BORG Modular Design

One of advantages for BORG-proprietary modular system is to allow for the easy user maintenance or improvement work. Especially users can reach each part inside after taken apart. That should be only possible for BORG. Here is one example. This white tube is 135mm long one (#7135). Originally inside tube is intended to be used with drawtube. So half portion inside has no black anti-reflection sheet, otherwise drawtube doesn’t move back and forth.  But we want to blacken there when the drawtube is removed. Here is the result.




1st image is a bit exaggerated to easily see the difference. Anyway, there is huge improvement for the image contrast.

id3Added this sheet.

If you are feeling some issue of image contrast or your image background doesn’t go dark as expected, I recommend looking into all of BORG parts inside. Some parts inside might be reflecting.

id4Basically all of BORG parts including simple extension tubes and helical focusers are well finished to minimize the reflection. This is why BORG image shows the high contrast as one of factors.

Following was my write-up about the comparison test of M57-threaded drawtube. Since M57 drawtube is not used wtih 2″ nosepiece, plain section(where generally 2″ nosepiece comes) is really issue. So all of Hutech-supplied FTF-M57 focuser has the anti-reflection sheet inside.


This good-quality anti-reflection sheet (resin-made, not paper!!) is available from Hutech. If some BORG users are looking for this, contact me or your local dealer. This is not what generally described as as technical specs. But very important for the quality of the image. And you can do yourself. This is the privilege of BORG owners!!


~ by tedishikawa on March 24, 2015.

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