60 replies to this topic

[robcac26]

I just ordered a PVS-14 the other day to use both handheld and in my 11" F/4.5 Teeter dob, and am currently sorting out what accessories I will use with it. There is a wealth of information on this site which has been very useful, but some of it can be confusing or possibly outdated, so I still have a few things I'm hoping to get clarified.

 

1. When using a 3x magnifier, is it better to use a 2" filter mounted to the end of the magnifier using a 58mm to 48mm step down ring, or a 1.25" filter installed between the magnifier and PVS-14? If I go with the second option, what adapter do I need? I saw a post mentioning using 58mm filters, would that be better than both options?

 

2. Is there a way to achieve prime focus without taking the device apart and voiding the warranty?

 

3. Is there a generally agreed upon preference between a filter wheel or a filter slide installed inside the telescope?

 

4. I'll be using this in heavily light polluted Central New Jersey, near NYC. I understand I should probably go with a 685nm filter and an H-alpha filter that is somewhere between 3-6nm, any suggestions on specifically which I should go for? Any brand that is currently considered the best for either one? Does 685nm sound right for where I'm at?

 

5. Do the specs of the tube impact any of the aforementioned decisions? I'm not sure if posting the specs violates the rules, but from what I understand about these things, I believe I got lucky and called at the right time to get a very good one.

 

Any help is greatly appreciated, looking forward to getting started!

Edited by robcac26, 08 August 2024 - 06:11 PM.

[robcac26]

Jeez, not sure why none of the spaces between paragraphs went through in the post, sorry for the wall of text.  Looks like it's fixed now.

[Jethro7]

I just ordered a PVS-14 the other day to use both handheld and in my 11" F/4.5 Teeter dob, and am currently sorting out what accessories I will use with it. There is a wealth of information on this site which has been very useful, but some of it can be confusing or possibly outdated, so I still have a few things I'm hoping to get clarified.

 

1. When using a 3x magnifier, is it better to use a 2" filter mounted to the end of the magnifier using a 58mm to 48mm step down ring, or a 1.25" filter installed between the magnifier and PVS-14? If I go with the second option, what adapter do I need? I saw a post mentioning using 58mm filters, would that be better than both options?

Hopefully some one that has tried both will chime in here. I use 2" 48mm format universely. My hand held is using a TVNC filter adapter and a TeleVue PVS14 adapter at 1X.

 

2. Is there a way to achieve prime focus without taking the device apart and voiding the warranty?

Not to my Knowledge. The only way is to remove the objective lens assembly from the PVS14 body and add adaptors. 

 

3. Is there a generally agreed upon preference between a filter wheel or a filter slide installed inside the telescope?

This is a personal preference. I only use two filters and don't mind swapping the filters out on the eyepieces when needed.

 

As A side note : My most used eyepieces are the TeleVue 55/67 Plossl and a TeleVue 26 Nagler. (The 26 Nagler is no longer in production but a 27 Panoptic will work just fine) These eyepiece choices are a personal thing. With the exeption of Galaxies, Globular Clusters and Planetary Nebulae, By far most of my time is spent with the TeleVue 67mm Plossl. You are going to be amazed just how big things are out there.

 

4. I'll be using this in heavily light polluted Central New Jersey, near NYC. I understand I should probably go with a 685nm filter and an H-alpha filter that is somewhere between 3-6nm, any suggestions on specifically which I should go for? Any brand that is currently considered the best for either one? Does 685nm sound right for where I'm at?

I live under Bortle 8+ skies and need agressive filtering. The two filters I use are the Baader 685nm IR Longpass and a Antila 3.2nm Ha narrowband filters. I used to use a 6nm Ha filter and the 6nm Ha filter does work quite well but the 3.2 Ha filter works remarkably better for nebulae viewing. I thought that I should mention the 6nm Ha filter, simply because it is near half the cost of the 3.2nm. However, if I had known how well the 3.2nm Ha filter would work, I would have purchased it from the get go.

 

5. Do the specs of the tube impact any of the aforementioned decisions? I'm not sure if posting the specs violates the rules, but from what I understand about these things, I believe I got lucky and called at the right time to get a very good one.

