Saturday, July 1, 2017

UV-Nikkor 105mm vs Coastal Optical systems 105mm lens for reflected ultraviolet (UV) photography

Today about shooting with two dedicated UV lenses, the Coastal Optical Systems / Jenoptik UV-Micro-Apo f4 / 105mm and the classic UV lens, the UV-Nikkor f4.5 / 105mm in a non-scientific photographic comparision at shooting in reflected UV, using the Baader-U filter at natural light. Both lenses were used with a long 80mm sunshade, to avoid diminished contrast, which may happen if shot without.

[click on image to see a larger one]

reflected UV images taken at f4.5:


reflected UV images taken at f8:


The UV-Nikkor 105mm image is shown on the left side, the Coastal Optical Systems 105mm on the right side. First batch was shot at f4.5, second batch at f8. White balance was done for the UV-Nikkor 105mm.

The UV-Nikkor 105mm seems to have an edge over the Coastal Optics 105mm in terms of sharpness and contrast, especially when used fully open at f4.5, but stopped down to f8 the difference gets significantly smaller, as the Coastal gains quite a bit of sharpness and also contrast.

Both lenses require about the same white balance, due to their flat UV transmission (more about that later) and show about identical exposure, with exposure times having a slight nod towards the Coastal Optics lens (1/3 stop less), which in practice is insignificant.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Using a proper sunshade for best UV results using a Coastal Optical Systems / Jenoptik f4 / 105mm

Today about shooting with an UV lens (Coastal Optical Systems / Jenoptik UV-Micro-Apo f4 / 105mm) and considering how delicate those beasts can be to handle; here about using the right sunshade. Sounds rather boring actually, as we all rely on modern multicoated lenses and on my excursions I hardly ever see a photographer using his sunshade. But well, UV photography is a rather tricky subject anyway, and all aspects need consideration...

[click on image to see a larger one]





These are first normal visible light images, second reflected UV images and as one clearly sees here, using a sunshade (right side) can be rather critical, as the left image proves, showing very low contrast. In my case here, I used an 80mm deep shade for maximum effect, but w/o causing vignetting.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos