Hi
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]I have a 50D and the ef-s 17-85mm lens (came as a kit). I'm happy with the image quality most of the time and the zoom range is good. But feel it could be a little sharper.
I'm thinking about upgrading this lens to one or two of the following lenses.<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]1) ef-s 15-85mm f/3.5-5.6 IS USM
If I didn't had the 17-85 this is properly a excellent choice. <span style="mso-spacerun: yes;"]Can I justify the upgrade?<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]2) ef 24-105mm f/4 L USM
Is the IQ better than the new 15-85mm. If IQ is significant better I can live without the wide end.<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]3) ef 16-35mm f/2.8 L II USM
Is IQ better than the new 15-85 and will I miss IS.
It could be good for indoor without flash?<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]4) ef-s 17-55mm f/2.8 IS USM
I should have bought than in the first place along with the 50D.
I like the L lenses better by look or the new 15-85mm.<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="font-size: small;"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-family: Calibri;"]5) wait to see if there is a new 24-70mm f/2.8 L with IS coming out.
I would choose this one<span style="font-family: Wingdings; mso-ansi-language: EN-GB; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin; mso-char-type: symbol; mso-symbol-font-family: Wingdings;" lang="EN-GB"]<span style="mso-char-type: symbol; mso-symbol-font-family: Wingdings;"]J<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<o></o>
<p style="margin: 0cm 0cm 10pt;" class="MsoNormal"]<span style="mso-ansi-language: EN-GB;" lang="EN-GB"]<span style="font-size: small;"]<span style="font-family: Calibri;"]I have been starring blind at the iso crops to compare I and reading a lot of reviews. But not all are tested with the 50D.
By good IQ I will have very sharp images and good color/contrast.
I'm not going FF in the next couple of years.<span style="mso-spacerun: yes;"] Might get a 70-200mm f/4 L<span style="mso-spacerun: yes;"] IS for the long end later.
If I choose the ef-s 15-85mm I will also get the 24 mm f/1.4 L II for low light all round shoots (the 35mm f/1.4 L is also a possibility, but is rather old). These to primes are super sharp.

To make it more simple to choose:
- don't focus to much on the zoom range (can live without the wide or long end).
- outdoor daylight shooting.
- travel lens.
- hand held shooting.
- don't focus on the price of the lens.
- don't focus on distortion and vignetting.
- family and kids in and around the house.<o></o>


<span style="font-size: 11pt; line-height: 115%; font-family: 'Calibri','sans-serif'; mso-ansi-language: EN-GB; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB"]Which lens will give me the best IQ on the 50D? Hope someone can help me.