Yes, The higher the PS, SNR and to a point GAIN and Lower the EBI and HALO the better everything works. CN has its own rules about ITAR but you can post the specs, just don't post the supplied spec sheet that comes with the PVS 14. 

,

Any help is greatly appreciated, looking forward to getting started!

Welcome to the NVA club it is amazing. Purchaing a NVD is one of the best decisions that I made for the Backyard Astronomy Project. 

HAPPY SKIES TO YOU AND KEEP LOOKING UP Jethro

Edited by Jethro7, 08 August 2024 - 11:20 PM.

[Jethro7]

Hello robcac26,

Just a few other things coming from observations and personal experience with a NVD.

As I said in my previous post to you, many targets are huge, really huge. I pretty much use my 12.5" Dob for Galaxie hunting with a light intensifier. Most other targets are too big in the eyepiece even with a TV 67mm Plossl with the Dob. Even though I am not the biggest fan of SCT type scopes I like using my C8 Edge HD for NVA. these scopes are popular with the night vision crowd and work very well with a light intensifier for viewing Galaxies, Globular Custers and Planetary Nebulae and other really small targets. The narrow fields of view with an SCT dont matter here, the light intensifier only has a AFOV of 40° and that's that. I do go back and forth during my viewing sessions between The light intensifier and conventional glass and as a result I spend most of my time with one of my beloved Refractors that range from a Tak 76mm, Tak TSA 120  to a TS 155mm at F/7.5 - F/8 with and without a focal reducer. Many folks who do this Genre of Astronomy will pick up a cheap fast Achro at around F/5.  Recently I have acquired a fast 6" Astrograph Newt for Nebulae hunting and it works like a champ even though the visual stack is ridiculously long. ( This is where a MOD 3C in primary focus would come in handy)  because you view in real time with a light intensifier, you don't need  tracking mounts to use a light intensifier and a simple Alt/ AZ mounts work great and many Alt/AZ mounts can be moved for Push To. If you wish it. A light intensifier will enhance any scope and the choice of scopes are a personal taste.

 

Having owned three devices with varying specs from The Good, The Bad and The Ugly, I will say that you need a tube with minmum specs of at least PS 2000, 30K SNR, (The higher the Better) under 1.0 and a HALO under 1.0. (The Lower the Better) however I would trade off a bit higher EBI and or HALO (Still both under 1.0) for a very High P.S. and SNR spec. any GAIN over 62K will be good, higher would be nice. I don't feel that the Super GAIN tubes with GAIN over 100K are much of a benefit for NVA. Most of the time I can't use all of the 72K GAIN that I have anyway. 

 

Don't ever point the NVD at a bright light source such as the Moon or a bright street light. You have no benefit with a NVD for viewing the Moon if you do you will burn an image of the Moon onto the Photocathode screen. You can view the planets with the proper filters though. If you do manage to burn an image on the Photocathode screen don't freak out, all you do is put the cap on the objective lens, turn the NVD on and place it in a drawer and let it run for a day. The Photocathode tube will heal itself but it will still leave a faint scar. These devices have a spec life of 10,000 hrs (This does not mean the tube will only last 10,000 Hrs, it means the tube specs are good for 10,000 Hrs) so 24 Hrs is not that much. 

 

The objective lens assembly of the PVS14, has focus adjustments and can be turned in and out from Zero to infinity that can be used to help you reach focus with your scope if you find out you need more out travel on the scopes focuser. I mostly keep mine turned all the way out. 

 

MAY YOUR NVD BRING YOU THE JOY MINE HAS BROUGHT ME.

 

KEEP LOOKING UP Jethro

Edited by Jethro7, 08 August 2024 - 11:17 PM.

[robcac26]

Hello robcac26,

Just a few other things coming from observations and personal experience with a NVD.

