Two and Three Mark Sight-In Method

This document details the Two and Three Mark sight-in methods. These are the most commonly used sight-in methods, and are both extremely precise when executed correctly.

Should I choose the Two or Three Mark method?

For most archers, the Two Mark method is the best choice. It's simpler, quicker, and much easier to get right than the Three Mark method.

The Three Mark method is very accurate, but the degree of precision required to get it right is much higher. If you aren't an advanced archer with plenty of time to fine tune long-range marks, we recommend sticking with the Two Mark method.

Note

We only recommend the three mark method for very proficient archers who can take plenty of time to get extremely precise marks at long range (over 100 yards). The level of precision required for this method is very high, and it's easy to run into issues if the shot-in marks aren't close to perfect. In general, this method is not recommended.

If I sight-in my personal setup at 40, 80, and 100, changing my 80 yard mark by one click (approximately 0.004 inches) changes my calculated speed by almost 6 fps. For me, a single click at 80 is pretty tough to resolve on target consistently.

The Data We Need

Density Altitude

Ranges

These are the ranges you will shoot in marks at.

We recommend the first sight-in distance to be at least 35 yards. 40 or 50 yards is better yet. This allows you to see deviations in vertical point of impact more clearly on target and achieve a more precise first mark. We do not believe 20 or 30 yards are good distances to sight in at, as they are too close to see deviations in vertical point of impact clearly.

Said differently, there can be quite a bit of error in a 20 or 30 yard mark and still hit really well on target.

The other one or two sight-in distances should be as far as possible. In addition, we always recommend a minimum of 20 yards between sight-in distances to reduce relative measurement error.

Some good examples:

2x ranges (Two Mark, long range) - 40, 100+
2x ranges (Two Mark, short range) - 40, 60+
3x ranges (Three Mark, long range) - 40, 90+, 120+

Mark Data

We have three options for entering mark data:

Provide us with the target sight marks for each range (if using a target sight, recommended)
Measure the distance between the sight-in marks with a caliper (recommended if using a sight without target marks)
Measure the distance between the sight-in marks with our printable calibration tape (only recommended as a last resort)

The Sight-In Process

With our decisions made, it's time to get started!

The general process involves getting a reliable mark for each sight-in distance. If you're using a target sight, jot these marks down as you go.

If you're using a sight without target marks, place a blank sight tape on your sight to record each mark, which you can measure later. A piece of masking tape works well for this if you don't have a blank sight tape handy.

When you're done, your blank tape might look something like this. Try to be as precise as possible with your marks!

Tip

When sighting in, it's helpful to aim at a thin, horizontal line instead of a standard bullseye. This makes it much easier to see vertical deviation in your point of impact and know if your mark is spot on. The thinner the line you can consistently hit, the better. At closer ranges, aim for the EDGE of the line and try to break it!

Tip

Try to sight in on days with as little wind as possible, and consider validating your sight-in marks on more than one day if possible.

Tip

If you have a sight with multiple pins, make sure to use the same pin throughout the sight-in process. Once you have your sight tape made, you can then sight-in your remaining pins.

Tips for Shooting in Good Marks

Shoot at a thin, horizontal line. We like blue painters tape. At closer ranges (40 and in), aim for the EDGE of the tape and try to break the edge with the arrow.
Take plenty of time to ensure the marks are accurate. We'll often spend several different shooting sessions over multiple days to double check the marks.
Focus intently on just the marks that you need. For example, if you have 4 hours to shoot, we'd rather see you spend two hours each on 40 and 100 vs. 15-20 minutes each on 40, 50, 60, 70, 80, 90, and 100. You can always verify these other distances once the new tape is made!
Throw out bad shots. We don't care about the group so much as we do where the shots that break cleanly land. These are the ones to pay attention to.
Stretch the ranges out. We never recommend shooting in marks at 20 or 30 yards. We like 40 and beyond. The farther the better, in pretty much all cases. Reason being, at close ranges, there can be significant error in the mark that isn't noticeable on target. For example, for a typical setup, you can be a full yard off on your tape and stay within a 1” circle at 30. At 20, it’s probably 2-3 yards. When it comes to sight tapes, this is a big deal.

Measuring with a Caliper or Calibration Tape

First, take the tape off the sight and lay it flat on a table. This makes it easier to accurately measure the distance between each mark rather than trying to measure it while it's still on your sight. If you have a sight where the tape is on a wheel, such as a Spot Hogg or HHA, you will need to take the tape off the wheel and lay it on a flat surface before measuring.

Note

Precision is essential here. Measure the distances a couple of times to double-check! Aim to be within a couple thousandths of an inch if using a caliper. If using the calibration tape, try to be to the nearest 1/4 of a tick mark.

Entering the Data

Here's what it looks like to configure a setup with the Two Mark sight-in method:

Here's what it looks like to configure a setup with the Three Mark sight-in method:

Validating the Sight-In

Verifying your Mark Measurements

If you used a caliper or our calibration tape to supply your sight-in marks, the easiest way to verify your measurements is to print a sight tape and compare to your sight-in tape.

We offer a 'sight-in' printing mode that prints 5x tapes at 0.003" increments from the mark measurements specified. For example, if you specified your 40 to 80 measurement as 0.737", we would print tapes from 0.731" to 0.743" in 0.003" increments. This allows you to verify your measurements and tweak them slightly if needed.

Note

Remember - we base your arrow's drag model on these sight-in measurements, so if you end up using one of the other tapes on the sight-in printout, you'll want to make sure to update your sight-in measurements in the application!

Once your sight-in marks line up properly, the easiest way to validate the rest of the marks is to print out a sight tape or mark sheet and shoot it in at the range.

Tip

When putting a fresh tape on your sight, we always recommend 'zeroing' your tape as far as possible, setting your indicator on your tape once that distance is hitting, and then working your way in from there to validate the closer marks. If you set your indicator at 20 or 30 and then work your way out, there's a high likelihood that there's some error in this closer mark that will show up as you move to father distances.

Please check out the sight tapes page for more information about printing and verifying sight tapes.