Sharpness Test Images Opinions Please - They all look the same to me!

[Sxot]

Hi Folks,
Everyone tells me just about every lens is sharpest two stops down so I decided to find out for my lens. (70-300 F4.5/6.3 DX). I shot Steve's test target after doing the AF-Fine tune process. I set the camera to Aperature priority mode and shot consecutive images from a tripod, without re-focusing. Thing is, they all look identical to me! I'd appreciate some feedback as to the sharpness of these images and which one you think is sharpest. Maybe my process was flawed? Thanks for your feedback.

The images can be downloaded from my dropbox: https://www.dropbox.com/s/jy6wqn9je4he54n/Sharpeness%20Test%20Images.zip?dl=0

 

[DRwyoming]

Thanks for your feedback.

It's possible your test procedure might have had room for improvement as it's very hard to differentiate small changes without very careful technique (e.g. fix the exposure, use adequate shutter speed at low enough ISO so noise doesn't degrade apparent sharpness, mirror lockup, cable release or delay, etc.). but you may also be trying to split hairs on very close sharpness results.

Here's a link to Lenstip's review of this lens. If you're doing your testing at 300mm they measured very little change in sharpness from wide open to at least f/11 and then the lens started showing diffraction limited sharpness as it was stopped down further. https://www.lenstip.com/537.4-Lens_...300_mm_f_4.5-6.3G_ED_VR_Image_resolution.html

I'd expect it to be very difficult to differentiate the sharpness at 300mm between f/6.3 and f/11 based on the measurements linked above as they're virtually identical across that range. The good news being that if it's that hard to measure any sharpness changes with aperture then for all practical purposes you don't have to worry about that aspect in the field. If you can't tell the difference when shooting test targets in controlled conditions then you really won't be able to tell any difference with real world subjects shot under field conditions.

 

[Sxot]

It's possible your test procedure might have had room for improvement as it's very hard to differentiate small changes without very careful technique (e.g. fix the exposure, use adequate shutter speed at low enough ISO so noise doesn't degrade apparent sharpness, mirror lockup, cable release or delay, etc.). but you may also be trying to split hairs on very close sharpness results.

Here's a link to Lenstip's review of this lens. If you're doing your testing at 300mm they measured very little change in sharpness from wide open to at least f/11 and then the lens started showing diffraction limited sharpness as it was stopped down further. https://www.lenstip.com/537.4-Lens_...300_mm_f_4.5-6.3G_ED_VR_Image_resolution.html

I'd expect it to be very difficult to differentiate the sharpness at 300mm between f/6.3 and f/11 based on the measurements linked above as they're virtually identical across that range. The good news being that if it's that hard to measure any sharpness changes with aperture then for all practical purposes you don't have to worry about that aspect in the field. If you can't tell the difference when shooting test targets in controlled conditions then you really won't be able to tell any difference with real world subjects shot under field conditions.

Thanks for your thought @DRwyoming. You make a valid point, and I believe I had solid test procedure and can tick off the elements you mention. Having said that my results concur with that of lenstip so I am happy to call it good. It is nice to know that wide open or stopped down I am not going to see any sharpness differences. I am often in low light situations so shooting wide open (which isn't very wide) is attractive.

 

[Flyboy]

You are right...it's hard to see any difference in your lens tests... and that can be frustrating I know, having been there myself. In most, cases, our shooting technique is more important than the ultimate resolving power of a lens. No manufacturer sets out to make a bad lens, and even the least capable are plenty sufficient to 95% of our needs.
The Lenstip tests showed great resolution from f/5.6-11, and not much loss at f/16.
In the past, I also frustrated myself by taping lens test charts to my back shed...I could see some difference, but now my tests are crude, but effective. With my AF P 70-300 4.5-5.6, I backed across the office room, and across the hall, distance probably 20 feet max, and focused on a large flower on the curtains. At 300 mm/any f/stop/100% enlargement, I could count the individual threads in the fabric weave! Good enough for my purposes. I remember a Wildlife photog years ago, saying "Lens tests? I take pictures of fur! I test by taking pictures of fur!" Mounted animals, etc.
Focus tuning? It must be a real thing, or the manufacturers wouldn't have included it, right? "New and Improved" and my camera has more features than yours? I've tried it...once...and, in my never-humble opinion...if it is cold, raining, snowing, or windy outside, and/or the Good Lady Wife has asked you to hold her knitting yarn, or wash the cat....maybe. YMMV!
But...good luck in your search.