As I said in my previous post to you, many targets are huge, really huge. I pretty much use my 12.5" Dob for Galaxie hunting with a light intensifier. Most other targets are too big in the eyepiece even with a TV 67mm Plossl with the Dob. Even though I am not the biggest fan of SCT type scopes I like using my C8 Edge HD for NVA. these scopes are popular with the night vision crowd and work very well with a light intensifier for viewing Galaxies, Globular Custers and Planetary Nebulae and other really small targets. The narrow fields of view with an SCT dont matter here, the light intensifier only has a AFOV of 40° and that's that. I do go back and forth during my viewing sessions between The light intensifier and conventional glass and as a result I spend most of my time with one of my beloved Refractors that range from a Tak 76mm, Tak TSA 120  to a TS 155mm at F/7.5 - F/8 with and without a focal reducer. Many folks who do this Genre of Astronomy will pick up a cheap fast Achro at around F/5.  Recently I have acquired a fast 6" Astrograph Newt for Nebulae hunting and it works like a champ even though the visual stack is ridiculously long. ( This is where a MOD 3C in primary focus would come in handy)  because you view in real time with a light intensifier, you don't need  tracking mounts to use a light intensifier and a simple Alt/ AZ mounts work great and many Alt/AZ mounts can be moved for Push To. If you wish it. A light intensifier will enhance any scope and the choice of scopes are a personal taste.

 

Having owned three devices with varying specs from The Good, The Bad and The Ugly, I will say that you need a tube with minmum specs of at least PS 2000, 30K SNR, (The higher the Better) under 1.0 and a HALO under 1.0. (The Lower the Better) however I would trade off a bit higher EBI and or HALO (Still both under 1.0) for a very High P.S. and SNR spec. any GAIN over 62K will be good, higher would be nice. I don't feel that the Super GAIN tubes with GAIN over 100K are much of a benefit for NVA. Most of the time I can't use all of the 72K GAIN that I have anyway. 

 

Don't ever point the NVD at a bright light source such as the Moon or a bright street light. You have no benefit with a NVD for viewing the Moon if you do you will burn an image of the Moon onto the Photocathode screen. You can view the planets with the proper filters though. If you do manage to burn an image on the Photocathode screen don't freak out, all you do is put the cap on the objective lens, turn the NVD on and place it in a drawer and let it run for a day. The Photocathode tube will heal itself but it will still leave a faint scar. These devices have a spec life of 10,000 hrs (This does not mean the tube will only last 10,000 Hrs, it means the tube specs are good for 10,000 Hrs) so 24 Hrs is not that much. 

 

The objective lens assembly of the PVS14, has focus adjustments and can be turned in and out from Zero to infinity that can be used to help you reach focus with your scope if you find out you need more out travel on the scopes focuser. I mostly keep mine turned all the way out. 

 

MAY YOUR NVD BRING YOU THE JOY MINE HAS BROUGHT ME.

 

KEEP LOOKING UP Jethro

Awesome, thank you very much for the detailed response!  I think I worded my last question poorly.  I understand the specs are important, I was just curious if the specs would have an impact on which filter to use (for example if the 3.2nm Ha filter would be overkill if the SNR is above a certain level or something like that).

 

Here are the specs:

Resolution:  72

SNR: 36.9
FOM:  2656.8

EBI:  0.0

Halo:  0.7

Gain:  63,361

Photocathode Sensitivity:  2626

1 spot in zone 3

 

You mentioned viewing the planets with proper filters--is there any benefit to using night vision to observe the planets?  And if so, by "proper filters" do you mean the same ones previously mentioned or are there others that should be used for this purpose?

[Jethro7]

Awesome, thank you very much for the detailed response!  I think I worded my last question poorly.  I understand the specs are important, I was just curious if the specs would have an impact on which filter to use (for example if the 3.2nm Ha filter would be overkill if the SNR is above a certain level or something like that).

No. Your Light pollution level is the determining factor on how aggressive the filter. If you were viewing under Bortle 4 or 5 skies you may find all you need is 12nm Ha filter. A high SNR plus GAIN will allow your tube to work better.

 

Here are the specs:

Resolution:  72

SNR: 36.9
FOM:  2656.8

EBI:  0.0

Halo:  0.7

Gain:  63,361

Photocathode Sensitivity:  2626

1 spot in zone 3

Good job, you will love using that tube. 

