Testing sharpest aperture

[TreeofLifeStairs]

How do I test my lens to see what aperture it's sharpest at?

 

[480sparky38 37]

My method:

Camera on a sturdy tripod, ISO 100, sunny day, set up in my back yard.

Use a remote trigger and mirror lock-up to prevent any camera movement.

Aperture Priority setting, and take a shot at maximum aperture and every full stop after that down to minimum. With a zoom lens, repeat the shots at every focal length marked on the barrel.

Pixel-peep the resulting images at 100%. The center won't change much, but the corners and edges will. The one(s) with the sharpest corners I consider to be the sweet spot of that lens.

 

[TreeofLifeStairs]

Is there anything in particular I should be focusing on? Something with high contrast or a pattern like stripes or a checker board ?

 

[480sparky38 37]

I just use the trees, grass, siding on my house as a target. Since I don't go out to shoot test targets on a regular basis, I don't feel I need to shoot a test target to judge lens sharpness. I'd rather judge it with stuff I shoot all the time.

 

[table1349]

I have always found this to be a suitable target. The project is less tedious as well.

 

[ratssass]

...i can't find it,but i did a focus test thing that employs the method that sparky describes.It was suggested to use a soda/beer can due to the sharpness of print and contrast.

 

[TreeofLifeStairs]

Good ideas.

 

[480sparky38 37]

I have always found this to be a suitable target. The project is less tedious as well.

Yeah, but they don't stand still long enough for a proper test.

 

[KmH]

Indoors, a page of newsprint taped to a wall makes a good target.

Make sure the camera (on a tripod) is level and plumb.

 

[table1349]

I have always found this to be a suitable target. The project is less tedious as well.

Yeah, but they don't stand still long enough for a proper test.

Obviously you have never tried the lounge chair, Mai-Tai method of having them lay real still.