Polarized Sunglasses and Jumprun viewing

[kturnau 0]

I have been pondering this at work all day today and need some feedback here. I am sure that all of you have noticed, but when looking up at jumprun from the ground and trying to pick out the little black dots in freefall, there are times when you just can't see anything and other times that you can see people crystal clear. So I started thinking about this and now I am wondering why. It probably has something to do with the way light rays hit the atmosphere differently throughout the day but I just don't know for sure. If this is the case do you think polarized sunglasses would make it easier to see our little flying friends? I want to make sure they would be worth buying before I spend the money.

FALLATIO #13
PELT HEAD #20

[grue 1]

See people in freefall? Are you kidding? I still have trouble finding the plane!

cavete terrae.

[justinb138 0]

Quote

I want to make sure they would be worth buying before I spend the money.

You can always pick up a cheap pair at the local Wal-Mart for about $10 to try out before spending the money for a really nice pair.

[darkwing 5]

It depends on the atmospheric conditions. Sometime having polaroid glasses helps, and sometimes it doesn't. There are certainly polarizing effects in the atmosphere, but there are plenty of other things going on too. Lots of variables.

-- Jeff
My Skydiving History

[riddler 0]

I think it's more about the small object, big sky effect. I would be surprised if polarized glasses help you. A better strategy is to pick good weather conditions for viewing. Clouds that are only a few thousand feet above jump run provide a white backdrop to make it easier to see jumpers in freefall from the ground. Normally, I would not recommend binoculars or a long camera lens, because the risk of sunlight coming through the optics would be very bad for your eyes (and also cameras). But if there's enough cloud cover to block out the sun, you might try binoculars or a zoom camera.

Trapped on the surface of a sphere. XKCD

[droidicus 0]

I find that polarized sunglasses help immensely.

The great thing about them is that you can rotate your head around while looking up, and because of the nature of the light coming through the atmosphere it will get brighter and darker as you rotate your head. This really helps the clarity of the little dots, I find that when it is gray or hazy it helps to make it "brighter", and when it is clear blue or bright white it helps to make it "darker". The trick to this is that the little falling dot stays at the same brightness level, it is only the background that gets brighter and darker.

I LOVE EM! But people look at me strangely when I am rotating my head around looking for them on jump run.

~Droid

[diverdriver 6]

It has a lot to due with humidity in the atmosphere on a clear day. "Haze" is what can obscure your view especially if the sky is blue behind. There's no contrast. Now, if there is a high overcast then the background is white and the plane/jumpers are dark colored they will be easy to pick out.

Blue skies are bad for ground viewing.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[bch7773 0]

thats very true... but theres a guy at our DZ that wears a big all-white suit that shows up even on clear blue sky days. but when its overcast, you can't see him.

MB 3528, RB 1182

[Travman 6]

I think often I will be looking up at the sky and I can't see the plane, then someone will point it out and I will be able to see it and the jumpers coming out. But if I look away for an instant then I will loose the plane.
I think its the same if someone is wearing a camouflage suit. You can't see them, no matter how hard you look - then someone points them out and you can't figure out why you couldn't see them before.

[sweep 0]

I believe it's to do with being able to focus your eyes. If you know exactly where the jumpers/planes are then your eyes can focus on them and you see them. Once your eyes are focused on them they automatically stay focused as the dots move around/get closer.

If you don't know then your eyes will be focused on the sky (eg infinity) and so the small dots will blur into that. If you could pre-focus your eyes to 10k then you'd spot them every time. It's a bit like those wierd 3d pictures that you have to focus past to see...

Using binoculars/telemeters isn't a real problem even on a sunny day so long as you take precautions to make sure you know where the sun is and avoid pointing them in that direction.

Sweep

----
Yay! I'm now a 200 jump wonder.... Still a know-it-all tho..

[diverdriver 6]

Quote

I think often I will be looking up at the sky and I can't see the plane, then someone will point it out and I will be able to see it and the jumpers coming out. But if I look away for an instant then I will loose the plane.
I think its the same if someone is wearing a camouflage suit. You can't see them, no matter how hard you look - then someone points them out and you can't figure out why you couldn't see them before.

This probably has more to do with your eyes focal point rather than being camaflouged. When you have "empty field myopia" your eye relaxes and focusses at a neutral point. Now, if you were looking at say a densley wooded field you would realize that things were out of focus and instantly focus on what you wanted to. But because jumprun can be 2 - 3 MILES away (above you) and you are trying to see a few 5' to 6' tall human beings it's tough to know they are of focus. Your eye has relaxed while staring at the big empty sky and is focusing (unbeknownst to you) at a point relatively close to your face.

Hope that helps.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[diverdriver 6]

Beat me by 2 minutes.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[sweep 0]

I wouldn't expect it to happen again any time soon

Edit to add : and you know all the big words, which is probably why yours took longer to type

----
Yay! I'm now a 200 jump wonder.... Still a know-it-all tho..

[kelpdiver 2]

given a few more years to develop floaters in the eye, looking up at blue sky results in a lot of dancing dots!

And sometimes actual skydivers. Tandems are easiest to spot with the drogue.

[sweep 0]

I was on DZ control last weekend when a guy stood next to me mentioned he could see the drogue. I was a little confused as there were no tandems on the lift. Needless to say the white jumpsuited sitflyer was less than flattered when I told him his arse had been mistaken for the Vector drogue....

Sweep

----
Yay! I'm now a 200 jump wonder.... Still a know-it-all tho..

[AndyMan 7]

I think it's more to do with the uniformity of the picture rather than distance.

Lieing in bed, I often have trouble focusing on imperfections in a very bland, white ceiling. Playing tricks by focusing on one distinct object, then moving over to the imperfections while attempting to retain focus helps. I have perfect eyesight.

_Am

__

You put the fun in "funnel" - craichead.

[diverdriver 6]

Quote

I think it's more to do with the uniformity of the picture rather than distance.

Lieing in bed, I often have trouble focusing on imperfections in a very bland, white ceiling. Playing tricks by focusing on one distinct object, then moving over to the imperfections while attempting to retain focus helps. I have perfect eyesight.

_Am

Dude, that's what empty field myopia is. Unable to focus on bland viewing areas. Your eyes focus on a distance that you are not aware of.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125