Thank you, thank you, thank you for illustrating the parallax pitfall with the V-finger method, and an approach for dealing with it. Also, I love the drone footage - it is a good way to show how much more visible the mirror flash makes you to a potential rescuer. I've cringed at the number of videos, websites, and photos that show the V-finger method with the instructor holding the mirror far from their eye, and leading the viewer to believe that this posture will work well for them. The way I try to deal with parallax when using the V-finger method is that I: (i) position my eye at the very center of the narrow edge of the mirror (ii) hold my V-finger so that the corners of the edge I'm looking past are on the tips of my fingers, evenly centered (iii) put the target in the center of my V-fingers, along the line between the two corners of light on my fingertips, and (iv) rock the mirror back and forth about the axis of that narrow edge to deal with the (small) remaining parallax. In addition to parallax, there are two other challenges for learning this method: (a) The angular width of the signal mirror beam at long range is much smaller than it appears on your fingertips. Many tutorials give the impression that, as long as you are lighting both fingers, your beam will light everything inbetween. Not so - try reflecting your beam onto a relatively distant target in the shade - it is the same angular size as the sun. Since the full moon has the same angular size as the sun (hence solar eclipses), you can comfortably get an idea for that by holding up your "Vee-finger" to the sky against the full moon. Here's a photo that illustrates this: flic.kr/p/dQgCVq (b) At short range, you don't have to hit the target with the core of the beam for them to see it, so your friend or camera is going to score as "hits" what would be "misses" in a real life and death situation, with the search plane a few miles from you. You show a very short range version of that at 2:50 ( ua-cam.com/video/ea2qRi4Z7kc/v-deo.htmlm50s ) where you are off-target, but the mirror looks like a bright glowing ball of light, and someone at 50 yards might consider that a good flash - it is only seeing the full beam at 2:56) that you see what a real flash looks like. SImilarly in the drone footage at 400 ft - there are faint flashes at 5:02 to 5:03 that look like "hits", (ua-cam.com/video/ea2qRi4Z7kc/v-deo.htmlm ) but unlike the real flashes at 5:06, are not likely to be noticed a mile or two away. That's why my version of the V-finger method is so fussy about the details. That's also why I use a signal mirror with a retroreflective aimer, given the choice - it is FAR easier to hit the target with minimal instruction. Even with a retroreflective aimer, the fireball (glowing ball of light) created by the retroreflective aimer is about 3x the diameter of the core of your sunbeam, so it is important to pass the very center of the fireball across the target. There are a fair number of commercial signal mirrors out there with retroreflective aimers - my personal favorite is the 2"x3" glass Coghlan's Survival Signal MIrror (item 9902), which can be had for $12 on Ebay at the moment. If you use one of those, this illustrated instruction sheet may be helpful: flic.kr/p/nsrjRG You can also add a retroreflective aimer yourself to any signal mirror - there are videos and instructions at www.bsaontarget.org/mirrors
Thanks I got a mirror signal kit yesterday for my civil air patrol and so they suggested I look up some tutorials before Saturday for my SAR-AX training and so this efficiently helps
Nice lessons and thank you for the video. I wish you had shown more of the signalling from the ground to the drone. That was the high point of the video.
The reason you are having parallax issues and having to do all kinds of extra stuff to make your signaling mirror (yours isn't) work is because it's a cheapo from Walmart or something. On a USGI Mil-Spec signal mirror (actually made and designed for it) you have a sight viewing window in the middle to aim where you want to hit with the flash. Put down the cheap Walmart and Target made in China crap that came out of the ladies "Bathworks" aisles....... Best Glide ASE Mk 3 MIL-M-18731E 2"x3" Type 1 is NSN: 6350-01-455-6695 3"x5" Type 2 is NSN: 6350-01-455-6671 Made In USA John
It's not a cheapo from WalMart. It's 'just' a mirror. The video is how to use any reflective surface (mirror in compass, phone sceen, automotive mirror etc) as a signal mirror.
Man, your channel is a treasure chest in knowledge. Damn youtube algorithm was hiding it from me.
