What is a good test to see the difference between kit lens and Canon 24-105?

[spartans]

I'm trying to see the difference and justify the cost of the Canon 24-105 lens.

Current equipment is a canon Rebel XSi, 12.2 meg camera with the kit lens.

What I want to do is set up shots that are within the capability of the kit lens in order to separate and justify a lens that is three time more expensive then the camera itself. If I can't and the reason is that the camera is not good enough to tell the difference, then it's stupid to even look at that lens. Simply wait and get a better camera. If the lens can show me the difference even in a three year old camera, then it will also show me the difference in more advanced cameras.

Sooo....

What is a reasonable test between the kit lens and the Canon 24-105? Obviously it has to be within the 24-55 range that both are capable off. It has to be jpeg because I want to capture memories, not Photoshop material.

I will share the pictures. If you guys want, I can do a blind A-B test and you guys can tell me the difference. For me, I'm really, honestly neutral about this. I like to get a better lens, but I wont justify it unless I see results.

 

[subscuck]

Any DSLR will show the difference between good glass and cheap glass. What mystifies me a little is this:

It has to be jpeg because I want to capture memories, not Photoshop material.

A digital pic will never look like a 35mm film print straight out of camera. Just as the lab tweaks your film prints, you need to tweak your digital pics. Even more so as digital has less dynamic range than print film. If you're not going to maximize the improvement good glass will net you, why spend that kind of money on glass?

 

[bazooka]

Not sure which 18-55 you have, but check out this site for quality comparison....
Canon EF 24-105mm f/4 L IS USM Lens Image Quality

Note that the 24-105 is on a 1Ds (1.3 crop) and the 18-55 is on a 50D (1.6 crop) so the magnification is somewhat different.

 

[Robin Usagani]

Get your fact right. 1Ds is full frame, 1D is 1.3 crop

Not sure which 18-55 you have, but check out this site for quality comparison....
Canon EF 24-105mm f/4 L IS USM Lens Image Quality

Note that the 24-105 is on a 1Ds (1.3 crop) and the 18-55 is on a 50D (1.6 crop) so the magnification is somewhat different.

 

[bazooka]

Ah, very good, my apologies.

 

[TheBiles]

You don't even need a test for that. Any piece of L glass will curbstomp the kit lens.

Also, who suddenly made the rule that "memories" have to be ****ty straight out of the camera JPEGs?