IDAS Ha & OIII Dusk to dawn (DTD) Filters
A new generation filter covering multiple objects including comets, galaxies, the Milky Way, and emission and reflection nebulae, by making use of the extra transmission in the NIR region.
Features
The IDAS DTD filter not only passes through the Ha and OIII regions in the same manner as of the IDAS NBZ, but also provides a pass band for comet ion tails in the visible spectrum range (400nm to 700nm, susceptible to light pollutions). This filter furthermore enhances the contrast of the continuous spectrum lights from comet dust tails, galaxies and the Milky Way by making use of the NIR region that is hardly interferenced by light pollutions. The DTD filter makes it possible to shoot more objects in the visible to NIR spectrum range at higher contrasts.
Optical filters such as IDAS DTD and GNB utilizing infrared tend to cause haloing in the NUV and NIR regions. This is because the anti-reflection properties of off-the-shelf cameras' optical systems (oiptical window and sensor cover glass) are optimized for the visible spectrum only, not for the NIR region. Thus, haoling at the camera end in the unoptimized region becomes more apparent, coupled with haloing from the filter itself.
Here is a rough estimation of the magnitude of haoling where the haloing maginute of NBZ (NBZex) is counted as 1:
DTD + IMX294 sensor results in 7.9 times
DTD + IMX585 sensor results in 23.7 times
M31 Photo taken by Mr. Numazawa:
Comet Nishimura Photos taken by Mr. Numazawa:
Comet 12P/Pons-Brooks Photo taken by Mr. Numazawa:
Technical Specifications
In the Box
DYD FIlter at selected size :
M48 x 0.75, with 2.5mm substrate thickness (48S)
M48 x 0.75 with 2mm substrate thickness (48ST2)
M52 x 0.75 with 2mm substrate thickness (52ST2)
For Canon EF-EOSR (DRE)
Manual & Warranty
IDAS 3-Year Warranty
