I need a couple (?) of cheap basic camera lenses for testing and general investigative work prior to mounting spectroscopes onto a ‘scope. Not having a photography background I need a little guidance please.
Can anyone recommend a specific config? Do I simply have to play with F = focal length/diameter to get the spec I need?
For a front-end lens (to ‘replace’ a scope) presumably something that goes to > f5 (to match the spectro optics) and a reasonable diameter needs to have a zoom to get the focal length? Or have I got that wrong?
Or is it easier just to buy a cheap ‘scope?
With regards to a cheap lens to use as a collimator/Camera lens in a Littrow – F 1.8 ~ 2 and 35 mm or 50 mm?
Any advice appreciated.