Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

TNVC Night Vision-Am I crazy or just insane?

  • Please log in to reply
47 replies to this topic

#26 chemisted

chemisted

    Ranger 4

  • -----
  • Posts: 338
  • Joined: 24 Feb 2012

Posted 12 February 2020 - 11:23 AM

The use of a reducer ahead of the 55mm Plossl in the afocal approach has another benefit.  Any telescope has some sort of aberration that to the eye may be minimal but with a camera (or NV device) becomes very obvious.  Take my RC-10 for example.  The Ritchey Chretien pretty much eliminates all aberrations except field curvature.  It has been long known that the A-P 0.75X reducer lessens this curvature as well as shortens the focal length.  My combination of the Plossl and this reducer on the RC-10 gives me absolutely perfect stars across the entire FOV and I don't get this with the Plossl alone.

 

Similarly, my Sky 90 gets the same result with the GSO 0.75X reducer/55mm Plossl combination.  Don't ask me to explain this as it was just a trial and error discovery I made and I know other small refractors have been tried and did not yield the same results.  My combo gives a 5.8 degree FOV at f/2.0 and is totally competitive with my Nikkor 200mm f/2.0 view (FOV 5.0 degrees) used with the same NV device at prime.  It has the advantage of using a diagonal so I can look straight up without discomfort.

 

At the same time I agree with Eddgie's comments that prime can have a lot going for it and I use my telescopes at prime with reducers and both my NV devices.  I do not switch filters so I have no need for a filter wheel.  I do run out often on poor nights with a SLR lens for quick views.

 

All these options take a bit of time to understand and the field is still evolving somewhat but right now is the time to buy and take advantage of all this versatility whichever way you choose to go.


  • GeezerGazer and Gavster like this

#27 Eddgie

Eddgie

    ISS

  • *****
  • Posts: 25,603
  • Joined: 01 Feb 2006

Posted 12 February 2020 - 11:53 AM

And I am sure that some people are wondering why I say that afocal has a lot of complexities.

 

Here is a real world example and one that is not readily apparent to someone that has not used both systems as extensively as I have.

 

Let's say you have a big dob that you use for NV..  You buy a PVS-14 with an afocal adapter and you start using it with 2" eyepieces.  Well, first of all, you probably had to buy a 2" filter so you paid $300 for that vs $200 for a 1.25" filter (and this is just the H-a filter, but the long pass 2" filter costs more than the long pass 1.25" filter and you can use 1.25" filters at prime focus)

 

Now you decide you want to go from your 41mm Panoptic to your 24mm eyepiece (or whatever).  You take off the night vision device, remove the eyepiece, pull the filter off, put it on the new eyepiece, put the eyepiece into the scope, and then you put your device on.  Hey, that is not so hard.   

 

After doing this 10 or 15 times in a night, you say "Darn, wouldn't it be nice if I had a filter slide in my dob?"   So you buy a filter slide ($135 vs $50 for a 1.25" filter wheel) and you mount it into your dob and the next time you use your dob, life is beautiful.  You've spend $185 more than prime focus but you got to use that 41mm Pan a bit and well, that is nice.

 

But one night you don't want to take out the dob.  You need your filter though, so you have to go pull your filter out of your dob (if you did not do it before storage, so another complexity... I leave my filters in my filter wheel all of the time).

 

Now you have your filter but when you use it in your f/5 refractor, you are back to the old filter change dance.  Pull the device off, pull the eyepiece, pull swap filter, put eyepiece back in, put device back on.  Now using a 2" filter wheel with a refractor and an eyepiece, most refractors won't reach focus, because the 2" filter wheel will usually need a 2" diagonal and because you have to put an eyepiece holder on to the back of the filter, you are adding 60mm to the light path and most refractors will not allow that much inward focuser travel.

 

For the purpose of this post though, lets say you can use 2" filter.  Well, now you need a 2" filter wheel.   Ah, no problem, 90 bucks.  But now you have to transfer the filter back and forth.   Or you could buy a dedicated set of filters for your filter wheel.  60mm is a lot of in focus travel though and a lot of refractors will not have it.   A potential solution is to use a Baader T2 mirror diagonal because this has a 50mm light path so you cut off 50mm from the focuser travel requirment (you need the T2 mirror because it has a bigger front opening and the long light path will cause your fully illuminated field to fall below 18mm.  That might not matter to you though, but I think a fully illuminated field is very desirable with night vision). 

