Need help testing Canon 17-55 vs 17-85

Hey guys,





So I just got my copy of the 17-55 after lots of forum reading about it. After viewing the sample shots on this website comparing the two lenses I had expected a massive increase in IQ compared to the 17-85 but after doing a few test shots I can't seem to see much of a difference.


I tested them with my canon T2i on a tripod at same focal lengths and same apertures. I manual focused them using live view to make sure the focus was right.


Here are two shots:


[img]/resized-image.ashx/__size/550x0/__key/CommunityServer-Discussions-Components-Files/8/1200.test-1.JPG[/img]


This one is the 17-85


[img]/resized-image.ashx/__size/550x0/__key/CommunityServer-Discussions-Components-Files/8/0358.test-2.JPG[/img]


This one is the 17-55





Now I wanted the f2.8 for indoor shots but I was also hoping for better IQ.


I'm not sure if I have a bad copy of the 17-55 or a really good copy of the 17-85 (probably not)


Or is it just the way I tested it?





I would just like to be sure it's not a bad copy before my return period expires.





Thanks guys

Hi, and welcome to the TDP forums!

Quote:

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Originally Posted by tk303

I tested them with my canon T2i on a tripod at same focal lengths and same apertures.

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Sorry, but are you certain? The framing is different (the 17-55mm is shifted to the right, but even compensating for that, the 17-55mm framing is slightly tighter - that may be due to imprecision on the zoom ring markings - check the EXIF data). Also, the OOF area appears blurrier with the 17-55mm, suggesting the aperture is wider (again, check the EXIF - if the same, the 17-55mm is delivering more background blur).


Image quality is difficult to judge in a 550 pixel-wide forum image - a common convention is to post 100% crops from center (assuming that's where you're focusing) and corner (framed identically so we're looking at the same part of the image). Also, to check corner performance, you really want a subject that's flat, so the corners are in the plane of focus (or focus on a corner with 10x live view).


--John

Ps. I

Thanks for the reply John,


You are 100% correct. I accidently posted the wrong photos of the handheld shots I did outside.[:$]


Ok so I've just done another test:


This test is 100% crop 17mm f4 on a tripod.


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/8611.100_2500_-crop-17mm-f4-17_2D00_55.jpg[/img]


This is the 17-55


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/7713.100_2500_-crop-17mm-f4-17_2D00_85.jpg[/img]


This is the 17-85





I know the crop is slightly different from each other but I didn't think that would matter.


The crop was center and about 20% to the left of the image.


I hope this is a better sample to show thew IQ of the lenses.





Thanks for your quick response.

To me, the 17-55mm image appears to be sharper and also has better contrast and saturation - pertty much what I would have expected. I'd expect even greater differences in the corners, where the 17-85mm performance is reportedly not so great.

I

I guess it is a little sharper.


I was just hoping for more of a difference like this:


http://www.the-digital-picture.com/Reviews/Canon-EF-S-15-85mm-f-3.5-5.6-IS-USM-Lens-Comparisons.aspx


If you scroll down to the 17mm test at f4 there is a huge difference between the two lenses.





I know it's not really a <span style="background-color: #ffffff;"]L lens and not a prime <span style="background-color: #ffffff;"]so I can't really compare it but when I got my 100mm f2.8 macro L the first photo blew me away compared to anything I had.


<span style="background-color: #ffffff;"]I guess I was just expecting too much from this lens.





<span style="background-color: #ffffff;"]Thanks for all your feedback

I also find a big difference, particularly in areas with high contrast, for instance the texts on the books. I guess that the ISO charts are made to reveal small differences that you hardly would find in lower contrast pictures. I know that there are many that prefer to test lenses in "real life" rather than on ISO-charts, because the chart is too artificial. I can't judge what is best, but your test seems sensible to me.


Lars

Quote:

---

Originally Posted by tk303

I was just hoping for more of a difference like this:


http://www.the-digital-picture.com/Reviews/Canon-EF-S-15-85mm-f-3.5-5.6-IS-USM-Lens-Comparisons.aspx


If you scroll down to the 17mm test at f4 there is a huge difference between the two lenses.

---

I think you're seeing a similar difference between your lenses, actually. Bryan's test scenes have more fine detail and harsh contrasts than your bookshel and gumball machine - the detail and contrast accentuates the differences between the lenses. What's also evident in your images that Bryan's comparison doesn't show is that the 17-55mm also delivers better color than the 17-85mm.

Hey John,





So I took a couple of crops from the bottom left corner of the image and can more clearly see the difference.


I guess my eyes are just not as perceptive.


Ill put them up just encase anyone else is looking at upgrading to this lens and they want to see the difference.


17-55


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/3513.100_2500_-crop-17mm-f4-bot-left-1.jpg[/img]


17-85


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/2705.100_2500_-crop-17mm-f4-bot-left-2.jpg[/img]





Thanks again for all your advice and comments.





I'm off to go enjoy my new toy [:)]