Antlia 2" ALP-T Dual Band Filter 5 nm Highspeed Narrow Band Nebula Filter

The 2" narrow band nebula filter allows nebula photography with extreme contrast with MONO and COLOR cameras - light pollution is no longer an issue.

♦ 2" low profile filter mount with M48x0.75 thread

♦ Suitable for telescopes and lenses with a focal ratio between f/2 and f/3.6

♦ Optical Schott base substrate

♦ Blackened edges to avoid internal reflections

♦ Extremely narrow bandwidth of only 5 nm for maximum contrast

♦ Precise transmission in H-alpha and in O-III

♦ Filter thickness 2 mm

♦ Supplied in convenient plastic transport box

 

Antlia ALP-T Dual Band 5 nm Highspeed Nebula Filter for B/W and Color Cameras

ALP-T Dual Band 5nm Highspeed Filters are further optimized to work with high-speed imaging systems by shifting slightly the passband and center wavelength. Using these highspeed filters between optics f/2 and f/3.6 shows much stronger and more contrasted in nebulae imaging compared to the standard version.

For optics f-ratios slower than f/3.6, the standard ALP-T Dual Band 5nm filter is highly recommended. Meanwhile, if you seek the best possible performance with any optics faster than f/2, the highspeed version is the best choice.

But keep in mind, the blue shift data by the computer simulation indicates narrowband filter shifts its bandwidth to shorter wavelengths with faster optics than f/2, transmission at the emission wavelength may decrease perhaps 15%-20%. Although the Antlia ALP-T highspeed filter has similar transmission rates reduction in the H-a and OIII when the filter is used on fast optics, based on current standard version users’ data, it is evident that the filter still has the high performance of increase in emission nebula contrast and minimized halo.

The highspeed version price is the same as the standard filters and double benefits for the high-speed optics users. Worth mentioning is that Antlia inspected and measured products piece by piece with one of Agilent Cary’s professional spectrophotometer, resolution/slit width is up to 0.2 nm, which make us provide highly reliable and consistent products to you.
 

Antlia 5 nm Dual Band Filters

The Antlia ALP-T dual band 5nm series filter is a dual line-pass filter that was designed to be used primarily with one-shot color (OSC) cameras such as DSLRs and astronomical OSC cameras. It can also be used as a narrowband filter for monochrome cameras to save imaging time. The advanced multi-coatings on the ALP-T ultra dual band filter effectively isolate the red Ha and the blue-green OIII lines light from emission nebulae, with almost total suppression of optical density (OD4.5) on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that the ALP-T dual band 5 nm filter creates a superior signal-to-noise ratio and better contrast in your images.

The filter allows capturing of the two main emission nebulae bands at the same time, whilst suppressing unwanted light pollution. It enables you to capture cleaner data and reduces the post-processing efforts to isolate faint details from the background light pollution.

 

The features of Antlia high speed narrow band filters at a glance:

♦ High light transmission and smallest bandwidth to maximize contrast.
♦ Steep spectral profile minimizes halos around bright stars
♦ Single substrate to eliminate internal reflections
♦ Usable in light-polluted areas and dark locations
♦ Extends exposure time in moonlight conditions
♦ Antlia narrowband Pro filters can be used very well between F/3.6 and F/2 focal ratio.
♦ All Antlia narrowband filters are blackened at the edges to prevent internal reflections of stray light
♦ Superior optical reliability reduces image post-processing effort
 

Suitable f-ratios:	f/2 to f/3.6
Substrate:	Schott optical substrate
Filter thickness:	2 mm
Cell:	Low-profile metal cell with M48x0.75 filter thread
FWHM:	5 nm
CWL:	657.8 nm (88%), 502.2 nm (82%)
Off-line blocking:	≥OD4.5 @ 300-1050 nm
NIR blocking:	up to 1050 nm
Surface quality:	S/D (scratch/dig)= 60/40 (Refer to MIL-O-13830)
Surface accuracy:	Lambda/4 or better