Quierschieder Weg 38, 66280 Sulzbach anfrage@apm-telescopes.de

APM Professional Telescopes

APM Professional Telescopes

1m F/8 Ritchey Chrétien with dual Nasmyth Foci, Cape Town (South Africa)

Another large telescope for the South African Astronomical Observatory (SAAO). An 1m F/8 Alt-Az mounted Ritchey Chrétien for robotic use. It has dual Nasmyth Foci. The main telescopes used for research are located at the SAAO observing station (32°22.795’S 20°48,657’E) near Sutherland in the Northern Cape, a 4-hour drive from Cape Town.

Product enquiries

Inquiry now

Please make your enquiries about the products you require here. We will contact you as soon as possible with a customised quote.

Optolong Filters

Optolong filter adopts precision coating based on Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change.

Optolong Filters

Astrodon Filters

Astrodon RedCon Filters

available filter sizes

Astrodon Narrowband Filter Features:

  • Peak transmission guaranteed >90-percent assuring you of the highest performance.
  • Bandwidths of 5 nm for general use and 3 nm for highest contrast, moonlight rejection and light pollution rejection
  • > OD 4 (0.01-percent T) out-of-band blocking
  • Hard-oxide coatings on clear 1/4-wave substrates go to the edge, eliminating uncoated rims that leak light.
  • Sides are blackened to minimize reflections
  • 3 nm filters can be used with fast optical systems to f/3 with little signal loss
  • Parfocal with all Astrodon filters

 

ASTRODON 5NM RED CONTINUUM NARROWBAND FILTER

This Red Continuum filter (645 nm, 5 nm FWHM) produces a star map without the H-a or SII emission in order to subtract stars from emission images. Astrodon NB filters are renowned for not producing halos around stars and not leaking NIR light.


When it comes to Narrowband filters, no one knows more or does it better than Don Goldman of Astrodon Filters. Narrowband (NB) filters enhance contrast of emission objects by accepting only a narrow range of wavelengths around the emission lines of hydrogen (H-a, 656 nm), oxygen (OIII, 501 nm), sulfur (SII, 672 nm) and others.

Astrodon filters can be used to image when the moon is up, thereby extending imaging time and can be used in light-polluted locations.

The narrow range of wavelengths of Astrodon filters is defined as the FWHM (full-width at half- maximum intensity). Narrower filters decrease the background noise. However, narrower filters are more difficult to manufacture consistently, and are thus more expensive. Furthermore, it is difficult to maintain high transmission through the bandpass of the filter as it becomes narrower. If the peak transmission decreases as the filter is made narrower, the emission signal decreases and the gain in S/N (signal-to-noise) is not realized. Astrodon has achieved this goal of high transmission for narrower filters.

Astrodon has evolved its narrowband product line from 6 nm to 5 nm FWHM, significantly lowered the prices on all filters, and added the ultra-narrow 3 nm FWHM filters for H-a, OIII and SII. We added a Red Continuum filter (645 nm, 5 nm FWHM) that produces a star map without the H-a or SII emission in order to subtract stars from emission images. Astrodon NB filters are renowned for not producing halos around stars and not leaking NIR light.

The 3 nm FWHM filters are stocked and are not custom ordered. The 3 nm OIII filter provides the best protection from the effects of moonlight, producing half the background signal of a 90-percent T, 6 nm FWHM filter, resulting in an increase in S/N of ~21-percent. This will even be larger in comparison to wide 7 or 8 nm FWHM filters.

Most imagers do not realize that their 4.5 - 10 nm FWHM H-a filter for 656.3 nm also includes NII emission at 658.4 nm. These emission lines are so close together that only a filter with 3 nm or less FWHM can readily separate their signals. Professional astronomy papers will state H-a + , signifying that data from both emission lines are combined in the signal. The brackets refer to as a forbidden transition, such as . Many objects are enriched in nitrogen and have emission, such as planetary nebula, Wolf-Rayet bubbles and supernova remnants. The Dumbbell Nebula, M27, is a classic example.

 

APM Professional Telescopes

1m F/8 Ritchey Chrétien with dual Nasmyth Foci, Cape Town (South Africa)

Another large telescope for the South African Astronomical Observatory (SAAO). An 1m F/8 Alt-Az mounted Ritchey Chrétien for robotic use. It has dual Nasmyth Foci. The main telescopes used for research are located at the SAAO observing station (32°22.795’S 20°48,657’E) near Sutherland in the Northern Cape, a 4-hour drive from Cape Town.

Creative Contact Form

Contact Us
Feel free to contact us if you have any questions

COMPANY HQ

APM Telescopes
Quierschieder Weg 38
66280 Sulzbach
GERMANY

Telefon: +49 (0)6897 - 924929-0
Fax:       +49 (0)6897 - 924929-9
E-Mail: info@apm-telescopes.de
WWW: https://www.apm-professional-telescopes.com

Wir benutzen Cookies

Wir nutzen Cookies auf unserer Website. Einige von ihnen sind essenziell für den Betrieb der Seite, während andere uns helfen, diese Website und die Nutzererfahrung zu verbessern (Tracking Cookies). Sie können selbst entscheiden, ob Sie die Cookies zulassen möchten. Bitte beachten Sie, dass bei einer Ablehnung womöglich nicht mehr alle Funktionalitäten der Seite zur Verfügung stehen.