 

You mentioned viewing the planets with proper filters--is there any benefit to using night vision to observe the planets?  And if so, by "proper filters" do you mean the same ones previously mentioned or are there others that should be used for this purpose? 

 The filters used for planetary viewing are not the same filters Some folks do view the bright planets. Personally this is something that does not interest me. The views of the bright planets are so much better viewing with conventional eyepieces. 

HAPPY SKIES AND KEEP LOOKING UP Jethro

Edited by Jethro7, 09 August 2024 - 07:41 AM.

[bobhen]

Others have made some good suggestions and I'll add another good suggestion. Your Newtonian will be excellent but you might want to consider adding a smaller, fast scope with a wider field, as you will soon discover that low power, wide field observing with an intensifier is absolutely fantastic, even from light polluted locations.

 

I happen to use an inexpensive 102mm F5 achromat and love the low power, wide views. A scope like that pointed at Cygnus or Sagittarius will give you a completely new perspective on the Milky Way! 

 

Been doing Night Vision for 8-years and my intensifier is the best astro accessory I have ever purchased. 

 

Good Luck

 

Bob 

[Speedy1985]

Rob, Jethro and bobhen were both a big influence when I made the decision to jump into NV as well. I got my device from the same vendor as Jethro too. They’ve given you the same advice they gave me. I don’t remember if I mentioned to you when you were at my house checking out the setup that I also have an AT-102 EDL f/7 refractor that I use the device in on occasion as well. Don’t let that discourage you though, there are still plenty of objects that don’t need a wide field that the dob will show. 
 

Don

Edited by Speedy1985, 09 August 2024 - 08:20 AM.

[robcac26]

I really appreciate all the input, guys! I'm still deciding on which size filters to use. I read a post on here from Eddgie four years ago with links to an adapter that will allow for using 1.25" filters, and another adapter that lets you connect the 3x magnifier over the filter, but does anyone know if TeleVue's eyepiece adapter will attach to the PVS-14 with a filter installed? If not, then I'll probably need to get 2" filters anyway in order to use this with my telescope.

Also for whatever it's worth, ChatGPT recommends using the 1.25" filters because it says putting the filter closer to the PVS-14 could provide better image quality and reduce vignetting since having the filter further away could result in light scattering and reflecting inside the eyepiece before reaching the PVS-14. Are any real humans on here able to verify that makes sense, or is the difference negligible anyway?

[Jethro7]

I really appreciate all the input, guys! I'm still deciding on which size filters to use. I read a post on here from Eddgie four years ago with links to an adapter that will allow for using 1.25" filters, and another adapter that lets you connect the 3x magnifier over the filter, but does anyone know if TeleVue's eyepiece adapter will attach to the PVS-14 with a filter installed? If not, then I'll probably need to get 2" filters anyway in order to use this with my telescope.

Also for whatever it's worth, ChatGPT recommends using the 1.25" filters because it says putting the filter closer to the PVS-14 could provide better image quality and reduce vignetting since having the filter further away could result in light scattering and reflecting inside the eyepiece before reaching the PVS-14. Are any real humans on here able to verify that makes sense, or is the difference negligible anyway?

Hello robcac26,

Eddgie is one of the main contributors that convinced me to get into the Night vision Astronomy. The Tele Vue PVS 14 adaptors don't have a means for using  1.25" filters. However something could be 3D printed that could. I'm not confident on the 3D printed components stability. TVNC does make an adaptor that allows you to attach a 2" filter to the Tele Vue PVS14  adaptor and I use this set up for hand held at 1X. I have tried both 1.25" filters as well as 2" and prefer the 2" format even though the 2" format is more expensive. You will have some slight vignetting around the field stop with a PVS14 but the vignetting has never been enough to bother me. 

 

This my 1X set up

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

[robcac26]

Sorry, my question was if Tele Vue's eyepiece adapter, to attach an eyepiece to the PVS-14 would still be able to do that when there is a 1.25" filter on the PVS-14. I guess once the PVS-14 gets delivered I'll have a better idea of if that would work.

