Ease of focus clockwise vs. counter-clockwise rotation of the focus wheel. (1 Viewer)

[mskb]

Hello folks,

I am on a Monarch 82 ED-A. At high zooms, I am finding that I am able to snap into focus when rotating the focus wheel clockwise (moving from nearer toward the subject), but when approaching the subject through counterclockwise rotations (moving from beyond the subject to the subject), I find that I nearly always miss the point of focus.

Any thoughts on why this could happen? Or is this all in my head? 😅

Thanks!
Kumar

 

[Gzoladz74]

This is actually a good question, my contribution:

1. For focusing, I am more accurate with my finger when I "pull" than when I "push" the focus knob...what relates to what you are describing and results in it being easier for me to lock focus when I "pull".
2. A few years ago I had to return some alpha binoculars because overtime they developed much more resistance when I turned the focus know in one direction (but not in the other direction), what made them a pain to use.

So it may not be in your head!

 

[mskb]

Thanks @Gzoladz74 !

I am also wondering if this could be a result of aberrations. Trusted experts Joachim @jring / Henry @henry link , any thoughts? Thank you!

 

[Hermann]

I am on a Monarch 82 ED-A. At high zooms, I am finding that I am able to snap into focus when rotating the focus wheel clockwise (moving from nearer toward the subject), but when approaching the subject through counterclockwise rotations (moving from beyond the subject to the subject), I find that I nearly always miss the point of focus.

Any thoughts on why this could happen? Or is this all in my head? 😅

My first thoughts: For how long have you been using the Monarch? And have you been using a helical focuser before? Because maybe the problems you have are caused by a lack of experience with that particular type of focuser. Practice makes perfect ... Also, does that happen at all magnifications or only at high magnifications? These focusers can be quite tricky at high magnifications ... At least that what I find with the ED82, the predecessor of the Monarch.

Hermann

 

[mskb]

Thanks Hermann! A week with the 82 ED-A . However, I didn't have these problems with a Meopta S2 I had spent significant time with before. That system also had a helical focuser. Clockwise/anti-Clockwise, I was never confused by where my focus was. And yeah, the confusion occurs at higher magnifications.

It is also clear to me that navigating through the side that has clear well defined rings of defocussed rings (like in a star test) snaps to focus, and the side that has less well defined/blurry rings is confusing and doesn’t snap.

Because the behavior of the rings are known to be dependent on the distance to subject, I will try to get a sense of this in the field at longer distances, and report back! Thanks!