I've just bought PVS 14 with AG tube.
Image is pretty clear IMO, bud center of image looks a little bit brighter.
What do you think about it?
And there are also some tiny blemishes in image. It can be dirt or blems in tube, but I can't estimate if it is only dirt or tube blems.
This image was fired in pretty high light scenario (about full moon).
This is only detail of tiny blems, there are visible only in high light scenes.
Thanks a lot for any input.
If it is any consolation, what you see in your image (the black spots) are only cosmetic, i.e., dust in the tube or between the intensifier and the lens internally. If you get a copy of the Army TM 11-5855-306-10 Operator's Manual for the AN/PVS-14 it covers all of the functions and the Preventive Maintenance Checks and Services (PMCS) for acceptable conditions. We used this TM in the Army to do our checks on our NVDs every time before we used them. As to the black spots you're seeing, the TM states on page 2-28, SECTION 2-4 under INSPECTION CRITERIA FOR PROPER IMAGE INTENSIFIER OPERATION, PARAGRAPH C. COSMETIC BLEMISHES, SUBPARAGRACH (3) :
Black Spots. These are cosmetic blemishes in the image intensifier or dirt or debris between the lenses. Black spots are acceptable as long as they do not interfere with viewing the image. No action is required if this condition is present unless the spots interfere with the operator’s ability to view the image or to perform the mission.
So for military missions your tube is a GO.
That being said, many builders/companies "grade" their NV tube (not the generation 1, 2, or 3) by how many black spots are visible and charge a higher price for fewer "blemishes". This is better explained at http://www.nightvision4less.com/education-center-night-vision-tubes-grades.aspx. They explain how they charge more for better quality (fewer blemishes) tubes. Fewer blemishes usually equals higher price.
Hope this helps.