Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
PSA
Member Login

Site Notices
Posted: 1/26/2014 10:11:35 AM EDT
Hello! I'm not from the USA hence export laws restrict the specs of the kind of NVDs I can buy. Of late I've spoken to the rep of a reputable company (I think!), based in the USA and can help me with international shipping paperwork, who presented me these specs for a Gen 2+ White Phosphor tube sourced from Russia

Photocathode response: <350mA / lm
Signal to Noise Ratio: up to 23
MTTF: 30000-35000hrs
Resolution 47-51
MCP hole pitch >12.1

Just wondering if these numbers, particularly the photocathode response vs. SNR and the service life are indeed plausible numbers?

In case I spark the White vs Green debate, the reason I'm choosing white phosphor is because the Green tube is rated for a SNR of 21 vs 23 for the White tube.

I have utterly no experience in NVGs but I'm hoping to use them for wildlife observation in mostly jungle areas and for astronomy. Since I'm non military I don't mind active IR although not having to worry about battery drain and an extra piece of equipment (the IR light) would be nice.  Naturally no amount of IR light will illuminate astronomical targets so some light sensitivity would be great especially since I intend to use it through a telescope.

Thanks for all your advice! I'm going to leave out the manufacturer for now in case I run afoul of forum laws (this being my first post!) and also so there's no brand bias but suffice to say most of the reviews for the company I've read are mostly positive.
Link Posted: 1/26/2014 10:32:01 AM EDT
The specs seem reasonable although I take issue with the MTTF numbers. I have never seen a tube with that kind of longevity. I will admit Russian tubes are not my strong point.
Link Posted: 1/26/2014 10:34:02 AM EDT
Originally Posted By night_blind:
Hello! I'm not from the USA hence export laws restrict the specs of the kind of NVDs I can buy. Of late I've spoken to the rep of a reputable company (I think!), based in the USA and can help me with international shipping paperwork, who presented me these specs for a Gen 2+ White Phosphor tube sourced from Russia

Photocathode response: <350mA / lm
Signal to Noise Ratio: up to 23
MTTF: 30000-35000hrs
Resolution 47-51
MCP hole pitch >12.1

Just wondering if these numbers, particularly the photocathode response vs. SNR and the service life are indeed plausible numbers?

In case I spark the White vs Green debate, the reason I'm choosing white phosphor is because the Green tube is rated for a SNR of 21 vs 23 for the White tube.

I have utterly no experience in NVGs but I'm hoping to use them for wildlife observation in mostly jungle areas and for astronomy. Since I'm non military I don't mind active IR although not having to worry about battery drain and an extra piece of equipment (the IR light) would be nice.  Naturally no amount of IR light will illuminate astronomical targets so some light sensitivity would be great especially since I intend to use it through a telescope.

Thanks for all your advice! I'm going to leave out the manufacturer for now in case I run afoul of forum laws (this being my first post!) and also so there's no brand bias but suffice to say most of the reviews for the company I've read are mostly positive.
View Quote


There are a lot of gen2 tubes out there, so it is possible. Some gen2 sucks, while some gen2 (certain Photonis tubes come to mind) is pretty impressive.
It doesn't take much to spark the white vs. green phosphor debate. I personally prefer green phosphor as I pick up more details in my current setting (woods and small fields) while hog/predator hunting.
That said, certain groups of the military do use WP, due to certain attributes, but it's not close to the WP tubes you'll see in exportable units. For whatever reason (CJ or Dino could probably answer this) most WP tubes I have encountered have lower resolution than comparably priced GP tubes, while SNR may be a touch higher, or maybe not.
Link Posted: 1/26/2014 11:07:31 AM EDT
Can you share more about certain groups in the defense context using white phosphor tubes?

I'm not saying I outright don't believe you, but the proof is in the pudding, so they say.

Personally I would rather have a 21 SNR green tube than a 23 SNR white tube.
Link Posted: 1/26/2014 2:45:21 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By blackghost:


Can you share more about certain groups in the defense context using white phosphor tubes?



