Hellow from Poland (Minsk Mazowiecki)

[JMC]

As David said, don't be too hard on the FSI sensor. In the UVB region there wasn't much between the d800 monochrome and d850 monochrome. My d800 does not have a quartz window though, so I can't go below 300nm with it. 

[lukaszgryglicki]

If it has quartz window then it should be Ok down to 200nm or even 180nm I believe... my quartz glass from Dan is supposed to pass 180+ nm.

 

[JMC]

56 minutes ago, lukaszgryglicki said:

If it has quartz window then it should be Ok down to 200nm or even 180nm I believe... my quartz glass from Dan is supposed to pass 180+ nm.

 

Sorry, I made a mistake in my last post so have corrected that. My d800 does not have a quartz window so can't use it below 300nm. It has a WG280 window.

[Andy Perrin]

9 hours ago, ulf said:

Andy's findings above could be interpreted as: if you had used a Nikon-D850 for your images it would have recorded light from 313nm to 322nm.

We still do not know the sensitivity characteristics of your non-BSI sensor, but it is likely worse than the D850.

 

Your results are still quite interesting as they are from a wavelength range rarely seen in images.

The label UV-B might not be that important?

 

I agree with both of these comments - the UV-B label is kinda arbitrary anyway. Even if non-BSI sensor shifted the results somewhat, it would still be pretty interesting. It sounds like from what Jonathan said, though, that the difference is not that much in UV-B.

[lukaszgryglicki]

OK calling that UV-B is not important, it's just a name, I will call it shortwave UV-A in around 310-325 range next time.

 

[lukaszgryglicki]

Just a few UIV images (UIV -> R=UV, G=IR, B=Vis) GF 45/2.8 with SEU2, R72, Kolari UV/IR cut.

 

[Stefano]

Very abstract, I like them.

[photoni]

why did not you aligned with photoshop?
the second post-nuclear makes me shiver XD

[lukaszgryglicki]

Don't have Photoshop.

[lukaszgryglicki]

Not UV, but wanted to share:

 

[lukaszgryglicki]

[ulf]

Magic evening skies.

I like them.

 

A tip.

You could separate the images by doing insert and CR between each image instead of just adding the images.

[lukaszgryglicki]

Good news

- Flashlight from maxmax arrived - it has 3 x 3W diodes: https://maxmax.com/shopper/product/16141-xniteflashf-255-310-365-3w-xniteflashf-housing-with-a-255nm-310nm-365nm-3-watt-led-s

- I can see UV-A one (365nm) and my GFX 50R is also able to see it very easy.

- I can very very very barely "see" 310nm one (no idea why, higher UV leaks?) - camera and UV-Nikkor also "see" it (but intensity is rather low - can see light directly in live view but not anything that I shine on).

- I cannot see 255nm diode at all (which is good imho) but camera & lens see it as a very faint glow, I guess I won't be able to use it as a light source at all, but I can *confirm* that my setup sees 255nm light, so if I use my bulbs (3 x 25W low pressure mercury bulbs) and have enough blocking I should eventually be able to recordf UV-C image.

[ulf]

UV-LED types shorter than 365nm use different materials and structures that have way less conversion efficiency.

If I remember correctly the efficiency is at least one magnitude less than the 365nm-LEDs that approach a 30% conversion efficiency.

The shortwave-LEDs are essentially heating elements with a tint bit of light output.

 

The low optical output in combination with less sensor sensitivity at 310nm give that result.

 

[lukaszgryglicki]

I know that they are around 1-3% efficient (don't remember now where I read that).

 

[lukaszgryglicki]

Some UV-B fun (and also some shortest UV-A as already discussed).

- Full sunlight, close to noon.

- Fuji GFX 50R - monochrome + quartz coverglass (QCG).

- UV-Nikkor.

- Hoya U-340 4mm thick.

- Invisible Vision UV 308nm filter.

- Video with lens wide open and ISO max possible 6400. Still a bit too dark, camera was blinking ISO 6400 meaning "light too low".

 

[lukaszgryglicki]

And this is me in UV-B (and shortest wave UV-A) - needed to stand still and try not to move for 30-50s.

 

[lukaszgryglicki]

Finally some shots of my city in UV-B (and shortest UV-A):

 

[Nate]

That lens is remarkably sharp! Nice deep UV

[Stefano]

I thought the same, that lens is very sharp. Although I believe you are seeing UVB, how does glass look like? Like a water glass or glass containers. From my experience they look black or very dark.

 

Filming in UVB is impressive. I don't think you can do that with a color sensor using only sunlight.

[lukaszgryglicki]

All glass is black (buildings/houses windows, car windows). All peoples skin is also black. Foliage is black. Skies are white and hazy, clouds are barely visible, light almost seems like coming from everywhere - see how soft shadows are - it was sunny outside time was around noon.

 

There is a separate thread about this, this is UV-B and very shortest UV-A, basically 300-330nm.

 

That lens is UV-Nikkor sn. 200008, no other lens is able to do any photos with those filters (I've tried my other lenses and I'm getting nothing).

Indoor when I close window - there is just blackness, nothing is registered. When I open windows then I can only see light coming in through open balcony door. Windows are totally black from inside, even when looking at bright skies with sun.

 

[Andy Perrin]

The situation with filming is weird because you can get away with a lot more noise in moving images than in photographs and have acceptable quality due to persistence of vision averaging things out. My experience is that if you can get 10 second exposure with acceptable brightness/noise in a still than you can probably do video also with good quality.

[lukaszgryglicki]

Seems like this is what worked there.

[ulf]

18 hours ago, Andy Perrin said:

The situation with filming is weird because you can get away with a lot more noise in moving images than in photographs and have acceptable quality due to persistence of vision averaging things out. My experience is that if you can get 10 second exposure with acceptable brightness/noise in a still than you can probably do video also with good quality.

That is exactly what is done for astrophotography where there is a problem with seeing (turbulence of the atmosphere).

https://en.wikipedia.org/wiki/Astronomical_seeing#:~:text=In astronomy%2C seeing is the,light path of the object.

Then a movie is recorded and the best frames are extracted and stacked to improve noise.

 

 

[lukaszgryglicki]

I've just received my Fuji GFX 100s - so this will be my main body now (unconverted and I'm not planning to convert it, it has IBIS that is tricky to convert according to maxmax).

I'll be converting my GFX 50R to full spectrum 280nm+ (but leaving CFA intact), so I will have two 50Rs - one full spectrum color and one mono. I have a guy who converted all my cameras to full spectrum here in Poland, he will do the conversion for 50R too. Will see how 50R performs in color (in addition to mono which is my fav conversion till now).