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  Reviews by: steveprice  

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Canon EF 24-105mm f/4L IS USM

Review Date: Jan 20, 2006 Recommend? yes | Price paid: Not Indicated | Rating: 10 

Pros: Outstanding (qualified - see below)
None (my third copy)

I dont know if gwhitegoeg's explanation is correct (see below)
but it fits in with my experience. I originally hunted high and low in early December for a 5D and 24-105 lens kit and have since had and returned two. See my previous post criticising this lens for vignetting. The reason I persisted was that Canon said it shoud not vignet and they advised me to exchange it. Vignetting is light fall of at the corners and edges of the picture frame, for whatever reason. In the case of the first two copies I had bad vignetting. It was correctable in Photoshop but not easily. I teach Photoshop by the way. This week I got my third copy of the kit and wow, what a difference. There is no vignetting even at 24mm and f4. And it is much sharper. I am not doing any post sharpening whatsoever and I have left the in-camera sharpening on the default setting of 3, on previous versions I had to up the setting to 7, the maximum, or sharpen a lot in pshop.

The difference I noticed is that I did not have to hunt high and low for the third copy, my local dealer actually had some in stock, as did other local dealers. This is what makes me think gwhitegoeg' report might be correct.

The moral: be persistant, stick to your guns, read these reviews and you will be rewarded.

Canon EOS 5D

Review Date: Dec 31, 2005 Recommend? yes | Price paid: Not Indicated | Rating: 9 

Pros: Big LCD with zoom feature (niiiiiice), feels good, 12.8 megapixels, good at high ISO, easy to understand and navigate buttons and menus, not too heavy (until you add the must-have battery grip)
Minor niggles are: I found I pressed buttons with my left thumb when holding in portrait orientation; battery only lasted one afternoon (about 100 shots), second battery a must-have, as is probably the extended battery grip, costly batteries and grip, ISO is static i.e. it doesn't change automatically to suit the lighting, exposure compensation involves a switch, a button and a dial, I will never use the direct print function.

If it wasn't for the battery issue I would have given overall 10.

Canon EF 24-105mm f/4L IS USM

Review Date: Dec 30, 2005 Recommend? yes | Price paid: Not Indicated

Pros: Analysis of December reviews

Some people like this lens, some dont. So how does it stack up by type of camera? I did some sums. I counted who likes it, who doesn't and what sort of kit they have i.e. full frame or crop sensor. In Dec 05 (up to 28th: aVOlanche) there are 31 reviews, this is the breakdown:

Full frame (i.e. 5D owners): 4 out of 4 dislike
Crop sensor: 17 likes, 3 dislikes
Kit not indicated: 5 likes, 2 dislikes.(1)

(1) Reading between the lines I suspect those people whot did not indicate their kit are sub-full frame users. The full frame users who dislike it do so largely because of the vignetting.

My vignetting tests by f stop:
[email protected] severe vignetting, correctable to moderate
[email protected] moderate, correctable to slight
[email protected] slight, correctable to very slight
[email protected] very slight, correctable to imperceptible
[email protected] imperceptible, correctable to none
[email protected] none visible

(Severe, moderate, slight and very slight all mean visible).

My vignetting tests by focal length:
[email protected] severe vignetting, correctable to moderate
[email protected] slight, correctable to very slight
[email protected] imperceptible, correctable to none
50mm none
70mm none
105mm none

Cropping test
Instead of correcting the vignetting why not just crop it out using Photoshop? Taking the worst instance of vignetting i.e. [email protected], the original image size of 14.6x9.7 inches had to to be cropped to 12.3x7.5 inches. The new size gives about the same angle of view as the 35mm lens setting or, I suspect, a 1.6 crop! Even after correcting as much as possible for vignetting before cropping I still ended up with about the same size picture, 12.4x7.9 inches. Whats the point of having a full frame sensor at twice the cost if you have to restrict your focal length or crop it to a sub-full frame equivalent.

Shooting conditions
I do a lot of architectural photography and my test shots were of an interior with white walls. I used the camera on its default settings i.e. fine quality jpegs etc.

Post production
My citeria when correcting in Photoshop CS2 (v9), using the vignetting sliders under the lens correction filter option, was not to let whites burn out or to introduce other artefacts as a result of correcting e.g. colour distortions. I did not other correction.

At 24mm, on a 5D, vignetting is apparent at all apertures except f22 and only fully correctable under my test conditions at f16.

Lovers of this lens are sub-full frame. If vignetting is a problem for you and you shoot full frame then test this lens under your typical shot situations first. If like me you like shooting architectural interiors, i.e. wide open in low light then get used to vignetting or go sub-full frame. This is a shame because by going sub-full frame many people are missing the joys of wide angle photography. Some preliminary shots showed that spot on exposure is imperative to keeping vegnetting down to these levels.

I knocked this out fairly quickly. If you see any flaws in my argument I will be delighted to hear from you. I am looking for reasons to keep the lens and the 5D.