How does SCATT unit determine distance / scale based on distance

Skill Level
Amateur/Hobby Shooter
Primary Discipline
High-power Rifle
SCATT Experience
Less than 1 year
Joined
Aug 25, 2020
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This is for the SCATT MX-W2

Let's say I am shooting at 10 meters and have the focus / distance ring on the unit set to 10 m. When I print the target I specify a distance of 10 m. When I run the software on my laptop I do not specify the distance to the target, just select the type of target I am using.

Then I switch to shooting at 15 meters. I create a new printout of the same target, this time specifying a distance of 15 meters. However I leave the focus / distance ring on the unit set to 10 m (forgot to change it to 15).

How does the SCATT unit / software determine how to scale the movement on the target in this situation. Is it done solely on the measurement of the size of the target black relative to the type of target selected in the software when starting the practice? Or does the focus ring on the unit have anything to do with it?

In my case the results were what I would have expected, i.e. the result of practice at 15m were comparable to the results at 10m, I did not obviously shoot 50% smaller or larger. This would indicate that the focus / distance ring on the unit is not a factor for determining the distance / scaling of the shot in the software, is that correct? I.e. that it is strictly for optical focus adjustment? Just trying to understand whether changing the setting of the focus / distance ring on the unit is required for the scaling of the shot to the target in the software to be correct.
 
Your highest shooting achievement
10m pistol French Championship qualifications
Skill Level
Amateur/Hobby Shooter
Primary Discipline
Air Pistol
SCATT Experience
3 years
Joined
May 13, 2020
222 Posts
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Hi, this subject has been abundantly discussed on the forum for quite some time. Here is a summary based on those discussions. It explains what you have been experiencing and answers your questions.

Scatt models Basic, MX-02 and MX-W2 use a camera sensor (and not infrared,laser nor any alternative technology). When you calibrate you capture a sensor image which becomes the reference for a perfectly centered shot. From there on,when you aim and shoot the sensor perceives digital images and the hardware + software compute a pixel offset from the reference image. Based on the optic system, pixel offsets equal to distance offsets at the specific target distance. Hence the traces and scores.
- The system doesn't need to evaluate the target distance because you indicate it yourself when choosing a kind of target as you begin a session. For instance "10m ISSF pistol", 50m small-bore (22LR), 300m, whichever.
- The sensor doesn't need to determine the bullseye size because it is not necessary for the software to compute the sensor's picture offset. Besides, the bullseye size is known from the discipline and target. For instance it is 6cm for 10m ISSF pistol and 20cm for 50m small-bore pistol.
- As you guessed the distance dial on the sensor' frame is only a focus ring, like on a camera lens.
- When you shoot at shorter distances, optical angles remain the same therefore the sensor pixels/target offset ratio doesn't change. For instance a shot at the bullseye border on a real target at 50m will still be at the bullseye border on a 1/5 scaled target set at 10m.

There has been discussion on how to scale down short distance targets. Scatt recommends measuring the actual distance from the sensor. Although this is a strict requirement for older technology sensors, it is not compulsory for image sensors. Some shooters argue that what counts most is that the bullseye always keeps the same optical appearance in the sights. This means the scaling ratio should be determined with distance measured from the shooter's aiming eye. At very short distances (for instance 3 or 4m) a 1 meter gap between eye and sensor can make a significant visual difference, especially in riffle sights.
If you are more curious of how tolerant the sensor is to bullseye size and appearance, here is a test I conducted some time ago for fun. In any case Scatt's recommendation remains to use the software's scaled target printing tool.

Scatt does not openly explain how its technology works, but it is not pure secret either since @Peter (Scatt staff) has been answering most questions on that subject. I suppose Scatt simply does not consider this relevant for using its products.
 
Last edited:
OP
H
Skill Level
Amateur/Hobby Shooter
Primary Discipline
High-power Rifle
SCATT Experience
Less than 1 year
Joined
Aug 25, 2020
14 Posts
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Thanks, great reply.
 
Your highest shooting achievement
National Senior Champion Smallbore High Power Rifle
Skill Level
Professional
Primary Discipline
High-power Rifle
SCATT Experience
3 years
Joined
Apr 5, 2020
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I notice that when I use the preview, I can get a better focus of the target at a setting different than what I am actually using. I would think that the focus would coincide with the actual distance to have the focus ring truly "calibrated". Am I wrong in this thinking??
 

Peter

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Amateur/Hobby Shooter
Joined
Sep 9, 2019
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I would think that the focus would coincide with the actual distance to have the focus ring truly "calibrated".
That indeed does make sense. Could you test it at exactly 7 meters, with setting the focus ring to 7, please?
If the Preview Image is still blurry, your lens factory setting could be slightly messed up

However, if the Calibrations goes through without an issue, it doesn't really matter that the image is blurry
You are getting the same precision regardless, it's not like the image has to be super sharp.
So you are definitely not losing any data due to this
 
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