May 23, 2013, 11:00:26 PM

Author Topic: Is This Normal?  (Read 3183 times)

Sinsear

  • Guest
Is This Normal?
« on: April 16, 2012, 04:12:16 AM »
Is it just me or is my 16-35mm II lens pretty hideously awful on the borders when viewed at 100%? This is the first time I've shot my lens on a full frame, and the borders/corners look extremely distorted/not sharp compared to a reference image on photozone.de. Should I send it in to Canon?

My lens: http://img10.imageshack.us/img10/7360/mg0607.jpg
Photozone's lens: http://photozone.smugmug.com/photos/532740702_syfbi-O.jpg
More Photozone samples: http://www.photozone.de/canon_eos_ff/435-canon_1635_28_5d?start=2

Note: My aperture on that shot was f6.3, and the shot was taken on a tripod.
« Last Edit: April 16, 2012, 04:14:53 AM by Sinsear »

canon rumors FORUM

Is This Normal?
« on: April 16, 2012, 04:12:16 AM »

NWPhil

  • Rebel T4i
  • ****
  • Posts: 113
  • one eye; one shot - multiple misses
    • View Profile
Re: Is This Normal?
« Reply #1 on: April 16, 2012, 09:56:07 AM »
well, at 6.3 should be sharper, but I could not see exactly where the focus point went. I see a lot of CA too, and with some hazee in the sky, you shot this at 16mm,it won't look too pretty in gloomy days.
I think you need to test it in a few more scenes, with different light conditions, and that you might need a focus calibration.
Can you test test in another body? Did you perform any PP? and btw, what iso were you using on this shot?
If nothing yelds better results, it might be that indeed you need to return this one or send it to Canon
Canon: all started with AV-1
40D(IR);5Dmk2;1Dsmk3: Samyang 14mm 2.8; ef 15mm 2.8; Zeiss T*18mm 3.5 ZE; Zeiss T* 21mm 2.8 ZE; TS-e 24mm 3.5LII; ef 35mm 1.4L; Zeiss T*50mm MP2.0 ZE; TS-e 90mm 2.8;ef 100mm 2.8; ef 180mm 3.5L;ef 24-105mm 4/5.6L; ef 80-200mm 2.8L

Sinsear

  • Guest
Re: Is This Normal?
« Reply #2 on: April 16, 2012, 11:54:22 AM »
The focus point was set to the mountains in the background, but at 6.3, everything from about 30 feet in front of me to infinity should be in focus. I had sent it back to Canon about 6 months ago for a focus calibration, so I doubt that focusing was an issue. I did the RAW to JPEG conversion via ACR 6.7, which does not exhibit the softness issue experienced by DPP. I did not touch the photo in post, and simply did a straight conversion. ISO 100 was used.

zim

  • 6D
  • *****
  • Posts: 455
    • View Profile
Re: Is This Normal?
« Reply #3 on: April 16, 2012, 12:25:29 PM »
I'd have thought 6.3 would be to open for front to back sharpness on this kind of photo? would not have used infinity focus either. Try at least f8 - f16 and focus a third of the way 'up' the scene I think that's a quick and dirty hyperfocal distance but am happy to be corrected.

kubelik

  • 1D Mark IV
  • ******
  • Posts: 794
    • View Profile
    • a teatray in the sky
Re: Is This Normal?
« Reply #4 on: April 16, 2012, 01:04:11 PM »
I agree with what Zim said.  in my experience, f/6.3 on a full frame is nowhere near small enough to get front-to-back sharpness in any type of photo.  for landscapes, f/11 and up are where you should be shooting.  also, as Zim said, don't trust infinity focus; I always have to rack it back in slightly from infinity, even when shooting something like stars in the sky (which are very, very far away)

Sinsear

  • Guest
Re: Is This Normal?
« Reply #5 on: April 16, 2012, 03:16:32 PM »
Just to clarify, I didn't set it to infinity focus (as that's actually beyond infinity focus, as some of you have commented), I just focused on the hyperfocal point, so at 6.3 @ 16mm, it calculates out to be about 35ft to infinity is in focus. Also, the DLA on the 5D3 is f10.1, so anything after that, the MTF drops significantly. The largest aperture I'd shoot at is f9, but even then, the sharpness degrades (f6.3 is about the sharpest my lens gets).

kubelik

  • 1D Mark IV
  • ******
  • Posts: 794
    • View Profile
    • a teatray in the sky
Re: Is This Normal?
« Reply #6 on: April 16, 2012, 05:32:49 PM »
Sinsear, while you are technically correct about softness from DLA, that is actually different from softness that occurs due to insufficient/shallow DOF.  DLA uniformly soften an image, as it is a optical property that happens at each and every pixel.  it can pretty easily be compensated for in post-processing.  having too shallow of a depth of field, however, results in much more foreground/background blurring, which can not be uniformly corrected for through sharpening the image in post-processing.

so, even if you are losing some per-pixel sharpness in stopping down from f/6.3 to f/11, you are gaining even sharpness in terms of more of the image area being in focus.  simplest solution is to try it out; but trust me there is a reason most landscape photography (and even product photography) is done between f/11 and f/22

canon rumors FORUM

Re: Is This Normal?
« Reply #6 on: April 16, 2012, 05:32:49 PM »

zim

  • 6D
  • *****
  • Posts: 455
    • View Profile
Re: Is This Normal?
« Reply #7 on: April 16, 2012, 06:09:36 PM »
Just to clarify, I didn't set it to infinity focus (as that's actually beyond infinity focus, as some of you have commented), I just focused on the hyperfocal point, so at 6.3 @ 16mm, it calculates out to be about 35ft to infinity is in focus. Also, the DLA on the 5D3 is f10.1, so anything after that, the MTF drops significantly. The largest aperture I'd shoot at is f9, but even then, the sharpness degrades (f6.3 is about the sharpest my lens gets).


