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11-26-2010, 10:52 PM   #1
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Lens testing: advice

I want to finally test all my lenses at once.
This will not be very scientific.

I was going to try them all
1. on my DSLR
2. on my program plus
3. on my spotmatic.

Zoom lenses I want to try at three focal lengths
and I want to try each lens at 3 different apertures

Do you have any suggestions for what I should shoot?

I'm trying to decide whether it should be indoors, with lots of objects I set up like DPreview does. Bottles, paper clips, textures, charts etc.

If I do this, where can I find some good charts?

Or outdoors in a shady area, place objects at different distance.

11-27-2010, 12:00 AM   #2
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Do you think there's something wrong with your lenses? Looking at your sig I think they all should be reasonably good. Or are you considering selling some of them? I see no doubles in focal lenghts especially when you have three different cameras for them.

I'd suggest you just dedicate a day or two with each lens and shoot all kind of stuff indoors/outdoors and make a note of apertures/focal lenghts used. That way you find out how each lens behaves in normal use and what works and what doesn't. Also sharpness to close distances can be very different than sharpness at infinity...

If you have lots of spare time then a contrast/sharpness test indoors with constant light (fixed ISO and WB with a DSLR) and a target with a lot of color/detail also near the frame edges would be start. But to rule out focus errors I'd shoot multiple shots with each aperture/fl and pick the best one.

Then a high contrast scene (tree branches against a bright sky?) to see chromatic aberrations.

Then the infamous brick wall to see distortions/vignetting.

Then some shots with a strong sidelight, then straight into the strong light to see flaring.

Of course you have to make notes to remember which shot is which when reviewing the results. A lot work and not much fun, unless you're into that kind of
thing.

Personally I wouldn't bother because I have so little spare time I'd rather use it for "real" shooting.

Last edited by ovim; 11-27-2010 at 12:05 AM.
11-27-2010, 10:04 AM   #3
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If you consider testing of lenses, you need to do more than 3 apertures.

As a minimum, on film
- wide open
- first aperture stop below wide open
- F5.6, F8 and F11
- stopped down all the way
but for digital shoot every aperture stop.

All shots done against uniformly lit block wall

You will do 2 sets of shots,
- one with the camera metering for each aperture, and
- one where you follow a fixed exposure, usually F5.6 and a shutter speed /iso combo in the 1/250 range to give correct metering, so that you can check linearity of the aperture as you go from wide open to stopped down


At the same time, measure the EV with a hand held light meter

The reasons are as follows.

You need to know how the camera meters at each aperture, and you need to know how linear the aperture control behaves.

The wide open shot, and the stopped down 1 stop shots can be used to judge vignetting as well.

Once these are done, go out and shoot buildings, (check for distortion) and then view close on the edges for CA.

Shoot through brances, out of focus before and behind the line of focus shows longitudinal and lateral CA, you don't really need bright background for this, just some contrast.
11-27-2010, 06:06 PM   #4
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what is the uniformly lit block wall?

I mostly want to do thhis to get better acquainted with my lenses. to have a nice idea of how my lenses see.

but the more complex methods you've both mentioned interest me, as I have a long vacation coming up

11-27-2010, 09:02 PM   #5
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A uniformly lit wall is just that a wall lit by sunlight usually. It allows you to check the metering and vignetting accurately if you measure the vreyscale value of the center and corner in a photo editor

ComPlicated scenes with non uniform lighting can reliably be used to check metering or vignetting
11-27-2010, 11:45 PM   #6
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Mike Johnston is one of the best writers about photography. His head is on very straight.
This is good:
How to stress a camera lens


M
11-28-2010, 08:04 PM   #7
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Good non scientific tests don't need to involve charts and brick wall.
Go out and take pictures. If you want to check for various distortions, take pictures of buildings.
But mostly, just take pictures. You'll learn soon enough what your various lenses can do for you with pictures that you want to hang on your wall.
I've never met a picture of a test target that had any sort of emotional impact. And yet test targets seem to be what people spend their time taking pictures of.

I don't understand this fetish for finding every single flaw in our equipment. I don't understand the harping about "this is crummy for a 1.5k camera" and words to that effect.

Go out and take pictures. This is what your camera and lenses are designed to do. You will never, ever learn what your equipment is capable of in the real world by taking pictures of test charts. This will only teach you how capable your equipment is of taking pictures of test charts.
If you think this is important, go back and read the part about pictures of test targets and their emotional impact.

OTOH, still lifes have a long and revered place in art, though I find the DPReview style of still life to be dull and boring. If it's the kind of picture you'd hang on your wall, then I guess it's something to emulate, but I'd rather a nice bowl of fruit.
01-23-2011, 12:28 PM   #8
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Here is an article that does an excellent job of explaining lens testing technique:

How To Test A Lens

01-23-2011, 02:05 PM   #9
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Lots of good methods already offered, I did something like this with a couple of similar lenses and it was kind of fun. This is not scientific, except for using a somewhat controlled environment. Indoors you could set up a target of different colors of household items, packages, books, whatever, just to get many colors and details involved. Then you can control the lighting so it's consistent, and use a tripod so the camera the same distance from the target.
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