I'm not saying I outright don't believe you, but the proof is in the pudding, so they say.



Personally I would rather have a 21 SNR green tube than a 23 SNR white tube.
View Quote




 
The specifications provided were all generic, and "up to 23" might as well be "up to 1 million" - it's highly doubtful you'll achieve anywhere near that figure with a PC less than 350 uA/lm, because that's Gen2 territory. A good tube would probably be around 10:1, unless the gain were turned all the way down, which brings up the problem I've heard of in the past that some Russian companies don't measure S/N the same way as US companies measure it.




Also, Russian tubes are getting pretty good now around PC sensitivity - Even the SPARK CORE I recently reviewed has a sensitivity over 500 - And that's Gen1. I've heard of Russian tubes that do perform similar to Photonis, but most have PC's of well over 500 - Otherwise there's not enough signal after amplification for a high S/N.




Put simply, the specifications you provided are not really sufficient to tell if the tube will be anywhere close to Gen3-like performance. If you want to be sure, ask them for a single set of data from a tube ( assuming they have datasheets ) and make your decision around that. General specifications are usually something like "S/N 21 min" and "PC 350 uA/lm min" - Your specifications are all the other way around and state maximums.




As for WPT - From what I've seen of tubes in the past, WPT has a slightly lower S/N than an equivalent tube with P43. If you go for WPT, base your decision on wanting a whitish image over a greenish one - :) There may be batches where the S/N is higher, but that's probably the exception rather than the rule.




Regards

David



Link Posted: 1/26/2014 4:59:07 PM EDT
[Last Edit: 1/26/2014 5:24:20 PM EDT by Delta4-3]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By blackghost:
Can you share more about certain groups in the defense context using white phosphor tubes?

I'm not saying I outright don't believe you, but the proof is in the pudding, so they say.

Personally I would rather have a 21 SNR green tube than a 23 SNR white tube.
View Quote

NSW uses limited L3 Dual tube setups with WP. How wide spread that is, I don't know.
My choice, for my applications, is green.
ETA: we are not talking snake-oil second rate WP.
Link Posted: 1/26/2014 5:26:49 PM EDT
I'm guessing, as I'm sure you are, the tubes in question don't have data sheets. And actual SNR may be 17 for the tube received.



Discussion ForumsJump to Quoted PostQuote History
Originally Posted By cj7hawk:

  The specifications provided were all generic, and "up to 23" might as well be "up to 1 million" - it's highly doubtful you'll achieve anywhere near that figure with a PC less than 350 uA/lm, because that's Gen2 territory. A good tube would probably be around 10:1, unless the gain were turned all the way down, which brings up the problem I've heard of in the past that some Russian companies don't measure S/N the same way as US companies measure it.

Also, Russian tubes are getting pretty good now around PC sensitivity - Even the SPARK CORE I recently reviewed has a sensitivity over 500 - And that's Gen1. I've heard of Russian tubes that do perform similar to Photonis, but most have PC's of well over 500 - Otherwise there's not enough signal after amplification for a high S/N.

Put simply, the specifications you provided are not really sufficient to tell if the tube will be anywhere close to Gen3-like performance. If you want to be sure, ask them for a single set of data from a tube ( assuming they have datasheets ) and make your decision around that. General specifications are usually something like "S/N 21 min" and "PC 350 uA/lm min" - Your specifications are all the other way around and state maximums.

As for WPT - From what I've seen of tubes in the past, WPT has a slightly lower S/N than an equivalent tube with P43. If you go for WPT, base your decision on wanting a whitish image over a greenish one - :) There may be batches where the S/N is higher, but that's probably the exception rather than the rule.

Regards
David

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By cj7hawk:
Originally Posted By blackghost:
Can you share more about certain groups in the defense context using white phosphor tubes?

I'm not saying I outright don't believe you, but the proof is in the pudding, so they say.

