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Fujinon 10x50 Eyepiece play

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#1 Bosco

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Posted 22 June 2021 - 12:54 PM

Good afternoon

Ive observed that my new Fujinon has some play with one of the eyepieces. If I hold the left eyepiece and tilt it backward and forward it has some play whereas the right eyepiece has zero play.

Is this normal? Could this affect the sealing? Do your Fujis have this play??

Thank you

#2 Rich V.

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Posted 22 June 2021 - 01:08 PM

With my 16x70FMTs, the outer eyepiece housing that you twist to focus is held down onto the eyepiece body by a retaining ring underneath the threaded-on rubber eyecup.  Perhaps that retaining ring was not secured tightly enough.  If the 10x50s also share this design, as I suspect they do, unscrew the eyecup assy from the eyepiece and see if the ring under it can be tightened down firmly.  Perhaps that's all you need to do.  No harm done trying...

 

Rich



#3 gwlee

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Posted 22 June 2021 - 01:22 PM

With my 16x70FMTs, the outer eyepiece housing that you twist to focus is held down onto the eyepiece body by a retaining ring underneath the threaded-on rubber eyecup. Perhaps that retaining ring was not secured tightly enough. If the 10x50s also share this design, as I suspect they do, unscrew the eyecup assy from the eyepiece and see if the ring under it can be tightened down firmly. Perhaps that's all you need to do. No harm done trying...

Rich


That’s my guess too.

#4 Bosco

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Posted 22 June 2021 - 01:26 PM

Are you referring to the threatened ring where the rubber eyecup is held? this slim ring is screwed to the eyepiece near the lens. This is not the case. If I hold the entire eyepiece from the rubber central part that helps to improve the grip and then push it forward and backwars the eyepiece has a little play. This should not happen for this price of binos, I will return them and buy another pair :(

Edited by Bosco, 22 June 2021 - 01:27 PM.


#5 Rich V.

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Posted 22 June 2021 - 01:32 PM

I'm not referring to the ring that holds the eyecup, but the ring underneath it that surrounds the eye lens after the eyecup assy is unscrewed.  The outer housing is splined and engages with the inner body through those splines.  The retaining ring holds the two splined parts locked together.  Once tight, screw the eyecup assy back onto its threads.



#6 Bosco

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Posted 22 June 2021 - 02:15 PM

Ohh now I understand what you are referring to. I see that ring and seems to have some inks of glue in two parts. Im not able to tighten more and the eyepiece continues with play. When pushing the eyepiece the entire piece moves, including the eyepiece lens :/

#7 Bosco

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Posted 22 June 2021 - 02:31 PM

But definitely it seems to be due to a not enought tightening of this ring. The eyepiece body seems to be attached to the lens so the two parts move together as you rotate it so if they are not tightened together enough, both pieces will have some play. The play is not too much and the other eyepiece has a very little little play too. Is it ok to leave as it is or should I return them?



#8 Rich V.

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Posted 22 June 2021 - 03:12 PM

Bosco, I would consider any play you can't get out to be unacceptable.  If the eyepiece body/lens itself moves back and forth and not just the outer housing with the rubber ring and diopter markings, there's a problem. I've never heard of this happening before in a new FMT.

 

You buy FMTs because you want the highest quality build.  A "lifetime" Porro binocular.  Focusers should operate smoothly and without any free play anywhere; as should the hinge axis.  You shouldn't have to make any concessions regarding quality control for what you paid for them.

 

I would return them as defective and get a replacement at this point.

 

Rich


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#9 Bosco

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Posted 22 June 2021 - 03:36 PM

You're right. It is true that I have to apply some force to get this play but for what I paid I expect best of the best quality.

Thanks for all the given information I found it very useful.

#10 warpsl

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Posted 22 June 2021 - 04:49 PM

My 10x50 eyepieces are very tight,and take effort to focus.but my 10x70 are loose and easy to focus by comparison. But there is no sideways/lateral slop in either.

#11 Bosco

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Posted 23 June 2021 - 04:35 AM

Good to know, as it should be.

I will send them back today and buy another pair when get my money back.

I will keep you informed when having news! Hope the next pair will be perfect!
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