Photon Extreme

[Bramwith]

Have removed the lens from my 6.5 and ordered a M42 adapter looking for a 105 mm lens i know nothing about lenses

can anyone point me in the right direction on what to look for

[The_Dogge]

I don't know a lot, not being a camera buff, but I am one step further down this path than you, so I'll tell you my experience so far:

What you want is a low F-number https://en.wikipedia.org/wiki/F-number that indicates the brightness of the lens essentially. The Pentax Takumar lenses recommended on the night vision forums are plentiful on ebay in 55mm and 135mm but are scarcer and much more expensive in the 105mm.

I got a 55mm to start with and found it gives a great image, about the same ~6.5 mag as the factory, nice and bright and sharp with unfussy focus. I balked at the price of the 105mm Takumar, but I have another brand lens which I have yet to try, one thing that bothers me about it though is that the longer focal length lenses have more play movement in the objective lens, which may translate into zero shift. This would be of no consequence in a camera, but for the aiming job I imagine it is essential that the angle of the front lens is constant. I will test this before I try shooting with the longer lens. It may be less pronounced in the takumar than the one I have, but I think it may be a feature of the longer lenses generally.

I think you want to stay away from the lenses with automatic mechanisms, as you don't have anything to drive them with.

I would guess that camera lenses are not going to be anything like as weatherproof as "proper" shooting optics so I am not planning to use it in the rain for the time being. Also of course you lose any nitrogen fill when you change the lens.

 

If anyone can clear any of that up I'd appreciate any other advice too.

 

So far I'm liking the "Photon Extreme", it seems like a significantly better image than the original lens, looking forward to trying higher magnification, brightness with the 55mm lens indicates that I can go to a higher F-number and it should still work.

 

Just checking:- Brexit is a terrible idea and the numbers used to promote it were all lies. (You'll understand if you are the intended audience :-) )

[telf]

i had the 4.6 in the extreme version,be carefull which lens you buy,the pentax takuma is allegidly the best to get,but their old lenses and if theres any play in them they wont hold zero,although you can get them fixed at various camera shops for anything from £35-£100 apparently

 

have a gander on the NV forum,loads of info on there

[Barmyfarmer]

What calibre are you shooting? I destroyed plenty of good lenses with an xtreme on a 223, better with the doubler

[drum]

I have an old Zeiss 135 mm on a photon.Gives around 12x mag.Holds zero on everything I've tried up to moderated 223.FOV is a bit narrow but have shot it out to 250 yards with a t75 .A very cost effective way into night vision.I have a doubler on an original 5x photon which is also remarkably good with a t20 .Both units need treating carefully as a bang on the front end usually ends up with poi shift.