martin_aus_duesseldorf
Unregistered
Hello all,
something I do not understand regarding the verdict of the lens tests.
I got an offer to buy a pretty nice L lens from Canon and I compared those to my existing (much cheaper) lens. I found out the L lenses are much less sharper than my old ones, but the verdict says take the L and forget the old crap.
Ok, distortion and vignetting are bad compared to the new lens, end yes the old lens are EF-S and the other one is a L. But for distortion and vignetting the camera and later Lightroom will correct this pretty fine - but the sharpness of the old lens is much better!!!
Why does the verdict praise the L lens and condem the EF-S lens?
Because its L and EF-S???
Any idea???
In detail:
"New Lens": Canon EF 17-40mm f/4 USM L
"Old Lens": Canon EF-S 17-85mm f/4-5.6 USM IS
The advantages of each lenses are pretty clear to me… I struggle with the sharpness.
Example values (all values taken from border at F/8):
17 mm
New: 1872
Old: 2057
24 mm
New: 1677
Old: 2167
40 mm (new) / 50 mm (old):
New: 1638
Old: 2167
If I compare the values taken from centre the differences are much more.
Regards,
Martin
11-14-2013, 11:21 AM
(This post was last modified: 11-14-2013, 11:21 AM by Rainer.)
Martin,
I see the typical error of someone who compares apples to pears.
You took the 17-40L Test on 8mpix and compared it to the 17-85 test made
on 15mpix. You will agree (eventually after some thinking about it) that
this comparison is useless.
Take the tests within the same testfamily if you want to compare naked numbers,
or just compare the trend. You'll see, the 17-40 is indeed better than the 17-85
... and it delivers better pictures also ... nevertheless, I wouldn't swap a
17-85 for a 17-40 on a crop-1.6 camera.
just my 2cts ... Rainer
Quote:Hello all,
something I do not understand regarding the verdict of the lens tests.
I got an offer to buy a pretty nice L lens from Canon and I compared those to my existing (much cheaper) lens. I found out the L lenses are much less sharper than my old ones, but the verdict says take the L and forget the old crap.
Ok, distortion and vignetting are bad compared to the new lens, end yes the old lens are EF-S and the other one is a L. But for distortion and vignetting the camera and later Lightroom will correct this pretty fine - but the sharpness of the old lens is much better!!!
Why does the verdict praise the L lens and condem the EF-S lens?
Because its L and EF-S???
Any idea???
In detail:
"New Lens": Canon EF 17-40mm f/4 USM L
This lens makes most sense as ultra wide angle on full frame (5D, 6D, 1D). Not too much on APS-C, look for for instance a Sigma 17-50mm f2.8 EX DC OS HSM instead.
Quote:"Old Lens": Canon EF-S 17-85mm f/4-5.6 USM IS
A pretty undesirable lens, in my opinion. Strong CA, low contrast and a lot of barrel distortion at the wide end, and does not open much at the portrait end... Not a winner.
Quote:The advantages of each lenses are pretty clear to me… I struggle with the sharpness.
What are the advantages of the 17-40mm f4 on APS-C then?
Quote:Example values (all values taken from border at F/8):
17 mm
New: 1872
Old: 2057
24 mm
New: 1677
Old: 2167
40 mm (new) / 50 mm (old):
New: 1638
Old: 2167
You are comparing tests from an old and a newer camera body.
http://www.opticallimits.com/canon-eos/4...0d?start=1
http://www.opticallimits.com/canon-eos/4...0d?start=1
Compare these instead.
Quote:If I compare the values taken from centre the differences are much more.
Regards,
Martin
martin_aus_duesseldorf
Unregistered
ah - outch, if mixed up the tests.
Yes apples and pears! got it!
But I am more than happy about this answer, now I am sure what to do!
And for sure I know the new lenses will make much more sense on a full format body - that´s what I save up for.
But even on my eos 7 they will be pretty fine - replacing those looser-lens (where I disagree).
:-)
I can get a couple of lens and a body from someone who sells everything for a quite nice price. What I don´t need will be sold at eBay - but no budget for a new Sigma.
Thanks for helping!!
Regards,
Martin
Quote:Hello all,
something I do not understand regarding the verdict of the lens tests.
I got an offer to buy a pretty nice L lens from Canon and I compared those to my existing (much cheaper) lens. I found out the L lenses are much less sharper than my old ones, but the verdict says take the L and forget the old crap.
Ok, distortion and vignetting are bad compared to the new lens, end yes the old lens are EF-S and the other one is a L. But for distortion and vignetting the camera and later Lightroom will correct this pretty fine - but the sharpness of the old lens is much better!!!
Why does the verdict praise the L lens and condem the EF-S lens?
