photography for dummies (David A Smith)

"Nathan Jones" wrote in message
...
|
| I suggest you and everyone else take a good look at the picture.
| Aldrin (or whoever it really was) is IN MID AIR! Neither of his
| feet/boots were touching the rungs of the ladder when the photo
| was taken. There is no blur in the image, that requires a fast
| shutter speed and the shot was in the LM shadow side. Got it yet
| dummy?

Ho hum. David Percy and Mary Bennett again. Do you do any of your own
thinking?

We happen to know the camera settings for this photo (actually for the whole
egress sequence): 1/60 second and f/5.6. Armstrong remembered them because
f/5.6 is as far open as his lens would go, and as a photographer himself he
knew that photographs would blur if he used a longer shutter speed. The
Hasselblad would give him longer speeds, but he knew not to use them. And
so he said at the briefing he was not sure whether those photographs would
turn out.

1/60 second will stop most casual motion, either of the camera or of the
subject. In fact, many cheap-o cameras had a fixed shutter speed of around
1/60 second and were intended for use by amateurs.

I did what Bennett and Percy didn't do, and what apparently you haven't
done. I obtained a Hasselblad camera functionally similar to the Apollo
cameras and I loaded it with Ektachome 160 film and I set the exposure for
f/5.6 and 1/60 second to see if the photos I took under those conditions
would be blurred. And in general they were just fine. My subject was an
actor in a space suit, doing spacemanly things.

So prove that with a 1/60 shutter speed, Aldrin's foot or body must
necessarily have been blurred. Oh, and prove that f/5.6 and 1/60 is an
insufficient exposure setting for this photograph. I already asked David
Percy to prove it, and he refuses to. (I suspect he doesn't know how.)

--
|
The universe is not required to conform | Jay Windley
to the expectations of the ignorant. | webmaster @ clavius.org

Nathan Jones wrote:

snip

1/60 at f5.6 is not enough for those conditions. I'll try a simulation
experiment or if that proves unrealistic I will rule it out with other
definitive tests.

snip

I normally don't reply to the inanities of Min et fil, but
this is just too rich. If he can't rule out the results of
experiment and records with his own experiment, he will rule
it out in whatever way he can. Never consider the possibility
that he might be wrong, and someone who disagrees with him
might be right.

I'd love to have this guy teaching science to people I
really, really don't like.

Tom McDonald
--
remove 'nohormel' to reply

Dear Nathan Jones:

"Nathan Jones" wrote in message
...
Ho hum. David Percy and Mary Bennett again. Do you do any of your own
thinking?

Of course and I outwitted you twice in a row the last time.

Wrong responder, Jones. But it doesn't matter, since you are so clueless.

Cry baby, cry. Waa waa! Really thoughtful response: "I told you twice
already." You behave like a four year old. Just like your soggy Moon
case.

Learned any more about radiative heat transfer since the last time we
sparred?

David A. Smith

Dear Tom McDonald:

"Tom McDonald" wrote in message
...
....
I'd love to have this guy teaching science to people I
really, really don't like.

Instead of "teaching the man to fish", he'd be teaching the man to drown.
Definitely suitable students to take their appointed place on the welfare
roles.

David A. Smith

Dear Nathan Jones:

"Nathan Jones" wrote in message
...
During Aldrins alleged outing to the Moon it may be observed from the
photography that there is one large and glaring highlight to be seen on
the heel of his boot as he desends the ladder towards the ground. He is
in the shaded side of the LM and the only lighting source for this is
sunlight returned from the ground. There is no way on Gods Earth (or
Moon) that a hotspot type of reflection will be caused in such
conditions. It just had to have been point source lighting. The
asstronots never did take any lighting with them to the Moon. Go
figure!

Yeah, no one else was on the Moon, in a bright white suit, with a
reflective helmet. The picture took itself!

I suggest you and everyone else take a good look at the picture. Aldrin
(or whoever it really was) is IN MID AIR! Neither of his feet/boots were
touching the rungs of the ladder when the photo was taken. There is no
blur in the image, that requires a fast shutter speed and the shot was in
the LM shadow side. Got it yet dummy?

Yes. I realize that you just proved you were an idiot. The reason there
was no blurring is because, the reflected light is *much* brighter without
an atmosphere, and he wouldn't be falling very fast without as much
gravity.

You just shot your own case, in the foot, as it were.

You are not a good lap dog for Min. Perhaps you should go play in traffic
for a while.