 

If you can't reach focus though, you are back to having to pull the stack to change filters.

 

Now you do get to use the 41mm Panoptic though and this does give you lower power in a dob than you can easily get using prime focus. That sounds vital, but in fact, speed comes at image scale, and the biggest problem using dobs is usually image scale and not speed.  The built in eyepiece of the intensifier gives 55x in my 12" dob, and for most targets that is not quite big enough, so I often just Barlow up because that is easier than changing eyepieces. 

 

So, while afocal sounds like it is simpler than C mount, it has its own set of complications.   

I have used both extensively and I read that people think C mount sounds more confusing or more complex but both methods have their complexities and my own belief is that while the complexities are different, I don't consider one to be any less complex or easier overall, across the full spectrum of scopes that they might be used in.   To think that afocal is easier is to deny the fact that it is using a device for a purpose it was not intended to be used for and making it work with all telescope types will have its own issues.  

 

Neither approach will deny the user of the incredible views possible with image intensifiers.

And a lot of these posts make it sound far far far more complicated than it really is. It is just adapters an stuff.. A 15 year old could figure it out.  


Edited by Eddgie, 12 February 2020 - 11:57 AM.

  • GeezerGazer likes this

#28 GOLGO13

GOLGO13

    Aurora

  • *****
  • Posts: 4,801
  • Joined: 05 Nov 2005
  • Loc: West Virginia

Posted 12 February 2020 - 12:34 PM

I think the biggest benefit I find from prime focus is a normal imaging train. It looks like any other eyepiece is inserted. However, some of my afocal imaging trains stick out VERY far from the focuser. Especially true with the 6 inch F4 newt. In fact, I wouldn't suggest the 6 inch F4 newt for afocal. Not that it doesn't work, but it's just a huge stack after all is said and done.

 

However, being able to combine afocal with a reducer does make for a pretty good capability. 

 

Personally, I find I prefer prime focus the majority of the time. But I do dabble in the afocal here and there. And sometimes that's needed to fit an object in the FOV.



#29 GOLGO13

GOLGO13

    Aurora

  • *****
  • Posts: 4,801
  • Joined: 05 Nov 2005
  • Loc: West Virginia

Posted 12 February 2020 - 12:51 PM

Also, I think my point about complexity more has to do with the fact that the Tele Vue website gives you all the information you need for a full setup to do 1x and afocal observing in the Telescope. For the Mod3C it takes a bit of effort to piece together what you need. 

 

Bobhen's post #20 does a good job showing this. It would be good to take his listing and provide hyperlinks to where these items can be found. For instance the 1.25 to 2 inch adapter from scopestuff, The Antares reducer from Scopestuff, etc.

 

And also that it can be used in a different configuration using just a c mount to 1.25 inch adapter (not sure where these are because mine came with it. But I'd imagine Scope stuff has one).

 

Again, I think some sort of a buyers guide. Of course that buyers guide would be a bit subjective, such as whether to get 7nm or 5nm for HA filters (I think I'd suggest 12nm and something in the 7/6/5 range). And then explaining the level of light pollution may dictate the IR pass filter (which I would suggest getting multiples of these 612/640/685). 

 

We could put what a minimal "kit" would be...then what nice to have extras are. I'd call Afocal adapters a nice to have extra. But all of this sort of depends on the telescope being used. Afocal maybe needed if inward travel on the desired scope is not available. Or outward travel needed could be a negative (as I experience with the 6 inch F4 with afocal).

 

Sorry to muddy up the post...but it's good discussion.


  • Gavster and Peregrinatum like this

#30 Gavster

Gavster

    Viking 1

  • -----
  • Posts: 742
  • Joined: 07 Mar 2014

Posted 12 February 2020 - 12:56 PM

Actually, the out-focus that long focal length eyepieces (such as the TV 55mm Plossl) require is a benefit rather than a downside.  It enables the use of a reducer ahead of the Plossl which provides additional reduction in f-ratio and increase in FOV.  Gavster mentions this in his post above.  I do this routinely with my GSO reducer and my refractors and the Astro-Physics 0.75X reducer on my RC-10.  Which reducer/eyepiece combination works best with a given scope may take a little trial and error but when it works it is spectacular.  I would guess a good combination could be found for the OP's 9.25" SCT.

