SUIT L2A2 Focusing?

[Charlie303]

Having sorted the SUIT bouncing off it's cam (thank you John for the new spring), the focus was slightly out. I suspected, correctly, that the rear lens of the rear element had come loose again, the slight rattle when shaken gives it away. Easy enough to fix.

So 2 questions for those lucky armourers who got to put these right in service;

- What is the correct distance for focusing for the SUIT? The rear element is like that of a binocular, as it screws in and out focuses on different distances. I've set mine for about 200 yards.

- Did the internal lens, the rear one of the 'focusing element', ever come loose in normal service, and how was it fixed?

Thanks,

Charlie

Information

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[Peter Laidler]

It was actually Instrument Technicians who repaired SUIT sights in service and only a few Armourers were dual trade. But back to the question. The sights were focussed at infinity and we used infinity as a radio beacon mast on a distant hill!

The rear lens on the SUIT, the ocular is simply to focus the graticle that you see via a sort of binocular prism system. If my memory serves me right, the image (you actually see an image) is set and focussed at the focal plane of the grat by adjusting the focal length of the OG lens. There's more to it than that of course. But you kinow if it's all correct because when you have focussed the point of the grat via the ocular lens and then the image, via the OG lens, you will also have eliminated all parallax.

I am puzzled about your loose lenses as they came as matched sets in a housing or 'cell' and not available as parts - just a matched set. Or do you mean lens cells/assemblies? It is this/these cells that screw in and out and they didn't come loose because they were retained with tiny grub screws that even the most mechanical squaddie, with the most elaborate Leatherman or better still, Gerber multi tool couldn't get to.

There's good news though. They were made by AVIMO who are from your neck of the woods.

[skiprat]

New main springs!!!! They must have been expensive to re make !!!!!!!!! And there's not many people selling them

The rear lens cell should be a one piece unit that you screw in or out to get the pointer in correct focus. Then adjust the front lens assembly as described by Peter.

The rear lens assembly is two lenses screwed together and sometimes the inner lens is loose and needs to be nipped up to the rear lens. Or .... simply the small ( very small) grub screw needs to be nipped up.

It's a simple job to nip up the inner lens by FIRST REMOVING THE POINTER then removing the whole rear lens and prism assembly to access the inner lens.

[mrclark303]

Is there anyone you would recommend for servicing SUIT's Peter, I know you aren't a great fan of them, but they are now an important historical stepping stone (from a UK perspective at least) toward the modern standard infantry optic that is regarded as basic equipment these days, in the shape of the ELCAN and its future descendants

[tankhunter]

RE: 'Infinity', As Peter has described. ALSO known commonly in the Trade as: WDDO = Well Defined, Distant Object! The term was wildly used & abused by us All !

[Peter Laidler]

Skippy MUST be your man......... But like I said, AVIMO who made them come from your part of the world. What about asking them.

The only problem with someone doing these things at home without the charts and associated optics is that the home fixer focusses the scope by eye. HIS eye. Instead of an optical eye so to speak! So when you get it back one or several elements of the telescope system are out of focus to YOU. But done with the correct optical instruments, the repairer can say '.......no....., it's YOUR eyes that need fixing, not this telescope which is optically perfect'.

The bad news for a SUIT or a SUSAT is that if the prism system isn't exactly collimated, while the sight will appear absolutely perfect internally and optically, you'll never align the pointer with the bore. The good news is that with a deact, does it matter? It's the same with prism binos. Just tip a prism very slightly and you'll never get the two sides to mate-up.

[Charlie303]

Thanks Peter, Tankie and Skippy for the info and tips.

Skippy is completely right when he says ; 'The rear lens assembly is two lenses screwed together and sometimes the inner lens is loose and needs to be nipped up to the rear lens', exactly what's occurred and what I did.

Quite agree Peter, its my optics/eyes I'm trying to get in focus with the SUIT... and at my age (60) my eyes aren't ever going to be fixed! Whereas in the workshop the adjustment had to be defined and precise because it was going to an anonymous, younger user with reasonable eyesight anyway, I just focus it for myself and adjust accordingly.

And, as Peter will tell us, it doesn't actually improve the shooting. I've always had just as good (usually better) results with the iron sights (hythe) as the SUIT.

Cheers