9inch F4 Lens, DIY project?

[Daniel-K]

just stumbled across this on ebay http://www.ebay.co.uk/itm/Wray-Lens-36-inch-focal-length-F4-cold-war-aerial-reconnaissance-spy-telescope-/181411158916?pt=UK_Lenses_Filters_Lenses&hash=item2a3cf29b84  CA might be an issue though   oops should say 9 inch's not 36!

[laser_jock99]

Large, heavy & unknown optical quality. Will sit in someone's garage for another 20 years probably. 

[Cornelius Varley]

Title edited for you.

[michael.h.f.wilkinson]

Not much in the way of coating (single MgF₂ most likely). Could suffer from internal reflections. Having said that, it will almost certainly have good resolution, and a HUGE flat field. I know of several people who built meteor cameras from similar (if slightly smaller) aerial reconnaissance cameras. It might be more useful for imaging than visual, although you would need a massive chip to do it justice

[DaveS]

I doubt if it's cold war, more likely WW2. From the photo probably uncoated, the lens didn't look pristine either.

Dunno, might be worth a punt for a bit of fun, but don't expect APM or Tak quality out of it.

[Dude_with_the_tube]

maybe useful for imaging,but i will not hold my breath on that as i dont have a clue in AP,but for visual,i wouldnt take it as too short focal length,will have massive CA issues and everything else.

[michael.h.f.wilkinson]

If WW2 then it may well be uncoated. MgF₂ coating had been patented by Carl Zeiss in 1935, if memory serves.

[reddoss]

You would need one heck of a mount for a refractor that size!

[HD-AP]

I built a telescope based around a 6 inch f 6.3 lens system from a ww2 aerial camera . 

It certainly teaches you what chromatic abberation is. It was  usless visually even at low magnification .

On the plus side it wasn;t a bad astro camera used with filters very very heavy mine was all brass with an internal iris a freind of mine had the same lens as on e-bay only he had the entire camera used it as an astro camera results at the time were ok .surplus stuff used to be quite cheap in the 1970's i think mine cost £15 took many months of paper round money to save up for.

Might make an interesting project for someone .