Jump to content
The Education Forum

Shooter Location


Recommended Posts

  • Replies 149
  • Created
  • Last Reply

Top Posters In This Topic

Of course 11.2mph was going to be the average limo speed.

Do you think Shaneyfelt had to cross-multiply those previous results when he was figuring out where the limo was going to start on film? 

11.2mph x (1.47ft per sec =1mph) = 16.47ft per sec x 8.333... sec = 137.25ft

7.5ft elevation (CE884 Z161-Z313) x 18.3ft per elevated ft = 137.25ft

Mr. SHANEYFELT. That is the overall average from 161 to 313. It does not mean that it was traveling constantly at 11.2, because it was more than likely going faster in some areas and slightly slower in some areas. It is only an average speed over the entire run. 
Mr. DULLES. Over the entire run between what points? 
Mr. SHANEYFELT. Between frame 161 and 313. 

 

 

 

Link to comment
Share on other sites

16 hours ago, Chris Davidson said:

Now what span would give us 183 frames?

2+50 = elevation 429.7   ....    Shot #2 at 419.7 (not 419.07) is 10 feet lower in elevation

313 - 183 = 130...  just about the splice for the limo cut...

 

  

Link to comment
Share on other sites

On 3/5/2018 at 8:44 AM, David Josephs said:

2+50 = elevation 429.7   ....    Shot #2 at 419.7 (not 419.07) is 10 feet lower in elevation

313 - 183 = 130...  just about the splice for the limo cut...

 

  

You can move that elevation relationship from Position A (428.7) to extant z313 (418.48) = 10.22ft

The extra .22ft x 18.3 = 4.02ft = the Drommer label for a location near, but not indicative of extant z313.

Equals the very close 2nd head shot.

Link to comment
Share on other sites

David,

Bingo.

Earlier in this topic(shown below), I supplied a breakdown for the Bronson flash frame and how that could be incorporated into the two headshot scenario.

The only change now needed was the conversion using 18fps instead of 18.3fps, which will then match the previous post's distance difference of .22ft elevation = 4.02ft

It would look like this now:

The extant Zfilm(z301-z313) shows the limo travel (18/12 = 1.5 x 7.2ft = 10.8ft per sec /18frames)

10.98(from below graphic) - 10.8 = .18ft

4.2 - .18ft = 4.02ft 

The equation below should still reflect(or very close to) the excised frames around the two headshots. Imo

39767626375_42f3de3410_b.jpg

 

 

 

 

Link to comment
Share on other sites

13 hours ago, Chris Davidson said:

10.98(from below graphic) - 10.8 = .18ft

168-171 is 3 frames

161-166 is 5 frames

.09 foot per frame

2frame diff is .18 foot...    does this change at 166 equate to the .18’ change at 313?

or just a coincidence?

Link to comment
Share on other sites

 

I think a coincidence.

That location z161-166 / z168-z171 does impact the area circa extant z313, but I believe in this way.

Previously, I converted the extant  zfilm in correlation with Bronson's film.

But I didn't convert from a 48fps version stepped down to 18fps. Only converted from 18.3Z/12Bronson

When you use 48fps, 18/12, the frame conversion between Bronson and Z ends up this way:

4Bronson x 1.5 (18/12) = 6z x 2.666666(48fps/18) = 16 zframes

 

4.02ft / 16 frames = .25125ft per frame

.25125 x 18frames (1sec) = 4.52ft

 

The distance the limo travels when plotted from extant z156-z166 = 10.8ft in 10 frames = 1.08ft per frame = 13.44mph

z161-z166 = 5 frames x 1.08 ft per frame = 5.4ft

5.4ft - .9(distance traveled entry on CE884 for z161-166) = 4.5ft

5.4ft/18fps = .3ft per frame = z168-z171= .9ft per 3 frames

 

 

Link to comment
Share on other sites

David,

The difference you are referring to between .3(z168-z171) and .18ft(z161-z166) per frame =.12ft per frame

It might help to convert to a whole second:

.12ft per frame x 18fps = 2.16ft per sec / 1.47(1mph) = 1.469ft per sec = 1 mph difference

Apply the 1.111111 pass(removing 1 of the leftover 39.22 frames) to the average 11.2mph WC standard = 11.2 x 1.11111111 = 12.444...mph x 1.47 = 18.293ft per sec = 1to1 ratio @ 18.3fps

Apply the 1.2 pass(removing 1/6 frames) to the average 11.2mph WC standard= 11.2 x 1.2 = 13.44mph

Difference between 13.44 and 12.44mph =1mph

The difference of 2.16ft separating 2 frame spans 161-166 (5frames) and 168-171(3 frames) in 1 second of time, is a  2 frame difference / 2.16ft = 1.08ft distance per frame = average limo speed per frame plotted at this location- approx z156-z166 = 10.8ft/10 frames.

 

Link to comment
Share on other sites

  • 1 year later...
On 2/1/2018 at 7:49 AM, Chris Davidson said:

The extant Zfilm(z301-z313) shows the limo travel (18.3/12 = 1.525 x 7.2ft = 10.98ft per sec / 18.3frames) = .6ft per frame = 7.47mph

At .6ft per frame, 7 additional(non synced) frames = 4.2ft

From Z313, the limo will travel 7 standard Zframes + 7 non-synced frames for a distance of 4.2ft.

I'm quite sure this is what gave Tom Wilson his "4 feet farther down the road" conundrum.

Listen again:

https://drive.google.com/file/d/1T_L-ofjszZmZnMK9raiElwQfYA9YjZqx/view?usp=sharing

 

 

 

 

Drommer Confirmation:

Elevation 490.9 - 161.1 = 329.8 + 88.8 = 418.6 - 418.48 = .12 x 18.3 = 2.196 + 4.2 = 6.396 - .9 = 5.496 / 18.3 = .3ft x 14frames = 4.2ft

Elevation.gif

Link to comment
Share on other sites

On 3/4/2018 at 3:59 PM, Chris Davidson said:

Now expand 18.3 frames per 12 inches (ten-fold):

183frames = 120inches

Now what span would give us 183 frames?

38812939480_abfde73905_b.jpg

 

I forget, Chris, if the plat posted above was a WC exhibit, or not. My recollection is that it is a West/Purvis document with the frame numbers added in by Purvis. Is that right? Or are the numbers on the street on one of the WC's exhibits? 

Link to comment
Share on other sites

16 hours ago, Chris Davidson said:

Drommer Confirmation:

Elevation 490.9 - 161.1 = 329.8 + 88.8 = 418.6 - 418.48 = .12 x 18.3 = 2.196 + 4.2 = 6.396 - .9 = 5.496 / 18.3 = .3ft x 14frames = 4.2ft

Elevation.gif

More Drommer confirmation:

The rifle barrel elevation for survey 313 was 492ft.

492- 161.1 = 330.9 + 88.8 = elevation 419.7

The elevation listed from the attached plat (shot #2)  is 419.07.

The 0 and 7 were transposed in 419.07, the elevation should have read 419.70

A quick check will show 419.70 - 418.35 = 1.35 x 18.3 = 24.7ft = approx (257 -232) red box

Translated, the WC was trying to move one of the two shots circa extant z313 farther east up Elm St.

46855674644_809bd2071c_o.png

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...