question about focus or paralax

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Hurlflink184

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I was on my way to my deer stand the other day walking very slowly to keep noise down and keep my eyes peeled as I went. I saw a couple deer about 150yds through thick Bush (maple and beech) along the edge of a coniferous treeline. As i raised my rifle to get a sight I couldn't get It to focus that far away. The scope would only focus on closer trees and branches maybe 50yds out. Tried the whole zoom range and nothing.
The scope is the cheap Bushnell that comes with rifle packages.
My question is would this be a paralax problem or something different alltogether?

All help is greatly appreciated!
 
Was the reticle(cross hairs) blurry or the image seen through the scope? Fogged lens?

Sounds strange, specially if it was working fine when you sighted in.
 
Normally, one would aim the rifle at the sky (especially a cloudy sky) and adjust the focus until the cross hairs are absolutely crisp. That's it. Leave it there. Adjusting the power ring or Adjustable Objective (AO) parallax shouldn't affect the ability to see the target.
 
Loosen off the lock ring for the eyepiece, then unscrew it, ( or screw it in, doesn't matter ) until everything is blurry. Pick a spot about 200 yds away, check the focus through your scope, then screw the eyepiece in a few turns. Don't stare through the scope, your eye will try to compensate. Look through the scope, check the focus, look back at the target, screw it in a few turns then check through the scope again. Do this until both crosshairs and target are in focus. If you wear corrective lenses, use them, because it will make a difference.
 
If your scope does not have a parallax adjustment, then it is set at the factory usually at 100 yds. Any other range may not focus perfectly-the eyepiece should be adjusted to have the reticle in sharp contrast/clear as above.
 
That's right. I have a 3-12 Sightron S2 Bigsky ($800 scope) with no parallax - reticle and image are clear at 100 yds but only the reticle at longer ranges. No problem for hunting but not precision work at longer ranges or for long range varmints.
 
Eye piece focus is adjustable to get the reticle clear. Parallax knob is used to get the TARGET clear. As they both get clear, you SHOULD then get no parallax errors. AKA reticle should at this point not float all over the target.

cheers.

If you have a focus. Adjust it so the RETICLE is clear. If you DON'T have a parallax adjustment, you will be forced to shoot at the minimum distance the scope is design for. Could be 50. Could be 100... Check out the owners manual. Should be there.
 
Your problem has nothing to do with parallax. Most hunting scopes without parallax adjustment are factory-set to be parallax-free at 150 yards. However, objects closer or farther away will not be unfocused, even though a little parallax may be present. The amount of parallax that you'll encounter at, say, 50 yards, or 200 yards will be trivial. The suggestions above to get your eyepiece properly focused are the solution to your problem. 9.3mauser's suggestions should work fine.
 
South Pender said:
Your problem has nothing to do with parallax. Most hunting scopes without parallax adjustment are factory-set to be parallax-free at 150 yards. However, objects closer or farther away will not be unfocused, even though a little parallax may be present.
Click to expand...

This is not quite true. Take a scope with a 100-yard parallax, set it to the highest zoom and aim it at something 10 yards away. The image will be blurry. The amount of blur gets worse the further away you get from the optimal distance. It also gets worse with larger objective lenses and with higher amounts of zoom.

Airgun FT shooters use the focus adjustment for ranging (they shoot 10-60 yards, basically) and you'll often see them using something like a 10-50x60 with a gigantic sidewheel to read the distance off of.
 
I think South Pender get's it, 10 yards on full power with a hunting scope....... Why?

Shooting Airguns or .22lr indoor at short range then an AO scope is the way to go. Hunting at typical range a non AO scope should be clear as a bell at 150 yards.
 
A lot of people seem to be confused about the difference between parallax and focus. Parallax occurs when the primary image of the target is focussed in front of, or behind the reticle. When the primary image coincides with the reticle, the scope is parallax free, usually set at 100 yards, but it could be greater or lesser than that. To check for parallax, set your rifle up on sandbags, aimed at the target, then move your eye side to side, up and down; if the crosshairs appear to move or drift then you have parallax for that given range. The effects of parallax are more noticeable at higher magnifications, which is why some optics have parallax adjustment.

It has nothing to do with whether the image looks blurry or not.
 
9.3mauser said:
A lot of people seem to be confused about the difference between parallax and focus. Parallax occurs when the primary image of the target is focussed in front of, or behind the reticle.

It has nothing to do with whether the image looks blurry or not.
Click to expand...

Lets look at this from 2 angles. If the primary image is focused in front or behind the reticle, the image will not be in focus. In other words, if a scope is set parallax free at 100 yds, and your target is 300 yds, the image will be blurry. The reticle will be clear at any range provided the eyepiece is adjusted to the shooter's eye.

Try this by taking a scope with no parallax adjustment and focus on a quarter sized target at 300 yds. The image (e.g. the quarter) will be blurry. Now take a scope with parallax adjustment and try to focus on the quarter at the 100 yd setting-it will be blurry. Now adjust the parallax to 300 yds and that quarter will become razor sharp.

You will never see a long range shooter using a scope without parallax-targets will not be resolved.
 
South Pender said:
The amount of parallax that you'll encounter at, say, 50 yards, or 200 yards will be trivial.
Click to expand...

For the purposes of hunting this is generally true. For target shooting it's not.

As an example, the max parallax error is given by: 0.5 D (ABS(t-p))/p

where D is the objective diameter, t is the target distance, and p is the parallax setting of the scope. If you have a big 56mm scope that is set for 150yds then shooting a target at 50 yds you would end up with a max parallax error of 19mm.
 
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