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MOD3 WP Honeycomb

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#76 Jeff Morgan

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Posted 02 September 2020 - 04:08 PM

There is only ONE manufacturer of unfilmed tubes.  And that is L3 (or whatever they're calling themselves these days).  Given a thin-filmed tube with similar specs to an unfilmed, the unfilmed produces a crisper, less 'filmy/hazy' view with fast optics, every time.  You have a great tube.  If you go with a thin-filmed, you'll lose image contrast with fast optics.

 

My L3 filmless is a great tube with a 0.3 EBI and has delivered 300 objects out of the Sharpless Catalog, but the breed does seem to have improved. Perhaps as marginal as upgrading from a 95 strehl refractor to a 97 strehl refractor, but I am interested in upgrading. So I have been data-mining AR15.com and SnipersHide NV forums.

 

There are many threads with photo and video comparisons of the various tubes. Keeping in mind these tubes are somewhat like snowflakes, but the consensus on those forums favors the L3 filmless, especially in low-light. Based on the comps I have seen, I would tend to agree.

 

Of course a prospective buyer should see the comparisons and as always your YMMV.



#77 Astrojedi

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Posted 02 September 2020 - 04:47 PM

I have put a thin-filmed up against several unfilmed tubes at 1X with f1.2 objectives.  The TF tube had higher specs than the either unfilmed.  The sky in the unfilmed tubes looked crisp.  The TF tube appeared to show a faint milky haze compared to the unfilmed.

 

When you run with slower optics, the difference becomes far less obvious.

Ok thx. I have a PVS-14 with a Gen 3 thin filmed WP tube - SNR of 35. It does quite well in my 14" F3.5 dob when used afocally with a 50mm EP effectively operating at ~f1.8. I have seen the pillars of creation which look like a long exposure image. I also like the sharp stars although the halo on the brightest stars is quite pronounced. I am wondering if an unfilmed WP would do any better - would I notice a difference observing fainter nebulae?


Edited by Astrojedi, 02 September 2020 - 04:49 PM.


#78 cnoct

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Posted 04 September 2020 - 06:57 AM

Dark multi-boundary fixed pattern noise (honeycomb FPN)

 

Koko Crater L3 P45 Honeycome FPN.jpg


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#79 a__l

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Posted 04 September 2020 - 07:31 AM

Beautiful crater :)



#80 star drop

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Posted 04 September 2020 - 10:35 AM

Dark multi-boundary fixed pattern noise (honeycomb FPN)

 

attachicon.gifKoko Crater L3 P45 Honeycome FPN.jpg

The pattern reminds me of a bug's eye.



#81 GOLGO13

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Posted 04 September 2020 - 10:26 PM

Jay,

 

Got to test my unit out at 1x finally on the sky. No filter I can see some aspects of the honeycomb. It's not extremely detailed, but it's there when using full gain. Mostly goes away dialing it back a little. Moon was out also which may have helped. It's pretty rare that I use the unit without a filter though.

 

With the 3.5nm the view was quite nice and no issues observed.

 

I think with normal astronomical use this is not an issue for me. Interesting to know why I was seeing things I was seeing in certain situations. However, I don't think this is a problem from my perspective with my unit.

 

I'm not in the mood to get the scope out, but next time I do I'll see if I see it even with a filter on. I don't ever remember seeing it though.



#82 cnoct

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Posted 06 September 2020 - 06:10 AM

The pattern reminds me of a bug's eye.

 

Such an intrinsic characteristic of MCP image intensifiers, that the MCP architecture is even incorporated as a prominent feature of Robocops NV goggles. 

 

Robocop NV Goggles.jpg

 

Image Citation/Credits: https://www.propside...2014-p-148.html


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#83 Solar storm

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Posted 27 October 2020 - 08:13 AM

Honeycomb appearance is also present in the fiber optic component of the image intensifier tube. And that is also the part you look through so it could be that.



#84 havieair

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Posted 25 November 2021 - 02:01 AM

Just found this really informative thread after looking for honeycomb pattern examples. So I just received a MOD3C with L3 unfilmed WP tube.  It’s been cloudy since so I haven’t had any scope views with it yet, just some handheld 1-8x views. I’m assuming I’m also dealing with some pretty apparent FPN. I sent some photos to TNVC to confirm but with the holidays I don’t expect a response from them until next week. Does this look like FPN? Im assuming since it’s pretty consistent throughout the entire field it’s not chicken wire but maybe I’m mistaken. The photo was taken with the gain turned up maybe 20% looking at a cloudy night sky. The pattern is still visible with a 685 IR filter. I got the specs I requested but after a super long wait this is a bit of a downer. 

