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-   -   Do Lens Reducer's help you? Give opinion, please. (http://forums.thecmp.org/showthread.php?t=274073)

Rootsy 01-01-2021 12:26 PM

Quote:

Originally Posted by Gewehr43 (Post 2000049)
So I'm considering joining this century and going optics.........
I've been playing around with them and winding my way thru the various options.......

So I appreciate your input....as with the others who have actually used them.

My question is this:

So idea goes that you need consistent head position/cheek weld etc or else you will introduce parallax issues.....parallax leads to opened groups or wandering zero--(for lack of better terms).....

But if the parallax is so small (so affect on groups).. then why worry about it?

So then, of course, within reason, why worry about forcing your head/eye into a particular spot? (So no need for the reducer).......?

In other words if the affect on groups by the question of parallax is so small, why worry about going thru all these steps to correct or eliminate it?

Parallax isnít the issue unless you have your eye alignment so off that the image is heavily shadowed and you are shooting very Close or very far. I once did a spreadsheet to calculate parallax and with a 24 mm objective and parallax set @ 300 yards maximum possible parallax error at 200 and 600 was only like 0.1 moa.

Varying head pressure and position creates varying loading on the rifle butt that causes shots to go where they were not aimed when you pull the trigger. With a huge field of view in a scope it is easy to get sloppy whereas with a .042 aperture it forces you to place your head consistently

Gewehr43 01-01-2021 01:40 PM

So I've also been reading the primer on the NM forum, which is quite good BTW.....

So short version:

So the parallax effect could be quite small, depending on the exact situation, but to minimize the variable as much as possible, you have several choices:

-choose a scope or modify so the parallax is set at, say 300yds, instead of say 100yds.
-For that matter choose one that has adjustable parallax.

-use one of these reducers to either:
+reduce the affect even more with the above.
+if you don't have a scope that is adjustable (or you haven't gotten it done).

-Or just rely on the idea that your cheek weld/head position is consistent enough and "drive on down the road....."
(because of course if you are really consistent, you have in effect, eliminated the parallax, because your head isn't changing shot to shot).

Is that in a nut-shell?

But you also bring up the idea of the FOV being too big generally...... Can you expand on that?

HighpowerRifleBrony 01-01-2021 09:14 PM

Quote:

Originally Posted by Gewehr43 (Post 2000092)
But you also bring up the idea of the FOV being too big generally...... Can you expand on that?

My interpretation:

Some relationship of exit pupil and eye "box". The eye can be moved around the ideal focal point some while still maintaining a full, mostly clear image. C_Does and 9-Hole Reviews have some great optic review videos, often showcasing the eye "box".

Whereas moving the eye 0.020" from ideal alignment would be obvious with a 0.040" aperture and 3" eye relief, many scopes wouldn't show misalignment unless they're rigidly fixed and the parallax is way off, say 30yds when shooting at 300yds. The reticle is relatively small compared to the ~1.5" ocular lens.

jcj54 01-03-2021 10:35 AM

Having shot scope in smallbore matches for 40 years, I can attest that keeping your head and eye in the same spot is critical. I regularly shoot 50 yard conventional prone smallbore with the local gun Club in the summer and have blown shots in the 9 ring by failing to keep my head position consistent. Pretty disgusting to shoot a 199 25X because of the error.

Danny 01-07-2021 09:10 AM

Quote:

Originally Posted by Gewehr43 (Post 2000049)
So I'm considering joining this century and going optics.........
I've been playing around with them and winding my way thru the various options.......

So I appreciate your input....as with the others who have actually used them.

My question is this:

So idea goes that you need consistent head position/cheek weld etc or else you will introduce parallax issues.....parallax leads to opened groups or wandering zero--(for lack of better terms).....

But if the parallax is so small (so affect on groups).. then why worry about it?

So then, of course, within reason, why worry about forcing your head/eye into a particular spot? (So no need for the reducer).......?

In other words if the affect on groups by the question of parallax is so small, why worry about going thru all these steps to correct or eliminate it?

Nooooooooooo

Gewehr43 01-09-2021 07:03 PM

Quote:

Originally Posted by Danny (Post 2001675)
Nooooooooooo

OK..... I'll play this game............

YYYYYYYYYEEEEEEEEESSSSSSSSS

What did I win?


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