sorpa wrote:
I maintain my point of view.
Wikipedia is not a reliable source : " people have measured it " - scoff emoticon-
I invite you to look down from the top of a 10 stories building. Then you'll understand what I mean.
I looked at those vids. Conclusion: same cameras used to film UFOs. No zoom, shaky hands, etc.
I have to reconsider what I said about the velocity. It's much bigger than I calculated initially. First time I didn't take into consideration any initial velocity or what it's called Vo. The guy from Dustin's link comes into the frame like he was thrown from a slingshot. I'll venture to say that, given the 100 feet fall, he's touching the water with ~30m/s. That's a whopping ~100 km/h. Now imagine yourself into a car that hits the wall with that speed.
I rest my case. ...Show more →
No need to rest a case. I'm not arguing with you. But, I think it is close to 100. 80+ for sure. There are many variables. A few that come to mind are: they may have measured from where the water begins its decent (not going straight down for 10's of feet). You have an arc to deal with. Also, they did not go into solid water, but much, much softer water (white foamy). But if you really want to know, Google it, then maybe email with the ones who measured it. I go here nearly every weekend, so maybe I'll drop a line down there and see for myself.
Rajan Parrikar wrote:
An atmospheric scene, well composed. I don't much like this long an exposure. Say, 0.6 sec may have worked better, in my view.
Thank you Rajan. I do have a tendency to gravitate toward the more dreamy exposures, but I agree that 0.6 might have been a nice choice too. This year I'm going to do a wider variety of water textures on my Gorge shots so I appreciate the feedback.
A nice vantage point that all of us who have been there many times can appreciate. I know I won't ever do that. I'm not a climber. I take my photos from the BOTTOM
Excellent image Mark! In my print calibrated monitor I don't see the exposure as "hot" at all, more like slightly high key and that makes for a wonderful capture of the mist, which adds a lot of atmosphere. Great framing as well with an unique perspective. Great stuff!
Mark Metternich wrote:
No need to rest a case. I'm not arguing with you. But, I think it is close to 100. 80+ for sure. There are many variables. A few that come to mind are: they may have measured from where the water begins its decent (not going straight down for 10's of feet). You have an arc to deal with. Also, they did not go into solid water, but much, much softer water (white foamy). But if you really want to know, Google it, then maybe email with the ones who measured it. I go here nearly every weekend, so maybe I'll drop a line down there and see for myself.
Interesting.... I watched the video and in the comments they mentioned 82-feet. Based on the length of the kayak I estimated the height to be ~70-feet so close enough. The fall takes ~2-seconds so the final velocity is somewhere around ~54 MPH or ~ 24 m/s. The thing is that hitting the highly aired water at the bottom of the falls at that speed is infinitely more survivable (obviously) than hitting a solid wall.
jsuro wrote:
Interesting.... I watched the video and in the comments they mentioned 82-feet. Based on the length of the kayak I estimated the height to be ~70-feet so close enough. The fall takes ~2-seconds so the final velocity is somewhere around ~54 MPH or ~ 24 m/s. The thing is that hitting the highly aired water at the bottom of the falls at that speed is infinitely more survivable (obviously) than hitting a solid wall.
Best,
Jose
I am not any expert in measuring waterfalls or of science or velocity... but one question that could be asked is from where do you start the measurement? If you see the water in the shot with me in there, it starts descending rapidly but WAY before it is ever reaching vertical. It takes a very wide arc of 10's of feet before it is technically falling nearly straight down. So I think the measurements could be correct (not exaggerated) but taken from different starting points. Another variable would be the season. This is a punchbowl, where it fluctuates in depth radically depending on river levels.
I am not any expert in measuring waterfalls or of science or velocity... but one question that could be asked is from where do you start the measurement? If you see the water in the shot with me in there, it starts descending rapidly but WAY before it is ever reaching vertical. It takes a very wide arc of 10's of feet before it is technically falling nearly straight down. So I think the measurements could be correct (not exaggerated) but taken from different starting points. Another variable would be the season. This is a punchbowl, where it fluctuates in depth radically depending on river levels. ...Show more →
Bingo on the water levels. Could definitively change things quite dramatically. The calcs are actually pretty simple. Those Kayaks are between 6 and 8-feet long so take seven. Then, when the kayak just went vertical on the video I counted how many kayaks to the bottom - came out to ~10 so an 7-foot kayak would be 70 feet, 80-feet for an 8-foot kayak. It took ~2-seconds to splashdown so the average speed was 40 feet/second. Because it is a vertical drop, initial velocity is 0, so to average 40 it has to be going 80 f/s at the end. after that it's just multiplying by sixty a couple of times and dividing by your favorite distance scale, meters, feet whatever . Parabolas, as in a gradual turn to vertical cancel out for pure vertical acceleration without propulsion so that's a minor issue.