[Speedy1985]

Sorry, my question was if Tele Vue's eyepiece adapter, to attach an eyepiece to the PVS-14 would still be able to do that when there is a 1.25" filter on the PVS-14. I guess once the PVS-14 gets delivered I'll have a better idea of if that would work.

Rob, I don’t think that would work because the TV eyepiece adapter screws into the front of the NV device and clamps directly to the eyepiece. I suppose that some type of adapter could be made to accomplish that but I don’t know how it would affect the views. 

[robcac26]

Rob, I don’t think that would work because the TV eyepiece adapter screws into the front of the NV device and clamps directly to the eyepiece. I suppose that some type of adapter could be made to accomplish that but I don’t know how it would affect the views. 

Is it not possible to thread the filter onto the NV device, and then thread the eyepiece adapter onto the filter, or are these filters not threaded on both sides? Or are the threads not the same?

[Jethro7]

Sorry, my question was if Tele Vue's eyepiece adapter, to attach an eyepiece to the PVS-14 would still be able to do that when there is a 1.25" filter on the PVS-14. I guess once the PVS-14 gets delivered I'll have a better idea of if that would work.

Hello robcac26,

Speedy is correct it is not possible. Back to an earlier question of yours. I screw the filter into the end of the eyepiece skirt and this causes no issues even though the filter is further away From the PVS 14's objective lens. 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

[Speedy1985]

Is it not possible to thread the filter onto the NV device, and then thread the eyepiece adapter onto the filter, or are these filters not threaded on both sides? Or are the threads not the same?

Yes, the threads are 2 different sizes. The threads in the PVS-14 are M30.3 x 0.8 and I believe 1-1/4” filters are M28.6. 

[robcac26]

Yes, the threads are 2 different sizes. The threads in the PVS-14 are M30.3 x 0.8 and I believe 1-1/4” filters are M28.6. 

Hmm not to belabor the point, but what about using these adapters?  One on either side of the filter.

 

https://rafcamera.co...s-to-astro-1-25

 

https://rafcamera.co...f-to-m28-5x0-6m

[chemisted]

Hmm not to belabor the point, but what about using these adapters?  One on either side of the filter.

 

https://rafcamera.co...s-to-astro-1-25

 

https://rafcamera.co...f-to-m28-5x0-6m

Welcome to the wonderful world of NV astronomy.  I have been doing what you ask for many years.  I keep the first raf adapter that you have listed permanently on the NV device objective (an ENVIS lens in my case that I C-mount to my device).  I find this exceedingly convenient as I have many eyepieces that I use afocally that are not from TV but have standard 1.25" male threads (by means of adapters) at their eye lens.  For my TV 55mm Plossl I super-glued a retainer ring from an old filter to the top of their adapter to accomplish what the second raf adapter that you have listed now does.

 

I started doing this with an Astronomik 12nm filter which is threaded on both sides.  When they came out, I switched to the Baader High Speed 6.5nm filter which is also threaded on both sides.  Essentially all of my setups have final focal ratios around f/2 or faster and these new HS filters fit the bill perfectly.  I live at a dark sky site so I have never found a need for the more aggressive filters.  

[robcac26]

Welcome to the wonderful world of NV astronomy.  I have been doing what you ask for many years.  I keep the first raf adapter that you have listed permanently on the NV device objective (an ENVIS lens in my case that I C-mount to my device).  I find this exceedingly convenient as I have many eyepieces that I use afocally that are not from TV but have standard 1.25" male threads (by means of adapters) at their eye lens.  For my TV 55mm Plossl I super-glued a retainer ring from an old filter to the top of their adapter to accomplish what the second raf adapter that you have listed now does.

 

I started doing this with an Astronomik 12nm filter which is threaded on both sides.  When they came out, I switched to the Baader High Speed 6.5nm filter which is also threaded on both sides.  Essentially all of my setups have final focal ratios around f/2 or faster and these new HS filters fit the bill perfectly.  I live at a dark sky site so I have never found a need for the more aggressive filters.  

