Serene Life

by garik

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7

It doesn't look too bad to me. You have to consider that when you're looking at a 5D mkIII image at 100%, that amounts to a considerable enlargement. It's rare to get something really pin sharp at that magnification. The focus point is quite forward so the trees in the centre of the frame are at or near the far limit of the DOF. That combined with the ...


5

Your logic is sound. If your assumptions were right, then your conclusion would be right. Let me turn one of your questions around. You ask: Why does crop factor apply with APS-C-lenses, while it sounds like the image circle is compressed onto the APS-C-sensor (thus making a wider FOV)? In fact, the image circle isn't compressed, and does not make a ...


5

The blur can be measured by converting to XYZ colorspace and zooming into a tree trunk with a bright sky as the background. You then measure the brightness profile accross the rapid change in brightness (make sure you pick an area with small gradient in the direction parallel to the tree trunk). I then used this method to estimate the blur. Since the image ...


2

I can't look at the RAW image at the moment, but it should be fairly sharp, but likely won't be pixel sharp on a 5D Mark iii at 100% magnification. The 24-70 f/4L isn't a prime lens and it isn't the f/2.8II. It isn't as strong of an optical performer and 22mpix is a lot of image data. (I use the f/2.8 II on my 5D Mark iii regularly.) The f/2.8II will come ...


1

The image circle produced by a lens is independent of the focal length. It is the combination of the focal length and the sensor size that determine the effective FOV. For example, a 90mm lens designed for a view camera with film that is 4x5 inches in size will have a wide angle FOV on that camera. But take that same lens and mount it on a DSLR with an APS-C ...


1

You are misunderstanding a few things that are causing you confusion. The only difference between a lens designed for a full frame sensor and a lens designed for an APS-c sensor is that the APS-c lens collects less light since it is producing a smaller image circle. The light per surface area of the image circle is the same, but the circle is smaller. An ...


1

The problem with any attempt to reverse optical blurring by estimating/modelling the point spread function is noise. In principal if you know how the lens blurs an image and have an accurate version of the blurred image you can reconstruct the original "unblurred" image. But in the presence of noise you don't really have the blurred image, you have the ...



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