Ed, I am very grateful for your suggestion of using the gso 0.75x rc reducer in conjunction with the 55mm plossl. At only £60 it’s a bargain imo. Using this combo with my fsq85 I get a flat field to the edge and a fov of over 6 degrees (which negates the  need of a camera lens for me) and effective speed of less than 2! As you say, trial and error of various combinations and scopes is a very worthwhile thing to do. I’ve now got two of these reducers and 2 55mm plossls which I use with my Williams optics pegasus binoscope to give lovely two eyed nv observing (although the double stack does look pretty ridiculous!)

The RC reducer coupled with my 41mm panoptic also works better than my 55mm plossl on its own in many of my setups (similar effective speed and fov but better edge correction).

But probably my most surprising discovery was with my c11 edge which I also use with the specialist 0.7x celestron edge reducer. This gives very nice views with my 55mm plossl attached. However recently I decided for a joke to try adding the 0.75x rc reducer as well (so 2 reducers and a 55mm plossl in the lightpath). Surprisingly this worked exceptionally well (the c11 had enough focus travel to reach focus) and the views were around 1.5 degrees fov with great edge correction. Lovely stuff!


  • GeezerGazer, chemisted, Tyson M and 1 other like this

#31 Eddgie

Eddgie

    ISS

  • *****
  • Posts: 25,603
  • Joined: 01 Feb 2006

Posted 12 February 2020 - 03:29 PM

I think the biggest benefit I find from prime focus is a normal imaging train. It looks like any other eyepiece is inserted. However, some of my afocal imaging trains stick out VERY far from the focuser. Especially true with the 6 inch F4 newt. In fact, I wouldn't suggest the 6 inch F4 newt for afocal. Not that it doesn't work, but it's just a huge stack after all is said and done.

 

However, being able to combine afocal with a reducer does make for a pretty good capability. 

 

Personally, I find I prefer prime focus the majority of the time. But I do dabble in the afocal here and there. And sometimes that's needed to fit an object in the FOV.

Afocal has some powerful benefits.  Even I use afocal on occasion becuase there are times when it is the best tool.

 

Afocal is highly capable though and I could not say no one should ever buy a PVS-14, but I can say that anyone that buys a Mod 3 can do afocal if they want. Now to be fair, the 25mm CCTV lenses are not as good as the ENVIS, but they will show everything the PVS-14 objective can show.

 

If someone only wants to do afocal though, and does not want to pay the money for a used ENVIS, then the PVS-14 is the way to go.  I would never say it is a mistake to buy a PVS-14.

 

And if someone at some point thinks they made a mistake, they can always re-mount their tube into a Mod 3 housing. That would be cheaper than taking a hit on resale.  The Mod 3 housing is about $700, but selling a use PVS-14 knocks $1000 off of the value.  At least some of the cost of the Mod 3 housing would be recovered by the sale of the PVS-14 empty housing, so the cost to convert would probably be less than $400. 

So, if someone goes afocal and later wants to go C mount, it isn't like they have to start over.  They can always just re-house the tube.  The eyepeices and image intensifers are interchangeable between the PVS-14 and Mod 3.

 

A lot of new people probably don't know that, but the major difference is just the housing they are put in.  The Mod 3 can even be purchased with a PVS-14 objective but the PVS-14 objective on the Mod 3 is not field removable. 

 

I think buying a Mod 3 with PVS-14 objective would be a better option than buying a PVS-14.  Exactly the same objective.  Exactly the same eyepiece, and exactly the same features. If they wanted to convert to C mount later, they would only have to swap the housing and pick up an objective. 



#32 Jeff Morgan

Jeff Morgan

    Voyager 1

  • *****
  • Posts: 11,505
  • Joined: 28 Sep 2003
  • Loc: Prescott, AZ

Posted 12 February 2020 - 04:49 PM

Afocal has some powerful benefits.  Even I use afocal on occasion becuase there are times when it is the best tool.

 

Especially for a Newtonian user.

 

Standard Newtonians (as opposed to optimized astrographs) always have limited focuser travel, so using focal reducers is problematic. A 0.7x reducer will require around 1/2" of truss tube shortening. Very doable. Using a 0.5x reducer would require another 7/16" shortening. Not everyone wants to do that.

 

Yes, I love my C-mount device and take full advantage of my flexibility with it. With my Newtonian however, I am using the afocal mode 50% of the time. Maybe more. Simply put, it gives me maximum speed reduction.



