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IDAS M48 DTD（Dusk to Dawn Filter）

IDAS
ID-61063

特價

新品

現貨

HK$ 1323

+ -

圖片僅作供參考，並不代表產品實物及所包括配件。
Pictures shown are for illustration purpose only and may not be an exact representation of the product and accessories included.

詳細內容

原價：HK$1470

[IDAS DTD 濾鏡（黃昏到黎明）]
捕捉更廣闊更深邃的城市星空——IDAS
的 DTD（黃昏到黎明）濾鏡是一款寬頻濾鏡，可傳輸從可見光到近紅外線 (NIR) 的寬光譜，同時支援 Hα 和 OIII 等發射線區域。

它旨在捕捉各種天體的光線，例如星系、星雲、彗星和銀河系，在抑制光污染影響的同時，實現自然的色彩還原和對比。它是一款多功能濾鏡，適用於各種拍攝風格。

[特點]
・相容 Hα + OIII 的寬頻設計
・透射從可見光到近紅外線 (NIR) 的光譜
・抑制光污染和月光的影響
・適用於彗星、星系、銀河係等的連續光譜描繪
・日本製造，高精度玻璃，AR塗層

[規格]
・螺絲直徑：M48mm
・間距：P0.75mm
・基板厚度：2.0mm
・透射特性：主要在 Hα / OIII 波長範圍內具有高透射率

・想要在光污染地區拍攝從星雲到星系和彗星的廣泛圖像的人
・想要以自然色彩描繪彗星的塵埃尾和星系擴散的人
・使用單色 CMOS 或具有紅外靈敏度的相機的
人・尋找可以一機多用

Feature:
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.

n.b. on halos:
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

Light Pollution Cut Functions:
The most of the light pollution sources are conspicuous below 600nm, i.e. in the visible wave rage. There are almost no light pollution sources available in the NIR range of 630nm and 700nm or above.

Suitability of DTD Filtes for shooting comets:
The DTD's transmission bands allow you to captures the blue-green coma (C2 ions) at the head of the comet, the blue CO+ plasma at the tail, and the overall reflected light. In addition, in low-altitude and hazy conditions such as mist, the transmission of the near-infrared range is utilized to increase contrast.

Suitability of DTD Filtes for shooting emission and reflection nebulae (including molecular clouds), the Milky Way, extragalactic galaxies, and star clusters:
For nebulae with Hα and OIII emission lines, the DTD will increase contrast by using a quasi-narrowband transmission band in the visible range, while keeping the light loss of continuous spectrum objects minimum by using the entire transmission band in the visible and infrared ranges.

M42 Orion Nebula

NGC7023. Ghost nebula.
Reflection nebula and molecular clouds

Molecular cloud Ghost nebura

Shigemi Numazawa, Niigata Prefecture

M31 Andromeda Galaxy

M83 outer galaxy

Sh 2-308 Dolphin-Head Nebula

Shigemi Numazawa, Niigata Prefecture

Comments from Masaaki Uto, Shizuoka
Prefecture (Blog link)

Shigemi Numazawa, Niigata Prefecture

M20 and M8 nebulae

Sh 2-264. Dorsal
fin of the Angelfish Nebula

The North American Nebula in the HII region of NGC 7000

Comments from Masaaki Uto, Shizuoka
Prefecture (Blog link)

Shigemi Numazawa, Niigata Prefecture

Enhancement of Color Saturation:
The visible range characteristics of the DTD allow for effective use of the RGB range of the image sensor.
Our Nebula Booster series (NBZ-II and GNB) and other companies' dual band NB filters produce images with poor color reproduction in the B-ch. In contrast, the DTD provides sufficient light for the B-ch, resulting in richer color reproduction.

QE Data