Nikon UV-Nikkor f4.5 105mm vs CERCO f4.3 94mm

As I was testing a Nikon UV-Nikkor f4.5 105mm, I thought it would be interesting to compare it to my CERCO f4.3 94mm workhorse lens, especially about possible chromatic aberration, sharpness and contrast. Target was a metallic precision ruler, light was sunlight. Only visible light photograhy was done here.

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CERCO top, Nikon bottom. Increasing f-stop setting towards the right, starting fully open leftmost.




Both lenses do not show CA. But interesting to note, how much higher the contrast of the UV Nikkor is. The CERCO shows futher decreasing contrast when stopping down (to the right) although flare control was used by using a deep hood against stray light. Both lenses are very sharp, but overall the Nikkor seems to be the clear winner here and it also covers FF sensors, which the CERCO does not do. Both are excellent lenses in terms of sharpness, but contrast and flare always need special attention, especially when using the CERCO multispectral lens.

I have compared quartz fluorite lenses in terms of their transmissions HERE

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

Golden reflected UV ultraviolet photography VII

Today was one of these last sunny October days with golden sunrays in the evening, so I grabbed my UV equipment and went to the park for some more "golden" UV shots. I used the 94mm CERCO quartz fluorite lens for those. Also here my special "golden" processing for these shots has been used.

[click on image to see a larger one]

Salvia leaf:


Delphinium seedhead:


iridescent blue Delphinium:


water droplets on leaf:


Quite amazing high resolution this type of UV photography shows.

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

Lens Resolution: Golden reflected UV ultraviolet photography VI

Today I would like to use those recent "golden shots" of autumnal Rudbeckia fulgida leafs to show the different performance of lenses, an older 50mm enlarger lens and the 94mm CERCO quartz fluorite lens. Distance to the leaf was chosen to achieve about matching images. Also here my special "golden" processing for these shots has been used.

[click on image to see a larger one]

old enlarger lens:


CERCO lens:


Here a diptych to make comparison easier, Cerco lens is left:



It gets pretty obvious, that the Cerco lens delivers a much higher resolution and sharpness.

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

UV enhances the resolution

I have always talked about here, that UV photography enhances the resolution of the images by a factor of about 546nm/365nm = 1.5x, so today some proof that this theorem holds.

And here now the results of these test shots, identical conditions, shooting a piece of old sandlewood, using my UV Rodagon 60mm lens @f8, Baader U-filter, Nikon SB-140 UV flash .

Visual shot is left, UV shot on the right (bw version) [click on image to see a much larger image]:



And here a recent shot using the UV Nikkor 105mm, Xenon flash at f8, left UV shot (Baader U-filter 310-390nm, right shot white light, unfiltered) of skin (female hand, afro-american heritage)



It gets quite obvious, that the resolution of the UV shot is much higher.

Should I find the time, I will re-shoot that test using a monochromatic light source for UV, such as my Nichia 365nm UV LED lamp and a narrowband filter for visible light also, such as 546nm (green), and again compare the results then.

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