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Thread: Slightly more scientific...

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    Subscriber Member tashley's Avatar
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    Slightly more scientific...

    Today I had a go with just the D800E with Sigma 35mm F1.4 ART lens and the A7R with Leica M 35 Lux FLE. Both tripod mounted with delay, and I used a manual exposure that was pretty far to the right but just avoided blowing the RAWS - same nominal exposure for both but of course the actual luminance of the files is slightly different between the two cameras due to the nominal/actual disparities in F stop, shutter speed and ISO.

    Nice flat and very constant light.

    I shot both cameras at F5.6 and F8 but the Sony I only focussed once, since it has such amazingly accurate magnified live view, a total joy to use compared to the Nikon's dodgy attempt. So I focussed the Nikon frames several times in a focus bracket series, some with LV and some with AF, and selected the best.

    I then set the WB to Daylight just to even the playing field somewhat: this was not intended to be about colour rendition, just about resolution.

    The Leica lens has a narrower FOV than the Sigma, again a nominal versus actual difference. No lens corrections were applied.

    Here's the scene:



    Here are the files and they can all be downloaded at full size (converted to JPEG from RAW)

    My take: colour shading and FOV considerations aside, I would much rather use the A7R combo: both the lenses have odd field effects but at this distance and these apertures they M lens has them better tamed and is much, much easier to focus accurately and reliably than is the Sigma on the Nikon - and the D800 setup just looks and feels huge in comparison… and the edges of the Sony/Leica frame are in a different league of sharpness...

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    Subscriber Member tashley's Avatar
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    Re: Slightly more scientific...

    I have just added two new frames to the gallery linked to above - they are very interesting: they use the Lightroom RC5.3 DNG flat filed correction plugin to apply calibration frames I shot on a different occasion to the 35FLE frames, and the corrections, though not made with reference files shot specifically at the same time and with the same shooting conditions, are pretty good. They are correctly matched for aperture and closely matched for distance. What do people think of these?

    Here are small versions of the F5.6 file both before and after correction with the plugin:



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    k-hawinkler's Avatar
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    Re: Slightly more scientific...

    Many thanks Tim. I greatly appreciate your effort demonstrating the technique with great results.
    I have a question though. Do you get equally good results if there is fine detail in the corners.
    Of course, I will try this out myself once my A7R arrives.
    Thanks again for pushing ahead!

    PS: It's really a great scene with lots of fine detail to be captured.
    The blue house stuck in a corner would make an excellent test.
    With best regards, K-H.

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    Senior Member Taylor Sherman's Avatar
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    Re: Slightly more scientific...

    Thanks Tim! I haven't looked at the full-size, but at the viewing size, both look great and they are in fact quite similar once the FF plugin has run.

    On a complete tangent - I usually only correct for color, not falloff, when using FF or cornerfix. I normally like a bit of vignette on many scenes. However, looking at these photos, I realize: for overcast / gray light, I greatly prefer without the vignetting. I don't know why I never realized that before!

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