Interesting Mono UV Gear at MegaVision

[Andrea B.]

(UVP has no monetary associations with any company.)

 

I was reviewing the available information about the MegaVision 120/4.5 Macro UV-IR ApoChromat lens which is listed in the UV-Dedicated section of the Lens Sticky. I learned that for Archival and Cultural Heritage Imaging, MegaVision offers a complete setup of camera, lens, LED lighting and software.

LINKIE: http://mega-vision.c...l_heritage.html

SEE ALSO: N-Shot Capture

 

The camera is a 50 megapixel monochrome with no internal filtration. Nice.

 

The LED lighting panel can be configured with 365 nm UV and 395 nm UV/Violet modules as well as with 10 different visible modules and 6 different IR modules. Again, nice! (And I'm willing to bet that a UV module below 365 nm would not be impossible to ask for.)

 

The software controller permits a 12-band image capture in less than a minute. Woo, fast!!

 

Here is the unusual thing: no filters are used with their "leakless" LED lighting. This would be a nice thing, methinks. But I do hope instructions are given to shoot in the dark.

 

I particularly liked this: "Spectral confusion due to Bayer filter transmission overlap is eliminated, thereby reducing potential metameric failure and allowing improved display/printing flexibility."

That's what we get here sometimes - spectral confusion. La!!

 

Finally, I really enjoyed reading the last part of the LINKIE which discussed making not tri-colour but 5-colour to 8-colour images from a monochrome camera. The claim is made that to make "good" visible images from a mono cam, one needs more than 3 bands. Very interesting!

 

What do you think this gear would cost? I'm not sure I even want to ask. :lol:

[Andrea B.]

Finally found some examples from this system. The PDF includes tri-colour Infrared, UV-induced Vis Fluorescence, Blue-induced Vis Fluor and the usual IR and UV photos. The photos were made of a 19th Century British painting, artist not mentioned.

 

I think you will enjoy looking at these examples.

 

(They did, of course, use filtration for the Fluorescence photos.)

 

The tri-colour IR is not quite all IR:

• blue channel: 535 nm
  
• green channel: 625 nm
  
• red channel: IR 940 nm
  

I know absolutely nothing about this, but presumably there is a reason for using those 3 wavelengths and that particular channel map. The caption indicates something about distribution of certain pigments.

[Andrea B.]

My Goodness!!! The images are stitches from sixteen 50-MP shots. Wowie. Some overlap.

 

I wish I had had this as a job when I was working.

Of course, like any job it probably would have become boring. But still........

[Cadmium]

What do you think this gear would cost? I'm not sure I even want to ask. :lol:

 

I asked about the E7. Will let you know if I get an answer.

[Andy Perrin]

I bet they don’t sell to consumers. Also, these places that sell to cultural heritage institutions overprice everything, like that Kaiser UV lamp I posted a while back.

 

Frankly, this is the kind of system I’ve started to assemble for my TriWave except going even further into IR. I want a 3-LED system. 12 will have to wait.

[Stefano]

I may be able to build a similar setup in the future. I already have LEDs emitting at about 340, 365, 385, 405, 425, ~450, ~465, ~480, 500, 525, 565, 587, 600, 625, 660, 685, 736, 770, 850, 880, 940, 970 and 1050 nm. I can add a 810 nm LED later. Some of them still need to be mounted on the heatsinks, and I also have to find appropriate connectors and make them look better in general. It is in my long to-do list.

[Andy Perrin]

That is impressive Stefano. The thing is, the light output for some of them will be very dim compared to others. You would have to put potentiometers or something on them to individually tune them.

[colinbm]

I may be able to build a similar setup in the future. I already have LEDs emitting at about 340, 365, 385, 405, 425, ~450, ~465, ~480, 500, 525, 565, 587, 600, 625, 660, 685, 736, 770, 850, 880, 940, 970 and 1050 nm. I can add a 810 nm LED later. Some of them still need to be mounted on the heatsinks, and I also have to find appropriate connectors and make them look better in general. It is in my long to-do list.

 

 

I found a Chinese seller on eBay advertising 1watt x 310nm, expensive but actually 303.5nm, gets you into UVB.

https://www.ebay.com.au/itm/254936301509?hash=item3b5b633fc5:g:gDEAAOSw0xJgcZeS

Can you tell me where you got the 340nm LED please ?

[Stefano]

That is impressive Stefano. The thing is, the light output for some of them will be very dim compared to others. You would have to put potentiometers or something on them to individually tune them.

 

Thanks. I use a bench power supply to run them. I can dim them from zero to max. They run at 900 mA (except for the 340 nm one).

[Stefano]

The original eBay listing is gone, but this should be very similar if not identical: https://www.ebay.com/itm/High-Power-3W-UVA-340nm-Led-Chips-Deep-UV-Led-Emitter-Diodes-Radiant-flux-55mW/202120730112?hash=item2f0f559600:m:mjTkCxAMKs2aloJPxecaFYg

[Stefano]

Colin, those are interesting LEDs. The 250-255 nm version is particularly interesting as below 265 nm LEDs are hard to find and especially not in 1 W versions.

 

In the future I want to add a 310 nm and a ~280/285 nm LED to my collection, but I am looking to get four of them on a single 20 mm PCB star to have more power.

[colinbm]

Thanks Stefano

[ulf]

Thanks. I use a bench power supply to run them. I can dim them from zero to max. They run at 900 mA (except for the 340 nm one).

 

Do not forget to design for proper cooling.

LEDs lose conversion efficiency when hot and their life time will be very short if overheated!

 

I had a project similar to this, but for outputting a reasonably collimated beam for lens transmission evaluation.

That was before I got a proper strong light source for that.

 

Each LED had a separate module that was exchanged, from the mount sitting at the end of the collimation optics.

I think I finalised 10-15 different modules, with different types of LEDs, before the project stalled. As there is a need for much light with an integrating sphere, I did not go below 365 nm

[Stefano]

They are individually attached to big heatsinks, and I have never measured temperatures above ~45°C after running them for hours.

[Cadmium]

Andrea, Just to give you an idea, the price for the E7 is about $24,000.

http://mega-vision.com/e7.html

[dabateman]

All the products have very uncommon CCD sensors. I am not surprised by that quote. They would be comparable to the Hasselblad and phase one medium format cameras that are $50000 and up.

 

I like how they refer to a 49.1mm (H) X 36.8mm (V) sensor as full frame CCD. Dpreview needs a correction.

 

 

[Andrea B.]

Holy WOW !! That is a BIG price. Geez.

Does that include the lens?

[Doppler9000]

The lens, designed by Brian Caldwell, is approximately $15,000.

 

It is par-focal from 365 - 1,050 nm with a 70mm image circle.

 

[Alaun]

 

Here is a new publication about what can be done with the camera system:

 

https://journals.sagepub.com/doi/10.1177/00218286221128289

 

(New evidence for Hipparchus’ Star Catalogue revealed by multispectral imaging)

 

Many details in subnote 4