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Canon 17-40mm L, sharpness ok?

Started May 1, 2014 | Discussions thread
Timbukto Veteran Member • Posts: 4,988
Re: Canon 17-40mm L, sharpness ok?

DrShouter wrote:

Hey everybody,

A few days ago i bought a new 17-40mm L UW Lens, but I´m very dissapointed about the sharpness.
Is the blurriness at the edge and the corners normal for this lens?

Sorry for the silly question but this is my firs UW, 90% of my pictures were taken with the 70-200 f2.8 and this thing is razorsharp (Yes i know its a Tele).

Orginal Raws, out of the cam!

https://www.dropbox.com/sh/9r2ka4n8pn63hhb/g15WdQb8VX

Thanks!

Your copy looks very good, it makes me want to buy the lens. DxOMark rated this lens as very good for the size/money. Wonderful when stopped down as you did in these RAWs.

There is nothing wrong with the corners, you are likely confused about wide angle distortion and used to telephoto distortion. Extension vs Compression.

Some of the blurriness is likely due to shutter speed and moving carriage. You may think the shutter speed is enough to freeze anything at such a wide focal length but again consider the properties of the UWA...subjects that move around in the center of the frame will shift pixels at a far slower rate compared to those that move near the edge or corners of your frame (at a rather high rate of movement across the pixels of your sensor).  You can prove this by just taking video at 17mm and examining movement across the frame...I bet movement at borders/corners will shift faster than center...

Although it is the f11 shots that look good...your impromptu paper chart is meaningless with the UWA as 99% chance your test is wrong just looking at your taped up scissor cut test chart...

I would be more interested in seeing real photo UWA's taken at say f8 to really see if your copy is good, or even f5.6

 Timbukto's gear list:Timbukto's gear list
Canon EOS M Canon EF 200mm f/2.8L II USM Canon EF-M 22mm f/2 STM
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