Hello folks,
im brand new to this forum and im making this thread as a resource for myself and for everyone else in the future to stumble upon. I am fairly experienced with night vision devices and image intensifier tubes already, but im very new to the topics of telescopes, optical lenses and astronomy in general. So im not in a position to convey any information here and this is not the purpose of this thread, rather i was hoping to spark discussions and knowledge sharing from experienced users regarding everything related to using the PVS-7 (both on a telescope aswell as with various C-Mount camera objectives)
After many months of searching i finally found a C-Mount adapter for my PVS-7D, so now im ready to purchase a telescope and dive into night vision astronomy. There is already a good chunk of information about this topic on this site and i have browsed various threads, but sadly none were at the lower level of abstraction necessary that i as a complete beginner to this topic was able to gather the information i need so i will post my noob questions down below
#1: Will the PVS-7 work as a binoviewer without an intensifier tube installed?
This is what interests me the most. I have used my PVS-7 a few times with the objective lens and intensifier assemblies removed, from what i can tell the optics do a good job of resolving virtually anything that is placed on the focal point in front of the collimator where the intensifiers phosphor output window usually sits. The optics are designed to rectify the naturally distorted image on the concave shaped phosphor window into a flat image so there is some slight edge distortion, but the image quality itself is good. So if i want to get started with more natural non-intensified views of the sky first, will i be able to use it as a binoviewer in that way?
#2: How does magnification and FOV work with the PVS-7 in prime focus?
as i understand, the PVS-7 attached with a C-Mount and 1.25 inch adapter effectively becomes the telescopes eyepiece and i will not be able to alter the magnification or field of view characteristics on whatever scope i buy with it attached, because all of this is done by switching out the eyepieces and adding various other elements to the "optical stack" of the telescope. This sounds unfortunate and like a huge limitation, but since i never owned or used a scope since i was 12 years old i honestly have no idea at all and stand to be educated on this.
#3: Which lenses will work well for handheld observation?
I have seen users on here attach various camera lenses to their PVS-7 units to achieve different results. Since my knowledge on lenses and other optical elements is basic at best, im simply overwhelmed by the sheer amount of lens options and mounting interfaces, but mainly the characteristics of lenses like aperture and focal length that i need to consider to make the night vision goggle perform what i want it to do. For example, if i attach a F1.6 10-100mm c-mount TV camera lens to my device, with my current knowledge i would expect to get a 1-10x variable zoom out of it with an image thats a bit less bright than the standard milspec F1.2 1x objective lens but still plenty bright due to the lens being "fast" (having a low F number) which as i understand means the light transmission is favorable. But since the PVS-7 was not designed with this use case in mind, i wonder if the image will even be usable considering the intensifier tubes photocathode input window has a specific useful circular area of 18mm and camera lenses afaik are all made to fit various different sensor sizes which might or might not fit with those dimensions. So will vignetting and resolution issues destroy the experience?
Thats everything for now. To close out, i will post the specifications of my intensifier tube down below since i hope to take and upload nice images in the near future. Thanks in advance for your help.
Intensifier Type:
Norinco NVT-6 Gen2+ 1956FOM P43 Green Phosphor
SNR - 30.7
Resolution - 64 lp/mm
Gain - 12.000
EBI - 1.4
Edited by SparrowNV, 10 September 2024 - 06:22 AM.