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#85 Gavster

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Posted 25 November 2021 - 11:05 AM

Just found this really informative thread after looking for honeycomb pattern examples. So I just received a MOD3C with L3 unfilmed WP tube.  It’s been cloudy since so I haven’t had any scope views with it yet, just some handheld 1-8x views. I’m assuming I’m also dealing with some pretty apparent FPN. I sent some photos to TNVC to confirm but with the holidays I don’t expect a response from them until next week. Does this look like FPN? Im assuming since it’s pretty consistent throughout the entire field it’s not chicken wire but maybe I’m mistaken. The photo was taken with the gain turned up maybe 20% looking at a cloudy night sky. The pattern is still visible with a 685 IR filter. I got the specs I requested but after a super long wait this is a bit of a downer. 

I know this is just a "standard" property of nv tubes, but personally I would be disappointed with this level of FPN. For many uses of astronomy, eg viewing nebulae with narrow band filters, viewing in clear skies at a darkish site it may well not be an issue. But I do like to use my nv tube for brighter stuff such as scanning the milky way and normal terrestrial use, so FPN like this would be disappointing.

 

It also just seems to be luck of the draw. My first three tubes had basically no FPN (unless you turned gain right up and looked at a plan white wall!! :) ). However my fourth tube does show some FPN, its not visible in normal astronomy use, but occasionally I do see it scanning around.

 

I'm due to receive another tube soon (which has nice high specs :) ), but I'm holding my breath that the FPN is very limited (and that there isn't any noticeable peppering of very small dark spots). Until you get the tube and use it, you just don't know...



#86 havieair

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Posted 26 November 2021 - 10:23 AM

Yeah I'm definitely disappointed with the level of FPN I got. One of the things I was most looking forward to was using the unit handheld and scanning the sky in my light polluted backyard. Since the FPN on my unit is visible no matter the gain setting, and still there with the 685nm filter, it's a huge let down. I get how the OP must have been frustrated. His description of a 'fence' in front of the entire field of view is a good one. For me it looks more like the image is being projected on a golf ball. I didn't see any noticeable FPN in the L3 WP tube I looked through before. Bad luck on this one. I'm excited to test it out next weekend at a dark site with the anticipation of not seeing the honeycomb. I'm sure I'm going to be blown away with the dark site views. Just sucks that I can't avoid the FPN handheld from my backyard LP conditions.

 

I don't know if most vendors will send a picture of the screen before shipping but for anyone concerned or picky about screen cosmetics I'd recommend at least asking them. One vendor I previously called said they would do this for a $250 fee since it involves building the unit first in order to fire it up. Me personally, with the amount of money being dropped on these devices and screen cosmetics being somewhat of a gamble I'd ask for a picture of the screen before finalizing the deal. 



#87 Van Huynh

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Posted 26 November 2021 - 12:32 PM

If I were you, I would be forcing a return.

 

Considering how much you paid and how long you waited, this level of honeycomb is absolutely unacceptable. Did you ask TNVC for a sample screen image before purchasing? If you did and they refused, then shame on them for sending you this tube.

 

Take a look at Kosher Surplus and Superior Tactical (stsolutionssales on eBay). They provide specs and sample screen images, so you know exactly what you are getting. I bought mine from ST and I am extremely happy with it. During the purchase process, I was very pestering. I had ST send me multiple screen samples of four different tubes, and they promptly did. They were very professional, and they certainly did not charge me $250 (or anything at all).



#88 havieair

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Posted 26 November 2021 - 04:18 PM

If I were you, I would be forcing a return.

 

Considering how much you paid and how long you waited, this level of honeycomb is absolutely unacceptable. Did you ask TNVC for a sample screen image before purchasing? If you did and they refused, then shame on them for sending you this tube.

 

Take a look at Kosher Surplus and Superior Tactical (stsolutionssales on eBay). They provide specs and sample screen images, so you know exactly what you are getting. I bought mine from ST and I am extremely happy with it. During the purchase process, I was very pestering. I had ST send me multiple screen samples of four different tubes, and they promptly did. They were very professional, and they certainly did not charge me $250 (or anything at all).

I didn't ask TNVC for a screen sample but should have. There was another vendor I was communicating with before that wanted to charge for the screen samples which I thought was over the top so I went another route.

 

Kosher Surplus was on my initial list of vendors I reached out to but they're not able to provide tubes in the MOD3 housings. If I were in the market for PVS-14 I would have gone with Kosher. I didn't find too many dealers that either had in stock or could order the housings from AB Night Vision but I did contact several of them. I am still currently on UNV's MOD3 astro waiting list but they're more pricey than my TNVC deal. I'm going to give TNVC the opportunity to make this right but will continue looking at other options.


Edited by havieair, 26 November 2021 - 04:38 PM.



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