BLURRY PEOPLE WITH SHARP SHADOWS

[Matt Cloud]

1 minute ago, Kevin Balch said:

Why don’t you do so?

I have provided the FOV for the lens at issue.  It's orders of magnitude above 11 degrees.

[Kevin Balch]

4 minutes ago, Matt Cloud said:

I fully accept the 11 degree FOV.  Th math is correct.  The implications form that however have thus far been incorrect.  The implications are that the frame is altered.  An 11 degree FOV is not possible with the equipment Zapruder had.

So is the math correct or incorrect? Are the inputs correct?

[Matt Cloud]

1 minute ago, Kevin Balch said:

So is the math correct or incorrect? Are the inputs correct?

I'm going to defer to Chris' math when he says the FOV on say Frame 314 of the extant Zapruder film is 11 degrees.  If that is accepted, and I do accept it, that FOV was unobtainable with Zapruder's lens.  Therefore, the FOV that we see has been altered from the original capture.  It's really quite simple.  

[Chris Davidson]

On 5/16/2024 at 9:11 AM, Chris Davidson said:

[Chris Davidson]

[Matt Cloud]

Yeah.  I have to make a MAJOR retraction.  Or at least offer a caveat.  I've done the FOV work now again based on the calculations at this site:

 

https://www.scantips.com/lights/fieldofview.html#top

 

I've entered 27mm lens data along with 65 foot distance data and sensor data of 4.8mm x 3.5mm (8mm film dimension) and the FOV returned is 10.2 degrees in the horizontal.  

 

So, the retraction -- and this will be cheered and jeered perhaps applauded for honesty -- is this: Zapruder's Camera IS capable of a 10.2 degree FOV, as well then of an 11 degree FOV.  

REPEAT: Zapruder's Camera IS capable of a 10.2 degree FOV, as well then of an 11 degree FOV.  

However -- however -- the caveat here is this:  Was Zapruder fully zoomed in?  If he was, I would expect to see far more camera shake at that focal length.  Indeed, if you read the camera manual, it recommends shooting on a tri-pod at the tele end (the 27mm) of the zoom.  See pdf p. 15 here:

 

https://www.chriswessling.com/pdfs/bell_&_howell_414_operating_manual_compressed.pdf

 

In other words, at the narrowest zoom setting, the 27mm on the 8mm film camera, the focal length is roughly that of a 200mm lens on a full frame 35 mm camera.  When shooting with a 200mm lens, as any photographer will tell you, it is advisable to use stabilization in one form or another (in-camera or out -- tripod etc), and that doesn't include secretary's holding your legs, as Zapruder's did.  

 

So -- the camera and lens are capable of 11 degrees FOV.  But is that what Zapruder shot at?  I am somewhat dubious that he did.  Again I think the camera would be far more shaky if he did.  I don't think this now disproves alteration possibilities.

 

So there.  Egg on my face, to an extent.  But I'm glad to have had the conversation and the ability to engage and correct, in this case by myself!  

 

Here's the math.  For some reason it's copying in my focal length as 28 although I entered 27 but anyhow close enough.  Everyone can try on their own.  Again, the site is here, and you'll need the dimensions of 8mm film which are 4.8 x 3.5 mm.

https://www.scantips.com/lights/fieldofview.html#top

 

 

 

Field of View Calculator	Field Dimension		Angle of View
Focal Length    mm Field Distance  units Any units for Distance, feet or meters. Dimension results are the same units.	Width Dimension	12.444	Width Degrees	10.159°
	Height Dimension	9.074	Height Degrees	7.417°
	Diagonal Dimension	15.401	Diagonal Degrees	12.556°
Show field size at 2nd distance (like at the background?)	Show 2nd distance at  units 2nd W×H is 5.333 × 3.889 units

Option 1: Sensor 4.8 × 3.5 mm, Diagonal 5.941 mm
Aspect Ratio 11:8 (1.371:1, Crop Factor 7.283x)
Magnification at 70 feet: 0.00127 (1:790). At 70 meters: 0.000386 (1:2593)
This field view is the same as the 35 mm film Equivalent focal length 196.65 mm.

1

Native Sensor Size, Width Native Sensor Size, Height

mm  mm

[Matt Cloud]

FYI, and FWIW, someone in 2013 was trying to figure things out.  His question went unanswered, nevertheless.

 

"What's the effective distance at telephoto setting for 8mm camera with 9-27mm lens?"

 

https://www.thephotoforum.com/threads/whats-the-effective-distance-at-telephoto-setting-for-8mm-camera-with-9-27mm-lens.321529/

 

There's actually astounding little detail about the Zapruder lens, the Varimat 9-27mm f1.8, which should perhaps be among the most famous in history.  

 

See also https://www.tumblr.com/shoothd/136607335688/the-camera-that-caught-the-kennedy-assassination

(Doesn't tell which setting along the zoom he was using, but impliedly states he was fully zoomed-in.)

  

"Zapruder had a 9-27mm telephoto lens (a description which is very much a stretch compared to today) at his disposal when he recorded his infamous film, but it could also be set to wide angle or “normal” (He was approximately 65 feet from the middle of Elm Street where Kennedy was shot)."

