Canon EF 50mm Macro: Is this normal?

[pierre_bize]

After taking a few macros with my new EF 50mm Macro I noticed some

severe drop in quality on the left side when open between f/2,5-4.

I know that lenses usually performe better when "screwed" down 1 or 2

stops. But is THIS normal?<div></div>

[PuppyDigs]

My EF 50 2.5 Compact Marco is tack sharp wide open from edge to edge. However, DOF at marco distances--especially F2.5--is extremely small, e.g., a few millimeters. If the film plane isn't precisely parallel to the subject you'll have out of focus areas. For example, a few millimeters skewed from square will yield similar results to your jpeg at 1:2 magnification and F2.5. Normally, you'll want to stop down to F16 or smaller to help cover any DOF or placement issues.

 

I find the use of a focusing rail and level very helpful when optimizing sharpness in macro shots. Trying to position a tripod head square by sight is an exercise in futility.

[dfdncithekxlbn8kaglf33]

Does not seem normal but the question it raises for me is if you have the film plane and subject plane parallel. Depth of field for even 1:8 or 1:16 is very shallow at f/4 so these results don't suprise me if you had even the slightest tilt with this lens, and this is not just at the corner of a full frame slr.

[pierre_bize]

Thanks for the above answers. I used a mirror to level the camera (trying to see my eye though the lens in the reflection) before I placed the news paper on top of it. The results seem to be always the same after a few trials (i.e: blurry on the left side at f/2.5 and f/4). no problem at smaller apertures. Would you return the lens on this basis if you were in my situation or would you just live with it?

[dfdncithekxlbn8kaglf33]

Using a mirror sounds like a sure way to see your eye, but not to level the camera. You need a spirit level that works on both axes the film and subject plane are on. It sounds like you are trying to use a shallow aperture when more depth of field is needed. From what you have told us, this lens sounds like a keeper, as this is the only chase you have had problems which is expected.