I understand the Bindon Aiming Concept; not applicable to my transition to RDS since I don't have binocular vision (I can't fuse left/right eye imagery). What about "Asymmetrical Dot Principle"? Google didn't produce much and I suppose this could refer to astigmatism? I've seen both terms used in descriptions for RDS-specific training classes.
https://gabesuarez.com/red-dot-shoot...asymmetric-dotOriginally Posted by rdtompki
Seems like Suarez is just saying take advantage of the "parallax-free" nature of RDS and just assume that where ever the dot is, assume it's a valid sight picture, no need to center up the dot. Which I guess is true? But you could do that with irons, too, really, as TLG himself would demo during AFHF, where as long as your front sight was within the notch, how misaligned it was generally didn't make a huge difference if you weren't trying to stack holes.
Ah. Not the terminology I would have used but worked on head-up displays for fighters for 35+ years. De-centered would seem to be a better term for the layperson. A discussion of both astigmatism and the effect on apparent dot size of dot brightness with respect to background would seem worthwhile.
I thought I was the only one. I had exotropia corrected in childhood and have some, but not perfect, binocular vision. I cannot fuse the image from my right eye perfectly with my left and initially discovered this when using rifle red dot optics. While the micro sized Aimpoints work great for most, I find a need for the larger windows such as EOtech. I've often wondered if pistol optics are going to benefit me outside of distance slow fire and have been experimenting with this in the last year.
This is an interesting topic to me. I'm no expert for sure, but I've been working lately on understanding "misalignment" of my eyesight with the dot.
What I've seen recently is the dot seems to be located in different parts of the optic, depending on my index. I can make the dot appear almost anywhere in the glass, as a function of where I look at it.
At first I was like, eh, that must just be me, since I wear glasses (near sighted, 20-1200 or something). But then I took a short video with my phone, to see if the camera caught it as well. Here's the video.
This is my G34+HS 507c game gun, clamped so it stays upright, pointed down into my workbench. I took the video from my iPhone, just looking at the sight, moving the phone around.
I was wondering, does anyone else see this effect? I mean, the gun isn't moving, so POI is going to be at POA for any shots. So even though I "see" the dot as misaligned, in different places, the rounds are all going through one (theoretically, of course) hole. I am trying to square this phenomenon with the claims that MRDS are "parralax free". I may not understand the term correctly, since I thought that meant no matter where you viewed the sight dot, it was in the same place in the glass. That doesn't seem to be the case?
@rdtompki I like your phrase "decentered". That seems to fit more than my "misaligned".
As to comparisons to iron sight misalignment, Gabe White did that demo in class. It was an eye-opener (sorry, I'll get my coat.) for sure. I think the emphasis was that trigger control had a vastly greater impact on repeatable shots than sight alignment, everything else being equal.
Good topic. I hope more people weigh in on this.
Some interesting reading in this 2017 study I found here:
https://www.greeneyetactical.com/201...ight-parallax/
Last edited by RJ; 01-22-2022 at 06:40 AM.
Ditto, r.e. exotropia correct 65 years ago. I don't know how many folks with binocular vision are really able to fuse pistol RDS. With a close-up rifle red dot your dominant eye is somewhat immersed in the optic field of view so perhaps if the magnification/distortion isn't too bad it's easier to fuse. FWIW I've only been able to fuse the imagery on, to say the least, exotic binocular displays (e.g., F-35 HMD).
I read this through, and am probably going to attempt to replicate the test protocol at home. This study was focused on rifles and rifle-mounted optics at 25, 50 and 100 yards. So as not to derail this thread further, I'll probably put my thoughts into a new thread, to discuss gathering some parallax error data on current production pistol-mounted MRDS sights (or at least the three Holosun I own) at 25 yards.
The RDS is a collimated display where the imagery, in this case a simple dot, appears at optical infinity. Assuming the device is perfect the maximum "error" at any distance would be no greater than 1/2 the diameter of the window, the "eye box" of the display: same principle that has been used in aircraft head-up displays since ~1970. Assuming a 1" eye box at 100 yards the max. RDS-induced error would only be 1/2". With your video taken through the RDS against a near surface you should be seeing this same sort of error, but against a near target the angular error is greater of course.This is an interesting topic to me. I'm no expert for sure, but I've been working lately on understanding "misalignment" of my eyesight with the dot.
What I've seen recently is the dot seems to be located in different parts of the optic, depending on my index. I can make the dot appear almost anywhere in the glass, as a function of where I look at it.
At first I was like, eh, that must just be me, since I wear glasses (near sighted, 20-1200 or something). But then I took a short video with my phone, to see if the camera caught it as well. Here's the video.
This is my G34+HS 507c game gun, clamped so it stays upright, pointed down into my workbench. I took the video from my iPhone, just looking at the sight, moving the phone around.
I was wondering, does anyone else see this effect? I mean, the gun isn't moving, so POI is going to be at POA for any shots. So even though I "see" the dot as misaligned, in different places, the rounds are all going through one (theoretically, of course) hole. I am trying to square this phenomenon with the claims that MRDS are "parralax free". I may not understand the term correctly, since I thought that meant no matter where you viewed the sight dot, it was in the same place in the glass. That doesn't seem to be the case?
@rdtompki I like your phrase "decentered". That seems to fit more than my "misaligned".
As to comparisons to iron sight misalignment, Gabe White did that demo in class. It was an eye-opener (sorry, I'll get my coat.
Good topic. I hope more people weigh in on this.
FWIW, a typical fighter head-up display might provide a 4-5" head box (as in eye box) with actual errors on the order of 1-3 milliradians over the field of view, the "de-center" errors being negligible at the distances involved. There may be imperfections in the RDS design that will introduce some additional error as the dot is de-centered; I don't see these as being readily disclosed by the manufactuers.
Last edited by rdtompki; 01-22-2022 at 06:52 AM.
Found further discussion here: https://pistol-forum.com/showthread....Sight-Parallax
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