Is this stuff as remarkable as it sounds?



Any videos or comparisons out there?



Why no new products coming out with it?

I'm not familiar with Gen 3+1, but if you mean Gen 4 I can tell you that the "Gen 4" designation was dropped by the military.  It is now referred to as "filmless" technology and while they can be very sensitive tubes that can have some very high specs, especially in the SNR and PCR numbers, they have been shown to be less durable and have significantly less of a lifespan when compared to standard filmed and thin filmed Gen 3 tubes.  I am one of the least knowledgable people here, but iirc thin film technology was born out of the need created when the military decided to ditch the so called Gen 4 tech, but was still looking for better performance.

Please disregard.  Looks like we are talking about something completely different here, my mistake!

It is a 25mm tube style that is not in as "common" use as it once was. Tubes like these are expensive to make and it is just not cost effective to produce super tubes in large numbers. I am sure a handful here and there are made for special forces and .Gov entity's.

The 3+1 is just a older technology good Gen 3 25mm tube even more amplified by the addition of a second stage of amplification (simple explanation). CJ can give a more scientific explanation. They don't have the crystal clear resolution of say a modern Omni VIII tube. What they do have is OUTSTANDING light gain. They will destroy the best Gen 3 modern tubes when it gets really dark. Nice tubes but I doubt we will ever see them in full scale production.

Just costs to much to make them and only the Gov with deep pockets will pay for that. They were never mass produced tubes which is why they are rare to find. I have only found one and I keep my eyes peeled. I will find it again before I die.

The more I read about them, the more I want one lol. So they are like the holy grail of nightvision?



 

Pretty close if not the Holy Grail. I here tale of a film less 25mm tube. Never seen one. I still don't think even a film less version would beat the 3+1. The three stage Gen 1 cascade tubes have very good gain. Glass input 25mm Gen 3 tubes is what you want to look for. They are not marked 3+1 for the naked eye to see. You have to do some detective work. I can't educate future competition to much though.

To be honest I stumbled upon mine purely by accident. It was a Star-Tron surveillance scope I suspected to be Gen 3 (sold as Gen 2). It was Gen 3 but I found a strange contract number on it. Errr, FBI something or other from memory. I learned it was a 3+1. The FBI contract number was a clue this was not a normal production tube off the line. Special tubes.

Never seen another FBI contract number in my life so far. I used to have pics and all that of the tube and its performance. Sadly they were lost. Was around the Agent Wu scare and pictures were flying out of the night vision forums all across the land. We can't have nice things anymore and fewer pics get posted of cool gear.

Slightly off topic, but I was one day reading Photonis tube specs and they say you can order a tube with one, two or three layers of MCP. I guess that would lead to extreme gains too, but with a different effect on image quality than what I'd think 3+1 looks like.

As someone who finds thin filmed Gen 3 technology lacking on really dark nights, this is an interesting topic...

Does these high gain tubes help in very low light situations? Is the photocathode the limiting factor or MCP or something else? I don't fully grasp how a cascade Gen1 for example works because if the first photocathode fails to generate electrons then there just is nothing to amplify. And then, when I use my NV in very low light all I get is that weird noise and no image what so ever - is there still electrons being formed in the photocathode but their energy is so low that MCP fails to amplify them? I have been in the belief that if an electron is generated from the photocathode then it will almost surely get amplified in the MCP. If that was the case then these high gain tubes would not help in very low light, but how is it in reality?

 

Thank you once again for a great explanation. Also interesting thoughts on the Photonis tubes.