Night Vision Neat Photonis vs Elbit post...

[GBMaryland]

This is from one of the astronomy folks, but it does demonstrate what I've seen with many of the current Elbit stuff:

Photonis 4G vs Elbit Thin Film - Carpe Nocturnum

The Intens tubes tend to have low EBI/Halo (they are spec'ed to be that way), with a decent overall luminous gain, and usually a good Signal to Noise ratio. The center resolution can be in the 80s as well (as opposed to 72lp/mm)... though I think L3 may be or may have once just not put anything above 72lp/mm on the sheets or tested above it, etc.

I've been curious in that I've seen some Elbit tube with crazy high signal to noise (like 38-40), but also with pretty high EBI and over 1 on the halos.

This video more or less shows that.

L3 tubes, not so much... even the unfilmed ones.

Anyone know why Elbit is looking a little different than the ITT Pinnicle days of <=1 on EBI/Halo?

 

[sheepdog697]

I think it depends entirely on what grade elbeit tube you are comparing. If you are comparing a xlsh tube to the intens line it’s not really apples to apples. XLSH tubes are probably half the price of intens tubes. Intens tubes are about the same price as L3 unfilmed That being said the better grade elbeits (YH) have a max halo of 1.0, and max EBI of 2.5...

Not really sure what you were asking, but did this kind of give you what you were looking for?

cheers

 

[GBMaryland]

Yeah, but and EBI of 2.5 is huge compared to either L3 or Intens (specifically - other Photonis products aren't really in the Gen 3 range performance wise).

At one point ITT was producing tubes with significantly lower EBI, whats changed with EBlit that the EBI is so comparatively high? Do they have other commercial tubes with lower EBI specs?

 

[MarinePMI]

Just a speculation, but the tubes could be being manufactured to a certain spec for specific reason/need other than being put in 14's. I'm not going to get into specifics, but NV is needed for applications beyond a human eye peering into dark terrain at night...

These may just be the excess of that particular manufacturing run(?), and would explain the peculiar pattern of tube specs.

 

[TNVC_Augee]

Elbit Systems of America (ESA-NV) appears to be trying to push the envelope of tube performance that they can squeeze out of thin-filmed Gen. 3 tubes, and as you push the limits of performance there can be a “ripple effect” in other specs. Gen. 2 architecture, for better or for worse is a different animal, though the 4G MIL-SPEC (formerly INTENS) can be some impressive tubes for what they are

Remember that EBI allowances went up from 2.5 to 3.0 for OMNI VII as other performance metrics were pushed up, though many MIL-SPEC tube tolerances from the manufacturer are still stated at 2.5.

Something worth noting about many of these very high spec ESA tubes these days is that most of them are XLSH P/Ns, which, as we‘ve noted are technically “MIL-SPEC Fallouts” (though the EBI spec max is the same between the XLSHs and YHs), in some ways they can be viewed almost as “experimental,” however, again, ESA is clearly trying to push performance as far as possible (possibly in response to OMNI IX projections), however the process of building a high spec tube that can meet ALL MIL-SPECs is easier said than done—and some of the tolerances/specs that can push a tube out of consideration for MIL-SPECs may not necessarily be the ones listed on the factory data record provided to consumers.

ESA has stated that they do have some “higher than YH spec” tubes, but they are not cheap and hard to come by—and while not necessarily at the same level as USSOCOM Unfilmed systems, the contract minimums for the SBNVG and ENVG-B programs are no slouches.

At the end of the day, with the exception of export tubes, neither L3H nor ESA “want” to produce lower performing tubes, however the process of pushing performance limits to the edge will necessarily result in a few cracked eggs along the way, and IMHO, the commercial market is benefiting in a huge way from this process with fallout tubes that cost in the order of 60% of a MIL-SPEC tube sometimes far exceeding them in raw performance, but maybe having a slight defect out of tolerance or an extra .003 micron spot.

L3H, to their credit seems to have “cracked the code” not just on Unfilmed, but on producing consistent and tight high-spec tubes with boring regularity. There are arguments to be made that when Harris acquired ITT, they did not really “nurture” the Roanoke Night Vision division (you might notice lots of former ITT employees floating around there in the world if you pay attention-most of them doing good things, but at least one going to prison...) and fell behind, resting on their laurels, but ESA-NV is hungry and pushing hard.

~Augee

 

[sheepdog697]

Also, in regards to the MAXIMUM EBI that I quoted for elbeit. The max EBI on my 18MM L3H unfilmed unit is 2.5 EBI, and my actual in both tubes is .6/.7

 

[yakmastermax]

At the end of the day, with the exception of export tubes, neither L3H nor ESA “want” to produce lower performing tubes, however the process of pushing performance limits to the edge will necessarily result in a few cracked eggs along the way, and IMHO, the commercial market is benefiting in a huge way from this process with fallout tubes that cost in the order of 60% of a MIL-SPEC tube sometimes far exceeding them in raw performance, but maybe having a slight defect out of tolerance or an extra .003 micron spot.

~Augee

I know it varies batch by batch, but just roughly speaking what rough fraction (averaged across batches or just taken from a single representative batch) of com spec XLS/XLSH tubes that get downgraded are downgraded for blems or EBI spec, vs SNR or res spec?

 

[sheepdog697]

I know it varies batch by batch, but just roughly speaking what rough fraction (averaged across batches or just taken from a single representative batch) of com spec XLS/XLSH tubes that get downgraded are downgraded for blems or EBI spec, vs SNR or res spec?

They could be downgraded for specs that arent even listed on the spec sheet. Its probably pretty hard to even put a rought estimate on that. We will know shortly what kind of tube specs are min, max, and average. TNVCs sale brought in a ton of customers. Once all those units go out, im sure we will have a better idea of what to expect as "average". Its important note for example that 18UM tube minimums are much lower than what some, and probably even most people get....

 

[DoubleHaul]

That Photonis tube Luminance Gain ~ 17310 cd/m^2/lx

FWIW my similarly speccd in all other aspects p45 echo tube has roughly half that gain on the data sheet. Max is 10,000 according to my sheet (at 20µlx). Are the Intens tubes that much brighter?

 

[GBMaryland]

It’s my impression that the echo tube is really a fall out from the intens production line.

However it’s also possible that it’s an older technology that they’ve just gotten the process down to the point where they’re producing decent tubes.

I recently had the opportunity to look at a couple of echo spec sheets and I compare them to the intens spec sheets I have for my old mod3 bravo.

As stated the luminous gain was the primary difference. However the other two things that stand out for the INTENS tubes are the power supplies, which are not just auto-gating but include highlight mitigation circuitry, and the have some sort of funky diffraction grating, which enhances their capabilities. The the defration grating appears to do is separate out light wave lengths prior to entering the photocathode. This may be part of the high light mitigation, and/or the part of the tube that allows for the use of higher IR wavelengths.

Part of the Intens claim to fame is that they are using more of the IR light spectrum, which enables their MILSPEC tubes to function, pretty much, on part with US L3 tubes. Certainly, the tubes we all get as 20UA or 22UA which appear to be L3 fallouts (the military gets the best of the tubes).

CNOCT from Cloudy Nights - Diffraction Grating 1