 

Again -- shooting handheld with a 200mm equivalent lens is very difficult to keep stable.  And the further away things are, the harder it gets. 

 

 

What's the effective distance at telephoto setting for 8mm camera with 9-27mm lens?

•  Thread starterMikeHi 
•  Start dateMar 20, 2013

 

 

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• Mar 20, 2013

• #1

Assume the 8mm camera specs listed below. The lens is f1.8 / 9-27mm.

My understanding is that the normal focal length for 8mm film is 12.5 mm. Assume the camera is 70 feet away from the filmed object.
The camera is set to telephoto. Does it mean that the effective distance is decreased by the factor of 27/12.5 = 2.16,
i.e. the effective distance is 70/2.16 = 32.4 feet?




--------------------------------------------------------------------------------
Camera Specifications
Camera Maker: Bell & Howell.
Model: 414PD Director Series
Film Type: Double 8mm - 25ft or 50ft film roll
Film Speeds: ASA 10 to ASA 40
Running Speed: Single frame, 16fps and 48fps (slow motion.)
Lens: Bell & Howell Varamat f1.8 / 9-27mm - Power Zoom
Mechanism: Spring Motor
Lightmeter: Built-in Dual Electric-Eye.
Non-reflex viewfinder (parallax corrected and coupled with zoom.)
The camera zooms from telephoto to wide angle. It focuses from 6.0 feet to infinity. The camera has built in haze filters.
The camera can adjust from f/1.8 to f/22 to accommodate all types of film

[Matt Cloud]

2 hours ago, Chris Davidson said:

Where are the top images from?  The color frames using the B&H, at the three different settings.  Can you provide a link?  

[Chris Davidson]

1 minute ago, Matt Cloud said:

Where are the top images from?  The color frames using the B&H, at the three different settings.  Can you provide a link?  

I filmed back in 2005.

Frame credit below to Rick Janowitz:

Maybe you could ask him for some examples. Better quality.

 

 

[Matt Cloud]

1 minute ago, Chris Davidson said:

I filmed back in 2005.

Frame credit below to Rick Janowitz:

Maybe you could ask him for some examples. Better quality.

 

 

Thanks but I don't understand.  What does "frame credit" mean?  And if you filmed it, cannot you provide more examples? 

It would be especially helpful to have the area where limo turns onto Elm too, if you took that.  Indeed here would be a lot that would be helpful but I'll await clarification from you.  Thanks.

[Kevin Balch]

1 hour ago, Matt Cloud said:

I'm going to defer to Chris' math when he says the FOV on say Frame 314 of the extant Zapruder film is 11 degrees.  If that is accepted, and I do accept it, that FOV was unobtainable with Zapruder's lens.  Therefore, the FOV that we see has been altered from the original capture.  It's really quite simple.  

I’ve calculated the Angle of View with the formula

AOV = 2*arctan(film length/(2*focal length))

I obtained very similar results to what was supposedly determined from the extant film. I don’t see a conflict.

[Kevin Balch]

1 hour ago, Matt Cloud said:

Yeah.  I have to make a MAJOR retraction.  Or at least offer a caveat.  I've done the FOV work now again based on the calculations at this site:

 

https://www.scantips.com/lights/fieldofview.html#top

 

I've entered 27mm lens data along with 65 foot distance data and sensor data of 4.8mm x 3.5mm (8mm film dimension) and the FOV returned is 10.2 degrees in the horizontal.  

 

So, the retraction -- and this will be cheered and jeered perhaps applauded for honesty -- is this: Zapruder's Camera IS capable of a 10.2 degree FOV, as well then of an 11 degree FOV.  

REPEAT: Zapruder's Camera IS capable of a 10.2 degree FOV, as well then of an 11 degree FOV.  

However -- however -- the caveat here is this:  Was Zapruder fully zoomed in?  If he was, I would expect to see far more camera shake at that focal length.  Indeed, if you read the camera manual, it recommends shooting on a tri-pod at the tele end (the 27mm) of the zoom.  See pdf p. 15 here:

 

https://www.chriswessling.com/pdfs/bell_&_howell_414_operating_manual_compressed.pdf

 

In other words, at the narrowest zoom setting, the 27mm on the 8mm film camera, the focal length is roughly that of a 200mm lens on a full frame 35 mm camera.  When shooting with a 200mm lens, as any photographer will tell you, it is advisable to use stabilization in one form or another (in-camera or out -- tripod etc), and that doesn't include secretary's holding your legs, as Zapruder's did.  

 

So -- the camera and lens are capable of 11 degrees FOV.  But is that what Zapruder shot at?  I am somewhat dubious that he did.  Again I think the camera would be far more shaky if he did.  I don't think this now disproves alteration possibilities.

 

So there.  Egg on my face, to an extent.  But I'm glad to have had the conversation and the ability to engage and correct, in this case by myself!  

