Re: Pictures on the Lunar Surface

[Herb Schaltegger]

In article >,
rk > wrote:

> Just curious, and I remeber reading about this here a while ago, but
> there was a good technical explanation for why, in some lunar surface
> pictures, the cross-hatch patterns did not come out in the pictures.
> JimO hasn't written that book yet and the sci.space.history threads that
> address these things are long and make it difficult to find the
> information. So, if it is not too much trouble, can someone post a link
> or a brief explanation on why they are not visible?
>
> Thanks in advance,

<http://www.badastronomy.com/bad/tv/foxapollo.html#crosshairs>

--
Herb Schaltegger, Esq.
Chief Counsel, Human O-Ring Society
"I was promised flying cars! Where are the flying cars?!"
~ Avery Brooks

[Sam Seiber]

rk wrote:
>
> Just curious, and I remeber reading about this here a while ago, but
> there was a good technical explanation for why, in some lunar surface
> pictures, the cross-hatch patterns did not come out in the pictures.
> JimO hasn't written that book yet and the sci.space.history threads that
> address these things are long and make it difficult to find the
> information. So, if it is not too much trouble, can someone post a link
> or a brief explanation on why they are not visible?
>
> Thanks in advance,

IIRC:Because the object behind the cross-hatch was so bright as to
saturate the film, washing out the cross-hatch.

Sam

[OM]

On Thu, 24 Jul 2003 17:04:28 -0600, Sam Seiber
> wrote:

>rk wrote:
>>
>> Just curious, and I remeber reading about this here a while ago, but
>> there was a good technical explanation for why, in some lunar surface
>> pictures, the cross-hatch patterns did not come out in the pictures.
>> JimO hasn't written that book yet and the sci.space.history threads that
>> address these things are long and make it difficult to find the
>> information. So, if it is not too much trouble, can someone post a link
>> or a brief explanation on why they are not visible?
>>
>> Thanks in advance,
>
>IIRC:Because the object behind the cross-hatch was so bright as to
>saturate the film, washing out the cross-hatch.

....Here's something related to the reseau plate markings, from the
ALSJ:

[Journal Contributor Markus Mehring, from a 13 December 2000 e-mail
message - "The second Hasselblad was not a lunar surface camera. It
had a black exterior, designed to suppress stray reflections, and not
the silver protective cover added to the EVA cameras for thermal
protection. The second Apollo 11 LM camera was for intravehicular use
only and, had it been necessary to use it during the EVA, the
photographic record of Apollo 11 would have been seriously
compromised."

[Mehring - "If you have a look at the photographs that Neil and Buzz
took out the LM windows during the mission and, also, the pictures
they took inside the LM (such as AS11-37- 5528), you'll notice that
quite a number of them do not have reseau crosses in them. These were
taken with the black, IVA camera. Only the cameras designed for EVAs -
the silver ones - had a reseau plate, simply because the need to make
photogrammetric measurements only existed for surface photographs. You
can use this as an ID helper for 70mm photographs throughout the rest
of the missions: if a picture has reseau crosses, it's from a silver
EVA-Hasselblad; if it hasn't, it's from a black IVA-cam. Note that
this is not related to magazines, since the magazines fit on either
body, A particular magazine could contain both photos with and photos
without reseau crosses if the magazine was used on two cameras."]
["Finally, on a cultural note, these black Hasselblads made for NASA
were the primary reason why 'black' suddenly was a kind of a favored
'professional look', hence almost every commercially available camera
was released in black during the subsequent decades. Only recently
have the companies begun to be a more creative, producing cameras with
metal exteriors of different kinds, and colorful plastics. This is
probably one of the lesser known results of the early manned
US-spaceflight program!]


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[Jay Windley]

"rk" > wrote in message
...
| Just curious, and I remeber reading about this here a while ago, but
| there was a good technical explanation for why, in some lunar surface
| pictures, the cross-hatch patterns did not come out in the pictures.

http://www.clavius.org/photoret.html

Here's what I wrote, but it's not as complete as it should be. I'll see if
I can get hold of some photos a photographer friend of mine took
intentionally to show the effect. Also, keep in mind that they don't show
up as well in JPEG versions of certain photos even though they're visible in
prints.