Notwithstanding, and excellent image!!! And that is what is important.
too funny, I saw the picture (I live in troutdale) and was like "nice shot, how the **** did you get up there to take it from that perspective?" Nice job.
jsuro wrote:
Bingo on the water levels. Could definitively change things quite dramatically. The calcs are actually pretty simple. Those Kayaks are between 6 and 8-feet long so take seven. Then, when the kayak just went vertical on the video I counted how many kayaks to the bottom - came out to ~10 so an 7-foot kayak would be 70 feet, 80-feet for an 8-foot kayak. It took ~2-seconds to splashdown so the average speed was 40 feet/second. Because it is a vertical drop, initial velocity is 0, so to average 40 it has to be going 80 f/s at the end. after that it's just multiplying by sixty a couple of times and dividing by your favorite distance scale, meters, feet whatever . Parabolas, as in a gradual turn to vertical cancel out for pure vertical acceleration without propulsion so that's a minor issue.
Notwithstanding, and excellent image!!! And that is what is important.
But what if one measured the level water level, in elevation (left upper pool of the image with me in it) before it starts its beginning decent that might be another way to approach the measurement of the total height of the waterfall? In other words, the water is falling far before it reaches vertical free airborne... I just don't know how the technical people do it.
I'll kick in as a whitewater boater, although the highest drops I've done are 45 and 55 feet respectively. Metlako was one of the places where the "Oregon Tuck" was perfected. The oregon Tuck is a position in which the weight is forward, head turned sideways and placed as clos to the deck as possible wit the paddle parallel to the side of the boat. The reason the paddle is held in that position is to keep the shaft from breaking the paddlers nose when it's shoved backwards. For a while boaters would put gallon jugs in the bows of the boats to ensure that the drop was plugged rather than boofed. That is ,the angle of entry was parallel to the falling water rather than perpendicular to it. Angle of entry is an artform in dropping falls. Within the past five years the "Stomp" was developed in order to drop the bow in mid dair. this allows the paddler to clear any troublesome boils that might shove the paddler behind the curtain where rescue is exceedingly dangerous and still land nose down in the aerated water. A green water entry is a no no, but it's amazing how fluffy a high drop can be if landed correctly.
And as far as measurement goes paddlers usually measure using the throw ropes they use for rescue purposes as plumb lines. On a drop like Metlako the actual freefall would be measured from the point where the water breaks the lip. A rolling drop like that helps control angle both by setting intitial angle of attack and providing a last bit of green water to dig a stroke in. This is called the "golden stroke."
There, more about dropping falls than you ever wanted to know.
One more thing, it's not like hitting a wall, remember you are IN the flow of the water at this point, not sitting on top of it. You're following thousands of gallons down the same path. It's more like drafting behind an armored car as IT slams through a wall.
Without hijacking the thread, I though a few here may enjoy this. A wonderfully shot video of whitewater boating made by people who truly get the art of nature and sport videography.
river rover wrote:
I'll kick in as a whitewater boater, although the highest drops I've done are 45 and 55 feet respectively. Metlako was one of the places where the "Oregon Tuck" was perfected. The oregon Tuck is a position in which the weight is forward, head turned sideways and placed as clos to the deck as possible wit the paddle parallel to the side of the boat. The reason the paddle is held in that position is to keep the shaft from breaking the paddlers nose when it's shoved backwards. For a while boaters would put gallon jugs in the bows of the boats to ensure that the drop was plugged rather than boofed. That is ,the angle of entry was parallel to the falling water rather than perpendicular to it. Angle of entry is an artform in dropping falls. Within the past five years the "Stomp" was developed in order to drop the bow in mid dair. this allows the paddler to clear any troublesome boils that might shove the paddler behind the curtain where rescue is exceedingly dangerous and still land nose down in the aerated water. A green water entry is a no no, but it's amazing how fluffy a high drop can be if landed correctly.
And as far as measurement goes paddlers usually measure using the throw ropes they use for rescue purposes as plumb lines. On a drop like Metlako the actual freefall would be measured from the point where the water breaks the lip. A rolling drop like that helps control angle both by setting intitial angle of attack and providing a last bit of green water to dig a stroke in. This is called the "golden stroke."
There, more about dropping falls than you ever wanted to know....Show more →
Thanks very much for your input. Very interesting.
Dustin Gent wrote: " target="_blank" rel="nofollow">HERE is one of them rolling over Abiqua last year. I have been to this falls several times, and it is kind of tall.
too funny, I saw the picture (I live in troutdale) and was like "nice shot, how the **** did you get up there to take it from that perspective?" Nice job.