1. Optolong L-eXtreme Introduction
L-eXtreme is a two 7nm bandpass filter which can be used with one-shot color cameras like DSLR's (digital SLR), and monochrome CCD cameras, it is also more suited for fast systems. The convenience and cost effectiveness of this filter allows amateurs to image a rich emission nebulas, even in bright, light pollution skies. Optolong believes the design of L-eXtreme filter would be better choice for fast systems in competitive price. It isolates the H-Alpha, and Oxygen III nebula emission lines so that the contrast and signal-to-noise ratio between nebulae were maximized. For people who is living in very light polluted areas, or when the moon is out, the L-eXtreme will be a good filter.
Unlike the Optolong L-eNhance filter which is a tri-band (transmits Hb, Ha, and OIII), the L-eXtreme filter is dual band that passes Ha and OIII emission lines.The advantage of the L-eXtreme filter is that there is no transmission between the H-beta and OIII lines, as there is no nebula emission lines there. In this case, it isn't letting light pollution come through so that maximize nebulas signal and make the sky background darker while imaging. The L-eXtreme filter should better isolate the emission lines only and better protect from light pollution.
Hydrogen is the largest, the most primitive, the simplest, and the oldest element in the universe. Scientists consider that Hydrogen amounts to more than 90% of visible substance in space. Our sun is 5 billion years old, but so far hydrogen is still the key matter of nuclear fusion. While the sulfur element does not have much scientific significance, so keeping H and O is meaning for exploration of life.
Therefore, we highlight H-a, H-b, O3 and O2, and reduce the signal of sulfur.
2. L-eXtreme EOS-R Clip-in Filter Specifications
| Raw material | optical glass |
| Thickness | 1.0mm |
| Blocking range | 300-1000nm |
| Blocking depth | light polluton line blocking>99% |
| Surface quality | 60/40 |
| Surface shape | λ/4 |
| Parallelism | 30s |
3. Spectrum for Reference
※This curve is only for reference, and is not used as the final product data.
How to read the chart?
▲The horizontal axis is the Wavelength in Nanometers(nm).
▲The vertical axis is transmission in %.
▲The RED line shows the line of Halph. Green line shows the emmission of OIII. The artifical emission lines are shown in ORANGE.
4. Compatible List of Optolong L-eXtreme EOS-R Clip-in Filter
| Sony-FF specification | L-eXtreme |
| Applicable Camera |
EOS R/Ra、EOS RP、EOS R3、EOS R5
EOS R5II、EOS R6
|
| Applicable Lenses |
Full range of RF main and auxiliary lens
Full range of EF main and auxiliary lens (adapter is required）
|
※ Due to limit lens resource, we only test the popular lens in market. If any available lens, feel free to contact Optolong customer service staff. We appreicate for your valuab testing information.
5. How to install and remove?
6. Gloable Price
| L-eXtreme Gloable MAP | Unit Price in USD dollars |
| EOS-R Clip-in version | $259.00 |
7. Packing
Outer Box: silve box
Plastic Box: PP material
Lining: imported high pressure white EVA material
8. Optolong L-eXtreme Filter Performance
I. Compare: L-eXtreme VS no filter © Vincent Cheng
L-eXtreme of EOS-R clip-in filter
