Sharpness test on a 100-400 L IS?

[sai]

Hi everyone! I just got my new Canon 100-400 IS L lens and I couldn`t be happier :)

I would like to try it on sharpness, so basically how do I do that? Taking

pictures of a newspaper, bill or chart... ?

How do you test it fully? aberration, vignetting etc..

cheers!

[mark_chappell]

If you couldn't be happier, then why bother to test it? The ultimate test is simply this: do

you like the photos you get with the lens?

[zigzag]

There's the real world and there's testing:<br>

<a href="http://www.zen20934.zen.co.uk/photography/LensTests/simplemethod.htm">Simple Method</a>

[sai]

Thank you Glen. Just what I was looking for

[bob_osullivan]

I don't like the news print type tests. Because must lenses are just a bit front/back focused. And testing on something paper thin can be missleading. You should only be compelled to test if photo's are looking soft. If they are, shoot some real life photos' in a controlled manner and compare different focal lengths and apertures. Your lens should be a bit softer at it's widest aperture. And it may front/back focust a bit at different focal lenghts and subject distances. A simple test for front/back focus is to line up three batteries or film boxes in a row. Set each one about a half inch back from the next. Shoot aming the center AF point on the center one. Zoom in and make sure the text on the center one is the shaprest. If that's the case, I wouldn't worry about it.

[steve_crist]

I have the 100-400 and am pleased with the results. I use it on a 5D. A test I use for lenses is to use a tripod and shoot at a brick wall. Take shots using each F stop. This tests for sharpness as there is lots of detail to record in all the crevices and also the bricks act as a grid to check lens distortion. Enjoy your lens. Steve

[marcomariano]

try using focus chart. if its sharp or what...

[andrew robertson]

It's sharp enough. Don't worry about it.

[keith reeder]

Mark's answer is BY FAR the best suggestion, Simon - just go out and use it.

[lester_wareham]

"Because must lenses are just a bit front/back focused. And testing on something paper thin can be missleading."

 

There will be some variation from shot to shot due to the autofocus repeatability, they way to resolve that is to take several series of test shots each series with a different AF action. Three actions is normally sufficient to weed out the odd bad AF action, you normally see two good and one bad or they are all about the same.

 

To the OP, sharpness testing can be informative, but please don't obsess about it; photography IS about taking pictures.

 

Remember, you need to test several lenses in the same way so you have something to compare to, preferably a known good lens.

 

No lens will be perfect, you can expect the corners to be less sharp than the centre and for the lens to be sharpest normal at a mid fstop. Some difference in sharpness between corners is to be expected wide open but this should reduce when stopping down.

[sai]

Thank you'll! I'm not obsess or anything similar and I do agreed that photography is about taking pictures.

Happy shooting