1938 Aerial Photos

[Gloria Walker Burger]

Posted by: David Alan
« on: June 30, 2013, 10:18:42 PM » With regard to Gloria's question: Yes, ortho films are insensitive to portions of the red spectrum but no, they will not reproduce a red light as a dark area.  If a light is not bright enough or within the range of the film's spectral sensitivity it will not register at all but that is different than registering darker.  I believe Paul was referencing light reflected by an object as opposed to an object being the source of light. 

Interesting. Thanks David.

[Alfred Hendrickson]

Ric, when are you and Jeff going to see and photograph these negatives?

[John Ousterhout]

Film color sensitivity is relative, by which I mean that the portion of the spectrum whihc the film is "insensitive" to isn't ignored completely by the chemistry, it just takes a lot more intensity for the "insensitive" color to register on the film.  For example a "red-insensitive" film emulsion will show a red object as being dark, and a blue object as being light, if both have the same brightness or intensity.  However, a very bright red object will still look light if it is bright enough.  Signal flares are intensely bright, even though they are red.
The primary source of bright red color in a modern signal flare is usually Strontium Nitrate, although there are other.  I don't know what was used back in the 1930's, but wouldn't be surprised if it were the same thing as today.  The propellant industry (I work for one now, which used to be part of Olin) tends to use successfuly chemistry forever.

[Ric Gillespie]

Ric, when are you and Jeff going to see and photograph these negatives?

We'll be in Christchurch on Wednesday and Thursday, July 10 & 11.

[Alfred Hendrickson]

Ric, when are you and Jeff going to see and photograph these negatives?

We'll be in Christchurch on Wednesday and Thursday, July 10 & 11.

Great! I made a contribution to this effort. Anxious to see how this plays out.

[Tim Collins]

Ric -
Don't forget to ask your pilot to buzz Niku on your way over. It would be a shame to go right by the place and not have a look.

As departure is nearing, please do let us know if everything is sufficiently covered. I'm sure there are many of us who would be willing to pony up more beer money if you need it.

[Ric Gillespie]

I'm sure there are many of us who would be willing to pony up more beer money if you need it.

Aaaargh!  Thank you!  Beer money!  I forgot to budget in the beer money!  Whatever you can do would be (urp) appreciated.

[Glenn McInnes]

Great photos.

Any idea of the altitude that these photos were taken at? Just trying to compare with the search planes from the Colorado which I think were at 400 feet..



Glenn

[Ric Gillespie]

Any idea of the altitude that these photos were taken at? Just trying to compare with the search planes from the Colorado which I think were at 400 feet..

These photos seem to vary somewhat in altitude.  Some are quite high - 2 or 3 thousand feet?   Others are lower but not below about 500 feet would be my guess.

[Glenn McInnes]

Thanks Ric,


I certainly see how difficult it would be to see people on the ground,even at 400 ft while flying over the island.

You would think the Colorado planes would have flown lower but maybe not due to safety concerns or perhaps they just expected just to see the Electra from that altitude.

When viewing the helicopter tour of the island it was just about impossible to see the expedition members on the ground.




Glenn

[Monty Fowler]

Glenn, the Colorado's search planes quickly decided against low-level circling around the islands after one of them almost ate a few birds over McKean Island, if I remember correctly.

LTM,
Monty Fowler, TIGHAR No. 2189 CER

[matt john barth]

Hey Rick, we were sitting around here on the deck and I took the picture 38nwjpg, I think that is what it is labeled. Anyway I see something that looks like airplane wing and and some other things on the beach in this photo. I set this photo as my desktop and that is how I found it.

Respectfully Yours,
Matt Barth

[Ric Gillespie]

Anyway I see something that looks like airplane wing and and some other things on the beach in this photo.

That photo has been examined in great detail over and over again for many years.  There's no airplane and other things on the beach.  Something may turn up in the negative but I'll be surprised if there's anything on the beach.  When that photo was taken the New Zealand survey party was just about to start their work.  They camped on shore opposite Norwich City.  If there was airplane wreckage on that beach it's hard to believe they wouldn't have seen it.

[matt john barth]

I'm seeing a big piece of white metal on the beech in pic 38nw.jpg. Does anyone else see it? Why not speculate? If I wasn't speculating at this time I'd be working and we all know that's not good.

[Andrew M McKenna]

Pretty sure that is a flaw in the photo.

I'd suggest that before we all get wrapped around the axle looking at the low resolution scans of old prints of these photos, that we simply wait until Ric and Jeff have obtained high resolutions digital versions, then spend the time to look at them.  Will save a lot of time speculating over things such as flaws in the photos.

Andrew