#33 TOMDEY

TOMDEY

    Fly Me to the Moon

  • *****
  • Posts: 5,654
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 12 February 2020 - 05:17 PM

"TNVC Night Vision-Am I crazy or just insane?"

 

I think you're crazy for locking yourself into an afocal only setup (literally just my opinion and my approach to NV). But, I think you'd be insane not to try it if that's the conclusion you've come to. You might find that it is some of the best money you've ever spent on astronomy equipment, and maybe there's a method to the madness.

 

Honestly, cost v. performance, it may end up being the best money you've ever spent on viewing equipment.

Good point there. I have provided both choices on mine... afocal for its flexibility but also prime image directly onto the GaAs Photocathode... which removes a lot of glass from the imaging-chain (the telescope eyepiece and the 1x NV objective). That provides only one magnification (what you would get with a ~26mm eyepiece) and one feeding F# (native scope speed) --- but shortens and lightens the stack-up a lot, is much more efficient, and a way easier to swap in as ~just another eyepiece~  I generally don't call friends crazy or insane... but secretly believe that we all are; Obsessive Compulsive Astronomy is delightful!    Tom


  • outofsight likes this

#34 genelew

genelew

    Vostok 1

  • *****
  • topic starter
  • Posts: 148
  • Joined: 30 Aug 2015
  • Loc: Westchester County NY

Posted 12 February 2020 - 05:55 PM

Thanks to all for the very informative input . I've put in an order for the Televue package. I think that will suit me best at this point as I expect I will use it mostly afocal with the various TV eps I have. I may try to obtain a 3x objective which fits into the 1x objective of the tube to give me a little mag for prime focus use. Probably 8-10 weeks for delivery. I'll let you know how it goes when I get it.

Thanks again,

Gene


  • GOLGO13 and Peregrinatum like this

#35 outofsight

outofsight

    Surveyor 1

  • *****
  • Posts: 1,579
  • Joined: 31 May 2015

Posted 12 February 2020 - 05:58 PM

Good point there. I have provided both choices on mine... afocal for its flexibility but also prime image directly onto the GaAs Photocathode... which removes a lot of glass from the imaging-chain (the telescope eyepiece and the 1x NV objective). That provides only one magnification (what you would get with a ~26mm eyepiece) and one feeding F# (native scope speed) --- but shortens and lightens the stack-up a lot, is much more efficient, and a way easier to swap in as ~just another eyepiece~  I generally don't call friends crazy or insane... but secretly believe that we all are; Obsessive Compulsive Astronomy is delightful!    Tom

 

And to me, if you have a c-mount setup you can go to an afocal setup anytime you want, but if you have an afocal setup then it's significantly harder to go to c-mount, or can't be reasonably done at all. C-mount simply is more direct with less things in between, the way most of us would want to do any kind of astronomy viewing, or at least have the option. There surely is no perfect optical system: if it can do one thing well, then there's something else it probably can't do at all. That's made more than a few of us crazy.

 

Although I'm sure the Televue approach is plenty nice, why limit your setup. 


Edited by outofsight, 12 February 2020 - 08:10 PM.

  • Jeff Morgan likes this

#36 dr.who

dr.who

    Hubble

  • *****
  • Administrators
  • Posts: 15,149
  • Joined: 05 Jan 2012

Posted 12 February 2020 - 08:21 PM

Did you specify certain values for the tube you want to get and that is pushing things out 8-10 weeks? Or is the lead time for them just that long? Or is it they just have a large backlog with limited tubes that meet their criteria from the manufacturer/supplier?

 

I am about 6-8 weeks away from having the money to buy one and plan to go with the TV (Ed and I had long conversations on this and it is the best option for my use case. Thank you again Ed for all your help!) version but I would like to know what is driving the delay... Thanks!



#37 genelew

genelew

    Vostok 1

  • *****
  • topic starter
  • Posts: 148
  • Joined: 30 Aug 2015
  • Loc: Westchester County NY

Posted 13 February 2020 - 09:32 AM

Hi, dr.who,

I asked about the specs and was told that everything they get meets the military spec as a minimum and there is some variation above that but all are very suitable for astronomy. They have a back order right now and they are taking names for the list but not taking any money until they notify of availability.

Hopefully they'll get them sooner.

