What is wrong with my Baader TZ4

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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Ljungmann
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Re: What is wrong with my Baader TZ4

Post by Ljungmann »

This has been very interesting. I really respect Rupert point of view as a dealer. But Alexandras tests shows that we should look after tilt problems with our TZ4 or TZ2.
The talk had put me closer to nail my own problem with tilt in the system. I can see it with my 0.3Å SS filter but minor to Alexandras TZ4. And interesting note is that my 0.6Å Quantum filter is not much affected. It tells me that these extreme fitlers really need "more than straight light" to work perfectly.
But my dealer TS is great to work with if I need to replace the TZ4.


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Re: What is wrong with my Baader TZ4

Post by Astrograph »

Tilt with rear mounted filter systems is a common problem because the image train is always very long. That on its own will magnify problems.

This is not helped by the fact that many of the focusers out there have poor load capacity and resistance to tilt. I check all the scopes I sell and the amount which have sloppy focusers is unreal.

It is also not ideal, that after spending significant sums of money on filters and telecentrics etc, users then decide to rely on 2" nose pieces and compression clamps as a means to join everything together. This is the very worst way to connect such an image train (or test it for tilt!). These can work but will usual slip, move off axis or both. You should always use something that is either screw based or dovetail based. You then know everything is properly supported and should be on axis. The significant bending load on the TZ is also prevented.

Baader already offer such a set in the M68 Compendium ( https://astrograph.net/epages/www_astro ... AGBPM68COM ). It is viewed as expensive but it is only a small percent of what they have invested in everything else. You can also make up part of this kit from individual parts as the kit cost is not really a saving over doing that. I would advise this so the actual filter can be screwed in place rather than using a nose.

It is correct that tilt does also affect filters with narrow bandpass more. It has the same effect as using a barlow or a poor telecentric. Daystar suggest that at F25 a 0.5A filter will act more like a 0.7A. In reality it has been shown that despite the accepted wisdom of using F30, going above this will usually result in a slight reduction in the filters quoted bandpass. Getting the beam angle absolutely square to the filter is very worthwhile where imaging is concerned. Above F30 causes problems visually because the optical limits of eyepieces are already reached based on the 2x f ratio = optimum focal length of eyepiece for max sharpness / contrast.


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