Scope side focus question

[bikemutt]

The riflescope in question linked here: https://sightron.com/products/siii-long-range-10-50x60?variant=39278115258526

Considering the side focus knob, I've always been able dial an ultra-crisp image at 200 yards or less, now at 300 yards, the dial hits the end stop, which I assume is the infinity position, where the target is clear, but not crisp. Magnification is set at 25x or so. The side focus knob has no distance hash marks like I've seen on other scopes.

I guess my question is, what distance is considered infinity? 

[DHuffman]

Infinity is infinity....

The markings on any parralax dial rarely ever line up with clarity at the marked distance.
You just dial them to the clearest position. It should be able to get a crisp image at 300 though.
I'd adjust the rear eyepiece as well.

[gman47564]

Just make sure the parallax is good after clearing the target the best you can.. move that head up and down a little and make sure them cross hairs aren't moving on the target..

[jvw2008]

Do you wear corrective lenses to shoot?

Start by reading the scope instructions for setting the ocular lens focus. Once that is set the parallax focus will function at its best for you.

[bikemutt]

Infinity is infinity....

The markings on any parralax dial rarely ever line up with clarity at the marked distance.
You just dial them to the clearest position. It should be able to get a crisp image at 300 though.
I'd adjust the rear eyepiece as well.

Well, Leupold seems to believe infinity is any distance greater than 600 yards 🤔.



The confusing thing about "side focus" is it's really about minimizing or eliminating parallax error. How we set the dial is by turning it until the target is in sharp focus. As you said, the distance markings, if any, are usually not perfectly accurate and really only useful for crude distance estimation.

What I think "infinity" means is the target distance is sufficiently far away that parallax error is insignificant and unworthy of further correction. Since there are no numerical has marks on the Sightron dial, there's no way for me to know what they consider "infinity" to be. Regardless, the side focus dial stops right before the target is in crisp focus at 300 yards.

The eyepiece bell adjustment is solely meant to bring the reticle into crisp focus, that works just fine.

It could be I need to play around with the magnification to see if I can find a sweeter spot.


 

[bikemutt]

N

Do you wear corrective lenses to shoot?

Start by reading the scope instructions for setting the ocular lens focus. Once that is set the parallax focus will function at its best for you.

No corrective lens worn while shooting, just readers for the library.

The ocular focus is for bringing the reticle into focus. I did play with that; it had no effect on the target focus, it affected the reticle focus only.

[DHuffman]

On the ocular focus there appears to be a range IME where the reticle is clear and the magnification of the reticle itself increases and decreased while holding clarity.

[bikemutt]

Figured it out today; altered the magnification by just a bit, that moved the parallax side focus knob back into play, target once again crisp 

[LeadHammer]

Figured it out today; altered the magnification by just a bit, that moved the parallax side focus knob back into play, target once again crisp 

Glad you got it figured. When at the range today, I was struggling with my cheap Bushnell on my 10/22. I swear I could make my crosshairs move with just my eyeball lol. I was at 40 meters only on 9x.