David A. Smith

Dear Nathan Jones:

"Nathan Jones" wrote in message
...
Windley wrote:
Ho hum. David Percy and Mary Bennett again. Do you do any of your
own
thinking?

I wrote:
Of course and I outwitted you twice in a row the last time.

Smith wrote:

Wrong responder, Jones. But it doesn't matter, since you are so
clueless.

I'm writing to Windley here you fool Smith!!

Pin prick, you titled it to whom? Look above. You are a clueless idiot.

Empty arguments from an empty head.

David A. Smith

"Nathan Jones" wrote in message
...
|
| I'm writing to Windley here you fool Smith!!

Hm, my ISP's normally faithful server doesn't seem to be giving me most of
your posts. Pulled this off Google:

|Ho hum. David Percy and Mary Bennett again. Do you do any of your own
|thinking?
|
| Of course and I outwitted you twice in a row the last time.

Can't imagine what you're talking about. And it's very telling that you
think this is about "outwitting" someone. It's about getting the facts
right.

| I don't buy your 1/60 at f5.6 experiment. You must have erred.

And you obviously base this judgment on the fact that my results contradict
your conclusion. You certainly haven't tried to duplicate it or understand
it. You just say it "must" be wrong because I got the "wrong" answer!

|So prove that with a 1/60 shutter speed, Aldrin's foot or
|body must necessarily have been blurred.
|
| That is faulty logic

Of course it's not. The premise of your argument is that 1/60 is too short
an exposure to capture movement without blur. My experience -- and that of
other photographers -- is different. I don't accept your premise and I
require it to be proven.

| A longer exposure must be used and that would cause
| blurring.

What have you done to determine that a longer exposure "must" be used?

| 1/60 at f5.6 is not enough for those conditions.

What have you done to determine that 1/60 and f/5.6 is not enough for these
conditions?

| I'll try a simulation experiment...

Oh, this should be good. What exactly are you going to "simulate"? And why
would your simulation be considered more reliable than empirical proof with
an actual example of the actual cameras and film?

| or if that proves unrealistic I will rule it out with other
| definitive tests.

What do you mean "other" definitive tests? What makes a simulation in any
way definitive, especially over empirical tests? And why do you presume you
will rule it out? This seriously undermines our faith in your methods; you
have the outcome already planned.

| I will take Lunar ground as having 7% reflectance and I'll
| double that to allow for heleigenschein on the shady side.

I'll save you the trouble.

[doodles on the back of an envelope]

The reflected light at 7% would be roughly equal to a grid of 100-watt light
bulbs placed every square meter.

| I'd bet he [David Percy] knows more photography than you and
| I 3 fold.

This is photometry, not photography. And David Percy has no clue about
photometry. Not a one. He can't even answer simple questions about
computations of light intensity, and he gets frustrated and belligerent when
you ask. All he can do is wave that seven-percent solution at you along
with an exposure table from the Big Book of Photography and claim it proves
his point. Albedo is the *beginning* of a photometric analysis, not the end
of it.

I am pretty confident I know a lot more about photography than you do. And
from my discussions with David Percy I'm fairly confident I know more about
it than he does. But that's a somewhat stilted comparison because I
strongly suspect he knows exactly what he's doing, and I feel he's
withholding the points of photographic expertise that he knows will
undermine his conclusions. He counts on his audience not knowing much about
photography, and so far you're exactly the gullible reader he's aiming at.

| (Anyhow, I suspect if you can do it anyone can)

Well, that's the problem. I and my colleagues seem to be the only ones who
have tried. We solved the problem analytically using photometric and
radiometric equations. We solved the problem in simulation using radiometry
and heat transfer software -- the kind I use all the time in my work. And
finally we did the empirical testing that agreed with our theoretical and
simulational work.

You haven't done the photometric computations. I doubt you even know how,
since you obviously have absolutely no clue what a form factor or view
factor might be. You haven't yet done any simulations. And you sure
haven't done any experiments. The same holds for Percy: he hasn't done any
computations (doesn't know how), any simulations, or any experiments. Yet
both of you are convinced -- absolutely convinced -- that you are right and
I'm wrong. You are willing to cling to David Percy's claim of expertise. I
am not.

Nobody's buying the albedo handwaving anymore. If you want to show that the
Aldrin egress photography is not credible because of exposure issues, then
you have the burden of proof -- not I -- to show (not merely claim) that the
published camera settings would not have worked. These things *can* be
computed. There is a method. So use it and prove your point.

--
|
The universe is not required to conform | Jay Windley
to the expectations of the ignorant. | webmaster @ clavius.org