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IDAS/IDASmio LPS-D3 (ex NGS1):
The World First Night Glow Suppression Filter!

M48mm P0.75mm
for use inside the body mount of EOS APS-C DSLR cameras
for ue inside the body mount of EOS M DSLR cameras
for use with EF EOS R Drop-in Mount Adapters: substrate thk. = 2.0mm
for use inside the body mount of EOS RP cameras
for use inside the body mount of EOS R cameras
for use inside the body mount of EOS R5 cameras


Feature 1
The LPS-D3 is the world-first filter that suppresses both man-made and night glow interferences to the green, orange and red ranges.
Night Glow: OI (557.7nm、630.0nm、636.4nm), NaI (589.0nm、589.6nm)

Feature 2
The LPS-D3 is the successor of the LPS-D2, and thus can suppress the inteference from white LED lights. This filter is also effective against low- and high-pressure sodium lamp pollutions.

Night glow interferenced image (photo taken by Mr. Shigemi Numasawa):

Image ideally processed to reproduce the LPS-D3:effect

Feature 3
The LPS-D3 is designed based on the same concept as of other IDAS LPS filters so that it maxmizes the transfer of the light emissions from various emission nebulae, C2 comae of comet heads and CO+ ionized tails of comet tails as well as coninuous spectrum emissions from space. Its transmittance range is intentionally shifted to the longer wave length side. allowing margins for "the shift tendency towards the shorter wave length side against oblique incidences" typically associated with thin-film interference filters. The LPS-D3 can almost fully transfer the abovementioned nebular emission lines under the conditions , for example, where the incidence of the parallel flux is kept below 14 degrees, or a lens of the F value 2 or faster (or 1.4 or faster depending on lens) is used before this filter.

Feature 4
The LPS-D3 filter utilizes the IGAD (ion-Gun AssistDeposition) coating technology which has been applied to our regular LPS-P2 and LPS-V4 series. The IGAD technology densifies the multi-layers - the heart of interference filters - resulting in the physical properties that cannot be obtained from the conventional multi-layers.
1) Highly durable thin layers of which hardness equals to quartz glasses. Tremendously improved adherence between the substrate and the multi-layers set.
2) Absolutely almost no aging variation in optical spectral characteristics due to temperature and humidity change as far as used in the regular human living environments.

*This product is an interference filter.  Its spectrum characteristics will be subject to the incidence of incoming light. Please carefully read the following instruction for proper use:
When the LPS-D3 is placed before the lens:
Use a lens having the light incidence angle of 14 degrees or lower (field angle of 34 degrees or lower).

When the LPS-D3 is placed between the lens and camera:  (applies to IDASmio filters)

When your camera is equipped with an APS-C image sensor and uses a lens with a *back focal distance of 40mm or greater and F value of two or faster, it is possible to hold down the maximum averaged incidence angle of the incoming light ray against the filter within about 14 degrees. Under the conditions of the above mentioned camera, there will be almost no field angle requirements for the lens to be used.

* Please note, however, that the smaller the diameter of the rear lens element is, the more likely the maximum averaged incidence angle would exceed 14 degrees where the transmittance of nebula emission lines could be deteriorated around the perpheral of the image.

28mm F2.8
50mm F2.0 

*This is NOT the flange focal length..

Examples of night glow images taken and commented by Mr. Shigemi Numasawa

Orange night glow:
"I happened to come across orange night glow in October, 2007 at the northenr sea coast of Niigata Pref. The bearing is north west as the Swan was going to set. I need to be cautious of night glow occurrence at all time esepecially during the shooting."

Gree night flow:
"I came across green night glow in May, 2012 in Utah, USA. Pale green light expands towards South East. I had not noticed it at all during the shooting, but came to find this glow when I opened this image on my laptop at a later date."