anatomy of an eyepiece

[blacksaltire]

i have an Antares W70 series 4.3mm ep that concerns me somewhat ! recently noticed the dashed thing had a bit of a rattle to it ! closer inspection revealed the reason, the bottom lens element and it's mounting ring were as loose as a goose ! it's always been a bit tetchy to focus but i had just put it down to the fact that it's a reasonably powerful ep. My question now is what the proper distance is for the element to be situated in relation to the barrel and the rest of the ep ?? any one out there got one they could measure for me ? or are they all different ?? ta much folks if anyone can help cos it's doin me nut in !!

[FraserClarke]

It will depend on the eyepiece design. However, a common way that optics are mounted is to have a fixed flange on one side, and use the mounting ring to compress the lens up against that flange. If you try delicately tightening the mounting ring, the lens may seat back into it's proper position. As you tighten, tap the side of the eyepiece to help the lens seat properly on the flange. You may need a special tool to tighten the ring though :-\

Depending on how the lens barrel is assembled, it may be the ring *inside* the lens which is loose -- in which case you'll have a much harder job getting it back to the right place

You could try emailing the dealer, or Antares direct?

[blacksaltire]

thanks for that teadwarf:icon_salut:

[blacksaltire]

got nowhere trying to get in touch with antares (website with no blumming contact details ! chocolate fire-guard springs to mind ) spoke to a helpful chap at rother valley optics and he said that the one he had in front of him had the bottom lens element about 5mm or so from the end of the barrel(so as not to interfere with the filter threads) so i am still officially confused as to the right position of said mounting ring and lens element. conflicting veiws etc ! further tests in my mates scope pending !! anyways here's a pic just in case somebody has any comparison! cheers all !

[NGC 1502]

Hi, Dunno if this will help, but here goes.

I don't have a 4.3mm Antares W70, but I do have a 5.7mm W70. On mine, when

looking at the bottom lens element, there is not a lock ring to tighten.

However, the whole lower lens assembly (it's effectively a built in barlow) simply

unscrews, to reveal a securing ring on the inside. It has two holes for tightening,

a tiny screwdriver could be used (with care !)

Of course, I don't know if the 4.3mm is constructed in the same manner, but I

also have the 8.6mm W70, and it comes apart in the same way as the 5.7mm.

Go carefully though, just in case the 4.3 is different.

Good luck ! Ed.

[blacksaltire]

oh blast it's not the same:( but thanks all the same ed !