Q: Hey Stephen, I newly bought a red dot sight and I’ve learned that if I use both iron sights and red dots sights while shooting, it will be more accurate and also increase the speed of target acquisition. Is that true?
A: Yes, that’s true! Cause red dot sights may fail sometimes, using both of them will be more insured.
Q: Wow, then how about Absolute co-witness and Lower 1/3 co-witness? I am hesitant which one to choose, which one is better?
A: Emm. There is nothing good or bad about them, both have their advantages and disadvantages. Absolute co-witness and Lower 1/3 co-witness are just different installation methods.
Q: Can you tell me more about it?
A: Yes, of course. to put it simply, it is the height of your red dot sights the biggest different between Absolute co-witness and Lower 1/3 co-witness. There are 3 popular center heights, as picture 0 shows, one is 36mm(1.4")---Absolute co-witness; one is 40.4mm(1.6 ")--- Lower 1/3 co-witness; the other one is 38.1mm(15").
Q: It is still kind of difficult for me to understand.
A: OK! Just as picture 1 shows, If you mount the red dot sight at the same height as the iron sights and the red dot is aligned with iron sights, it is called Absolute co-witness.
Q: Oh, how about Lower 1/3 co-witness?
A: If you mount the red dot sight higher than the iron sights and the iron sights appears in the lower 1/3 of the optic window, it is called Lower 1/3 co-witness. You need to change your line of sight to make red dot align with the iron sights.
Q: Ok, I got it. But I am still puzzled about which type to choose.
A: I’m sure you can make the decision after I tell you their advantages and disadvantages!
A: Using Absolute co-witness, the red dot is always aligned with iron sight so you can react faster and more accurate when the target appears in your field of view BUT the iron sight will block part of the field of view.(Picture 2)
Q: Well, how about Lower 1/3 co-witness?
A: Using Lower 1/3 co-witness can provide wider field of view and less interference (Picture 3)BUT you need to change the line of sight when you need both red dot sight and iron sight. (Picture 4)
A: Therefore, the choice depends on personal preferences and habits.
Q: I see! I will try both of them and choose the more proper type! Thank you so much!
A: You are welcome~