Canon EF 24-70mm f/2.8L USM, look like a good copy to you?

[lextalionis]

Hey gang,

Based on the shots below does this lens perform avg./good/great? Shot with a Canon 30D in RAW, all ISO 400. Post processed in Bibble Pro 4.9 with Auto-Levels only, first past resize to 640X480 and second pass is a 100% crop. I can post a few full non-resized if needed.

Last what's a fair price for this lens which seemed to be in great condition, with box, original owner bought 2 years ago from B&H?

F/2.8 24mm


100% Crop from original RAW



F/4.5 24mm


100% Crop from original RAW



F/8 24mm


100% Crop from original RAW



F/2.8 70mm


100% Crop from original RAW



F/4.5 70mm


100% Crop from original RAW



F/8 70mm


100% Crop from original RAW



F/2.8 40mm


100% Crop from original RAW



F/4.5 40mm


100% Crop from original RAW



F/8 40mm


100% Crop from original RAW



F/4.5 70mm


100% Crop from original RAW



F/4.5 35mm


100% Crop from original RAW



F/5 28mm


100% Crop from original RAW



F/6.3 32mm


100% Crop from original RAW



F/7.1 24mm


100% Crop from original RAW



F/3.5 63mm


100% Crop from original RAW



F/3.5 65mm


100% Crop from original RAW




Thanks,
Roy

[Demonic]

Roy, they look sorta soft... i'll check it out tonight when i get home..try to post a 100% crop from my 24-70.

seems like i saw someone selling a copy of this lens for around $950 used.

[Gordon]

Roy, what sort of tripod were you shooting these from ?

Are you using a cable release, mirror lock up etc ?

If not, it isn't really possible to determine if the lens is any good or not. A whole lot of other factors come in to play, other than the lens (available light, the type of light, ability of the photographer, appropriate shutter speed etc)

Also, obviously, where you focus vs where you crop will make a big difference. At f3ish and close to a subject, you'll only have a few cm of sharp focus and a pretty quick fall-off, particularly if you are cropping in 100%. At f2.8 if you focus on the front of a building, the side going away from you could easily be falling out of focus pretty quickly.

Just a thought.

[lextalionis]

Gordon,

I thought about the crop areas and I'm relativly new to this. I thought since the center is usually sharp that I could crop to the side more. I used Giottos tri with ball head and the shots were taken w/o timer and w/o cable release and w/o mirror lock up...just standard push the shutter button.

Humm...it's hard to try this again since I would have to meet the person selling it again.

-Roy

[Gordon]

Roy - do you understand about depth of field ? That's the fall-off in sharpness from the point of focus, to points further away and closer to the camera, than where you've focused.

Depth of field varies by aperture (the f-stop) and the distance from the camera of the point focused upon.

If you focus on something close up, all things being equal, the depth of field will be smaller than if you focus on something far away.

If you shoot at a very open aperture (a small f number) the depth of field will be smaller than if you shoot at a larger aperture.

There's a flat plane that's in focus, parallel to the camera, at the point where the camera focuses. So if you focus on someone's eyeball and they are facing you, their ear will be out of focus at a wide open aperture.

Same way if you focus on the front of a building - the back of the building is further away and will be softer as a result. Where you crop relative to that plane in space will have a big difference on how sharp or soft the result is.

As an extreme example. The 100mm is one of the very sharpest lenses I own. Here it is shooting at f2.8. You can see that where you would pick a crop out of that shot would tell a very different story about how sharp a lens it is. You have a similar, but perhaps less extreme situation above.


(click for a larger version)


Then also, the handholding, low light, camera shake etc all make an image much softer than it could be on a tripod. If you need to prove that to yourself, get a laser pointer and point it at a wall 6 feet away from you. Stop the point from moving. Now put the pointer on a table and stop it moving. The tripod is like that - even at high, fast shutter speeds.

[lextalionis]

I have a decent grasp on DOF...I just should have croped at the center or where the center point focus locked.

Here are all of the RAW's

http://www.motleypixel.com/public/IMG_3533.CR2
http://www.motleypixel.com/public/IMG_3534.CR2
http://www.motleypixel.com/public/IMG_3535.CR2
http://www.motleypixel.com/public/IMG_3536.CR2
http://www.motleypixel.com/public/IMG_3537.CR2
http://www.motleypixel.com/public/IMG_3538.CR2
http://www.motleypixel.com/public/IMG_3539.CR2
http://www.motleypixel.com/public/IMG_3540.CR2
http://www.motleypixel.com/public/IMG_3541.CR2
http://www.motleypixel.com/public/IMG_3542.CR2
http://www.motleypixel.com/public/IMG_3543.CR2
http://www.motleypixel.com/public/IMG_3544.CR2
http://www.motleypixel.com/public/IMG_3545.CR2
http://www.motleypixel.com/public/IMG_3546.CR2
http://www.motleypixel.com/public/IMG_3547.CR2
http://www.motleypixel.com/public/IMG_3548.CR2
http://www.motleypixel.com/public/IMG_3549.CR2
http://www.motleypixel.com/public/IMG_3550.CR2

[The Philos]

Sorry for the aside, that looks like the UCS building.

[Gordon]

Got them to load in LR. Must by my RAW converter isn't up to date for the other software. I'm still guessing you were handholding most of these, given you are shooting around ISO400 ?

It isn't the best way to tell if a lens is any good, camera shake and sensor noise are going to be as much a factor as lens quality, potentially.

[lextalionis]

Yes RAW from the 30D...they load find for me in Bibble and FastStone. Odd, maybe someone else will try.

It's the National Instruments building off MOPAC and Duval.

-Roy