White balance for BUG-stack images

[ulf]

When posting UV-images like from a Baader U in the botanical section on this forum they must be properly white balanced against an UV-neutral reference due to the rules.

For BUG stacks I think more latitude for WB is allowed and that is a good thing.

 

WB to taste can reveal many interesting features and shades that are hidden by a WB on PTFE.

 

Below I have an example of that.

Camera: FS modified Sony A7 III.

Lens:  EL-Nikkor 80mm old metal type, at f/16.

Two UV-modified Godox flashes.

Filter: a BUG stack of S8612, 2mm and a UG5, 1.5mm

 

WB to PTFE:

 

WB to taste by sampling around in the blue-green areas, until I found an useful colour scheme:

The image a cropped version of a Dandelion.

 

Creative WB can also be used to enhance details with a WB that gives unnatural colours of VIS images.

 

The same flower in VIS with proper WB, where the the yellow colour is so dominant that you forget the intricate details. Filter BG40:

 

Creative WB of the same RAW file:

[colinbm]

Very artistic Ulf.

[ulf]

Thanks Col

 

[Andy Perrin]

Interesting, I like the colors in the modified vis image (last photo) Ulf. Not sure I like either of the BUG colors, but I see the point you are making!

[ulf]

11 hours ago, Andy Perrin said:

Interesting, I like the colors in the modified vis image (last photo) Ulf. Not sure I like either of the BUG colors, but I see the point you are making!

Well I like the colour explosion in the BUG image that the WB revieled.

There are so many different colours and details brought forward, from the original image with mainly very dominant green with some yellow.

I agree that it is a lot of intense colours and if it should be paired with the paler VIS image you like, the saturation can be reduced to improve the harmony between the two images.

[Andrea B.]

Ulf writes: When posting UV-images like from a Baader U in the botanical section on this forum they must be properly white balanced against an UV-neutral reference due to the rules. For BUG stacks I think more latitude for WB is allowed and that is a good thing.

 

Ulf, that is a valid comment about BUG stacks. It is not always clear what white balance "should be" for false colours under any UV, IR, UV/IR filter. I do not have a rigid set of requirements for making a false colour white balance. Although I do ask that we all try to WB the UV photos posted only in the botanical section. Any BUG photos, aerochrome, or unusually-filtered photos posted in the botanical section are exempt from that requirement.

 

For any documentary photo, I think that the best thing to do is provide a brief explanation of how the false colour was processed. For any other photos, let your artistic sense be your guide.

 

In the botanical section it is always OK to post a visible documentary photo followed immediately by an unusual rendering (such as you show above) which brings out details of the flower.

[Andrea B.]

Regarding the yellow dandelion above....It was noted that details are missing in the visible version that can be seen in the bug filter version due to the predominance of shorter wavelengths passing through the bug filter which scatter more on the surfaces of photographic subjects to bring out small surface details. (Ulf and most others already know this.)

 

But remember that whatever details are present in the visible version can be enhanced by a judicious application of large radius USM or by using whatever detail enhancer a converter might supply. Granted, this can be a bit tedious because detail enhancement is best brushed in only to areas which need it. (Applying detail enhancement to backgrounds and large OOF areas creates a noisy look.) Another useful tweak is to slightly reduce the saturation and contrast of the large yellow area. Digital cameras still seem to oversaturate reds/oranges/yellows. 

 

Just thought I'd toss this out there in case readers don't know these tweaks. 

(I also slightly reduced exposure, but only in the center of the flower.)