D.F.A.T. appears to be a picture of a range, which you put against a wall at home, and a vision restricting device you attach to the end of your scope. Apparently, that device allows you to focus the scope at 10-15ft-ish, allowing you to view the picture you attached to your wall, and simulate long range shooting, indoors.
Just checking some basics, and I'm not sure this thing can work - I'm hoping someone can explain the optics of it.
For example, I have a 4-16x Vortex scope. Minimum parallax about 25 or 50yds. When I am standing about 10-15ft from a target on my wall, and zoom is decreased to 4x, I can make out a very fuzzy target. (very fuzzy). Increasing magnification just makes it worse, as does increasing the side-knob.
So: I found a note on the web that suggested that a DIY version of this DFAT device could be made by cutting a disk the diameter of the scope, then cutting a hole in the centre, with a diameter 1/3 of the disk. So my 44mm scope, has an outside diameter of about 50mm, and the inside hols about 16mm. I tucked this plastic donut into my scope cap, and installed it. Looking back at the target again, I didn't see any improvement at all.
Not being an expert in optics, I can't say it wouldn't ever work, but if the focal distances of the lenses are such that something would be in focus at 25-50yd, I can't imagine how putting a disk with a hole would change that fact.
Has anyone tried one of these, and actually had success? Does anyone know how this device would make it possible to clearly see targets at 10-15ft, and apparently even zoom in on them?
It might be a decent training aid, but if the DIY one doesn't do anything, I'm hesitant to spend money on a professionally-made one.
Just checking some basics, and I'm not sure this thing can work - I'm hoping someone can explain the optics of it.
For example, I have a 4-16x Vortex scope. Minimum parallax about 25 or 50yds. When I am standing about 10-15ft from a target on my wall, and zoom is decreased to 4x, I can make out a very fuzzy target. (very fuzzy). Increasing magnification just makes it worse, as does increasing the side-knob.
So: I found a note on the web that suggested that a DIY version of this DFAT device could be made by cutting a disk the diameter of the scope, then cutting a hole in the centre, with a diameter 1/3 of the disk. So my 44mm scope, has an outside diameter of about 50mm, and the inside hols about 16mm. I tucked this plastic donut into my scope cap, and installed it. Looking back at the target again, I didn't see any improvement at all.
Not being an expert in optics, I can't say it wouldn't ever work, but if the focal distances of the lenses are such that something would be in focus at 25-50yd, I can't imagine how putting a disk with a hole would change that fact.
Has anyone tried one of these, and actually had success? Does anyone know how this device would make it possible to clearly see targets at 10-15ft, and apparently even zoom in on them?
It might be a decent training aid, but if the DIY one doesn't do anything, I'm hesitant to spend money on a professionally-made one.
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