About this deal
High quality optical filters are not cheap. Hence, it is also no surprise if observers complain about „unaccountable“ picture deterioration when using cheap filters in front of binoculars, tele-compressors or Barlow lenses, either visually or photographically. The higher the magnification, the softer and more blurred the picture appears when using a cheap filter, for both visual and photographic observations.
screw-in thread for 2" eyepieces on telescopes as well as for lens-side mounting on binoculars up to 45mm aperture, and finally
Our 1.25" filters have a M28.5 male (and M28.5 front female) thread / our 2" filters have a M48 male (and M48 front female) thread
Swan-Band-Filter wurden bislang nur von Lumicon produziert. Baader hat einen Filter herausgebracht, der sich von den Lumicon-Filtern unterscheidet. The Swan-Band filter is indeed a very special filter with central wavelength at 512 nm and ≤15nm half-width – for the first time without any O III transmission. It is therefore suitable for a variety of unusual applications some of which require further investigation, whether as an “O III parallel filter” to better remove stars from the image, or as a solar filter in a previously inaccessible section of the spectrum. We would be pleased about your experience reports also apart from the comet photography. Please allow 3 working days for us to process a return. We will organise a suitable date and time for our couriers to collect the item Also a only mag 16.2 faint C/2022 U2 (ATLAS), which is overtaken by the mag 5.8 bright C/2022 E3 (ZTF), could be photographed:You can clearly see the amount of "doubly ionized carbon" (the carbon excited to glow radiates only in the wavelengths 511 and 514 nm ) were emitted by the comet. They say that if only one cosmetically flawless, smooth glass surface is required, it is not necessary to achieve a high degree of plane-parallel polish. They further believe it is adequate to cut filters from a big stained glass sheet – usually in the format 20x20 cm – and to so-called “raw polish” the filter on both sides. With this process, the glass surface is slightly molten and all saw scratches and surface inaccuracies are invisibly levelled. But so-called „raw-polished“ glass surfaces are completely irregular and deform the wave front of the light significantly!