DeltaOptical dark green filter #58 1.25″
Looking for a reliable color filter to get the most out of your eyepiece when observing planets and the Moon? The DeltaOptical dark green filter #58 in 1.25″ size is a classic tool for every serious planetary observer. The dark green #58 is part of the proven Wratten filter series that has been used in astronomy for decades - and for good reason.
Optical characteristics and applications
The green #58 filter transmits light in the range of approximately 490-580 nm, centered in the green part of the spectrum. This provides significant contrast enhancement on planetary surfaces:
- Mars - helps distinguish dark albedo features from bright polar ice caps by suppressing the red component of light that can obscure finer details.
- Jupiter - improves visibility of cloud bands and atmospheric structures, revealing subtle detail that is otherwise easy to miss.
- Venus - reduces the overwhelming glare of the disk and helps reveal atmospheric cloud features.
- Moon - increases contrast of fine surface details and brings overall lunar brightness down to a comfortable viewing level.
Mechanical design and build quality
The 1.25″ thread allows easy and secure screwing directly into the eyepiece barrel of any standard 1.25″ eyepiece - the most widely used format in amateur astronomy. The filter is mounted in a solid metal cell with a precisely cut thread, preventing slippage or cross-threading. The optical element is made from glass with uniform color across the entire surface, free from visible optical defects or distortion.
Who is this filter for?
The filter is appreciated by both beginners who want to improve their planetary viewing sessions and experienced astronomers making detailed sketches or capturing planetary video with a camera. A few things worth keeping in mind:
- The green #58 is a relatively dark filter, so it is best suited for telescopes with an aperture of approximately 100 mm or larger - with smaller instruments it may reduce image brightness too much.
- For visual use, combining it with eyepieces that have good light transmission is recommended.
Astrophotography use
The filter can also be used in astrophotography as part of an RGB color filter set for planetary imaging, or as a selective filter to emphasize specific details in lunar photographs. Its long-term stability and the durability of the optical coating ensure it will serve you reliably across many seasons of observation.
About DeltaOptical
DeltaOptical is an established manufacturer and distributor of astronomical optics, popular throughout Central and Eastern Europe. DeltaOptical filters are characterized by solid mechanical construction with precisely threaded metal cells, controlled optical glass quality, and an accessible price point that does not discourage those who are just building their filter collection. If you are looking for a reliable color filter without unnecessary risk, the DeltaOptical #58 is exactly what you need.
Key specifications
| Parameter |
Value |
| Filter type |
Dark green / Wratten #58 |
| Thread size |
1.25″ |
| Transmission range |
approx. 490-580 nm |
| Frame material |
Metal |
| Recommended minimum aperture |
100 mm |
| Suitable for |
Visual observation, astrophotography |
| Compatible eyepiece format |
Standard 1.25″ |
