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Jet Vapor Trail, Red Filter Question

Loren Sattler

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Attached is a photo of a building in New Orleans taken recently with Tri-X film (shot asa 200) and a red filter with a Rolleicord camera. Exposure was 1/100 second at f11 on a very bright sunny day. The sky was very deep blue and cloudless. I took several similar pictures of the building and this one had a vapor trail from a jet in the upper right hand corner. To my surprise, the vapor trail came out black. I of course, expected it to be white.

Can anyone explain why it came out black? It must have something to do with the red filter? Note, the sky in the scan appears to have stars, but it is only dust from the scanner. In the photo, the sky is plain dark, as intended for high contrast with the building.
 

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  • New Orleans, building, 1.17.11.pdf
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It should indeed be white.

So the first question has to be: are you sure it is a vapour trail?
 
Have you looked at the neg? Doing so would eliminate the possibility that this was somehow caused by the computer/scanner.

I am assuming that you definitely saw that it was a vapor trail when you were taking the picture. If this is not the case, then it must be a power cable.
 
It doesn't look like a vapor trail to me. Its too uniform. Also, there is usually more than one trail since most airplanes flying high enough to produce them have more than one engine.
 
Jeff Kubach said:
Looks like a cable to me also.

Jeff
Click to expand...

I confess that I've had all sorts of things appear in my finished pictures which I never noticed when I shot them....cables, trash cans, rubbish, odd signs, even vapor trails.....

Seriously, I can't see how a vapor trail would appear black, unless there was something very seriously wrong with the aircraft's engine or the exhaust was colored as in an Airshow display. The contrast of a normal white trail would be enhanced by a red filter, just as would a white cloud.
 
Vapor trails should be white, as they are just linear clouds. Looks like a cable to me too.
Note that vapor trails are not caused by the engines. They are caused by the plane disturbing supercooled air, causing the moisture in the air to condense out. The reason it looks like it coming from the engines is that there is a lot of turbulance around the engine nacells. Note where the vapor trails are coming from in this photo.
 
Bruce, the photo you attached shows condensation because of the different pressure between the upper and lower parts of the wings and, indeed this happens (wingtip vortex). But jet fuel is just a mixture of hydrocarbons, which when burned form mostly carbon dioxide and water. The water, when formed at high altitudes where the airliners fly (very low temperatures) will condense and make clouds. Have a look here.
 
Water - product of combustion causes the trails in cool and moist upper atmosphere. Its a form of a cloud.
See the definition on vapor trails or contrails on wiki.
 
Which developer did you use? I've had PMK give me the "black sun" tone reversal on more than one occasion. Your vapor trail would have had to have been seriously overexposed, however. If you look at the negative, is the line more dense than the sky or less dense? If it's less dense, there's either a wire or cable in your picture or a tone reversal of some kind. If it's more dense, your scanner is playing games with you. Without more information, this is a tough one to pin down.

Peter Gomena

Peter Gomena
 
That's no vapor trail. Looks an awful lot like a utility cable to me too.
 
Does the OP remember seeing an vapor trail at the time of shooting? This seems like a silly thing....

If somehow the vapor trail was solarized and reversed its tones, why not the building?
 
This photo was taken over New Years weekend, 2-3 weeks ago. I admit, my memory is a little weak, but I had expected a vapor trail. As posted originally, I took several exposures of this scene at slightly different angles. I remembered a jet flying by and taking a shot with the vapor trail. I expected to see a white vapor trail on one of the contact sheet pictures, but as you can see, it turned out black. I thought possibly there was something I didn't know about shooting with red filters. That is why I made the post.

The responses have me questioning if this is the shot with the vapor trail. I admit, it looks like a wire. Looking closer however, the width of the black line appears too wide for an electrical line. This was taken with a normal lens, 75mm on 2-1/4 format. Some of the responses have questioned the scan. The line is in the negative, the original print and the scan as it appears on the post.

Perhaps I can talk my sister in law in New Orleans to stop by the site and see if there is an electrical line in view where the photo was taken.
 

Too wide perhaps, but if so probably due to being unsharp.
 
Overhead electric service or phone line.
 
holmburgers said:
Does the OP remember seeing an vapor trail at the time of shooting? This seems like a silly thing....

If somehow the vapor trail was solarized and reversed its tones, why not the building?
Click to expand...

I was thinking the same thing. The way the line is so perfectly parallel to the building makes me think wire of some sort too. A wire would be running parallel to the street and building facades. Jets take their own paths. just ask the patriots.
 
That's absolutely not a contrail. Waaay too regular. If it were a contrail it would also be getting less dense and less well-defined as it gets wider. It does neither of those. If that was a contrail, we'd be talking about 1/11 or whatever the date was on the national news, because the building next door to the one you photographed would have come down.
 
Maybe it is actually a black building with white windows and the vapor trail is really is white?
 
The fact that the OP called it a contrail made me assume that it was known to be a contrail, because he/she took the darned picture and saw it in the viewfinder. If it really was not, well this has to be one of the most "silly" posts ever.

To the OP, I know it is on the negative. I asked so that you could look and see what tone it is on the negative. Is it clear or is it black on the neg? If it is clear, it obviously was not a contrail. If black, then some scanner setting reversed the tone for some reason. There isn't any reason a contrail should reverse the tone on the negative itself, because contrails are just not bright enough to do so. Things like the sun will do that.
 
It's a street car cable, you can see it in google earth.
 

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  • nola-streetcar.jpg
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