Kolari UV-pass - handheld test

[lukaszgryglicki]

Setup:

- Nikon D600 mono.

- Nikkor 50/1.8 AF-D.

- Kolari UV-pass filter.

 

*Note* the frame edges - those are Bayer CFA ramainders - photos would be that darker with CFA.

 

All photos handheld, the aperture was usually f=2.2 but from 1.8 to 2.8.

Exposure usually 1/50s, sometimes 1/30s.

ISO auto from 100 to 1600 - this is what actually changed. All photos were just Live View "auto" with fixed aperture mode, usually at f=2.2, minimum shutter time 1/50s or 1/30s sometimes.

[lukaszgryglicki]

Kindly asking admin to remove this duplicate, my internet was slow and I must have clicked "post" twice.

[dabateman]

Definitely UV photos there.

Your frame edge is thin and curved, offers a nice frame to the black and white photo. I kind of like it. Your own photo signature.

 

The fourth photo is my favorite. Uv flower fenced in (UV behind bars). But maybe I have been locked in for too long due to COVID.

[lukaszgryglicki]

Thanks, yep that frame from debayering is indeed a signature, what's interesting is that it's almost invisible in IR only photos.

[dabateman]

Thanks, yep that frame from debayering is indeed a signature, what's interesting is that it's almost invisible in IR only photos.

 

Yes it should be as above 830nm all the colors of the color filter array pass the same.

[lukaszgryglicki]

The same OK, but still CFA should absorb some (no matter if in R, G or B channell - there should be some absorption - I guess??) It looks like with IR850 filter - all 3 CFA channels are just totally transparent.

[Andy Perrin]

I think they are pretty much transparent? That’s why they are the same. Jonathan measured that once I think? I can’t find the link but he has a half-debayered sensor and he probably can confirm.

[Stefano]

These are microscope images: https://www.ultravioletphotography.com/content/index.php/topic/4095-microscopy-of-a-monochrome-converted-camera-sensor/page__view__findpost__p__38640

[dabateman]

Yes and no.

He has a point that even though its transparent, it should still block some of the light as its still an additional thing that light goes through to be detected.

But since you don't see it in IR, than it must be small or negligible. Like plastic wrap. I don't know if its also due to the wavelength just penetrating better as well.

[Andy Perrin]

He had a point in principle, but I think Jonathan pretty much showed it's the plastic wrap situation. The light gets refracted but otherwise goes right through with only small losses.

[Cadmium]

Nice photos!

[Cadmium]

PS: Where did you have the camera converted to monochrome? I have not seen monochrome conversions with a darker outer frame left on the sensor, but perhaps it is common?

[Andy Perrin]

He said by Herra on this board in fact!

 

Remember this?

https://www.ultravioletphotography.com/content/index.php/topic/1743-monochrome-dslr-imaging-uva-vis-nir/page__hl__%20herra%20%20monochrome

[lukaszgryglicki]

Yes, it's Herra's camera, CFA was physically removed/scraped from the sensor - but it wasn't possible to do this on the final few pixels on the sides - I've accepted that.

The camera also had a problem with infinity focus due to missing cover glass, Daniel Gaworski from irstudio.pl installed one for me years back. I think it was the thinnest possible 280+ nm glass (almost sure about that, I was not into UV at that time, so this is probably my limit now). There is a small chance that I wanted quartz glass at that time, but I just don't remember now - it was a phone call.

[lukaszgryglicki]

My wife in UV (handheld):

[Andy Perrin]

Amazing tones

[lukaszgryglicki]

Thanks! I'm saving files just as JPEGs - no raw processing at all.

[lukaszgryglicki]

Now some "color" photos from UV & Kolari vision (Nikon D600 full spectrum with Bayer CFA).

Shoot as RAW and then just "auto white balanced" by this: https://github.com/l...in/dcraw_wb.sh

 

https://teststats.cncf.io/backups/cuv/

 

It also contains some videos (in-camera MOV dumped to audio AAC and each frame saved as PNG, then each frame "auto white balanced", finally MP4 created from auto white balanced frames and AAC audio dump), this is a program doing this:

- In bash (was too slow): https://github.com/l...600_wb_movie.sh

- In golang (faster, because it processes data in parallel): https://github.com/l...wbmov/awbmov.go

 

And similar video from Hoya U-340 4mm (it leaks IR):

 

And on youtube:

 

Needed to remove almost all links because it says "I've posted too many media files" which makes no sense because I've posted *none* - I only post links to files on my own server which takes no UVP server resources.

[lukaszgryglicki]

So, adapter M42->Nikon-F (with the lens) is not able to focus at infinity at all (with Soligor 35/3.5) and it looks like it is not able to focus at 60% or more lens distances... adapter without the lens/optic element works a lot better (macro). Anybody can suggest any M42-Nikon-F adapter that is able to focus at infinity and is not blocking 35/3.5 lenses transmission?