3x prism vs. 3x in a 3-sometjing variable

Quote:

---

Originally Posted by jsbhike

I hope the Vortex works for you with the 1x. I picked one up back in the summer to use with a Holosun 515 and so far I am really liking it.

---

I got a Vortex 3x micro magnifier a couple of months ago and I’m loving it. It works really well behind the Romeo5 and it has helped me a little bit with my astigmatism.

Quote:

---

Originally Posted by jsbhike

I was wondering if there was some quirk of 3x in a prism being quicker to acquire than 3x in a non prism. Hadn't thought of the usually shorter eye relief in most prisms.

---

Yes, yes there is. Prism and conventional magnifying optics (tube-type refractor telescopes) give you a view for wherever the scope's objective lens happens to be. The closer that objective lens is to your eye, the more the view is like what your eye would see unaided, and the easier and faster it will be for your brain to process. The farther that lens is from your eye, the worse it is. A 1-6x or 1-8x scope with a 10" tube and 4" eye relief is forming its image 14" away forward of your eye, somewhere down the barrel of your gun. A prism sight (ACOG or not) with a 4" length and 3" eye relief is forming that image 7" forward of your eye, which isn't ideal but is tons better than the tube scope. The 4x32 ACOG, with its short length and terribly short eye relief, can work great for this if you spend enough time practicing, and don't develop a flinch from the eyepiece hitting your glasses. I find the 3.5x35 to be an ideal compromise, even though it sticks the objective farther out.

The closer the target is, the more this difference matters. The longer scope would still slow you down at, say, 500 yards, but the difference would be small, while at 5-10 yards it's a big difference.

You can play around with this with an unloaded gun in a safe area trying different scopes, and it will be immediately obvious in back to back testing.

Red dots and holographic sights work completely differently and this doesn't apply to them, only to scopes using lenses and/or prisms.

(For hyper-technical people, note that what matters is the physical location of the objective lens, not the optical path. Prism sights normally have an optical path much longer than the external physical length of the scope. Also, an ultra-short refractor scope would provide the same benefit, but they are extremely rare - the IOR Valdada Pitbull is the only one I'm aware of, and it was never widely seen in the US.)

Quote:

---

Originally Posted by SomeOtherGuy

Yes, yes there is. Prism and conventional magnifying optics (tube-type refractor telescopes) give you a view for wherever the scope's objective lens happens to be. The closer that objective lens is to your eye, the more the view is like what your eye would see unaided, and the easier and faster it will be for your brain to process. The farther that lens is from your eye, the worse it is. A 1-6x or 1-8x scope with a 10" tube and 4" eye relief is forming its image 14" away forward of your eye, somewhere down the barrel of your gun. A prism sight (ACOG or not) with a 4" length and 3" eye relief is forming that image 7" forward of your eye, which isn't ideal but is tons better than the tube scope. The 4x32 ACOG, with its short length and terribly short eye relief, can work great for this if you spend enough time practicing, and don't develop a flinch from the eyepiece hitting your glasses. I find the 3.5x35 to be an ideal compromise, even though it sticks the objective farther out.

The closer the target is, the more this difference matters. The longer scope would still slow you down at, say, 500 yards, but the difference would be small, while at 5-10 yards it's a big difference.

You can play around with this with an unloaded gun in a safe area trying different scopes, and it will be immediately obvious in back to back testing.

Red dots and holographic sights work completely differently and this doesn't apply to them, only to scopes using lenses and/or prisms.

(For hyper-technical people, note that what matters is the physical location of the objective lens, not the optical path. Prism sights normally have an optical path much longer than the external physical length of the scope. Also, an ultra-short refractor scope would provide the same benefit, but they are extremely rare - the IOR Valdada Pitbull is the only one I'm aware of, and it was never widely seen in the US.)

---

Thank you! That was what I was curious about.