The Explore Scientific 1.25" S-II Nebula Filter (12nm) filter uses the property of the so-called emission mist. These objects glow in certain colors, the so-called emission lines. The emission lines are linked to certain chemical elements, in this case ionized sulfur. This filter blocks almost all artificial light to improve viewing of nebulae, passing only the emission lines of the the ionized sulfur at 672nm. The effect is amazing: Suddenly fog becomes visible in the photos in places that appear completely empty without a filter. The Explore Scientific mist filters are supplied with an individual test report, so you can be sure that you are receiving high-quality filters.

• High quality Explore Scientific S-II filter
• Absorbs all other emission lines
• Absorbs almost all artificial light
• Passband bandwidth: 6.5nm
• For observing faint planetary nebulae, emission nebulae and supernova remnants
• More contrast and details for all urban observers and astrophotographers
• An individual test report of this premium filter is included

Related Questions and Answers

Q: 1. Can you use this the same as a light pollution filter?

A: Light pollution filters and OIII filters pass different spectra and are used for different purposes. OIII are good for specific objects that emit in the OIII spectrum strongly, such as some nebula (veil, crab) and especially planetary nebula (dumbbell, ring). LPR filters are designed to filter light pollution - mostly sodium vapor light and are good for increasing contrast across a broader range of objects.

Q: 2. Will this [safely] fit a 130mm (5.1") reflector tube?

A: This Cradle Assembly from Explore Scientific is a replacement for the cradle assembly included with the white 127mm telescope OTA but can also be used with other telescopes that would snugly fit its 5" inside diameter.

Q: 3. I have Explore Scientific ED80 80mm f/6 Carbon Fiber APO Refractor Telescope, iOptron SkyGuider Pro EQ Camera Mount, iOptron 1.25" Stainless Steel Tripod, and my camera is Sony A6000, what should I need to make it work?

A: If you want to mount your Sony A6000 body on your scope you will need a Celetron camera mount (B&H# CETA1.25). This will go into the scope in place of the eyepiece. A T-ring which will mount onto the camera body in place of the lens (B&H# VELANEXT). These two pieces will now screw together.

Q: 4. Will this filter work with the Vaonis Vespera II ?

A: The Vaonis Vespera II Observation Station does not use eyepieces and therefore cannot use an eyepiece filter.

Q: 5. I have an older Televue Pronto 70.4mm f6.8 ED Doublet with a 2 inch focuser. Can I use this focal reducer with this telescope?

A: Yes you should be able to without any issues.

Q: 6. Will this be a good filter to view the Lagoon Nebula?

A: Ask this question at cloudynights website it's a com address

Q: 7. What are the interior dimensions?

A: The case's interior measurements are 42.5 inches by 6.5 inches by 8 inches.

Q: 8. HOW THIS EYEPIECE'S QUALITY COMPAIR TO THE 24 MM PANOPTIC EYEPIECE ?

A: The Panoptic is slightly better... it's nowhere near 2x better, which is usually the price difference. I tested out quite a few televue vs ES eyepieces in 68, 82, and 100 degrees and have always found the ES to be the best bang for the buck by a pretty noticeable margin.

Q: 9. I have a 114 mm telescope I know this would probably be too big do you have a recommendation anything close would be good.

A: 114mm = 4.48819 inches. The closest size rings B&H would carry would be the Tele Vue Mount Ring Set for 4" OTAs BH #TEMTS4Q • MFR #MRS-4011 or the Vixen Optics Tube Rings with 115mm Inner Diameter (Pair) BH #VITRW115 • MFR #ES2665

Q: 10. Will this work with my Lunt 152mm ED APO f/8 which has a 3 inch Feather Touch focuser?

A: Yes, the ES 0.7x Reducer should work reasonably well with a 3 inch focuser. There are three options for attaching the reducer to a focuser, a 3 inch adapter and two smaller adapters. The upper left cylinder in the product photo is for a 3 inch focuser. It has a 76mm outside diameter and 74mm ID with female threads. The 3 inch adapter screws on to the bottom (scope side) of the reducer. It appears to be designed to either be inserted into the focuser tube or screwed on, depending on your setup. I use it with a 127mm f/7.5 APO and it covers a full frame (35mm) sensor with sharp stars, but with some vignetting in the corners. Two issues I have with the reducer are 1) the T adpater is standard 42mm, as opposed to 48mm, and so produces more vignetting than is necessary given its 3 inch optics. 2) Given the 55mm T adapter shoulder to sensor plane recommendation, there are no 48mm threads or room for a screw in filter. I just ordered and adapter that will allow for screw in filters on the focuser end of the reducer.Hope this helps.