Hi Sinsear,

I don't have a Canon EF 16-35mm f/2.8 USM L II but if 6.3 is the sharpest f stop then I'd have thought you have an issue with that lens. I don't think you need to own any lens to know 6.3 is a bit strange for sharpest image but again more than happy to be corrected on that.

TrumpetPower!

  • 1D Mark IV
  • ******
  • Posts: 969
    • View Profile
Re: Is This Normal?
« Reply #8 on: April 16, 2012, 07:38:56 PM »
Sinsear, you also need to understand that the hyperfocal calculations and what-not are for a particular circle of confusion, and that the circle of confusion depends a great deal on the print size. Chances are, you're using a formula for an 8" x 10" print from 135 film fiewed at arm's length, and your results look just about right for that. But, once you start pixel peeping, you're doing the equivalent of pressing your nose against a door-sized poster and the CoC calculations need to be adjusted for that size of an enlargement.

The tags say you shot that with a 5DIII. With that (or any other modern) camera, consulting DoF charts and calculators to determine your shooting settings is, quite literally, the worst possible technique to maximize sharpness. Instead, you want to be using live view with the DoF button engaged. Zoom in to increasingly higher magnification levels while scrolling all around the image and manually adjusting both aperture and focus. Your eyes will tell you when you've achieved the optimal settings for both for that particular scene. It might mean a bit smaller aperture and slight overall loss of sharpness due to diffraction but an increase in sharpness in the foreground, or you might be able to get away with a bigger aperture because you don't have as deep a field to focus on, after all. Regardless, you'll know before you trip the shutter just where you stand, what results you'll get, and that you've got the least-bad compromise to be had for that combination of camera, lens, and scene.

Cheers,

b&

Mt Spokane Photography

  • 1D X
  • *******
  • Posts: 5831
    • View Profile
Re: Is This Normal?
« Reply #9 on: April 16, 2012, 07:56:29 PM »
Just to clarify, I didn't set it to infinity focus (as that's actually beyond infinity focus, as some of you have commented), I just focused on the hyperfocal point, so at 6.3 @ 16mm, it calculates out to be about 35ft to infinity is in focus. Also, the DLA on the 5D3 is f10.1, so anything after that, the MTF drops significantly. The largest aperture I'd shoot at is f9, but even then, the sharpness degrades (f6.3 is about the sharpest my lens gets).

You cannot set this lens by the scale.  The focus ring uses magnets to couplle it to the focus mechanism and will slip.  The scale really means nothing unless you  reset the scale it by first focusing on infinity and then setting the focus ring to infinity.
 
That meand you might have thought it was at the hyperfocal point, but it wasn't.  In any event, it might be in focus from 35 ft to infinity, but not to someone who is picky.

Matthew19

  • PowerShot G15
  • **
  • Posts: 44
    • View Profile
Re: Is This Normal?
« Reply #10 on: April 17, 2012, 04:38:53 AM »
This does not look like a focusing problem to me. The far mountains in the center are way sharper than the ones on the left side. I just created a post on the distortion/softness of this lens in the top left corner. Its really noticeable in video. pisses me off.

akiskev

  • 7D
  • *****
  • Posts: 325
    • View Profile
    • My flickr gallery
Re: Is This Normal?
« Reply #11 on: April 17, 2012, 06:14:06 AM »
Sinsear, is this the best edge sharpness you can get? If so, it is kinda disappointing.
Can you try f/8-f/11 range?
My 17-40 has its best edge sharpness around f/11 when I use it on FF.
Flickr | Canon EOS 3 | Canon EOS Digital Rebel XTi
EF 17-40mm f/4L | EF-S 17-55 f/2.8 IS | EF 70-300mm f/4-5.6 IS | EF 100-400 f/4.5-5.6L
Zeiss 35mm f/2.4 | Zeiss 50mm f/1.4 | Zeiss 85mm f/1.4 | Zeiss 200mm f/2.8 | Zeiss 80-200 f/4

Sinsear

  • Guest
Re: Is This Normal?
« Reply #12 on: April 17, 2012, 01:25:31 PM »
Sinsear, is this the best edge sharpness you can get? If so, it is kinda disappointing.
Can you try f/8-f/11 range?
My 17-40 has its best edge sharpness around f/11 when I use it on FF.



http://www.dpreview.com/lensreviews/widget/Fullscreen.ashx?reviews=43&fullscreen=true&av=3&fl=35&vis=VisualiserSharpnessMTF&stack=horizontal&&config=LensReviewConfiguration.xml%3F2
The maximum sharpness occurs between f5.6 to f8, so yeah, f6.3 is one of the best sharpness apertures.

Sinsear

  • Guest
Re: Is This Normal?
« Reply #13 on: April 17, 2012, 01:26:41 PM »
This does not look like a focusing problem to me. The far mountains in the center are way sharper than the ones on the left side. I just created a post on the distortion/softness of this lens in the top left corner. Its really noticeable in video. pisses me off.

I agree Matthew, it doesn't look like a focusing issue for me either. The mountains on the side of the photos are in the same plane of focus as the ones in the center. Therefore, the natural conclusion is that it's a sharpness/distortion issue, not a focusing issue.

Sinsear

  • Guest

canon rumors FORUM

Re: Is This Normal?
« Reply #14 on: April 17, 2012, 02:12:20 PM »