Use of Spotting Scope to shoot
- Thread starter Jennb
- Start date
F-class- I use my spotter for mirage at distance 1/3 downrange and my rifle scope defocused slightly to 50 or so yds before target. This was suggested by a very competitive FTR shooter and my scores improved solidly after I became accustomed to the set up. Prior to that I only used my rifle scope for near target mirage in addition to the wind flags. I use all indicators I can see....flags, grass, trees etc....watching for potential changes because mirage is not always present of course.
Thanks Jade
.
Thanks Jade
.
Liven The Dream
Gold $$ Contributor
As a Long Range Shooter in Palma and F-Class from 300 to 1000 yards I would say No Spotting Scope would be Next to Impossible.
Things it is for : Seeing your Target . shot placement , reading Mirage changes , in Full Bore you score your Partner on your position . You may want to see the shot on the Target next to you , we call that the Wind Dummy . It is very nice to see very small little groups at 200 or 300 yards testing loads .
Things it is for : Seeing your Target . shot placement , reading Mirage changes , in Full Bore you score your Partner on your position . You may want to see the shot on the Target next to you , we call that the Wind Dummy . It is very nice to see very small little groups at 200 or 300 yards testing loads .
6MMsteve
Gold $$ Contributor
enlighten me on the focus deal at 50yds before target, how does this work and can it be done at all ranges anything could help me if I can comprehend it.F-class- I use my spotter for mirage at distance 1/3 downrange and my rifle scope defocused slightly to 50 or so yds before target. This was suggested by a very competitive FTR shooter and my scores improved solidly after I became accustomed to the set up. Prior to that I only used my rifle scope for near target mirage in addition to the wind flags. I use all indicators I can see....flags, grass, trees etc....watching for potential changes because mirage is not always present of course.
Thanks Jade
I think you need to learn what flags are the ones to watch at any range they will give direction and what value wind is then focus on something in the area where you can see the mirage a bench or berm, then back the scope off a 1/4 turn and you will be looking at the wind at that point. now you have the speed....... Jim
Keith Glasscock
Gold $$ Contributor
Try this:
Focus your scope (spotting or rifle, doesn't matter) on the target. Now, turn the focus enough to bring the focus 20-50 yds one side of the target. Take note of the direction and amplitude of the mirage. Now, turn it to 20-50 yards the other side. Did the direction of the mirage switch? Did the amplitude change?
At certain ranges I frequent, that is the case. It can be quite confusing. If you are going to try to read the mirage near the target face, be very careful how you do it. You can get some really unexpected results. On a really bright day, I'll use a modifier ring to increase the depth of field at the target. I get a more true and consistently readable indication that way.
Focus your scope (spotting or rifle, doesn't matter) on the target. Now, turn the focus enough to bring the focus 20-50 yds one side of the target. Take note of the direction and amplitude of the mirage. Now, turn it to 20-50 yards the other side. Did the direction of the mirage switch? Did the amplitude change?
At certain ranges I frequent, that is the case. It can be quite confusing. If you are going to try to read the mirage near the target face, be very careful how you do it. You can get some really unexpected results. On a really bright day, I'll use a modifier ring to increase the depth of field at the target. I get a more true and consistently readable indication that way.
I aim at the grass about 30-50yds before the target and focus the scope at that point, if I still get a good enough resolution of the X-ring, to get mirage in view at that distance. Of course it will be a focal 'trough' and be probably tens of yards of mirage effect. As Kieth pointed out, an aperture reducer ring will increase the depth of the focal trough.
Turbulent Turtle
F-TR competitor
Because riflescopes are afocal, an ordinary DoF calculator doesn't apply. However, since the riflescope is really made up of 3 optical systems, the one that provides the usable depth of field for our purposes is the objective lens system; the front of the riflescope. Now DoF is predicated on three components; magnification (combination of focal length and sensor size), aperture and distance to subject. We do not know the focal length of the objective lens system and the aperture is not something we control in the scope. However, if your riflescope is short and the objective lens is large, your DoF should be smaller than a longer scope with the same size objective lens or smaller. Most of the riflescopes I see on the line are of the longish variety. Using a modifier disk or other type of aperture reducer will increase DoF, but it will also darken the image; not a problem in the noontime sun, beware on dark mornings and cloudy days. Since the zoom lenses of the riflescope are not in the objective lens system, I don't think reducing the magnification will help DoF, unlike in a camera lens.
