FEChariot wrote in post #18352707
When LR does that though, doesn't it essentially have to crop the image down a bit to get everything straight? So a 10mm wide image corrected with more distortion would look more like a 11mm wide image than a 10mm wide image taken from a lens with less distortion? Do you still have both lenses where you could do a test at 10mm and then correct then in LR and see if one image looks wider?
OK. Here we go. The first image is an uncorrected Tamron image at 10mm. The barrel distortion is obvious.
IMAGE LINK: https://flic.kr/p/TwS6WA _P3A6476.jpg by
Patrick Knight, on Flickr
It turns out that Adobe has released the profile for the new Tamron, so the next image is the same shot with the profile applied. As can be seen, there is a bit of cropping that happens, as with any profile adjustment.
IMAGE LINK: https://flic.kr/p/TwS83U _P3A6476-2.jpg by
Patrick Knight, on Flickr
The amount of the image cropped out when applying the profile in LR, however, is very modest in my opinion. It is certainly not equivalent to taking the shot at 11mm, as shown by the next image, which is an uncorrected 11mm image from the Tamron. I left this one uncorrected, since the question was whether the corrected 10mm image would be equivalent in terms of AOV to an 11mm image. Correcting this one would only exaggerate the differences.
IMAGE LINK: https://flic.kr/p/TwS991 _P3A6477.jpg by
Patrick Knight, on Flickr
The corrected 10mm image is closer to the uncorrected 10mm image than to the 11mm image.
Now, here are uncorrected and corrected images at 10mm from the Canon EF-S 10-22.
IMAGE LINK: https://flic.kr/p/TzJWgP _P3A6475-2.jpg by
Patrick Knight, on Flickr
IMAGE LINK: https://flic.kr/p/TzJUst _P3A6475.jpg by
Patrick Knight, on Flickr
As was indicated in the reviews you cited, there is less barrel distortion with the 10-22, and consequently less cropping when the LR profile is applied to this image. Comparing these two images to the corresponding Tamron 10-24 images, it is obvious that the Canon is a bit wider at its 10mm setting than is the Tamron at 10mm. Which of these lenses, if either, is closer to a true 10mm, I have no way of knowing, but in a WA lens, wider is probably better, so that is a point for the Canon.
What is not readily visible in these images is the CA distortion. While both lenses produce some CA along high contrast edges, it is much better controlled in the Tamron. The colored fringes are 2-3 times wider in the Canon images. Of course, CA is also easily controlled in LR, but the wider the CA artifacts, the more likely that the correction will leave its own artifacts. I have already mentioned the better coma control in the Tamron.
Comparing the two corrected images (the second and the last), the Canon has a wider view, but the difference is small. For me, the better control of other distortions, and the availability of the excellent Tamron VC system for use in low-light situations (not to mention the 6-year warranty and the ability to upgrade firmware at home), the Tamron is the better choice. YMMV.
