Hold your filters tightly and safely without tools or mods to your equipment.
This filter holder for binoculars solidly grips via a sleeve, designed for TPU or other soft material. The solid rings clamp the sleeve between them and hold the filter material.
Two designs, one for OD 42 binoculars and one for OD 50. These may be scaled for other sizes or equipment. The binoculars used for these models are 51mm in barrel outer diameter for the OD42, and 62mm for the OD50. Photo shows OD50 version. There is some built-in wiggle room inside the sleeve.
Filter material diameter:
- OD42: Up to 60mm
- OD50: Up to 72mm
The sleeves:
- TPU recommended. Example uses 95A.
- The Short option is the easiest to fit, but also the least secure. Using this will make the holder easily removable.
- The Tight option is the toughest fit, but is very secure.
- The Flexy option is a balance between easy fit and security, but it's a bit more bulky.
- Sleeves can be modified (even with scissors) to fit your own equipment.
- Example uses Tight option.
Assembly:
- It's best to practice first with foil or paper cutouts instead of the actual filters.
- Place the inner ring onto the binocular barrel. (If you are using the Flexy sleeve, you may have to put the ring on the sleeve first, and skip step 4).
- Slide the sleeve of your choice over the binocular barrel snugly.
- Slide the inner ring down the sleeve as far as possible towards the end of the barrel (see photo). The sleeve has a notch that fits into an alignment groove in the ring.
- Place the outer ring in front of you, with the threads oriented up.
- Add clamp or gaskets into the outer ring:
- If you are using a thin film filter and you want to set it permanently and securely:
- Print the ridged inner clamp and insert into the outer ring with the ridge facing upwards, towards where the filter will be. This will solidly clamp the material, so you might practice with paper or foil first. No other gasket is necessary.
- If you are using a thicker material, or you are sandwiching the thin thin film between thicker materials, or in the case you are using a thin film material but might want to remove it again without damage (albeit less securely held):
- You can print a gasket (1mm and 0.5mm gaskets provided) out of solid material to insert into the outer ring first. Then add another gasket of soft material on top of that. The ridged inner clamp will not be used.
- Add the filter material on top of the clamp or gaskets.
- Finally, screw the outer ring onto the inner ring. It's easiest to hold the binoculars over the outer ring so gravity will keep the filter in. Be careful not to squeeze the ring too firmly while tightening or you may wrinkle or distort the filter material.
- The filter material should be held securely and should not wobble or move. If it does, check to make sure the rings are not cross-threaded. If this does not fix the issue, you may add more thickness with solid gaskets and try again.
Print on a smooth plate if possible as textures will increase friction where parts should move smoothly.
The gaskets are modeled with a tab to help remove them from the baseplate, which needs to be trimmed off before assembly. An inner ring version with a loop and without is included. The outer ring is provided in left and right versions, but this isn't strictly necessary they're just different styles that can mesh for smaller pupilary distances.
Use care when printing the threads, especially the outer ring. I printed these at 40% of max speed.
Be safe! Use approved filters for solar observation and always test your filter setup before looking at the sun.
Please let me know if you have any questions or suggestions. Thank you~