Now, focusing 50yards in front of the target to increase DoF is certainly valid, but I don't think you want that much at 300 yards or even 600 yards. Finally, do not depend on the markings of an AO or side focus for the exact distances. Do has stated above, focus on a spot in front of the target at what you think is 50 yards and then see if the DoF keeps the CoC in check at the target. If the Circle of Confusion is too high, you may want to focus closer to the target, especially at higher magnifications because that will just enhance the CoC. Yuck.
Now, focusing 50yards in front of the target to increase DoF is certainly valid, but I don't think you want that much at 300 yards or even 600 yards. Finally, do not depend on the markings of an AO or side focus for the exact distances. Do has stated above, focus on a spot in front of the target at what you think is 50 yards and then see if the DoF keeps the CoC in check at the target. If the Circle of Confusion is too high, you may want to focus closer to the target, especially at higher magnifications because that will just enhance the CoC. Yuck.
Last edited:
Here are a few comments:
-the rifle scope is useful for seeing what the wind near the target is doing.
-I use a spotting scope because I want as much information as possible. Perhaps the best use of the spotting scope is to keep an eye on adjacent targets.
-in mild, switchy conditions, mirage is perhaps the best indicator to keep up with the switches. I find it easier to see these changes with a spotter vs the rifle scope.
-in poor light conditions with a strong head/tailwind, I like to point my spotter at the row of flags in order to better see the subtle directional changes that will cause big changes on target.
Some people like to keep things simple and find a spotter causes information overload. Other people like to get all the info available and use spotters. Both are successful.
I also find that people who often run and gun tend to eschew a spotter and slower shooters who like to pick their way through a string do use spotters.
-the rifle scope is useful for seeing what the wind near the target is doing.
-I use a spotting scope because I want as much information as possible. Perhaps the best use of the spotting scope is to keep an eye on adjacent targets.
-in mild, switchy conditions, mirage is perhaps the best indicator to keep up with the switches. I find it easier to see these changes with a spotter vs the rifle scope.
-in poor light conditions with a strong head/tailwind, I like to point my spotter at the row of flags in order to better see the subtle directional changes that will cause big changes on target.
Some people like to keep things simple and find a spotter causes information overload. Other people like to get all the info available and use spotters. Both are successful.
I also find that people who often run and gun tend to eschew a spotter and slower shooters who like to pick their way through a string do use spotters.
Last edited:
Try this .... Set the spotting scope up as stated above and you will see the mirage. It ALWAYS looks like it's running right to left or left to right but is it? Turn your spotting scope into the mirage until you see it boil. Now, look at the angle your scope is pointed and where the target is.......that's the wind direction. Check often. If the mirage isn't in a boil you've got a wind change.
turning your parallax out of adjustment is giving away accuracy to see mirage. and it isn't where you think anyway. A rifle scope doesn't work the same as a spotting scope, you focus a spotting scope any where at a 1000 and see the mirage at that point and back it off a 1/4 turn and see the mirage there. Back the parallax off on your scope is different ball game. Why don't you try shooting you rifle at say 300 yds. with the parallax set and shoot a group and do it with the parallax backed off and see the group size. you leave a lot on the table......... Jim
Turbulent Turtle
F-TR competitor
I would not worry about any parallax error induced by focusing the riflescope 50 yards in front of the 1000 yard target. The effect is minuscule and add to that the fact the exit pupil is already getting quite small at the higher magnifications commonly used by F-class shooters at long range so the shooter has to be in a very exact position behind the riflescope to be able to get a sight picture. Any induced parallax would be inconsequential.
Liven The Dream
Gold $$ Contributor
Second Edition of Nancy Tompkins Rifle Book Try reading this Great Book by a great lady ....
Well I guess it is a waste of money even putting parallax adjustment on a F class scope then. Funny how it does have a huge effect on on short range and long range bench rest........ Jim
Keith Glasscock
Gold $$ Contributor
While this is obvious to the children of the spotting scope, others may not realize it...
There are conditions where a spotting scope is nearly the ultimate tool for detecting wind changes via mirage. There are many other conditions out there where there is little or no mirage to be seen. In those cases the spotting scope can be used on adjacent targets, or environmental wind indicators, or the flags themselves. There are a few conditions out there that even the most dedicated spotting scope user will push it away and just put rounds downrange.
The winner of an F-class relay is normally the person that picks the best technique for seeing the wind under the present conditions.
There are conditions where a spotting scope is nearly the ultimate tool for detecting wind changes via mirage. There are many other conditions out there where there is little or no mirage to be seen. In those cases the spotting scope can be used on adjacent targets, or environmental wind indicators, or the flags themselves. There are a few conditions out there that even the most dedicated spotting scope user will push it away and just put rounds downrange.
The winner of an F-class relay is normally the person that picks the best technique for seeing the wind under the present conditions.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.