How good are projection lenses usually?

[buerokratiehasser]

I know they have no aperture to change and are focused.. externally. But how good are they? In terms of sharpness? What are they optimized for?

These are pretty basic questions, but I did not find much information about those on the web (even better if you do)

[iangreenhalgh1]

They vary vastly. The best ones are superb Petzval types perfect for portraiture, but some are crap.

This is an example of a crap one, an Aldis Anastigmat 2.5/85, not sharp at all and with bad CA:



This is an example of a good one, a Rathenower Optische Werke Visionar 1.9/168, it has a tiny dof and fantastic smooth bokeh:



This is my favourite, a 1950's Kalee Bloomed 5 inch made by Kershaw, it's a Petzval type and a wonderful portrait lens:





My best advice is get a cheap set of bellows and keep your eye out for cheap projector lenses, try to avoid the small ones for 8mm or 16mm projectors, only way to know if a projector lens will be any good or not is to try it or seek out samples of pics taken with the same lens. Don't expect projector lenses to be suitable for all types of shot, but they do have their niche applications.

[Attila]

Last one is excellent Ian!

[iangreenhalgh1]

Thankyou Attila, that's my friend Simon who is actually a professional model so a good subject helps, the rest is that Kalee lens, it paints beautiful pictures.

[Attila]