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Posts: 8,469
Registered: ‎12-07-2012

Re: Can you pick......

My main most thing here is to show even though one of these lenses scores very high on lab score sheets and graphs, one lens doesn't, it is hard to tell that difference.  When used in a worldly snapshot, where 99% of us use them, it becomes difficult to pick.

 

The third lens, thrown in just to better confuse things, is a pretty decent lens and holds its own in lab tests.

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Esteemed Contributor
Posts: 2,220
Registered: ‎11-14-2012

Re: Can you pick......

As you know I'm a big user of superzooms & lab results for the majority of decent lenses mean nothing when panning a moving target. A sharp lens and poor panning skills = poor results. Throw the need to use a slow shutter speed in to get motion blur & lab tests are pretty much of no use. Add to all of that we generally downsize most images we share so they can be shared on the internet.

"A skill is developed through constant practice with a passion to improve, not bought."
Esteemed Contributor
Posts: 3,186
Registered: ‎06-11-2013

Re: Can you pick......

You don’t have consistent focus.  

 

In ‘a’ the word ‘subs’ is sharper than it is in ‘b’.  

In ‘b’ the ‘esh’ left of the word ‘subs’ is sharper than it is in ‘a’.

 

This tells me the focus distance wasn’t consistent between the two shots.

 

Tim Campbell
5D III, 5D IV, 60Da
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Registered: ‎12-07-2012

Re: Can you pick......

"You don’t have consistent focus."

 

These were snap shots just they way most people use their cameras.  The distances with each is similar, not exact but reasonably close.  This is not a lab experiment.

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Esteemed Contributor
Posts: 4,543
Registered: ‎11-13-2012

Re: Can you pick......

Plus, the place of the focus point doesn’t always mean the place of focus if the AFMA isn’t on target.

To me the bottom line is that there are many factors that ultimately affect how sharp an image is, and those factors can negate the lens quality. We try to control those factors to maximize image quality.
John Hoffman
Conway, NH

1D X, Rebel T5i, Many lenses, Pixma PRO-100, MX472
Respected Contributor
Posts: 1,787
Registered: ‎12-02-2012

Re: Can you pick......

The bokeh balls in shot "C" contain some onion rings and some inclusions.

 

"A" looks sharper than "B".

 

None of these differences are all lthat major in this shot.

 

Did you correct for CA?  I would have expected to see more of it in a shot including sharp edges against a bright background.

Scott

Canon 5d mk 4, Canon 6D, EF 70-200mm L f/2.8 IS mk2; EF 16-35 f/2.8 L mk. III; Sigma 35mm f/1.4 "Art" EF 100mm f/2.8L Macro; EF 85mm f/1.8; EF 1.4x extender mk. 3; EF 24-105 f/4 L; EF-S 17-55mm f/2.8 IS; 3x Phottix Mitros+ speedlites

Why do so many people say "FER-tographer"? Do they take "fertographs"?
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Registered: ‎12-07-2012

Re: Can you pick......

Scott, I have a preset in LR that does lens correction upon import.  I never change it and it runs on every photo.  So yes, CA was done.  One lens was the Sigma 35mm f/1.4 DG HSM Art Lens for Canon.  One was another 35mm and the other was a 50mm.  Perhaps that clue will help.

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Esteemed Contributor
Posts: 3,186
Registered: ‎06-11-2013

Re: Can you pick......


ebiggs1 wrote:

"You don’t have consistent focus."

 

These were snap shots just they way most people use their cameras.  The distances with each is similar, not exact but reasonably close.  This is not a lab experiment.


Ok but... that completely invalidates the whole point of a comparison.

 

If you were to say "I'm goint to take the same shot, the same settings, the same focus point, and the ONLY difference will be which lens I selected" then we'd know that any difference we see... must be due to the lens you chose and ONLY due to the lens you chose.

 

But when you focus on different spots... AND the lens changes between shots... we are no longer sure if the difference in focus has to do with the chosen lens... or the chosen focus point... or maybe a combination of both.

 

And since we can't safely draw a conclusion... it sort of defeats the whole point of doing a comparison.

 

I DO realize at this point you probably think I am picking at nits.   But it's because doing these types of comparisons at all is also sort of picking at nits.  I'm a scientific-minded person.  To my way of thinking ... if you're going to do a test at all... then do it accurately (otherwise what's the point?)

 

There's SO much more to a lens than how "sharply" it focuses.  Roger Cicala of LensRentals had a blog article where he picked at the term "sharpness" because it's not really "a" thing... it's a combination of things that combine to a result.   He also points out that sometimes a flaw creates a beautiful effect (a lens that scores more poorly can create a photo that is more beautiful).    

 

 

Some lenses have a more pronounced out-of-focus meridonal blur... so the out of focus areas sort of seem to be swirling around the center (but only because it's out of focus ... in focus areas are still in focus).  You might be tempted to think of it as a bit of a flaw... except it can actually look appealing.

 

And there are more factors... barrel distortion, focus breating, chromatic abberation, focus speed performance, image stabilization performance, and the list goes on.  

 

You have to be careful with expressions like "snap shots just the way most people use their cameras" because I suspect "most people" are using their phones and only the fussy people (like us) are using DSLR camers with expensive lenses.  Smiley Wink

 

 

 

I generally stay away from the "My ___ is better than your ___" debates.  Most modern equipment is pretty good (as long you don't happen to have a defective copy).   Often times those are subjective opnions or related to suitablility for a particular purpose that might not be valid for a different purpose.   What really matters is that the equipment is working for your purposes.  But when you really try to pin something down to a nit... "the focus motors in this lens respond faster than the focus motors in that lens".. now you've entered into area that can be compared based on an objective measurement and is no longer subjective.  But of course those objective measurements are only valid if you perform the experiement in way that isolates the variables.  It wouldn't be fair to test one lens' focus motor speed on a stationary subject... while testing the other lens on a moving subject.  Everything must be the same.

 

 

 

Tim Campbell
5D III, 5D IV, 60Da
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Registered: ‎12-07-2012

Re: Can you pick......

"But when you focus on different spots... AND the lens changes between shots..."

 

Tim Campbell you have missed the entire point of this little exercise.  The point is that even when the best, or what is considered the best is used the way people actually use it, how much difference is there.

 

"This is not a lab experiment."  People rarely to never use their gear in a lab or shoot pretty graphs.

 

 However, that said, everything is roughly similar.  It was all done pretty much the same way.  Each focus point was the center of the cup. Exposure roughly the same. I used a very good lens and a not so very good lens.  Then I threw in a spoiler just to complicate the matter so there wasn't just an A vs B choice.

 

The point, just how good is the best when used in real world situations?  I believe, part of how good a lens is how good the user thinks it is.  I have done this type test numerous times in my DSLR classes.  I am always amazed at the response.  Some are like yours!  It isn't fair. There is no right or wrong here.  Just can you spot the best lens outside of the lab? In this case, it is pretty difficult.

 

I have done another one that certainly surprises most folks.  I compare film vs digital.  If I can find it I might re-post it here.  Again the way people use both.  Not in  lab setting.

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Frequent Contributor
Posts: 162
Registered: ‎11-19-2017

Re: Can you pick......

Ernie,

Are we going to get an actual reveal on this (specific lenses).  Or was it entirely an exercise?

 

Thanks,

Rick
Bay Area - CA
~6D2 (f/w 1.0.3) ~16-35mm f2.8L II, 50 f1.8 STM, 85 prime, 70-200 f2.8L IS II ~Sigma 24-70 f2.8 Art
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