 

Gene



#38 GOLGO13

GOLGO13

    Aurora

  • *****
  • Posts: 4,801
  • Joined: 05 Nov 2005
  • Loc: West Virginia

Posted 13 February 2020 - 09:49 AM

Hi, dr.who,

I asked about the specs and was told that everything they get meets the military spec as a minimum and there is some variation above that but all are very suitable for astronomy. They have a back order right now and they are taking names for the list but not taking any money until they notify of availability.

Hopefully they'll get them sooner.

 

Gene

I believe they don't provide specs in order to avoid people waiting for the perfect tube. But they do list some minimums which for the most part are OK. The only minimum that I don't like is the 24 SNR. That seems a bit low. However, of the folks who have bought them so far the specs look pretty good. That could be something to discuss with them. But the rest seem Ok that they list. They don't list PC sensitivity or gain from what I could see. But they do talk to resolution 64 to 72, EBI under 1, and halo under 1. 



#39 Eddgie

Eddgie

    ISS

  • *****
  • Posts: 25,603
  • Joined: 01 Feb 2006

Posted 13 February 2020 - 01:57 PM

 it's significantly harder to go to c-mount, or can't be reasonably done at all. 

As long as it is a standard MX-11769 or F9815, it is easy to convert at any time during the future.

 

The Mod 3 housing kit can be purchased in C mount for about $600 without any lenses.  The PVS-14 eyepiece screws right on to the back of the Mod 3 housing so it would not be necessary to buy an eyepiece, though I probably would so that the PVS-14 housing could be sold to offset the cost of the Mod 3 housing.  

 

While I would not trust a 10 year old to do it, the conversion is well within the capability of almost any even moderatly handy adult. 

 

 

 

Here is a video where the guy swaps an image intensifier in a PVS-14 in 8 minutes. Now he uses a pocket knife to remove the retaining ring an you can buy a lens ring spanner for $20, and that is what I use, but the point is that getting the tube out is pretty easy and setting it up in a Mod 3 is not all that hard. 

 

https://www.youtube....h?v=buXafRgxFMA

 

For the first decade of civilian sales, image intensifier maintenance was treated like a dark art, but it is fairly simple to work on and anyone that decided to swap from a PVS-14 to a Mod 3 would not have any difficulty at all. Even if they sent it to someone to do the swap, I am sure that someone like Ed Wilcox would do it for a very reasonable price. 

 

There is an option go change housing though and if the empty PVS-14 housing were re-sold, that would recover much of the cost of the Mod 3 housing.



#40 Eddgie

Eddgie

    ISS

  • *****
  • Posts: 25,603
  • Joined: 01 Feb 2006

Posted 13 February 2020 - 02:06 PM

And I am headed out of the country for a while, but when I get back, one of the first things I am going to do is take one of the C mount pods off of my filmless binocular and one of the PVS-14 objective pods off of my green tube thin film and put the green tube in the C mount and the filmless tube in the PVS-14 Mod 3. 

 

I have really been loving the green thin film binocular, and I am dying to use the tube at prime focus!   So, I each binocular would have one pod that is Mod 3 C mount/ENVIS, and one pod that is Mod 3 14 PVS-14, and the best tube on each will be the C mount tube with the ENVIS.

 

I can do that because it is not particularly hard to do.  Then I could use my thin film green tube with Mod 3 C mount  for the binocular, afocal, or at prime focus.

 

I swear, I am just loving the thin fill binocular.  Now I got it at an auction on Ebay for $5999 or something, and it was PVS-14 Mod 3, but at the time, I thought I would only use it as a binocular, but I just love using it so much that I can't wait to use it at prime focus.  It is nosier than my other tubes but it has some serious gain and surprisingly low EBI, so yeah, had it been in a PVS-14 housing, I could have done the same thing. 

 

The tube is where the money and the performace is.  Housings are cheap by comparison. 



#41 dr.who

dr.who

    Hubble

  • *****
  • Administrators
  • Posts: 15,149
  • Joined: 05 Jan 2012

Posted 13 February 2020 - 03:41 PM

Thanks Gene!



#42 shohin

shohin

    Explorer 1

  • *****
  • Posts: 76
  • Joined: 06 Oct 2016
  • Loc: Los Angeles, CA

Posted 13 February 2020 - 11:26 PM

If money is no object, here's another ENVIS lens.  Get the benefits of c-mount and still do afocal like a PVS-14.

