Author Topic: Apollo 14 artifact ?  (Read 6803 times)

Offline QuietElite

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Apollo 14 artifact ?
« on: September 24, 2016, 03:09:53 PM »
Today I glanced through some Magazines of the Apollo 14 images on Flickr and found a interesting looking blue flare on AS14-66-9345. Here is the hi-res version from the ALSJ:
https://www.hq.nasa.gov/alsj/a14/AS14-66-9345HR.jpg
Do some of you guys know what it is ? I suppose that it is some kind of artifact in the image.

Offline 12oh2alarm

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Re: Apollo 14 artifact ?
« Reply #1 on: September 25, 2016, 07:11:01 AM »
There are also blue specks on a few more photos following this one, e.g. https://www.hq.nasa.gov/alsj/a14/AS14-66-9348HR.jpg
(two, one at the top edge; plus a red one at the right edge) Note that the ghost images of the CSM are caused by reflections in the LM window. The blue specks don't show ghost images (AFAICS), so I think it's safe to say they aren't objects outside the LM. Maybe scratches in the window? Emulsion imperfections? Processing imperfections?

Offline bknight

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Re: Apollo 14 artifact ?
« Reply #2 on: September 25, 2016, 03:58:00 PM »
Clearly they are UFO's following the mission. ::)
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline BertieSlack

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Re: Apollo 14 artifact ?
« Reply #3 on: September 26, 2016, 04:00:50 AM »
The colour emulsion on the Kodak Ektachrome film was applied in layers - red, green and blue. If there is damage to the film the colour of the resulting defect depends on how many layers of emulsion were affected.

Offline Rob48

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Re: Apollo 14 artifact ?
« Reply #4 on: September 27, 2016, 05:51:28 PM »
AS14-66-9295 has an almost identical blue flare.

https://www.flickr.com/photos/projectapolloarchive/21683578445/in/album-72157656723857913/


-9276 has it but over the LM, not the sky:

https://www.flickr.com/photos/projectapolloarchive/21062603283/in/album-72157656723857913/

Apparently these blue anomalies were a favourite of Mike Bara. Some speculation here (film damage?) https://dorkmission.blogspot.co.uk/2012/07/briefing-for-mike-blue-flares-in-lunar.html


Offline JayUtah

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Re: Apollo 14 artifact ?
« Reply #5 on: September 29, 2016, 06:15:13 PM »
Those may be actual GCR particle hits.

But yes, the part about the layered emulsions is exactly correct.  I did some scratch tests on E-6 emulsions, the same stock I shot in the desert for the television show several years back.  Deep scratches go all the way down and show up white.  Shallow scratches leave the blue layer intact.
"Facts are stubborn things." --John Adams

Offline BertieSlack

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Re: Apollo 14 artifact ?
« Reply #6 on: September 30, 2016, 02:53:37 AM »
Those may be actual GCR particle hits.

Yes - they don't look like scratches or other physical damage. A lot of scratches on Apollo photos are uniformly thin and vertical, probably caused by a bit of dust caught between the film and the reseau plate as the film was pulled vertically through the focal plane.
I have seen one other odd-shaped streak before - which doesn't look like a GCR hit but maybe caused by an electrostatic discharge inside the camera? The streaks are also outside the exposed image area right to the edge of the film. Modifications were made to the Hasselblads to prevent electrostatic build-up in the ultra-dry lunar environment, but maybe when a lot of photos were taken in a short space of time the preventative measures weren't sufficient.
Here's the photo: https://eol.jsc.nasa.gov/DatabaseImages/ISD/highres/AS17/AS17-137-20925.JPG
Notice the green streak just up and left from the centre fiducial, and the green streaks outside the exposed image area down the left side of the film.

Offline JayUtah

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Re: Apollo 14 artifact ?
« Reply #7 on: September 30, 2016, 11:39:47 AM »
The artifact near the center fiducial looks more to me like physical damage from some contaminant, perhaps a suit fiber trapped between the film and the reseau plate.  ESD is indeed a possibility in general, even with the silvering on the plate.
"Facts are stubborn things." --John Adams

Offline ka9q

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Re: Apollo 14 artifact ?
« Reply #8 on: October 05, 2016, 01:57:13 AM »
Color film is a sandwich of four layers. From top (lens-facing side) to bottom:

Blue-sensitive emulsion
Yellow filter -- passes red and green, blocks blue
Green & Blue sensitive emulsion
Red & Blue sensitive emulsion

The yellow filter blocks blue light from reaching the bottom two layers, so they respond only to green and red light. It dissolves away during processing, leaving dyes in each layer that are formed during color development.

For "reversal" film that develops to a positive, the blue layer develops to a yellow dye, the green to magenta, and red to cyan. In a black area, all three dyes are present so no light gets through. Scraping just the blue layer in an otherwise black area of the image inhibits the yellow dye, so the magenta and cyan layers together pass only blue light -- so the scrape appears blue. If you dig more deeply and remove all the layers down to the backing, the area won't block any light and will therefore appear white.
« Last Edit: October 05, 2016, 01:59:45 AM by ka9q »