Solar and Hg lamp spectrum lens test - Kamlan 50mm F/1.1

[Dmitry]

Gear used:

Olympus e-m5 body full spectrum converted myself.

Kamlan 50mm F/1.1 (design 5/5). There is also a mk-II lens in 6/8 design, bigger and heavier - don't be confused!

 

processed in xnview from ORF without white balance changes, all filters 2mm

 

Hg lamp:

no filters

 

315nm filter - only 365nm line visible

 

zwb3

 

Solar (heavy cloudy weather):

no filters

 

zwb1

 

zwb2

 

zwb3

 

Lens is 365nm capable

[Dmitry]

Some jpegs for reference

[dabateman]

Since the intensity of the uv is much lower in the zwb3 image than the zwb1 image, that implies to me that you must be really pushing it to get uv through this lens. 

So 365nm might be possible, but your mostly going to see only the upper 370/380nm to 400nm uv range through this lens.

 

[Dmitry]

I don't know how much UV blocked by clouds, maybe it can be better in direct sunlight. But there is no 334nm line from HG lamp.

EXIF is saved, you can see exposure was not same.

[Dmitry]

Same performance on direct sunlight.

[Andy Perrin]

It does sound like the lens is cutting it off below 365nm. 

[Dmitry]

There is no lens cement, but coating or glass material can block.