 

https://www.ebay.com...BIAAOSwkfReOh5Q



#43 GOLGO13

GOLGO13

    Aurora

  • *****
  • Posts: 4,801
  • Joined: 05 Nov 2005
  • Loc: West Virginia

Posted 14 February 2020 - 08:11 AM

If money is no object, here's another ENVIS lens.  Get the benefits of c-mount and still do afocal like a PVS-14.

 

https://www.ebay.com...BIAAOSwkfReOh5Q

I saw that one, but it looks a bit odd. Not like a normal envis at least.



#44 Doug Culbertson

Doug Culbertson

    Cosmos

  • *****
  • Posts: 7,806
  • Joined: 06 Jan 2005
  • Loc: N. Florida

Posted 14 February 2020 - 08:14 AM

I saw that one, but it looks a bit odd. Not like a normal envis at least.

That rubber hood on it comes off to expose the c mount thread. I got one like that with one of my ENVIS objectives and discarded it. 


  • Dale Eason and outofsight like this

#45 GOLGO13

GOLGO13

    Aurora

  • *****
  • Posts: 4,801
  • Joined: 05 Nov 2005
  • Loc: West Virginia

Posted 14 February 2020 - 09:21 AM

ahh...good to know.



#46 GeezerGazer

GeezerGazer

    Apollo

  • *****
  • Posts: 1,044
  • Joined: 06 Jan 2005
  • Loc: Modesto, CA

Posted 14 February 2020 - 01:27 PM

Gene, it was mentioned briefly in a post on page one, but to emphasize, the brightness gain of NV on DSOs is a definite boon to aging eyes.  NV provides a monochromatic image, but most nebulae, galaxies and globs do not show color through a glass eyepiece anyway.  The brightness and contrast of NV enhancement will keep you observing longer as we age.   And it does so while still using modest size equipment.  Sure I could have purchased a 16" or 20" scope instead, but, I do not want to deal with that bulk and weight.  My NVD and 8" Newt perform very much to my satisfaction and I do not feel the need for additional aperture.  

 

This thread has included much information concerning the merits of prime vs. afocal.  I have found that neither preference is of much concern after a purchase has been made.  We seem to adapt to what we have and deal with any shortcomings accordingly.  Having said that, I have tried both afocal and prime.  I prefer prime for two reasons:  1) shorter stack of stuff from the focuser and, 2) I really like taking snapshots with my phone using camera lenses as the objective for a super-wide FoV.  I did not start using NV with the intent of taking pictures... I thought I would only use it visually, the way all of my observing had been done.  BUT, NV provided the opportunity to use my phone camera to take photos, and I have found that I see more detail in the photos than I can see visually at the NV ocular.  So with NV, I started taking photos to replace my observing notes... but that has morphed into taking photos to see more detail.

 

Once you receive your new NVD, you will see major improvements using your existing equipment.  But be prepared... you might decide that you want a faster focal ratio scope to see a wider FoV for really big nebulae!   

 

Have you visited the BEST of NV thread near the beginning of the EAA forum listings?  Click on it for a list of subjects that are NV related; clicking on each topic that is listed will take you to a list of posts and web-based material that is linked.  If you want to know more about lenses to use, filters, or even photography, the information is there and easily found.  

 

The short story is that NV offers more than just visual observing improvements.  And, for aging eyes, it might be the best astro equipment investment you've made.  Congratulations on your purchase and welcome to the wider field of NV enhanced observing.  


  • Jeff Morgan, bobhen, john hraba and 2 others like this

#47 genelew

genelew

    Vostok 1

  • *****
  • topic starter
  • Posts: 148
  • Joined: 30 Aug 2015
  • Loc: Westchester County NY

Posted 14 February 2020 - 02:07 PM

Hi GeezerGazer,

Thanks for your insights and encouragement. I’m really looking forward to receiving my NV gear and getting started on seeing more objects than ever before.

Gene



#48 Dale Eason

Dale Eason

    Apollo

  • *****
  • Posts: 1,444
  • Joined: 24 Nov 2009
  • Loc: Roseville,Mn.

Posted 14 February 2020 - 10:34 PM

That rubber hood on it comes off to expose the c mount thread. I got one like that with one of my ENVIS objectives and discarded it. 

Well once you explained what I was looking at I decided money was no object.  Thanks.  I will see how it differs from the much cheaper 25mm Cmount lens I bought.


  • Doug Culbertson and Peregrinatum like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics