - the 397nm of Calcium are already ultraviolet radiation, and UV-radiation can cause phototoxic reactions which can harm your eyes. In addition, even young people can't see these wavelengths very good, and sensitivity decreases with the age. Because of this, the eye doesn't feel if the intensity is much too high. If you now try to increase the amount of radiation (e.g. with another mirror) to achieve a brighter image, you will increase the risk for eye damage. According to the newest norms for eye safety and to ophtalmologist conclusions, the sun must not be observed visualy at 397nm. We highly advise to only observe the sun in calcium photographically, then you also do not need a star diagonal. We can't understand why some manufacturers promote these calcium-filters for visual observations. We also advise against placing a filter so close to the focus - any energy rejection filter belongs in front of the front lens, even if this sets high demands to the quality of such a large filter. Placing the filter close to the focus will save money, because you can use a much smaller filter, be we absolutely can't recommend it - because of our own conscience as well as because of EU-regulations. The filter would receive all the energy collected by the front lens. We can only recommend putting the energy rejection in front of the front lens, which is the ethically and technically correct method.