Because its L and EF-S???
Any idea???
In detail:
"New Lens": Canon EF 17-40mm f/4 USM L
"Old Lens": Canon EF-S 17-85mm f/4-5.6 USM IS
The advantages of each lenses are pretty clear to me… I struggle with the sharpness.
Example values (all values taken from border at F/8):
17 mm
New: 1872
Old: 2057
24 mm
New: 1677
Old: 2167
40 mm (new) / 50 mm (old):
New: 1638
Old: 2167
If I compare the values taken from centre the differences are much more.
Regards,
Martin
We put high priority on the extreme corners with all wide-angle lenses and the 17-85 IS doesn't shine here.
The 17-85 has also mucher higher vignetting, CAs and distortions than the 17-40L.
martin_aus_duesseldorf
Unregistered
You are right, I have no doubt that the 17-40L is much much much better than a 17-85 IS!
(now)
But why do you all here stress vignetting, CAs and distortion that much? It is crystal clear being on the better site to take a good picture against having a poor one where software must help.
But vignetting and distortion (and with restrictions CAs as well) are issues where software can help pretty much.
I know the issues around my old lenses and correct them...
Okay perhaps I will see the difference when I took some pictures with the new lens and then I understand why my current are some poor undesirable looser lens are. :-)
I hope (but honestly I don´t think so).
Do you strongly disagree on my thoughts regarding software correction of optical issues (except sharpness)?
cu!
Martin
Quote:ah - outch, if mixed up the tests.
Yes apples and pears! got it!
But I am more than happy about this answer, now I am sure what to do!
And for sure I know the new lenses will make much more sense on a full format body - that´s what I save up for.
But even on my eos 7 they will be pretty fine - replacing those looser-lens (where I disagree).
:-)
I can get a couple of lens and a body from someone who sells everything for a quite nice price. What I don´t need will be sold at eBay - but no budget for a new Sigma.
Thanks for helping!!
Regards,
Martin
I am not sure what you are talking about here. (You could talk German if that helps)
Do you mean you have an old EOS 7 Film camera? The EF-S lenses will not fit on the old film cameras, they fit only the newer crop body digital cameras (Not sure from which model on, but EOS 30D, 350D, and higher should work I think).
Also, the 17-40 L lens is the oldest lens, older than the EF-S lenses that came afterwards. It was the first to give a normal range zoom on crop bodies. But for modern digital bodies, most of the time, i.e. if you don't have a FF body, and don't plan an immediate upgrade, you are better of with any of these lenses: EF-S 18-55 IS (STM), EF-S 15-85 IS (which is the newer version of the 17-85 lens, and quite a bit of improvement), or the EF-S 17-55 f2.8 IS.
martin_aus_duesseldorf
Unregistered
do I really appear as such as a novice? :-)
Well, I was writing about an EOS 7D and I am aware of the EF-S/crop aspects. Sorry for being imprecise. And yes "sometimes" I plan to have an full format EOS.
My point was whether issues around vignetting and distortion (and with restrictions CAs) are that bad or if they can corrected with appropriate software.
cu!
Martin
Quote:You are right, I have no doubt that the 17-40L is much much much better than a 17-85 IS!
(now)
But why do you all here stress vignetting, CAs and distortion that much? It is crystal clear being on the better site to take a good picture against having a poor one where software must help.
But vignetting and distortion (and with restrictions CAs as well) are issues where software can help pretty much.
I know the issues around my old lenses and correct them...
Okay perhaps I will see the difference when I took some pictures with the new lens and then I understand why my current are some poor undesirable looser lens are. :-)
I hope (but honestly I don´t think so).
Do you strongly disagree on my thoughts regarding software correction of optical issues (except sharpness)?
cu!
Martin
Software correction is mostly lossy. However, I have no problems with this per se. You just don't have 17mm anymore but probably something around 21mm if you apply distortion correction - thus the 17-85 deteriorates to a 21-80mm lens. Compensating the vignetting will increase the corner noise by 1.x stops. The CA correction is lossless - no issues here.
Nothing can help you regarding the slight corner softness though (although the distortion correction may push the worst part out of the image field but then it's stretching & interpolating some other image portions making them worse).
If you are happy with the results from your lens, there is no debate anyway. Just live a happy life then.
The reviews are meant for people out there choosing new lenses, not for reassurance. :-)
Quote:do I really appear as such as a novice? :-)
Well, I was writing about an EOS 7D and I am aware of the EF-S/crop aspects. Sorry for being imprecise. And yes "sometimes" I plan to have an full format EOS.
My point was whether issues around vignetting and distortion (and with restrictions CAs) are that bad or if they can corrected with appropriate software.
cu!
Martin
Klaus answered it already.
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