RDS and Astigmatism solution...

[Limeman]

Hey guys,

I have a mild case of astigmatism and recently put a new Sig Romeo 5 RDS on my m4. I got that all too familiar nike-style swoosh shape when viewing the 2 MOA dot. Had a friend with clear eyes confirm the dot was nice and sharp/round just to be sure. It was. Anyway...

So... out of curiosity (and I'm sure many of you may already know this?) I tried shooting the Romeo with the rear iron-sight up and set to narrow aperture. What do you know... the red dot was now clear and sharp. Made for easy and accurate targeting at 75 to 100 yards on paper and 10/10 accuracy on steel at those distances as well. So nice to see a clear red dot!

At 50 yards and in I don't care about the blur, so the rear iron sight will remain down in that situation, but was really excited to find a simple work-around for my astigmatism at further distances.

Just thought I'd share in case this might be helpful for some of you out there. Try it out and let me know if it helps.

Cheers!

[teflondog]

Another method that I use is to mount a magnifier behind my Aimpoint. The Nike swoosh becomes a blurred dot. It's not perfect, but it's good enough for me. Looking through the rear sight works better, but if I'm going to do that, then I might as well shoot with irons and ditch the optic.

The magnifier works for Eotech too. Without it, the Eotech reticle looks like a ring with flames to me.

[GoatLocker]

I tried shooting the Romeo with the rear iron-sight up and set to narrow aperture. What do you know... the red dot was now clear and sharp.

Kinda defeats the purpose of a red dot, speed, minimal parallax error, etc.

1X Prism sights like the Vortex Spitfire are probably the best reflex sight alternative for those with uncorrected astigmatism, but prescription shooting glasses are even better...

[Erion929]

Kinda defeats the purpose of a red dot, speed, minimal parallax error, etc.

1X Prism sights like the Vortex Spitfire are probably the best reflex sight alternative for those with uncorrected astigmatism, but prescription shooting glasses are even better...

Yeah, that small aperture method is fine at the range when you want to take your time and align each shot precisely.

Agree on the 1X Spitfire

[Limeman]

Yup. Got a prism sight for 100+ yards and it works great. I'm sure the 1x Vortex is a solid option as well, but for my intended use of this particular rifle, the rear iron sight does not defeat any purpose for me.

I am talking about shooting with the RDS + rear iron sight at moderate distance such as 75 to 100 or so yards. At that distance, the combination really helps eliminate the blur and allow for well-placed shots. The red dot also helps when shooting at dark colored targets or at dawn/dusk at those distances. Far better than iron sights alone.

Now... when I'm at 50 yards or less, then I don't really care about the RDS bloom and clearly, at 25 yards or less, the issue is totally inconsequential. Thus, with a simple "click" I can drop the rear irons sight if I so choose. It's an easy point and hit center mass regardless of the blur/bloom at those distances. I believe some highly decorated operators utilize fixed sights with their RDS - possibly for astigmatism? Who knows, but if it works OK for them, then I think I can make it an acceptable solution/option for myself. I like having the option, especially if the iron sights are already there and the RDS is small and lightweight. No loss that I can see with this solution.

[uniqueid002]

Wow. Thanks!

[Ki6vsm]

I am talking about shooting with the RDS + rear iron sight at moderate distance such as 75 to 100 or so yards. At that distance, the combination really helps eliminate the blur and allow for well-placed shots. The red dot also helps when shooting at dark colored targets or at dawn/dusk at those distances. Far better than iron sights alone.

I have a question, since there is no mention of the front sight, only the rear. You say you have an "M4" which implies a fixed front sight on the barrel. So are you using both the irons in a normal way, and with an RDS that's co-witnessed to the irons?.... so that what you're seeing is the little red dot atop the front sight post?

And BTW, congrats on finding a sight that works for you at the longer distances. I'd forgotten who makes 1x prism sights.

[Limeman]

Yup. Shooting co-witness with the M4. I have also tried this on my BCM with free-float hand guard and works just as well with the rear sight up, front sight lowered. Looking through that pin hole rear sight tricks my eyes and appears to reduce the astigmatism by about 85% or more. Again, I would only use this method for shooting past 75 yards. Anyway... So far really digging the Sig Romeo 5. A solid RDS.

[Ki6vsm]

Great! I mentioned prescription eyewear before because that also really helps by a huge amount. I have a BCM middy with the front fixed iron, and I'm using a Vortex Sparc on it, also co-witnessed. I've only used the irons for making adjustments to the RDS (or vice versa). But if ever I forget to grab my glasses, I'll try this for bullseye shooting.

BTW, the method you're using is an old benchrest trick. Shooters put a patch over their sighting eye and the patch has a tiny hold in it. Looks like what is below. You might try this as well with your shooting glasses. The you wouldn't need to bother with an iron-sight cheekweld etc. You might be able to use your RDS a little more like it's intended---with both eyes open. And obviously, you could make your own little eyepatch thingy for free. Hell, I might try it someday.

http://www.pyramydair.com/blog/2013/04/the-eyepal-peep-sight-master-kit-part-1/

[CSTactical]

I have Astigmatism as well and in my experience the newer Aimpoint H2 and T2's with the minor changed to the optics have improved (not eliminate) the comet like tail I see while indoors. Outside in sunlight it's even less of a problem but everyone's eyes are different and there are some customers who prefer only using etched reticles. YMMV

[Limeman]

BTW, the method you're using is an old benchrest trick. Shooters put a patch over their sighting eye and the patch has a tiny hold in it. Looks like what is below. You might try this as well with your shooting glasses. The you wouldn't need to bother with an iron-sight cheekweld etc. You might be able to use your RDS a little more like it's intended---with both eyes open. And obviously, you could make your own little eyepatch thingy for free. Hell, I might try it someday.

http://www.pyramydair.com/blog/2013/04/the-eyepal-peep-sight-master-kit-part-1/

Thanks for the idea. I'll look into that solution!

[Ki6vsm]

FWIW, I tried this technique on my RDS-equipped upper, rear sight flipped up while not wearing my glasses. It definitely helps to clear up the dot-shape aberration.