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

[Joe Durnavich]

Jay Windley writes:

>"rk" > wrote in message
...
>| Just curious, and I remeber reading about this here a while ago, but
>| there was a good technical explanation for why, in some lunar surface
>| pictures, the cross-hatch patterns did not come out in the pictures.
>
>http://www.clavius.org/photoret.html
>
>Here's what I wrote, but it's not as complete as it should be. I'll see if
>I can get hold of some photos a photographer friend of mine took
>intentionally to show the effect.

Is this what you had in mind?

--- Begin Quote ---

The camera used was a Hasselblad 500c/m with a 50mm lens. I removed
the standard film back from the camera and made a set of "crosshairs".
These are simply single strands of wire taken fron a lenght of
standard lampcord. I taped these wire strands (2) across the back of
the camera body to form a cross. They are offset from the center of
the frame so thay will miss the film advance claw and the shutter
saftey lock lever. When the film back is replaced on the camera these
wires will be right in front of the film plane just like the glass
plate with the etched crosshairs in the lunar Hasselblads. I mounted a
polaroid film back to the now crosshair equipped camera body and
stepped outside and took a picture with the camera held level. I
processed that polariod then took another picture with the camera
tilted. These two polaroids are shown together below. I also rescanned
each photo alone and each is also included below.

-- Craig Lamson in response to Jack White 4/17/2002

--- End Quote ---

http://home.earthlink.net/~joejd/images/test_of_crosshairs.jpg
http://home.earthlink.net/~joejd/images/level_crosshair.jpg


--
Joe Durnavich

[Jay Windley]

"Joe Durnavich" > wrote in message
...
|
| Is this what you had in mind?

Exactly so, thank you.

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

[Joe Durnavich]

Jay Windley writes:

>"Joe Durnavich" > wrote in message
...
>|
>| Is this what you had in mind?
>
>Exactly so, thank you.

Good deal.

I guess I should point out that the reason for Craig taking the
"tilted" photo was because Jack White couldn't understand how the
scene being photographed in one of the Apollo photos could be tilted
relative to the cross hairs.

One would think that would not need to be explained and demonstrated,
but, well...

--
Joe Durnavich

[Peter Smith]

Joe Durnavich > wrote...
......
> Jack White couldn't understand how the
> scene being photographed in one of the Apollo photos
> could be tilted relative to the cross hairs.
>
> One would think that would not need to be explained
> and demonstrated, but, well...

Most of the published surface photography has also been cropped, so the
cross-hairs are often not parallel to either the horison OR the edge of the
picture. This is where the unaware can become confused.

- Peter

[RAILROAD SPIKE]

I would like to get some pics of the last shuttle fatalities I didn't get to
see ****!
"Herb Schaltegger" > wrote in message
...
> In article >,
> rk > wrote:
>
> > Just curious, and I remeber reading about this here a while ago, but
> > there was a good technical explanation for why, in some lunar surface
> > pictures, the cross-hatch patterns did not come out in the pictures.
> > JimO hasn't written that book yet and the sci.space.history threads that
> > address these things are long and make it difficult to find the
> > information. So, if it is not too much trouble, can someone post a link
> > or a brief explanation on why they are not visible?
> >
> > Thanks in advance,
>
> <http://www.badastronomy.com/bad/tv/foxapollo.html#crosshairs>
>
> --
> Herb Schaltegger, Esq.
> Chief Counsel, Human O-Ring Society
> "I was promised flying cars! Where are the flying cars?!"
> ~ Avery Brooks

[Kevin Willoughby]

OM said:
> ["Finally, on a cultural note, these black Hasselblads made for NASA
> were the primary reason why 'black' suddenly was a kind of a favored
> 'professional look', hence almost every commercially available camera
> was released in black during the subsequent decades. Only recently
> have the companies begun to be a more creative, producing cameras with
> metal exteriors of different kinds, and colorful plastics. This is
> probably one of the lesser known results of the early manned
> US-spaceflight program!]

Alas, the black professional look predates Apollo. Black is a fashion
statement that comes and goes, just like hemlines or the width of
neckties.
--
Kevin Willoughby

We'd spend the remaining time trying to fix the engine.
-- Neil Armstrong