Astronomik OIII Filter visual 38mm (unmounted)
[ANK_OIII-38]

Astronomik OIII Filter visual 38mm (unmounted) - ANK_OIII-38

Het Astronomik OIII filter is ontworpen voor visuele waarneming van gasnevels en planetaire nevels. Doordat dit filter alleen maar de twee OIII golflengten doorlaat en verder elk licht tegenhoudt, biedt dit filter een zeer sterke verbetring van het contrast. Zelfs onder 'ideale' omstandigheden. Het Astronomik OIII filter maakt het verschil of dat zwakke supernova restant wel of niet gezien kan worden.

Dit filter werkt het best in kijkers met een openingsverhouding tussen F4, 5 en F6. Het is bruikbaar in kijkers van F4 tot F15. Verlies van licht en kleurschifting onstaat bij het UHC filter van Astronomik alleen bij zeer snelle systemen van F3 en sneller.

Gebruik van een OIII filter loont bij een opening van meer dan 15cm. Kleinere telescopen leveren niet genoeg licht. Ervaren deepsky waarnemers preferen OIII filters boven het UHC filter. Dit komt doordat het OIII filter nauwbandiger is dan een UHC filter en hierdoor nog nauwkeuriger filtert.

Dankzij de hoge glaskwaliteit van het filter blijven sterren net zo klein als ze worden getoond zonder filter.

Bent u op zoek naar een filter om planetaire objecten als M27, M57, Helix nevel en de uil nevel te zien. Dit is HET filter! De eerste keer dat je de sluiernevel in detail ziet, zelfs vanuit de randstad, vergeet je nooit meer....

From the start, the Astronomik OIII filter has been very specifically designed for the visual observation of gaseous and planetary nebulae. The extremely narrow pass band of the two OIII lines brings a substantial contrast gain to these lines even under best observation conditions. On faint super nova remnants and faint planetary nebulae the Astronomik OIII filter will often make the difference as to whether the object can bee seen or not!

The optimal aperture ratio for the use of the filter is 1:3 to 1:15 with apertures of more than 6" (150mm) . Transmission losses and chromatic distortions, which arise with other filters, occur with Astronomik OIII filters only when extremely bright aperture ratios of 1:3 and more come into play. The Astronomik OIII filters thus can expand the view of dispersed objects, generally speaking, to the whole visual field of view of the eyepiece and are not limited to only the center of the eyepiece.

Main use

Since enough light must be available to make use of the OIII filter it is best to use this filter with apertures of more than 6" (150mm) . Smaller instruments do not gather enough light for meaningful and satisfying astronomical work. However, please note: Many experienced Deep Sky observers, with apertures of more than 10" (250mm), prefer using the OIII filter instead of the more versatile UHC filter. Due to the high optical quality of the Astronomik OIII filter substrate you will see the same needle-sharp stars as you would from your regular telescope.

Suitability

Visual observation (dark skies) : Very good, huge contrast enhancement at O III-emission nebulas
Visual observation (urban skies) : Very good, huge contrast enhancement at O III-emission nebulas
Film photography: It depends, very long exposure time
CCD photography: Good, when used with an additional IR-block-filter
DSLR photography (original) : Very good, huge contrast enhancement at O III-emission nebulas
DSLR photography (astro modified) : Very good, huge contrast enhancement at O III-emission nebulas
DSLR photography (MC modified) : Good, when used with an additional IR-block-filter
Webcam / Video (Planets) : Unsuitable
Webcam / Video (Deep Sky) : Reasonable, if light pollution is a big problem and OIII Objects are beeing observed

Technical Data

• Transmission of nearly 100% of both OIII lines
• Complete blocking of all disturbing wavelength coverages
• The ideal filter for telescopes 10 " (25cm) and larger
• Main operational use: Planetary nebulas & super nova remnants
• No moisture-sensitivity, no aging, and totally scratch-proof
• Excellent carrier material - substrate is optically polished. The optical performance (resolution & contrast) of your telescope is not reduced in any way by the filter.
• Parfocal with other Astronomik filters
• Glass thickness: 1mm
• Completely resistant against high humidity, scratches and aging effects
• Diffraction limited, the filter will not reduce the optical performance of your telescope!
• Astronomik filters are delivered in a high-quality, long lasting, filter box