Spring meadow with flowering apple-trees and dandelions

[Nico]

A spring meadow with flowering apple-trees and dandelions (Taraxacum officinale):

 

 

This is the “normal” photo, with the colours that humans see:

 

http://2.bp.blogspot.com/-ti74jFXWPUI/UYGBQ48jRwI/AAAAAAAAAE0/MMuNQkveuII/s640/P1080094.jpg

 

 

 

Second, a UV-photo with the white-balance adjusted to a grey-card (exposure 1s):

 

http://2.bp.blogspot.com/-6MACFlSFctE/UYGBe4eWh3I/AAAAAAAAAFE/mYscVi3gaqw/s640/P1080096-2.jpg

 

 

 

The same UV-capture converted to black and white:

http://4.bp.blogspot.com/-GA6sC9rrZ2Q/UYGBfzIUDFI/AAAAAAAAAFM/cIp44k1KOHs/s640/P1080096.jpg

 

 

 

Finally, the “bee-colours”, when the bee-spectrum is pushed into the RGB-colour space.

http://2.bp.blogspot.com/-xx_ac42iCeM/UYGBd3rfIDI/AAAAAAAAAE8/7faVk5Rekus/s640/P1080094_RGB_UV_b.jpg

 

 

 

All Images were taken with the Novoflex, Noflexar 35/f3.5 at about f8.

[nfoto]

I have no problem with the colour composite as such, but you definitively need to do something about the overall image contrast. Now the result is flat and lifeless. The salient differentials in the colour domain are robbed of their clarity.

 

Digital UV straight off camera, just like the IR equivalent, can appear very dull so a gamma boost usually is required. I find this even more the case in landscape-type photography conducted in UV.

[Andrea B.]

Nico, it is not possible to properly white-balance a UV photograph against a conventional white balance card (or grey card). This is because such cards are not made from materials that properly reflect as white when you are imaging under a UV-pass filter.

 

Shane Elen originally pointed out the need for proper reflectance standards in UV imaging and suggested the Labsphere reflectance standards which maintain their reflectance across an extremely wide UV, Visible and IR range. I started using Labspheres and showed them to Bjørn. We subsequently realized that the Labspheres could be used to provide a standardized UV look across various cameras and editors. We have adopted that look for the website here.

 

In another post, I see that Bjørn has recommended using an inexpensive PTE disc for UV white balance. This is also a good, and less expensive, way to achieve a UV white balance.

 

Of course, it is not mandatory to white balance your UV images as we do. After all, all UV colour is false colour. :D

[nfoto]

I can add the following: while the white (or grey) PTFE material will allow a good in-camera UV colour balance for a Panasonic camera, it alone may not suffice for other brands.

[Nico]

An issue with UV-landscapes is probably that the sky is much brighter because only little UV that comes through gets reflected by plants or the ground.

 

I'm still struggling a bit with the white balance. I've tried PTFE, but I don't get the bright yellow that I see in your images. And there's a difference between the colour on the rear screen of my G1 and what I get afterwards in LR ...

[nfoto]

I've used different Panasonic cameras such as G-2 and GH-2, setting an in-camera "UV white" with a PTFE target or Labsphere targets, and getting an excellent balance that closely matches what other profiled cameras (D40X, D200, D300, D600) produce from their RAW files.

 

Thus, I'm at a loss why you cannot get a better in-camera result using a PTFE target . I presume the target is spectrally neutral of course. Camera colour space should be the widest possible, although this really does not matter if you are shooting RAW (a RAW file has no inherent colour space).

 

UV makes bright sky by the very nature of its light field. Thus exposures of landscape can be a bit on the tricky side.

[Nico]

I just did some more experiments that I will post soon. My current WB target is PTFE band, that I had handy. It has a slight yellow cast (in visible light), but reflects UV extremely well. Maybe I need to get another piece of PTFE and see how it works.

Another version of my "bee-colour" landscape is on my blog. Now it became a bit "Disney-like" ...