Single 39mm focal length Biconvex lens 50.5mm diameter

[dabateman]

By popular demand this is what my 39mm single element lens looks like:

 

This is close up image, sorry little blurry of the lens element in the thick 52mm ring I have for it:

 

Here are some photos taken outside today while the rain stopped and the clouds were coming an going.

 

330WB80 improved filter with lens wide open, shot handheld:

 

330WB80 improved filter with lens closed down to taste:

 

3x 1.45mm ZWB2 with 1x 2mm ZWB1 constructed in single filter frame:

 

3x 1.45mm ZWB2 with 1x 2mm ZWB1 constructed in single filter frame stacked with 2mm S8612:

 

3mm ZWB2 stacked with 2mm S8612:

 

4.5mm ZWB3 stacked with 2mm S8612:

 

Baader venus U filter with aperture to taste, same as above:

 

All shots above were shot handheld. I did a fairly good job lining it up. I tripod would be better to judge focus though. The colors were what I was interested in comparing. The ZWB1 mixed with ZWB2 is a little hot, doesn't block enough IR, but I still like it. My 8mm ZWB1 image was too blurry as seen here:

[Stefano]

Did you have trouble white-balancing your images? Did you use the same white-balance for all of them?

[Andrea B.]

David, nice artistic effects from this interesting construction. If WB were applied during conversioin, we would be seeing quite a lot of chromatic aberrations at the edges. But again, that can be used to artistic effect for those so inclined.

[dabateman]

I used the same white balance present I have on my camera.

All the above images were taken with my WB1 for BaaderU.

 

WB1 was set using Baader venus U filter.

WB2 was set with 313bp25 filter under UVb.

WB3 I have for IR chrome, set using lee 729 and genuine kg3 2mm thick

WB4 I have set outside using BN850 midopt filter for IR.

 

The Olympus cameras are easyish to set custom white balance under various lighting. I just like the ones I have preset.

 

I just thought of a new test. I also have some concave lens elements in C-mounts. I should test various to see which one improves the edge sharpness with the BaaderU filter. It seems the most central focussed.

In a test today my concave 200mm element was best with a Biconvex 100mm element, to improve edge sharpness. I can mount the concave element into the c-mount portion of my M43rds mount.

I could also test my 0.5x SvBony focal reducer to see what it does with this lens.

[Andrea B.]

Curious about this: if WB is set for BaaderU filter, then there should be no magenta/pink color in the BaaderU photo. Now that is *not* a criticism, just curiosity.

[dabateman]

Curious about this: if WB is set for BaaderU filter, then there should be no magenta/pink color in the BaaderU photo. Now that is *not* a criticism, just curiosity.

 

Except I can't remember what lens or what light I used to capture that setting. I have kept it on the camera for years now, as I generally like it.

It may have either been captured with a mercury vapour lamp or a 365nm led and It might have been taken with either the UAT or the Nikon 80mm EL lens.

 

So the light and original lens will affect the color. Since I rarely use it outside, I will probably just keep it as is.

 

My Em5mk2 has:

WB1 taken with BaaderU filter

WB2 taken with 390bp25 filter

WB3 was an mixture

WB4 is Lp720 filter, but might change that.

 

The Em5mk2 is stock not converted. Olympus cameras are leaky in both UV and IR. So its a goot walk around camera. It just doesn't have the deeper golden UV from less than 370nm.

 

[Andrea B.]

And I've always tried to remind people that 370-400 nm is a totally legitimate range in which to shoot UV photos. One need not "go deep" to make cool UV photos.

 

I like walk-around photos. It is always interesting to see what "ordinary" views look like in UV or IR.