Ultraviolet photography at night

[kogakunippon]

All Informations are in the EXIF from the picture Steve!

 

Nikon D7100

Noflexar 35mm

Baader U-Filter

ISO 6400

F/5.6

15sec

 

Regards

Wolfgang

[kogakunippon]

Fugu Sashimi (Tiger Blowfish):

 

http://gallery.photo.net/photo/18260947-lg.jpg

[Andy Perrin]

Interesting to see what the orange slice did there. Reminds me of a blood orange almost!

[kogakunippon]

Is it a sunflower...?

 

http://gallery.photo.net/photo/18260958-lg.jpg

 

Artist: Wolfgang Steiner;

Exposure Date: 2016:07:03 15:22:52;

Copyright: Wolfgang Steiner;

Make: NIKON CORPORATION;

Model: NIKON D7100;

ExposureTime: 1/15 s;

FNumber: f/3;

ISOSpeedRatings: 6400;

ExposureProgram: Manual;

ExposureBiasValue: 0/6;

MeteringMode: Pattern;

Flash: Flash did not fire, compulsory flash mode;

FocalLength: 35 mm;

FocalLengthIn35mmFilm: 52 mm;

Software: Adobe Photoshop CS6 (Windows);

[nfoto]

"is it a sunflower" ? probably, but not with certainty going towards 100%. The Asteraceae is a very large and diversified plant family.

[kogakunippon]

Bjørn, thanks for your help.

 

JR Yamanote Line:

 

http://gallery.photo.net/photo/18261004-lg.jpg

[Andy Perrin]

Ooh, that's a fun image!

[kogakunippon]

Panning Comic at Shinjuku:

 

http://gallery.photo.net/photo/18261325-lg.jpg

[kogakunippon]

Shinjuku:

 

http://gallery.photo.net/photo/18261324-lg.jpg

[kogakunippon]

Pagoda at Naritasan:

 

http://gallery.photo.net/photo/18262692-lg.jpg

[Andrea B.]

Oh that is so cool! I have always loved pagodas.

 

With this night UV technique you are using, it seems that we see only the most interesting parts of the night scene. The images aren't really minimalist, but they do suppress excessive detail - in a good way. And the simpler colour palette from your UV torches also promotes this look.

[kogakunippon]

without the comic conversion:

 

http://gallery.photo.net/photo/18262709-lg.jpg

[kogakunippon]

Japanese drawing at the wall from Torafugutei Bekkan:

 

http://gallery.photo.net/photo/18262693-lg.jpg

[kogakunippon]

Some guys were asking me why I am taking UV-Photos during the night when its so difficult to get real ultraviolet pics daytime?

 

This is the answer:

 

http://gallery.photo.net/photo/18262985-lg.jpg

 

 

Ultraviolet Photos are looking much better when you make them at night....

 

 

http://gallery.photo.net/photo/18262987-lg.jpg

[Andy Perrin]

Yeah, I think several people have tried it here; I got some colorful car trails but was never sure if I was seeing infrared leakage or not, and OlDoinyo did a whole set. He mentions seeing some red in his pictures (which he suggests implies IR contamination because it's not part of the false-UV palette). I'm gradually coming around to the view that we are seeing mixed UV/IR sources in these night photos, which may be unpreventable in this situation. But as you say, they ARE pretty!

 

Another thing to try is full spectrum night photos, which I've been experimenting with a lot lately. E.g.:

 

Wind turbine, Newburyport, Massachusetts, US

F?? 20" iso400

 

St. Paul's Labyrinth, Newburyport, Massachusetts, US:

F?? 8" ISO400

[kogakunippon]

Andy, I love your wind turbine picture, its beautiful. Thx for posting it.

 

I dont think that it always have to be an IR contamination if there is red color in our UV pictures. Here are 2 examples containing a lot of red light after doing a WB. It might not be the correct WB, but there is still red in the pictures, and no IR contamination so far.

 

http://gallery.photo.net/photo/18263222-lg.jpg

 

 

http://gallery.photo.net/photo/18263220-lg.jpg

[Cadmium]

I think what we are seeing there is not red, but more like yellow, and not from visual, but from 350-370nm UV.

With Andy's filter, I don't know, but with the Baader, I think the visual is ruled out.

[kogakunippon]

I think what we are seeing there is not red, but more like yellow, and not from visual, but from 350-370nm UV.

 

Andy was talking about an "false-UV palette", so if I dont understand that wrong, there can't be any red, even after the post-processing.

[Andy Perrin]

The false-UV palette is just the colors you get after a white balance off Teflon/PTFE or similar material.

 

Yeah, those seem to be yellow, not red in your examples. They may really be UV, I just don't feel confident in it with explicit testing of some kind! Might be interesting to try photographing an 800nm LED under the same conditions, because you know those are narrowband. TV remote controls probably would work...I may try it myself to see what my filter does also.

[Andrea B.]

Red false colour in a UV photograph does not necessarily indicate IR contamination. It simply indicates an editing choice.

 

The typical white-click edit produces a UV photo with no red in the false colour palette IF you are using a broadband UV-pass filter under sunlight or under a broadband UV illumination. Wolfgang is not using broadband UV illumination, so his false colour palette may include some reds or near reds - all depending on his conversion and editing choices.

 

Remember: there is no "correct" colour palette choice for UV conversion & edits.

 

Andy: the concept of "white-balancing" when dealing with false colours is not well-defined. I suppose you could extend the visible definition to the UV realm and say that a surface which is 99-100% UV-reflective "should" appear as "white" in the false-colour palette. But you also have to define your illumination standard to say what "UV-reflective" is actually reflecting. That gets a bit trickier.

[Andy Perrin]

Andrea, I mean "take a white balance under sunshine during the day against PTFE and apply it to all subsequent photos, including night ones." That seems well-defined enough to give a consistent set of colors? But I see your point that we don't know that kogakunippon is doing that, so his may have some red in it because he is using some other WB.

 

(The actual choice of WB is independent of whether there is IR in the image, though, which I guess you'd have to explicitly test for, as noted above.)

[kogakunippon]

.. I mean "take a white balance under sunshine during the day against PTFE and apply it to all subsequent photos, including night ones." That seems well-defined enough to give a consistent set of colors?

 

Its simple and well-defined, yes. Should there be any green inside such a picture then? Or just blue and violet and grey?

[Andy Perrin]

Should be green, blue, violet, grey, yellow (in my experience so far). Haven't seen anything outside those, but I haven't seen all there is to see in life, either. ;)

 

And Andrea's right, ARTISTICALLY, you can use any white balance. The above is just what I meant by "UV false colors."

[kogakunippon]

Andy, you are right about 95% from all pictures I made during my last trip, but some have red inside. Like one of my Asakusa Temple photo. There is a PTFE board inside the picture at the lower left and I made the WB with it. And as you can see, there is much red inside my picture. I tested it serveral times and because there was no posprocessing either its clear for me that red is also an UV false color. Maybe not seen many times, but it is.

 

http://gallery.photo.net/photo/18263398-lg.jpg

[Andy Perrin]

Yeah, but you have to take the WB under sunshine or other wideband source. You're taking WB using the available light in the image, so it's not the same. But there are definitely reds in that picture, I agree.