[UV] Old Achromatic vs modern Cerco Quartz Fluorite Lens for Ultraviolet Photography

Well, you may remember that I have shown here results using an older quartz fluorite lens from a spectrometer system. Here that now tested against my Cerco 94mm lens using a Gazania rigens flower that I have shown here a few times before. The Cerco images ("in dubio pro reo") have been adjusted in size a bit, to compensate for the different focal lengths (94mm vs about 82mm).

Here the results and I leave it to you to determine which shot was done using which lens; it is easy anyway as I will show also 1:1 crops.

[click on image to see a larger one]

Visual shot:


UV using Baader-U filter:


Visual shot (detail):


UV using Baader-U filter (detail):


[the UV focus is not exactly identical for that last shot, so I'm not sure if that was caused by focus shift or most likely by a slight movement when I changed filters ... oh well]

Not that bad for such a relatively cheap part...

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

Gazania rigens: human vision vs simulated bee vison using a quartz singlet lens for reflected UV ultraviolet photography (III)

This is a 3rd set of shots with the same flower Gazania rigens flower that I have shot previously with a quartz-fluorite lens and the same setup as in shots before using a custom made up UV lens from a simple quartz singlet, stopped down to around f16 (estimated as no scale). Shots are in normal human vision VIS, in UV using the Baader-U and Jupiter-U filter, as well as in simulated bee vision using my XBV2 and XBV3 filters respectively. Flower placed into the center, higher magnification, otherwise unchanged setup as before.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


Simulated bee vison using XBV5 filter:


UV using Baader-U filter:


UV using Jupiter-U filter:


I haven't re-adjusted the UV focus, so the rear of the flower drifts into blur, that could be avoided, if so wanted by individually adjusting focus for each shot.

I used a 365nm UV LED for focusing, that worked pretty well, even stopped down that much.

In my opinion this central placement is the best way to use this lens singlet, as it minimizes the visible blur, yet delivers acceptable sharpness in that whole spectral range.


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

Gazania rigens: human vision vs simulated bee vison using a quartz singlet lens for reflected UV ultraviolet photography (II)

This is a 2nd set of shots with the same flower Gazania rigens flower that I have shot previously with a quartz-fluorite lens and the same setup as in shots before using a custom made up UV lens from a simple quartz singlet, stopped down to around f16 (estimated as no scale). Shots are in normal human vision VIS, in UV using the Baader-U and Jupiter-U filter, as well as in simulated bee vision using my XBV2 and XBV3 filters respectively.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


Simulated bee vison using XBV5 filter:


UV using Baader-U filter:


UV using Jupiter-U filter:


The idea behind that 2nd set was to get a better estimate of the VIS-UV focus shift (measured 5.8%, VIS is quite larger) as well as to show the effect of out-of-center imaging, to get an idea how the blur develops. I guess that gets pretty clear now.


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

Gazania rigens: human vision vs simulated bee vison using a quartz singlet lens for reflected UV ultraviolet photography

This is a Gazania rigens flower that I have shot before but now using a custom made up UV lens from a simple quartz singlet, stopped down to around f16 (estimated as no scale). Took some shots in normal human vision VIS, in UV using the Baader-U and Jupiter-U filter, as well as in simulated bee vision using my XBV2 and XBV3 filters respectively.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


UV using Baader-U filter:


UV using Jupiter-U filter:


So and here you have the comparison as a quadriptych VIS-UV-BV2-BV3:




Missed the focus at the visible shot a bit obviously since this lens is not color corrected, i.e. has some focus shift. As you may further notice, the center is quite sharp, but of course the more outside it gets, the more the blur increases. For flowers this can actually be quite nice in my opinion.

Well, of course I cannot make a decision for somebody else if an investment of a few hours work and, depending if a mechanic is needed or not, the cost for making such a lens mount is within budget, but surely such a quartz singlet could be, as it can be had new for about $100. There is inconvenience of course, due to the "substantial" focus shift, but lifeview solves that easily.

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

Bidens: human vision vs simulated bee vison

This is about a Bidens ferulifolia flower, one of my fav UV "models". I took some shots, in normal human vision, in UV using the Baader-U and Jupiter-U filter as well as in simulated bee vision using my various XBV filters respectively, that simulate insect / bee vision in just one shot.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


Simulated bee vison using XBV5 filter:


UV using Baader-U filter:


UV using Jupiter-U filter:


This flower has a very prominent UV pattern on its UV-bright petal tips.


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

Zinnia: human vision vs simulated bee vison

This now is about a Zinnia hybride flower that I discovered on teh market today. Took some shots, in normal human vision, in UV using the Baader-U and Jupiter-U filter as well as in simulated bee vision using my XBV2 and XBV3 filters respectively.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


UV using Baader-U filter:


UV using Jupiter-U filter:


Interesting to note that this one hardly has any UV reflection.


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

Gazania splendens: human vision vs simulated bee vison

This now is about a Gazania splendens flower that just blossomed. Took some shots, in normal human vision, in UV using the Baader-U filter as well as in simulated bee vision using my XBV2 and XBV3 filters respectively.

[click on image to see a larger one]

Visual shot:


Simulated bee vison using XBV3 filter:


Simulated bee vison using XBV2 filter:


UV using Baader-U filter:


So and here you have the full comparison as a quadriptych VIS-UV-BV2-BV3:




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