6 replies to this topic

[Tuawcxs]

I just ordered an ITF replacement Filter from Beloptik. What tool do I need to remove the retaining ring

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[gstrumol]

See those two tiny holes? I believe you need what's called a spanner wrench.

 

If someone else holds the tube you could try two nails/pins by twisting them clockwise and counterclockwise.

[Tuawcxs]

Thanks. Found spanner wrenches online. Just what is needed . Thank you sir

[BYoesle]

Note that an adhesive may have been used to secure the filter cell, and liberal use of elbow grease might be needed to unseat the filter cell.

 

You can also make a sturdy DIY spanner for the purpose by using a solid hardwood bar or dowel and some nail brads. Measure the distance and drill some appropriately just slightly undersized holes for the brads, which can be further secured with an appropriate glue or epoxy.

 

Both the ITF and order selection filters (eyepiece side) are tilted, and when replacing the ITF/BelOptic filter cell the filters should have the opposite tilt orientations to avoid internal reflections.

[Tuawcxs]

Thank you. Is the tilt obvious to see?

[BYoesle]

Yes. The thickness of the filter cell around the filter varies - just look closely and the 1 to 2 degrees of tilt will become obvious.

 

Same as with etalon ERFs.

Edited by BYoesle, 27 March 2025 - 03:07 PM.

[SCTUSER]

I just ordered an ITF replacement Filter from Beloptik. What tool do I need to remove the retaining ring

Hi.

Go to an auto parts store and show them. They will have a "wrench" (kinda like a pair of pliers) which will do the job very quickly.


Allan