 

Here's the math.  For some reason it's copying in my focal length as 28 although I entered 27 but anyhow close enough.  Everyone can try on their own.  Again, the site is here, and you'll need the dimensions of 8mm film which are 4.8 x 3.5 mm.

https://www.scantips.com/lights/fieldofview.html#top

 

 

 

Field of View Calculator	Field Dimension		Angle of View
Focal Length    mm Field Distance  units Any units for Distance, feet or meters. Dimension results are the same units.	Width Dimension	12.444	Width Degrees	10.159°
	Height Dimension	9.074	Height Degrees	7.417°
	Diagonal Dimension	15.401	Diagonal Degrees	12.556°
Show field size at 2nd distance (like at the background?)	Show 2nd distance at  units 2nd W×H is 5.333 × 3.889 units

Option 1: Sensor 4.8 × 3.5 mm, Diagonal 5.941 mm
Aspect Ratio 11:8 (1.371:1, Crop Factor 7.283x)
Magnification at 70 feet: 0.00127 (1:790). At 70 meters: 0.000386 (1:2593)
This field view is the same as the 35 mm film Equivalent focal length 196.65 mm.

1

Native Sensor Size, Width Native Sensor Size, Height

mm  mm

I vote for applauded for honesty. And it’s nice to see more rigor. To much of opinions are based on feelings.

[Matt Cloud]

8 minutes ago, Kevin Balch said:

I’ve calculated the Angle of View with the formula

AOV = 2*arctan(film length/(2*focal length))

I obtained very similar results to what was supposedly determined from the extant film. I don’t see a conflict.

Right.  11 degrees is the FOV in the extant Zapruder film.  No issue there.  At least in the 304 frame area. I believe Chris states that the earlier frames are the same, I'm referring to when the limo turns onto Elm.  

 

And, it is evident that 11 degree FOV IS within capabilities of the camera and lens at issue.  

This still leaves questions however:

 

Was Zapruder in fact zoomed in all the way when he filmed?  Lack of stabilization might be an issue; however Chris Davidson, above, indicates he has actually used the camera at Dealey Plaza. I'm awaiting mroe info from him on his experience and testing.

 

If we can get past that, we may still have issues with placement of sign and lamp-post, both of which have been shown in other photographs to have discrepancies across photos.  That's about where things stand.

 

Edited May 18 by Matt Cloud

[Matt Cloud]

2 minutes ago, Kevin Balch said:

I vote for applauded for honesty. And it’s nice to see more rigor. To much of opinions are based on feelings.

Thank you.  Appreciated.

[Matt Cloud]

16 hours ago, Kevin Balch said:

In Willis 5, you have to extend the lamp post down to the curb. That would put the Newman’s (just to the left of the motorcycle helmet) to the west (left if your are looking north to the knoll), consistent with the Muchmore film.

What would be the purpose of moving the lamp post in Willis 5?

I see I did not respond to this by you.  I disagree. The Newmans appear, to me, to be in line along the North-South axis with the other two women.  Those women look to me as if they are right next to the Newmans, indeed the Newmans may even be a hair cloase to the camera.  If I extend the lamp post down, as you suggest, it necessarily has to be behind one of those women because she is what is blocking the post in the first place.  So, if Newmans and this woman are, again, aligned N-S, then Newmans too are to the east of that lamp post.

 

The purpose in moving the lamp post, if that happened, would be to extend the distance between the Stemmons sign and that lamp post, a distance which, based on the Zapruder film, takes about two seconds of film time to cover.  The purpose would be to make the still image more align with the Zapruder film.  I

 

The Zapruder film and, again this has been my central point all along, indicates a greater distance between the sign and the lamp post than was the case in reality.  

 

I fully recognize that this bend in Elm Street, plus the elevational changes, plus the width of the sidewalk, plus other topographical features all make for a complicated exercise in perspective understanding.  However, many photos, in my view, indicate that the distance between the sign and the post as not so great as certainly Willis-5 makes it appear.  Once more, the Smithsonian re-creation I referenced above, appears more accurate than any other descriptions of the actual layout.  There, the Stemmons sign is rather more easterwardly in the plaza and the lamp post not so far west of it.  That re-creation was not simply thrown-together but was achieved after apparently intensive study of the photographic record.  Here it is again:

 

https://www.google.com/imgres?q=dealey plaza smithsonian&imgurl=https%3A%2F%2Fth-thumbnailer.cdn-si-edu.com%2FS7kWaVctUOtm4Q3RMLGUeDIz4t4%3D%2F1000x750%2Ffilters%3Ano_upscale()%3Afocal(235x125%3A236x126)%2Fhttps%3A%2F%2Ftf-cmsv2-smithsonianmag-media.s3.amazonaws.com%2Ffiler%2F20131122100105JFK-3d-model.jpg&imgrefurl=https%3A%2F%2Fwww.smithsonianmag.com%2Finnovation%2Fan-interactive-3d-model-of-the-jfk-assassination-site-grassy-knoll-and-all-180947812%2F&docid=M96XmXZf_58shM&tbnid=sZb8XSCkwnWuGM&vet=12ahUKEwjIx-HphpiGAxWVFlkFHT-5Ca4QM3oECBcQAA..i&w=470&h=251&hcb=2&ved=2ahUKEwjIx-HphpiGAxWVFlkFHT-5Ca4QM3oECBcQAA