Below Rollover

[iang]

IS there any way in which AS can give a better printout for distances below rollover i.e. abotu 12 mtrs..? with ABA and IFAA I shoot down to I think 5 yards or so - very close. the sight tape is all but useless there.. woudl be good if it could be used somehow?

[James Park]

Below turnover the markings go down the sight tape of course. I thought a lot about what to do there, and wanted to avoid confusion. Hence, I show just the 5 metre or 5 yard marking (it is the small red line somewhere around 20 to 30 metres or yards).
The other way you can get it is to print out a list of settings, which will show each setting from 2 metres or yards up. From the list you can see what each of these short distance settings is equivalent to for distances over turnover.
I would be happy to be guided by yourselves as to what would be best - what would you like it to do?

[Eberbachl]

Great question Ian,

Jim....Ian is right, about the only confusion I have when using an accurate sights tape is when I'm shooting below my turnover distance....ie: IFAA bugs eyes, and ABA Group one targets.

The Five meter (or yard) line is a handy feature, but as we shoot varying distances at this range, only provides a starting place. Maybe there is room to have provision for lines ranging from, say the turnover distance to five meters in one meter increments with a number at each end?

For example, if the turnover distance was 13 meters (would be different for each bow), then the turnover distance is marked in red, and as wel as the normal sight markings, you have small red lines out to 5 meters in one meter increments. Only the turnover distance (in this case 13) and the five meter mark would need to be numbered.

What do you think? Certainly would take some of the guesswork out of those short shots... :wink:

[iang]

Hmm.. and I thought I was alone :-)

I think Eberbachl's idea is a good one.. use different colours to signify that these lines are for distances below the rollover point and yes just mark the rollover point with a number, then you can just count down the scale from that point. With IFAA and ABA Group one this is where we really need it. Probably need to go down to 3 yards, I think one of our bugs eyes are 11 Ft away

[James Park]

Ian and Luke,
Good suggestions. I will see what I can do.

[robbo]

For example, if the turnover distance was 13 meters :

Luke what is meant by the term turnover distance?

Thanks

[iang]

The turnover distance is the distance at which you sight setting will be the lowest.. i.e. the point when you scope will be highest in the slide rail. If yo shoot at every 5 yard interval from 5 yards right up to 80 yards you will get a nice j curve if you plot the sight setting results in a graph. The bottom of the J will be around 13mtrs or so depending on your equipment. So.. you might use the same sight setting for 7 yards as you use for 30 yards, hence why it looks like a J. This poses a few challenges and the fundamental point at which the sight setting or j curve bottoms out is call the rollover point. That is also the point at which you scope will be at it's highest setting, i.e. furthest to the sky from the arrow rest.

hope that makes sense :-)

[James Park]

For the mathematically inclined:
There are two components that make up the sight positon:
1. The necessary angle of elevation to have the arrow go the desired distance means that the sight pin needs to be below the height your eye is above the arrow.
2. Because your eye is not directly behind the nock, you have a parallax effect that you need to allow for.

The turnover distance is the distance at which these two contributing effects are equal. For distances shorter than that the parallax dominates and the sight pin has to move down closer to the arrow. For distances greater than the turnover distance the sight pin also has to move down closer to the arrow because the angle of elevation component dominates.

For most recurvers the turnover distance will be around 10 Metres. For most compounders the turnover distance will be around 12 Metres. It basically depends on your peep-arrow distance (or eye to arrow distance for a recurver), and on your arrow velocity.

[robbo]

Thanks I understood the concept, I used to do a lot of rifle shooting.
I just didn't connect turnover. the name makes sense now.
The highest point in the projectiles tragectory.

[James Park]

No, not the highest point in the arrow's trajectory, but the distance at which the sight is the highest up the sight bar. The following graph shows the height of the sight as distance varies.
http://www.archery-forum.com/4sale/20021110230957.jpg
You can see how the sight goes down for distances closer than the turnover distance.
An important point to note is that around the turnover distance the sight settings do not change much as you change distance. This is why I recommend that you use 15 Metres as the short distance for getting the sight gap to enter into Accurate Sights. I use 15M and 70M.

[robbo]

Jim

So the turnover refers to the actual point on the sight bar at which the sight is at it's highest?

[James Park]

robbo,
Yes, it is the distance for which the sight pin is at its highest on the sight bar. This is when you are shooting with the target at the same height as the arrow in the bow.
However, note that if you shoot steeply up or down hill at short distances, you may have to put the sight pin higher than that (Accurate Sights covers that bit in the "Slopes" menu).