Mercury Hg lamp spectrum lens test - Olympus M.Zuiko Digital 14-42mm f/3.5-5.6 EZ

[Dmitry]

Gear used:

Olympus e-m5 body full spectrum converted myself.

LENS: Olympus M.Zuiko Digital 14-42 mm f/3.5-5.6 EZ, a pancake kit lens.

 

Lines reference in index sticky - lines

Left orange line is 365nm

 

zoomed to f=42mm

iso 200, f/8 processed in xnview from ORF without white balance changes

 

1s, no filters

 

10s zwb3

 

20s zwb2

 

60s zwb1

[dabateman]

That is much better than I expected.

[Dmitry]

Good news this lens can focus at infinity in 15-42mm range on modified but not infinity corrected e-m5 body!

[Dmitry]

At wide angle 14mm it can focus infinity in manual focus mode, but body can not confirm focus lock.

[dabateman]

Interesting,

I think what you mean to say is that with a camera which has not been corrected with glass to focus lenses to infinity. This lens will still focus to infinity, as it has enough internal focus range.

The way you wrote it implies it will not focus correctly on a converted camera.

 

Is that only true for uv? Or does it also apply to to IR with a 830nm filter? The true test is high IR, as UV tends to generally focus closer.

 

Also, how does this directly compare to the Olympus 14-42 R? Is the R better or the same as the EZ?

[Dmitry]

With IR 850nm filter it can focus infinity in full range 14-42mm and does confirm focus lock. Even better!

 

I think compact collapsible design allow internal lenses to move in increased focus range.

 

For solar spectra they both have equal performance.

[dabateman]

After I said that and with your comment, I had to go back and look over some optical physics. Depending on convex and concave elements in the lens, used to correct chromatic aberrations. The focus can shift to be further away for UV than expected. Since you have focus confirmation in IR, but not UV. You may have found an example lens where UV is focused further away from the sensor plan. Interesting, but may not affect you.

I think too much in simple lenses, wher uv is close to sensor and IR is further. But this is not always the case.

Also, why am thinking about this is at high magnification I see focus shift for my UAT lens in a direction I was not expecting. Needing to focus closer in UVa to get objects behind more in focus under UVb illumination. But I have to test this again as I saw the reverse last Monday. I may just be slightly turning the focus unscrewing the filters.

 

[Dmitry]

I think vis and UV focusing trouble at wide end is related to focus shift. Too many chromatic aberrations at violet range maybe.