There are some H-alpha systems that also deliver impressive results at a much lower price. However, to make this possible, compromises are necessary in terms of image detail, resolution (maximum magnification), field size or durability, which we did not want to make with the SunDancer. As we all know, the last 10% of quality requires the highest effort... With the SunDancer, we want to maintain the same high quality standard for which the SolarSpectrum filters are known, so that our customers and dealers are do not have to cope with ageing ("rusting") filters or exchange orgies.
We are happy to explain the advantages of the SunDancer over competing models.
The Sundancer front blocker-filter has a hard, non-ageing coating. The Quark H-alpha filter, for example, uses...
The 3x telecentric system allows you to achieve very high magnifications or very small exit pupils very easily. A good guideline for the maximum magnification for H-alpha is an exit pupil of about 0.7-1mm, or a magnification that is not very much higher than the telescope aperture in mm. Due to the limitation to only one wavelength, the rules of thumb for observations in white light no longer apply! We were able to use a SunDancer on an 80mm refractor up to about 100x, and a few minutes later on a triband C8 at more than 200x – so before air turbulence became the limiting factor, magnification was limited only by the available aperture and not by the filter itself.
With telescopes with long focal...
All SunDancer II filters are subjected to final testing before they are released for sale. As delivered, the micrometer screw of the tilting device can therefore be used to get finetune a high-contrast image. For best results, the tilting filter (aka: the etalon) should be absolutely perpendicular to the optical path. In this optimal position, the micrometer screw is then at or near its inner stop, or at a value mentioned in the documentation. By unscrewing the micrometer screw, this etalon can then be tilted very quickly into the "blue wing" of the H-alpha line, for example, in order to quickly get a better impression of prominences without having to wait for the heater to readjust, for example.
However, it is important to know that...
The focus position of the SunDancer is pretty much the same as that of a 2" eyepiece if you use the 2" nose-piece cut into the TZ-unit. So you will usually not need extension tubes, but can simply plug the eyepiece into a 1 ¼“ or 2“ star diagonal. It is important that the telescope itself does not contain any plastic parts, but must be suitable for solar projection.
If you use a bino-viewer, the focuser must be moved inward a little further, but usually only about 1-2cm.
For photographic use, you only need extension tubes if you are working without a star diagonal. This straight configuration has the advantage that the image is not additionally mirrored and that the SunDancer is always protected from...
Unfortunately, we cannot predict the availability in general, as we usually already have pre-orders from private buyers and dealers, which will be delivered first as soon as we have new Sundancers available. Also, the etalons are grown crystals - i.e. natural products who can unexpectedly develop a high failure rate. For this reason we can never forecast how good the yield of excellent etalons will be that can be finished to produce a filter without compromizes.
This entry was posted on June 15, 2022Last modified on October 6, 2023.
Answer: 45,5mm is the value which we have for this Barlow in our design - so we did a quick-and-dirty-test of the magnification.
To do so, we used a finderscope which gives enough field of view to count the shingles on the next roof. We placed a small camera in the eyepiece clamp of the Barlow lens, so that the camera is as close as possible to the position of the field stop of the Classic Ortho/Plössl eyepieces, i.e. 2mm inside of the body.
Then I took one photo with the Barlow element removed from the body:
and another shot with the body; the camera now had to be ca. 22mm farther away from the finderscope:
Don't be too critical of the sharpness - it...
Why is the Neodymium Filter only 1mm thick?
For me, this is a problem because a) focusing and (much important) b) backfokus, sinc I have the filters between coma corrector and camera sensor.
Will this change with the coming CMOS-filters? Or can you already offer an alternative (I have got an 8" F4)?
Thank you very much!
Answer: First of all, the Baader Neodymium (Moon & Skyglow) Filter
(various versions available)
is primarily an absorption filter (just like the Semi-Apo filter), which reduces light pollution by neodymium ions in the glass melt which absorb the especially troublesome parts of the spectrum. Additionally (and in contrast to all copies which are offered nowadays) it has the dielectric coating of the L-filter (= UV/IR block filter),...
Each tilter essentially consists of 3 pairs of opposing set screws which independently move the inner tilt mechanics and are easily accessed from the side using the included hex key (Allen wrench). These screws have tapered and hardened points that bear against a precision hardened ‘zero-clearance’ steel-counterpart. The direction that each set screw moves the tilter is shown with an etched arrow next to the individual screw. On the FCCT the extra-long hex-key with handle also serves as torque-control against overtightening. As soon as the handle starts to rotate (to "flex") without continuing to turning the screw then the maximum torque allowed is reached and instead of continuing to increase pressure on that screw, the other screw in that pair first must be unlocked by a very small amount....
Within the last year (2021) we had twice the case that the pressure spring which holds the stepper motor in the filter wheel was too strongly tense, whereby the connection motor/filter wheel placed the rotating filter wheel somewhat crookedly, so that the wheel had ground at housing. As soon as this tension was reduced by stretching the pressure spring, both filter wheels were running again. We hope that this factory defect, which is obviously very rare but does occur, could also be the case with you. We apologize for the error and your trouble.
Customer reply: We can report that the defect mentioned regarding the blocking of the filter wheel was obviously indeed due to the spring. We have opened the filter wheel as well...
Baader FCCT - Filter Changer Camera Tilter
(Size: 3.4 MB)
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As a QHY dealer we do have access to all QHY cameras and when the design solution for such a "seemingly impossible product" like the FCCT I came up, we were able to use QHY cameras for all tests concerning RASA and FCCT adaptation and find out about all obstacles (there were many, one of them being the fact that not two RASA 8s have the exact same image plane position...). So for this combination we know that it works and we did add two 0.5 mm shims to enable the user to compensate for such fine focal differences. Now any 77mm diameter QHY-camera body featuring the 6.5 mm chip distance can...