Personally I would rather have a 21 SNR green tube than a 23 SNR white tube.

  The specifications provided were all generic, and "up to 23" might as well be "up to 1 million" - it's highly doubtful you'll achieve anywhere near that figure with a PC less than 350 uA/lm, because that's Gen2 territory. A good tube would probably be around 10:1, unless the gain were turned all the way down, which brings up the problem I've heard of in the past that some Russian companies don't measure S/N the same way as US companies measure it.

Also, Russian tubes are getting pretty good now around PC sensitivity - Even the SPARK CORE I recently reviewed has a sensitivity over 500 - And that's Gen1. I've heard of Russian tubes that do perform similar to Photonis, but most have PC's of well over 500 - Otherwise there's not enough signal after amplification for a high S/N.

Put simply, the specifications you provided are not really sufficient to tell if the tube will be anywhere close to Gen3-like performance. If you want to be sure, ask them for a single set of data from a tube ( assuming they have datasheets ) and make your decision around that. General specifications are usually something like "S/N 21 min" and "PC 350 uA/lm min" - Your specifications are all the other way around and state maximums.

As for WPT - From what I've seen of tubes in the past, WPT has a slightly lower S/N than an equivalent tube with P43. If you go for WPT, base your decision on wanting a whitish image over a greenish one - :) There may be batches where the S/N is higher, but that's probably the exception rather than the rule.

Regards
David


Link Posted: 1/26/2014 5:27:06 PM EDT
Thanks for all your advice!
I realised since the Spark has been reviewed here its probably OK therefore to name this tube: It's the Armasight Sirius Gen 2+ QS (international)
The youtube Video on this tube seems quite good but of course there's no indication of the true ambient lighting other than the reviewer saying it's "dark".
When I wrote in, the rep said the QS tube had the higher SNR although yes, he quoted "up to" values rather than min values.
Sadly export restrictions limit me from getting any tube with a photocathode response of more than 350 mA/ lm but the rep also said that the international version is no worse than the non exportable version.
Strangely of all the Russian factory specs I've seen, SNRs of greater than 21 were reserved for tubes with a photocathode response of at least 500 while the one tube I saw specced at 330mA/lm had an SNR of 18. Hence my doubt about whether 23 is really doable in a less sensitive tube.
I was thinking that for astronomy the white shades may look more natural than the green. :)
Link Posted: 1/26/2014 6:08:34 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By night_blind:


Thanks for all your advice!

I realised since the Spark has been reviewed here its probably OK therefore to name this tube: It's the Armasight Sirius Gen 2+ QS (international)

The youtube Video on this tube seems quite good but of course there's no indication of the true ambient lighting other than the reviewer saying it's "dark".

When I wrote in, the rep said the QS tube had the higher SNR although yes, he quoted "up to" values rather than min values.

Sadly export restrictions limit me from getting any tube with a photocathode response of more than 350 mA/ lm but the rep also said that the international version is no worse than the non exportable version.

Strangely of all the Russian factory specs I've seen, SNRs of greater than 21 were reserved for tubes with a photocathode response of at least 500 while the one tube I saw specced at 330mA/lm had an SNR of 18. Hence my doubt about whether 23 is really doable in a less sensitive tube.

I was thinking that for astronomy the white shades may look more natural than the green. :)
View Quote



Well, with white, you can always build yourself some shutters and take color images :)



If, as was mentioned, the tube had a S/N of around 17, well, while it's not great, it's more than adequate for most use if it's measured at 100 uLux.




Though... That's a fairly large monocular - Delta4-3, do you know if that's a Gen2 inverter tube?




