Planning on ordering a DTNVS L3 unfilmed from TNVC. Was wondering if these specs would be good to request and anything else to add?
FOM: 2400
EBI: .4
HALO: .6
SNR: 33
36

I’d ask for a higher SNR.

You can ask for whatever specs you want - the higher they are the longer your wait time will be.  Mine were pretty simple (SNR greater than 32, HALO/EBI less than 1 and cosmetically clean) and I got mine about a month before those that had asked for higher specs.  This was for an order from July of last year delivered in February.  I got tubes that beat my specs, but those that waited the extra month got SNR 10% higher than mine.

I'm happy with my TNVC purchase.  Just make sure you ask for what you want and are prepared to wait.

I'd ask for at least 35 SNR

How much higher , 36?

Yea I figure I'm already waiting awhile, I may as well wait a little longer for better specs .

You said at least,  35, what would be ideal?

So if one were looking to request the ultimate low light tube that you would actually receive in this lifetime what would one ask for. Cloud cover, no moon above it all under canopy, I know they all suck but I wouldn't mind something that sucked less.

I've been doing a lot of reading on this and think I have the basics down.

Fom: don't really care because resolution over 64 doesn't matter?

Snr: the higher the better. How high can you request and expect to actually get it? 36 maybe 38?

Ebi: this is the most important for this application is my understanding. Is .1 or .2 a thing?

Halo: don't really care as long as its not crazy high. I'm almost exclusively out in the woods and I'm willing to compromise on this to get my tube faster.

Photo: people don't seem to talk about this much but my understanding is high Photo is important for low light performance. I've seen people post stats of filmless L3 with 2600+ so is 2600 reasonable or is higher common enough you have a chance of getting one.

So let's say

Photo: 2600+
Ebi: .1 or .2
Snr: 36+

And I'm willing to compromise on the other numbers.
Device would be a pvs14.

The one I got from TNVC is great.  SNR is only 29.1 but I thought that was pretty good.  6 years I've been extremely happy with it.
Edit:  NVM, mine is a filmed L3 model.

This will be my request next time I order from TNVC:
  SNR: >32
  EBI: <1.0
  Halo: Both tubes within 0.2 of each other
  Photocathode Sensitivity: >2200

These specs were driven by me reviewing Sam's videos on Youtube. These are not crazy specs and certainly reasonable. I'm not looking for 'super tubes', but I don't want bottom of the barrel unfilmed tubes either. These specs will allow you to get very good tubes without waiting an extra long period of time for 'super tubes' to come down the line.

This is where I get confused and why I keep asking the same dumb questions in these kind of threads.

My tnvc/nightgoggles xls pvs14s

                  1st      2nd
Photo        2304   2307
Halo           .94      .73
Ebi              .81      1.49
Res             64        76
Fom            1996   2447
Sn                31.2    32.2

My tubes basically meet  the specs your seeking except for the high ebi on the one. Are the numbers apples and oranges because your looking at filmless tubes? I'm  very happy with my tubes but due to living in an area with heavy canopy where it rains 6 months of the year better passive  performance in the suck would be nice. Upgrading to filmless would cost me in the neighborhood of 2k so not a huge sum but I'd want to see a noticeable improvement in low light passive performance for that kind of $.

Hate to say it but try before you buy. I came from a 7 year old PVS-14 with an estimated SNR in the mid 20’s. When I finally made the jump to dual tubes I went with L3 filmless for my DTNVS and requested a minimum of 35 for the SNR. Photo cathode response was 2657 for that tube.

In my case, I wanted it to feel like I was buying into the next gen of tech and not just an upgrade. But basically even a filmed L3 tube would be a huge step up from what I have/had.  

The other tube unfortunately came in below what I had spec’ed and ultimately made the decision to return the unit. But I could not tell the difference between the low SNR (34) and the higher spec tube. Specifically due to the stereoscopic view provided by dual tubes.

For me personally, I wanted to feel like I was getting my money worth. Mainly because I do not intend to upgrade very often as is evident by my old ass pvs14, Ymmv.

@GreenMushroom It is my understanding that if you were to compare a thin-film and an unfilmed tube with exact same SNR, EBI, Halo, and Resolution, the unfilmed tube will still be noticeably better.

In a nutshell, the specs on the spec sheets do not fully represent the 'real world performance' of the tube. Again, this is my understanding after lurking here for years. I could be mistaken because I personally have not conducted this test.

@NoQuarters with mixed resolution/SNR units your brain processes both as having the resolution of the worse tube.

I had a good conversation with Will at TNVC the other day and here’s where I landed. I think everyone’s expectations and conditions are going to vary but I would be really happy with these specs

SNR 35+
EBI <.8
Halo <1
PC 2700+
Res 72

Even if I have to wait a little longer if I’m spending $4k on a tube I want to feel like I got my money’s worth.

First time hearing this, I always believed it was a eye dominance issue. Have the better tube spec for your dominant eye. In my case the lower spec’ed tube was for my dominant.

Thanks for posting that. On these subjects people seem to speak in generalities so its hard to nail things down. I know ultimately I would decide the specs while ordering with advice from them but I at least want to have some kind of idea what I'm talking about. I think for my usage I would be willing give up res and maybe some snr for lower ebi and hopefully still have a somewhat reasonable lead time.

My xls are quite nice and the only thing I'm looking to improve is the low light performance. I wasn't planning on upgrading but my brother is looking to pick up a tube and I could sell him one of my xls for what I have into it. He lives in the eastern part of the state in the desert and I think the xls would do very well in those conditions.

I’m in the same boat.  I have a nice Omni 8 tube but I need a little more in those really bad conditions.  The thing TNVC helped me decide is where is that balance between really good specs and so good your going to be waiting forever. The ones I listed above may take a little longer but they aren’t outrageous.

The other thing to keep in mind is that some specs like EBI and SNR fight against each other. Higher SNR typically means a higher EBI so finding a 38 SNR and .3 EBI may be really hard to find.

I came up a bit on my initial EBI to add more to my SNR / PC and not wait for a unicorn tube.

You too Will, it was a very helpful discussion. Appreciate the knowledge and service you guys are providing!

Tubes I've had:

34.1snr
0.1ebi
0.7 halo
220x pcr



39.3snr
0.3ebi
0.7halo


35.7snr
0.5ebi
0.7halo
256X Pcr


Between all three, the last tube is my favorite because of screen cosmetics. All were spec sheet spot free minus one, which had a small zone 3 spot. I did not use them back to back but could honestly not say the 39.3snr tube with 0.3ebi was crisper than the 34.1/0.1 tube, even in bad conditions. At this level it's almost like arguing between 64 and 72 line pair.

Chasing specs is like chasing dB in a mini can. Other factors all matter more. And this from an obvious spec whore.

I just placed an order for a DTNVS. No request on specs. I ordered a PVS14 from TNVC a couple years ago and was blown away by the quality. I took their Armed Pro class last year and Bill suggested that I grab one of these DTNVS when they came out. Cryptos have been good to me this year so very grateful for the opportunity to buy a dream pair of NODs.

I have faith that the chefs at TNVC will cook up a nice pair of goggles for me.

It can happen.  I have even seen 0.0 on the data sheet.  Obviously not actually zero, but below .05 and the data sheet rounds to the nearest tenth.