Good to know, thanks!  Any opinion on if this setup results in a better image than using a 2" filter further away from the NV device, or do you not have experience with that?  Are all of the Baader, Antila, and Astronomik filters threaded on both sides?  Unless there's something that makes the 2" filter setup better, I might as well go with this and save a few bucks on the filters.

[chemisted]

I have both 2" and 1.25" filters so I have done both configurations. If there is enough eye relief from the eyepiece I prefer using the 1.25" arrangement. My Antlia filter is not threaded on both sides while the other two are. This has been a lot of fun so I hope my experiences are a help to you.

Edited by chemisted, 11 August 2024 - 07:25 PM.

[robcac26]

I have both 2" and 1.25" filters so I have done both configurations. If there is enough eye relief from the eyepiece I prefer using the 1.25" arrangement. My Antlia filter is not threaded on both sides while the other two are. This has been a lot of fun so I hope my experiences are a help to you.

Great, so it sounds like I should be good to use this thing for handheld at 1x & 3x as well as with my telescope with the 1.25" filters as long as I get those adapters and Baader or Astronomik filters, unless for some reason some of their filters are threaded on both sides while others are not.  Any reason you prefer the 1.25" over the 2" setup? Thanks for the input!

[chemisted]

Quite honestly, I have done so many different arrangements that I can't be too specific about details. I know that I have experienced poor results with a filter attached to the eyepiece but never with the filter between the eyepiece and the NVD. If you look at my gallery you will see what I mean about a lot of different setups. The ones that use the homemade diagonal and 45 mm Plossl work well with the Baader HS between the diagonal and the ENVIS.

[chemisted]

I am posting this link to show a specific instance of what i referred to in my previous post.  In the image I have the Baader HS filter attached to the Plossl.  Subsequent to that useage I found that I liked the view better when the filter was placed between the diagonal and the ENVIS of the NVD.

 

Here is the link:  https://www.cloudyni...1221-192938518/

[robcac26]

I am posting this link to show a specific instance of what i referred to in my previous post.  In the image I have the Baader HS filter attached to the Plossl.  Subsequent to that useage I found that I liked the view better when the filter was placed between the diagonal and the ENVIS of the NVD.

 

Here is the link:  https://www.cloudyni...1221-192938518/

Thanks again.  I thought I was done asking questions but now that I go to buy the Baader 3.5nm H-alpha filter, I see they have options for different focal ratio ranges and I'm not sure which one I should get.  I'll be using this handheld at 1x and 3x, and on my f/4.5 telescope with Tele Vue's 55mm/67mm Plössl, and I'm guessing occasionally with my 31mm Nagler.  Assuming I'm doing this correctly, these are the effective focal ratios I've come up with for those uses:

1x - f/1.2

3x - f/3.6

67mm - f/1.75

55mm - f/2.12

31mm - f/3.77

 

Baader has three options, and the recommended uses of each one are >f/3.4, f/2.3-3.4, and <f/2.3.  The slower option appears to be ideal for the 3x and the 31mm, the faster option appears ideal for 1x, 67mm, and 55mm.  How do I know which option to go with?  Should I guess as to which I'll be using the most?  I would guess I'll get the most use out of 3x and the 67mm, but that doesn't help narrow it down.  Should I split the difference and get the middle one even though none of my effective focal ratios fall within that option's recommended range?  It also says these filters are CMOS-optimized, does that have any implications for night vision use or can I ignore that?

Edited by robcac26, 11 August 2024 - 11:38 PM.

[sixela]

For extremely narrowband filters putting them at the back (the telescope side) of the eyepiece will avoid transmission loss because of blue shift (because the angle of incidence is much lower).

Edited by sixela, 12 August 2024 - 07:11 AM.

[robcac26]

For extremely narrowband filters putting them behind the eyepiece will avoid transmission loss because of blue shift (because the angle of incidence is much lower).

When you say "behind the eyepiece" that means between the eyepiece and the NV device, correct? So the light is filtered after passing through the eyepiece?