Struggling to get Sharp images from my PRIMES :(

On my XSi i struggled to get sharp images from 35mm f2, 50mm 1.8 or 85mm 1.8 - i tried everything, and I'm speaking solely about taking candids of my nephew Eric. I then tried my first zoom, the 17-40 and got results i was very happy with immediately:

try a smaller aperture. Wide apertures are very particular about distance to subject. If you use wide aperture, try changing your distance and see what happens.


I've had the same problem at wide apertures... focus is tricky.

The 50mm f1.8 isn't notoriously sharp at 1.8. If you stop down it'll make your life easier.

Have you made any adjustments to your Picture Style Settings on the XSi ? What modes are you shooting in ? If your shooting portraits then you should be choosing your "Portrait" Picture Style . Go into your Menu and find Picture Styles and boost up your Sharpness and Contrast in your "Portrait" Style settings then besure to choose "Portraits" Picture Style and try it again and see if your images improve .

this was f/2.8 with the 85mm 1.8. I don't think its a focus issue, because i took about 70 frames today and all had the same general softness.

And i don't think its the lens, because i would get similar results when i used three different primes.

Celestron wrote in post #9514549
Have you made any adjustments to your Picture Style Settings on the XSi ? What modes are you shooting in ? If your shooting portraits then you should be choosing your "Portrait" Picture Style . Go into your Menu and find Picture Styles and boost up your Sharpness and Contrast in your "Portrait" Style settings then besure to choose "Portraits" Picture Style and try it again and see if your images improve .

I was shooting in Manual with the flash set on ETTL or whatever to properly expose on the XSi. thing is, i would do this with three different primes and not get good results, i buy one L zoom and straight out of camera i got very good results first try! Now that i have a 5d i'm attempting to get the same results of the xsi + 17-40 with a 5d + 85 1.8 and am getting the same crummy results as i did with the xsi + primes. it baffled me before, and its baffling me now.

A possible cause could be together the lens or body might need calibration.

The 85mm is normally a very good lens and can produce sharp photos wide open and even at F2 especially on the 5D.

I would verify with some sort of a focus test.

Good luck.

It looks like you are too close to the subject. What is the minimum distance on each lens?

I would start by:
1. Make sure you do not have a UV filter over the lens - sometimes this is the culprit and, in the very least, it is one more variable that you need to eliminate.
2. Watch your technique. Don't jab the shutter release button and shoot at a high enough shutter speed to prevent camera shake - or use a tripod.
3. Use aperture of f/4 thru f/8 - lenses are usually sharpest around there.
4. Make sure you are using the center focusing point only - multiple focus points may attempt to lock on to the wrong thing.

Hope this helps.

i also get sharper images with my 70-200 @ 2.8 than my 50 1.4 @ any aperture, so i've decided i'll just save up for the 24-70 and stick with L lenses for the sharpest shots possible.

Are you picking your own AF points, or letting the camera pick?

Are you manually focusing the zoom ?

If the 85 focuses properly when you ran your tests then you have to analyze what changed in the shooting environment between tests and real life.

Those shots, if not cropped, are really tight to be shooting with an 85 at anywhere near wide open on a 5D. Any movement of the subject or the photographer (you may not realize but you might be moving/swaying between focus lock and tripping the shutter) or focus and recompose will cause a misfocus. What were you focusing on, btw.

The 17-40 is f4... and if not framing as tight will have a much larger depth of field. If you are not used to shooting at 1.8 on a FF, it will reveal faults in technique.

The second shot looks like it was taken from about 7 feet. The first one, even closer.

A 85/1.8 on a 5D will have a depth of field of just over 2 inches at 7 feet.

At f2.8 DOF is about 4 inches

I will do another focus test with the 5d + 85mm tommorrow and post it. I use center AF and recompose - but this isn't an issue of technique--or knowledge of camera settings--because as shown with the first picture i was getting good results with the 17-40.

Moooney wrote in post #9514556
this was f/2.8 with the 85mm 1.8. I don't think its a focus issue, because i took about 70 frames today and all had the same general softness.

And i don't think its the lens, because i would get similar results when i used three different primes.

then you have a problem with either gear or operator . what was your shutter speed?

ed rader

It could be just that, the focus and recompose, especially at such a narrow DOF.