Thank you, thank you, thank you for illustrating the parallax pitfall with the V-finger method, and an approach for dealing with it. Also, I love the drone footage - it is a good way to show how much more visible the mirror flash makes you to a potential rescuer.
I've cringed at the number of videos, websites, and photos that show the V-finger method with the instructor holding the mirror far from their eye, and leading the viewer to believe that this posture will work well for them.
The way I try to deal with parallax when using the V-finger method is that I:
(i) position my eye at the very center of the narrow edge of the mirror
(ii) hold my V-finger so that the corners of the edge I'm looking past are on the tips of my fingers, evenly centered
(iii) put the target in the center of my V-fingers, along the line between the two corners of light on my fingertips, and
(iv) rock the mirror back and forth about the axis of that narrow edge to deal with the (small) remaining parallax.
In addition to parallax, there are two other challenges for learning this method:
(a) The angular width of the signal mirror beam at long range is much smaller than it appears on your fingertips.
Many tutorials give the impression that, as long as you are lighting both fingers, your beam will light everything inbetween. Not so - try reflecting your beam onto a relatively distant target in the shade - it is the same angular size as the sun. Since the full moon has the same angular size as the sun (hence solar eclipses), you can comfortably get an idea for that by holding up your "Vee-finger" to the sky against the full moon. Here's a photo that illustrates this: flic.kr/p/dQgCVq
(b) At short range, you don't have to hit the target with the core of the beam for them to see it, so your friend or camera is going to score as "hits" what would be "misses" in a real life and death situation, with the search plane a few miles from you. You show a very short range version of that at 2:50 ( ua-cam.com/video/ea2qRi4Z7kc/v-deo.htmlm50s ) where you are off-target, but the mirror looks like a bright glowing ball of light, and someone at 50 yards might consider that a good flash - it is only seeing the full beam at 2:56) that you see what a real flash looks like.
SImilarly in the drone footage at 400 ft - there are faint flashes at 5:02 to 5:03 that look like "hits", (ua-cam.com/video/ea2qRi4Z7kc/v-deo.htmlm ) but unlike the real flashes at 5:06, are not likely to be noticed a mile or two away.
That's why my version of the V-finger method is so fussy about the details.
That's also why I use a signal mirror with a retroreflective aimer, given the choice - it is FAR easier to hit the target with minimal instruction.
Even with a retroreflective aimer, the fireball (glowing ball of light) created by the retroreflective aimer is about 3x the diameter of the core of your sunbeam, so it is important to pass the very center of the fireball across the target. There are a fair number of commercial signal mirrors out there with retroreflective aimers - my personal favorite is the 2"x3" glass Coghlan's Survival Signal MIrror (item 9902), which can be had for $12 on Ebay at the moment. If you use one of those, this illustrated instruction sheet may be helpful: flic.kr/p/nsrjRG
You can also add a retroreflective aimer yourself to any signal mirror - there are videos and instructions at www.bsaontarget.org/mirrors
Finally, i was thinking the exact same thing with every V-finger video. The V-hand will not work on longer distances. Great job!
Thanks I got a mirror signal kit yesterday for my civil air patrol and so they suggested I look up some tutorials before Saturday for my
SAR-AX training and so this efficiently helps
Nice lessons and thank you for the video. I wish you had shown more of the signalling from the ground to the drone. That was the high point of the video.
That was good information. Thank you!
Excellent!! Thank you!!!!
Hey! Denton from prepperforums.net. Excellent video! Going to be watching more of these!
👍
The reason you are having parallax issues and having to do all kinds of extra stuff to make your signaling mirror (yours isn't) work is because it's a cheapo from Walmart or something. On a USGI Mil-Spec signal mirror (actually made and designed for it) you have a sight viewing window in the middle to aim where you want to hit with the flash. Put down the cheap Walmart and Target made in China crap that came out of the ladies "Bathworks" aisles.......
Best Glide ASE Mk 3 MIL-M-18731E
2"x3" Type 1 is NSN: 6350-01-455-6695
3"x5" Type 2 is NSN: 6350-01-455-6671
Made In USA
John
It's not a cheapo from WalMart. It's 'just' a mirror. The video is how to use any reflective surface (mirror in compass, phone sceen, automotive mirror etc) as a signal mirror.