Thanks

David



 


Link Posted: 1/26/2014 8:24:02 PM EDT
[Last Edit: 1/27/2014 2:51:32 AM EDT by night_blind]
Finally found some more data on another retailers website, there the SNR for the green tube is 15-20 while the White tube is 15-23. I must say that's quite a huge range!
I wonder if I place an order how I'll know if I'm getting a 15 db tube or a 23 db tube...
Makes me very hesitant to part with my cash, especially since I'm thousands of miles away physically from the retailer and returning the item will require another round of ITAR forms... *oh dear*

Edit: I've clarified that the typical SNR is 18-19 db. Must say its quite a let down compared to the 23 I was initially told.
Link Posted: 1/27/2014 5:14:09 AM EDT
I don't. They use a lot of different tubes in gen 2 units. If you are going to get gen 2 from them, go HD. It's a really good tube, much better than the WP, made in France.



Discussion ForumsJump to Quoted PostQuote History
Originally Posted By cj7hawk:


Well, with white, you can always build yourself some shutters and take color images :)

If, as was mentioned, the tube had a S/N of around 17, well, while it's not great, it's more than adequate for most use if it's measured at 100 uLux.

Though... That's a fairly large monocular - Delta4-3, do you know if that's a Gen2 inverter tube?

Thanks
David
 


View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By cj7hawk:
Originally Posted By night_blind:
Thanks for all your advice!
I realised since the Spark has been reviewed here its probably OK therefore to name this tube: It's the Armasight Sirius Gen 2+ QS (international)
The youtube Video on this tube seems quite good but of course there's no indication of the true ambient lighting other than the reviewer saying it's "dark".
When I wrote in, the rep said the QS tube had the higher SNR although yes, he quoted "up to" values rather than min values.
Sadly export restrictions limit me from getting any tube with a photocathode response of more than 350 mA/ lm but the rep also said that the international version is no worse than the non exportable version.
Strangely of all the Russian factory specs I've seen, SNRs of greater than 21 were reserved for tubes with a photocathode response of at least 500 while the one tube I saw specced at 330mA/lm had an SNR of 18. Hence my doubt about whether 23 is really doable in a less sensitive tube.
I was thinking that for astronomy the white shades may look more natural than the green. :)


Well, with white, you can always build yourself some shutters and take color images :)

If, as was mentioned, the tube had a S/N of around 17, well, while it's not great, it's more than adequate for most use if it's measured at 100 uLux.

Though... That's a fairly large monocular - Delta4-3, do you know if that's a Gen2 inverter tube?

Thanks
David
 



Link Posted: 1/27/2014 6:00:39 AM EDT
Thanks!
I'll check in with the Armasight people but I suspect the HD tube is non-exportable as it does not feature in the "International" section. The typical SNR x low end of the resolution already exceeds an FOM of 1400.
Ah well...
Link Posted: 1/27/2014 2:49:40 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By night_blind:
Thanks!
I'll check in with the Armasight people but I suspect the HD tube is non-exportable as it does not feature in the "International" section. The typical SNR x low end of the resolution already exceeds an FOM of 1400.
Ah well...
View Quote

The HD is NOT exportable from the US. I've spoke with Canadian Armasight dealer,
The two variant exportable for Gen 2 are Standard and Improved Definition.

Honestly, if you don't mind I asking where are you located in.
Europe have their dedicated NV dealer where they can get Photonis (French I believe) or Kato'd tube (Russian tube). While neither will beat the American L3 Gen 3 Filmless Autogated tubes they certainly do hold their grounds well.

In Canada there's a NV company called GSCI (General Starlight Company Inc). They offer Gen 3 tubes (FOM 1800-2100 aka SNR 28-29 given their resolution is probably around 64-72lp/mm) According to one of their dealer, the tube is Russian Kato'd. I tried confirming this with the company, they refused to disclose detail on such.

In terms of pricing, don't look at American High end pricing. Americans pay roughly 50% of what rest of Western World pays for equivalent stuff.

I strongly suggest go with companies that are local to you especially if your unit has problem. (It's one of main reason I chose Aimpoint over EOTech. If I have a problem with Aimpoint I can send it to Sweden, without ITAR-like laws. EOTech...not so much)
Top Top