Jump to content

Lens testing

Quenell Jones

Recommended Posts

What type of test? Exposure? Focus? Flaring? Are you testing a lens that you would like to purchase or is it a lens that has recently been on the workbench?


Shooting some footage with the lens will answer some questions but if you are testing for specific things, you need specific tests. For instance... If you are testing the focus/sharpness of a lens, you need a chart with a seimans star and you need to shoot it at varying distances.


More information will help you get more specific answers.


Jeff Tanner

Link to comment
Share on other sites

  • Premium Member

Might I suggest a DIY way? Get a film frame, preferrably of a mesh

or lines or something "busy" (ideally a start lead from a lab or a good

quality chart), cut it out and tape it to the gate of your camera snugly

(make sure it's flat - I stuck the film frame to one of those little glass

squares labs use in microscopes) use and stick a powerful light (Mag

Lite usually adequate) behind it. Turn the lights out and focus the lens

on the wall and your camera will now be a projector. Change

lenses and subjectively compare sharpness, color rendition, contrast

and so on at the same aperture. Surprisingly simple and surprisingly

useful. And exactly how the "big boys" do it, albeit with more snazzy

gear, on their MTF benches.

Link to comment
Share on other sites

Best to test it (them) on the camera you will be using.


If you have the lens - on the camera - checked on an autocollimator, you can see if rear focus, flange focal depth are correct and have that corrected if need be. (If that's off, your lens will not perform as it should regardless of how good it is). You can tell some things from the collimator, but a lens test projector will give you a better picture so to speak of how the lens is performing.


But really what I'd be inclined to do is simply shoot thekinds of things you intend to shoot with the lens, make a daily print project and look at it.


You want to see how it performs at its maximum aperature especially, if a zoom how it performs throughout its zoom range.


If you like to shoot into light sources, for instance, do that, see how it flares etc.

(I'd try to induce flare, see what you can get away with).


You can shoot from a shadoy room out a window to a bright sky, see if this causes veiling in shadows or do they remain black. And so on.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...